WorldWideScience

Sample records for twoleveled mobile agent

  1. Two-level modulation scheme to reduce latency for optical mobile fronthaul networks.

    Science.gov (United States)

    Sung, Jiun-Yu; Chow, Chi-Wai; Yeh, Chien-Hung; Chang, Gee-Kung

    2016-10-31

    A system using optical two-level orthogonal-frequency-division-multiplexing (OFDM) - amplitude-shift-keying (ASK) modulation is proposed and demonstrated to reduce the processing latency for the optical mobile fronthaul networks. At the proposed remote-radio-head (RRH), the high data rate OFDM signal does not need to be processed, but is directly launched into a high speed photodiode (HSPD) and subsequently emitted by an antenna. Only a low bandwidth PD is needed to recover the low data rate ASK control signal. Hence, it is simple and provides low-latency. Furthermore, transporting the proposed system over the already deployed optical-distribution-networks (ODNs) of passive-optical-networks (PONs) is also demonstrated with 256 ODN split-ratios.

  2. Security Infrastructure and Applicationsfor Mobile Agents

    OpenAIRE

    Shibli, Awais

    2010-01-01

    Research areas of this dissertation are security for mobile agents, for applications based on mobile agents, and for distributed network environments in which mobile agents execute. Mobile agents paradigm has captured researchers’ and industry’s interests long time ago because of its innovative capabilities and attractive applications. The ability of mobile agents to autonomously migrate from host to host, transferring their code and internal state, enables them to accomplish tasks in network...

  3. Mobile agents basic concepts, mobility models, and the tracy toolkit

    CERN Document Server

    Braun, Peter

    2005-01-01

    Mobile agents are software nomads that act as your personal representative, working autonomously through networks. They are able to visit network nodes directly using available computing power and are not limited by platform. This emerging field is now poised to become a cornerstone for new Web-based ubiquitous computing environments. Mobile Agents provides a practical introduction to mobile agent technology and surveys the state of the art in mobile agent research. Students and researchers can use the book as an introduction to the concepts and possibilities of this field and as an overview of ongoing research. Developers can use it to identify the capabilities of the technology to decide if mobile agents are the right solution for them. Practioners can also gain hands-on experience in programming mobile agents through exploration of the source code for a complete mobile agent environment available through the companion website.*Summarizes the state of the art in mobile agent research*Identifies the benefits...

  4. Mobile Agent Data Integrity Using Multi-Agent Architecture

    National Research Council Canada - National Science Library

    McDonald, Jeffrey

    2004-01-01

    .... Security issues for mobile agents continue to produce research interest, particularly in developing mechanisms that guarantee protection of agent data and agent computations in the presence of malicious hosts...

  5. Mobile Agents in Networking and Distributed Computing

    CERN Document Server

    Cao, Jiannong

    2012-01-01

    The book focuses on mobile agents, which are computer programs that can autonomously migrate between network sites. This text introduces the concepts and principles of mobile agents, provides an overview of mobile agent technology, and focuses on applications in networking and distributed computing.

  6. Security Measures to Protect Mobile Agents

    Science.gov (United States)

    Dadhich, Piyanka; Govil, M. C.; Dutta, Kamlesh

    2010-11-01

    The security issues of mobile agent systems have embarrassed its widespread implementation. Mobile agents that move around the network are not safe because the remote hosts that accommodate the agents initiates all kinds of attacks. These hosts try to analyze the agent's decision logic and their accumulated data. So, mobile agent security is the most challenging unsolved problems. The paper analyzes various security measures deeply. Security especially the attacks performed by hosts to the visiting mobile agent (the malicious hosts problem) is a major obstacle that prevents mobile agent technology from being widely adopted. Being the running environment for mobile agent, the host has full control over them and could easily perform many kinds of attacks against them.

  7. Constructing Secure Mobile Agent Systems Using the Agent Operating System

    NARCIS (Netherlands)

    van t Noordende, G.J.; Overeinder, B.J.; Timmer, R.J.; Brazier, F.M.; Tanenbaum, A.S.

    2009-01-01

    Designing a secure and reliable mobile agent system is a difficult task. The agent operating system (AOS) is a building block that simplifies this task. AOS provides common primitives required by most mobile agent middleware systems, such as primitives for secure communication, secure and

  8. Design of a Two-level Adaptive Multi-Agent System for Malaria Vectors driven by an ontology

    Directory of Open Access Journals (Sweden)

    Etang Josiane

    2007-07-01

    Full Text Available Abstract Background The understanding of heterogeneities in disease transmission dynamics as far as malaria vectors are concerned is a big challenge. Many studies while tackling this problem don't find exact models to explain the malaria vectors propagation. Methods To solve the problem we define an Adaptive Multi-Agent System (AMAS which has the property to be elastic and is a two-level system as well. This AMAS is a dynamic system where the two levels are linked by an Ontology which allows it to function as a reduced system and as an extended system. In a primary level, the AMAS comprises organization agents and in a secondary level, it is constituted of analysis agents. Its entry point, a User Interface Agent, can reproduce itself because it is given a minimum of background knowledge and it learns appropriate "behavior" from the user in the presence of ambiguous queries and from other agents of the AMAS in other situations. Results Some of the outputs of our system present a series of tables, diagrams showing some factors like Entomological parameters of malaria transmission, Percentages of malaria transmission per malaria vectors, Entomological inoculation rate. Many others parameters can be produced by the system depending on the inputted data. Conclusion Our approach is an intelligent one which differs from statistical approaches that are sometimes used in the field. This intelligent approach aligns itself with the distributed artificial intelligence. In terms of fight against malaria disease our system offers opportunities of reducing efforts of human resources who are not obliged to cover the entire territory while conducting surveys. Secondly the AMAS can determine the presence or the absence of malaria vectors even when specific data have not been collected in the geographical area. In the difference of a statistical technique, in our case the projection of the results in the field can sometimes appeared to be more general.

  9. Comparison of Communication Models for Mobile Agents

    Directory of Open Access Journals (Sweden)

    Xining Li

    2003-04-01

    Full Text Available An agent is a self-contained process being acting on behalf of a user. A Mobile Agent is an agent roaming the internet to access data and services, and carry out its assigned task remotely. This paper will focus on the communication models for Mobile Agents. Generally speaking, communication models concern with problems of how to name Mobile Agents, how to establish communication relationships, how to trace moving agents, and how to guarantee reliable communication. Some existing MA systems are purely based on RPC-style communication, whereas some adopts asynchronous message passing, or event registration/handling. Different communication concepts suitable for Mobile Agents are well discussed in [1]. However, we will investigate these concepts and existing models from a different point view: how to track down agents and deliver messages in a dynamic, changing world.

  10. Preemptive mobile code protection using spy agents

    OpenAIRE

    Kalogridis, Georgios

    2011-01-01

    This thesis introduces 'spy agents' as a new security paradigm for evaluating trust in remote hosts in mobile code scenarios. In this security paradigm, a spy agent, i.e. a mobile agent which circulates amongst a number of remote hosts, can employ a variety of techniques in order to both appear 'normal' and suggest to a malicious host that it can 'misuse' the agent's data or code without being held accountable. A framework for the operation and deployment of such spy agents is described. ...

  11. Protecting mobile agents from external replay attacks

    OpenAIRE

    Garrigues Olivella, Carles; Migas, Nikos; Buchanan, William; Robles, Sergi; Borrell Viader, Joan

    2014-01-01

    Peer-reviewed This paper presents a protocol for the protection of mobile agents against external replay attacks. This kind of attacks are performed by malicious platforms when dispatching an agent multiple times to a remote host, thus making it reexecute part of its itinerary. Current proposals aiming to address this problem are based on storing agent identifiers, or trip markers, inside agent platforms, so that future reexecutions can be detected and prevented. The problem of these solut...

  12. Pinning synchronization of a mobile agent network

    International Nuclear Information System (INIS)

    Wang, Lei; Sun, You-xian

    2009-01-01

    We investigate the problem of controlling a group of mobile agents in a plane in order to move them towards a desired orbit via pinning control, in which each agent is associated with a chaotic oscillator coupled with those of neighboring agents, and the pinning strategy is to have the common linear feedback acting on a small fraction of agents by random selection. We explore the effects of the pinning probability, feedback gains and agent density in the pinning synchronization of a mobile agent network under a fast-switching constraint, and perform numerical simulations for validation. In particular, we show that there exists a critical pinning density for network synchronization with an unbounded region: above the threshold, the dynamical network can be controlled by pinning; below it, anarchy prevails. And for the network with a single bounded synchronization region, pinning control has little effect as regards enhancing network synchronizability

  13. Mobile agent location in distributed environments

    Science.gov (United States)

    Fountoukis, S. G.; Argyropoulos, I. P.

    2012-12-01

    An agent is a small program acting on behalf of a user or an application which plays the role of a user. Artificial intelligence can be encapsulated in agents so that they can be capable of both behaving autonomously and showing an elementary decision ability regarding movement and some specific actions. Therefore they are often called autonomous mobile agents. In a distributed system, they can move themselves from one processing node to another through the interconnecting network infrastructure. Their purpose is to collect useful information and to carry it back to their user. Also, agents are used to start, monitor and stop processes running on the individual interconnected processing nodes of computer cluster systems. An agent has a unique id to discriminate itself from other agents and a current position. The position can be expressed as the address of the processing node which currently hosts the agent. Very often, it is necessary for a user, a processing node or another agent to know the current position of an agent in a distributed system. Several procedures and algorithms have been proposed for the purpose of position location of mobile agents. The most basic of all employs a fixed computing node, which acts as agent position repository, receiving messages from all the moving agents and keeping records of their current positions. The fixed node, responds to position queries and informs users, other nodes and other agents about the position of an agent. Herein, a model is proposed that considers pairs and triples of agents instead of single ones. A location method, which is investigated in this paper, attempts to exploit this model.

  14. Using Mobile Agents to Implement Workflow System

    Institute of Scientific and Technical Information of China (English)

    LI Jie; LIU Xian-xing; GUO Zheng-wei

    2004-01-01

    Current workflow management systems usually adopt the existing technologies such as TCP/IP-based Web technologies and CORBA as well to fulfill the bottom communications.Very often it has been considered only from a theoretical point of view, mainly for the lack of concrete possibilities to execute with elasticity.MAT (Mobile Agent Technology) represents a very attractive approach to the distributed control of computer networks and a valid alternative to the implementation of strategies for workflow system.This paper mainly focuses on improving the performance of workflow system by using MAT.Firstly, the performances of workflow systems based on both CORBA and mobile agent are summarized and analyzed; Secondly, the performance contrast is presented by introducing the mathematic model of each kind of data interaction process respectively.Last, a mobile agent-based workflow system named MAWMS is presented and described in detail.

  15. AN AGENT BASED TRANSACTION PROCESSING SCHEME FOR DISCONNECTED MOBILE NODES

    Directory of Open Access Journals (Sweden)

    J.L. Walter Jeyakumar

    2010-12-01

    Full Text Available We present a mobile transaction framework in which mobile users can share data which is stored in the cache of a mobile agent. This mobile agent is a special mobile node which coordinates the sharing process. The proposed framework allows mobile affiliation work groups to be formed dynamically with a mobile agent and mobile hosts. Using short range wireless communication technology, mobile users can simultaneously access the data from the cache of the mobile agent. The data Access Manager module at the mobile agent enforces concurrency control using cache invalidation technique. This model supports disconnected mobile computing allowing mobile agent to move along with the Mobile Hosts. The proposed Transaction frame work has been simulated in Java 2 and performance of this scheme is compared with existing frame works.

  16. Mobil's two-agent firetruck

    International Nuclear Information System (INIS)

    Lockwood, N.R.

    1985-01-01

    A unique, efficient fire truck that delivers both dry chemical and foam has been developed by Mobil Oil. It will extinguish three-dimensional fires 100 feet away, at grade or overhead, and spill fires 70 feet wide, 130 feet away. Knockdown, control or extinguishment occurs in less than 20 seconds. The foam water monitor has a reach of 200 feet - straight stream or spray. The truck can use any combination of dry chemical, foam or water and can extinguish tank fires to 120 feet in diameter

  17. An Effective Method for Protecting the Integrity of Mobile Agent

    OpenAIRE

    YARAHMADI, H.; KAMANKESH, M.

    2015-01-01

    Abstract. A mobile agent is software which performs an action autonomously and independently as a person or organizations assistance. Mobile agents are used for searching information, retrieval information, filtering, intruder recognition in networks, and so on. One of the important issues of mobile agent is their security. It must consider different security issues in effective and secured usage of mobile agent. One of those issues is the integrity’s protection of mobile agents.In this paper...

  18. FY1995 community support by mobile agents; 1995 nendo mobile agent ni yoru community keisei shien

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    The purpose is to develop fundamental technologies for navigation systems and mobile computing systems in museums, theme parks and cities. Concretely, we implement software agents into the mobile computing environment which consists of PHS, mobile computers and mobile robots, and realize various functions to access regional information. We have studied on Communityware which supports human activities and communities by using mobile agents implemented into mobile computers and town robots. The mobile agents, which intelligently process information obtained in physical and virtual worlds, access regional information which is omnipresent in the environment. With respect to the approach using mobile computers, we have provided one hundred mobile computers in the international conference on multiagent systems 1996 and carried out the first experimentation of mobile computing in the world. The mobile computer has two functions: Community Viewer which displays interactions between members of communities and Social Matchmaker which supports to hold meetings by searching for people who have common interests. With respect to the approach using town robots, we have developed a robot system which can robustly behave in a complex outdoor environment by using vision agents embedded in the environment. The system aims at support of people in streets. (NEDO)

  19. Framework for Securing Mobile Software Agents

    OpenAIRE

    Mwakalinga, G Jeffy; Yngström, Louise

    2006-01-01

    Information systems are growing in size and complexity making it infeasible for human administrators to manage them. The aim of this work is to study ways of securing and using mobile software agents to deter attackers, protect information systems, detect intrusions, automatically respond to the intrusions and attacks, and to produce recovery services to systems after attacks. Current systems provide intrusion detection, prevention, protection, response, and recovery services but most of thes...

  20. Software agent constrained mobility for network performance monitoring

    NARCIS (Netherlands)

    Bohoris, C.; Liotta, A.; Pavlou, G.

    2000-01-01

    During the recent years of research on mobile agents, significant effort has been directed towards the identification of models of agent mobility suitable for network management applications. Also, a lot of research work is currently being carried out trying to provide an assessment of mobile agent

  1. Java-based mobile agent platforms for wireless sensor networks

    NARCIS (Netherlands)

    Aiello, F.; Carbone, A.; Fortino, G.; Galzarano, S.; Ganzha, M.; Paprzycki, M.

    2010-01-01

    This paper proposes an overview and comparison of mobile agent platforms for the development of wireless sensor network applications. In particular, the architecture, programming model and basic performance of two Java-based agent platforms, Mobile Agent Platform for Sun SPOT (MAPS) and Agent

  2. A Novel Security Approach in Mobile Agent Using Encryption

    OpenAIRE

    Nidhi Gupta; Dr. Anurag Dixit

    2012-01-01

    The appearance of software agents has given rise too much discussion of what such an agent is and how it differs from programs in general. An agent is anything that can be viewed as perceiving its environment through sensors & acting upon that environment through actuators. The existing systems can be classified in the context of singleagent systems and multi-agent systems. Mobile agents cantransport themselves from one host to another. Mobile agents have been developed as an extension to and...

  3. A Secure Protocol Based on a Sedentary Agent for Mobile Agent Environments

    OpenAIRE

    Abdelmorhit E. Rhazi; Samuel Pierre; Hanifa Boucheneb

    2007-01-01

    The main challenge when deploying mobile agent environments pertains to security issues concerning mobile agents and their executive platform. This paper proposes a secure protocol which protects mobile agents against attacks from malicious hosts in these environments. Protection is based on the perfect cooperation of a sedentary agent running inside a trusted third host. Results show that the protocol detects several attacks, such as denial of service, incorrect execution and re-execution of...

  4. Mobile agents affect worm spreading in wireless ad hoc networks

    International Nuclear Information System (INIS)

    Huang, Zi-Gang; Sun, Jin-Tu; Wang, Ying-Hai; Wang, Sheng-Jun; Xu, Xin-Jian

    2009-01-01

    Considering the dynamic nature of portable computing devices with wireless communication capability, an extended model is introduced for worm spreading in the wireless ad hoc network, with a population of mobile agents in a planar distribution, starting from an initial infected seed. The effect of agents' mobility on worm spreading is investigated via extensive Monte Carlo simulations. The threshold behavior and the dynamics of worm epidemics in the wireless networks are greatly affected by both agents' mobility and spatial and temporal correlations. The medium access control mechanism for the wireless communication promotes the sensitivity of the spreading dynamics to agents' mobility

  5. Migration control for mobile agents based on passport and visa

    OpenAIRE

    Guan, SU; Wang, T; Ong, SH

    2003-01-01

    Research on mobile agents has attracted much attention as this paradigm has demonstrated great potential for the next-generation e-commerce. Proper solutions to security-related problems become key factors in the successful deployment of mobile agents in e-commerce systems. We propose the use of passport and visa (P/V) for securing mobile agent migration across communities based on the SAFER e-commerce framework. P/V not only serves as up-to-date digital credentials for agent-host authentica...

  6. A framework to protect mobile agents by using reference states

    OpenAIRE

    Hohl, Fritz

    2000-01-01

    To protect mobile agents from attacks by their execution environments, or hosts, one class of protection mechanisms uses 'reference states' to detect modification attacks. Reference states are agent states that have been produced by non-attacking, or reference hosts. This paper examines this class of mechanisms and present the bandwidth of the achieved protection. First, a new general definition of attacks against mobile agents is presented. As this general definition does not lead to a pract...

  7. N-grams Based Supervised Machine Learning Model for Mobile Agent Platform Protection against Unknown Malicious Mobile Agents

    Directory of Open Access Journals (Sweden)

    Pallavi Bagga

    2017-12-01

    Full Text Available From many past years, the detection of unknown malicious mobile agents before they invade the Mobile Agent Platform has been the subject of much challenging activity. The ever-growing threat of malicious agents calls for techniques for automated malicious agent detection. In this context, the machine learning (ML methods are acknowledged more effective than the Signature-based and Behavior-based detection methods. Therefore, in this paper, the prime contribution has been made to detect the unknown malicious mobile agents based on n-gram features and supervised ML approach, which has not been done so far in the sphere of the Mobile Agents System (MAS security. To carry out the study, the n-grams ranging from 3 to 9 are extracted from a dataset containing 40 malicious and 40 non-malicious mobile agents. Subsequently, the classification is performed using different classifiers. A nested 5-fold cross validation scheme is employed in order to avoid the biasing in the selection of optimal parameters of classifier. The observations of extensive experiments demonstrate that the work done in this paper is suitable for the task of unknown malicious mobile agent detection in a Mobile Agent Environment, and also adds the ML in the interest list of researchers dealing with MAS security.

  8. Forming Circle Formations of Anonymous Mobile Agents With Order Preservation

    NARCIS (Netherlands)

    Wang, Chen; Xie, Guangming; Cao, Ming

    2013-01-01

    We propose distributed control laws for a group of anonymous mobile agents to form desired circle formations when the agents move in the one-dimensional space of a circle. The agents are modeled by kinematic points. They share the common knowledge of the orientation of the circle, but are oblivious

  9. The mobile agent rendezvous problem in the ring

    CERN Document Server

    Kranakis, Evangelos; Marcou, Euripides

    2010-01-01

    Mobile agent computing is being used in fields as diverse as artificial intelligence, computational economics and robotics. Agents' ability to adapt dynamically and execute asynchronously and autonomously brings potential advantages in terms of fault-tolerance, flexibility and simplicity. This monograph focuses on studying mobile agents as modelled in distributed systems research and in particular within the framework of research performed in the distributed algorithms community. It studies the fundamental question of how to achieve rendezvous, the gathering of two or more agents at the same n

  10. On the efficiency of decentralised monitoring using mobile agents

    NARCIS (Netherlands)

    Liotta, A.; Knight, G.; Pavlou, G.

    1999-01-01

    This paper considers the problem of improving the efficiency and scalability of current monitoring systems, which generally follow a centralised and static management model. Several alternative solutions based on Mobile Agents (MAs), specifically tailored to network monitoring are described. In

  11. Information Sharing Mechanism among Mobile Agents In Ad-hoc Network Environment and Its Applications

    Directory of Open Access Journals (Sweden)

    Kunio Umetsuji

    2004-12-01

    Full Text Available Mobile agents are programs that can move from one site to another in a network with their data and states. Mobile agents are expected to be an essential tool in pervasive computing. In multi platform environment, it is important to communicate with mobile agents only using their universal or logical name not using their physical locations. More, in an ad-hoc network environment, an agent can migrate autonomously and communicate with other agents on demand. It is difficult that mobile agent grasps the position information on other agents correctly each other, because mobile agent processes a task while moving a network successively. In order to realize on-demand mutual communication among mobile agents without any centralized servers, we propose a new information sharing mechanism within mobile agents. In this paper, we present a new information sharing mechanism within mobile agents. The method is a complete peer based and requires no agent servers to manage mobile agent locations. Therefore, a mobile agent can get another mobile agent, communicate with it and shares information stored in the agent without any knowledge of the location of the target mobile agent. The basic idea of the mechanism is an introduction of Agent Ring, Agent Chain and Shadow Agent. With this mechanism, each agent can communicate with other agents in a server-less environment, which is suitable for ad-hoc agent network and an agent system can manage agents search and communications efficiently.

  12. An Agent-Based Auction Protocol on Mobile Devices

    Directory of Open Access Journals (Sweden)

    Yu-Fang Chung

    2014-01-01

    Full Text Available This paper proposes an English auction protocol to preserve a secure, fair, and effective online auction environment, where the operations are integrated with mobile agent technology for bidders participating in online auctions. The protocol consists of four participants, namely, registration manager, agent house, auction house, and bidder.

  13. Epidemic spreading induced by diversity of agents' mobility.

    Science.gov (United States)

    Zhou, Jie; Chung, Ning Ning; Chew, Lock Yue; Lai, Choy Heng

    2012-08-01

    In this paper, we study the impact of the preference of an individual for public transport on the spread of infectious disease, through a quantity known as the public mobility. Our theoretical and numerical results based on a constructed model reveal that if the average public mobility of the agents is fixed, an increase in the diversity of the agents' public mobility reduces the epidemic threshold, beyond which an enhancement in the rate of infection is observed. Our findings provide an approach to improve the resistance of a society against infectious disease, while preserving the utilization rate of the public transportation system.

  14. QoS Negotiation and Renegotiation Based on Mobile Agents

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shi-bing; ZHANG Deng-yin

    2006-01-01

    The Quality of Service (QoS) has received more and more attention since QoS becomes increasingly important in the Internet development. Mobile software agents represent a valid alternative to the implementation of strategies for the negotiation. In this paper, a QoS negotiation and renegotiation system architecture based on mobile agents is proposed. The agents perform the task in the whole process. Therefore, such a system can reduce the network load, overcome latency, and avoid frequent exchange information between clients and server. The simulation results show that the proposed system could improve the network resource utility about 10%.

  15. Who (Dis)Continues to use SMS in the Age of Ubiquitous Mobile Internet Access?: A Two-Level Investigation of Residential Mobile Communications Customers in Germany

    OpenAIRE

    Torsten J. Gerpott

    2015-01-01

    Using data of 11526 residential postpaid subscribers of the German subsidiary of a multinational mobile network operator (MNO) extracted from the firm's customer and billing records, this investigation empirically examines the association between monthly mobile Internet (MI) data traffic volume generated by consumers and their monthly number of SMS sent at the within- and between-subjects levels over 25 months from October 2011 to October 2013. Multilevel analysis of the time-varying and -con...

  16. Secure Mobile Agent from Leakage-Resilient Proxy Signatures

    Directory of Open Access Journals (Sweden)

    Fei Tang

    2015-01-01

    Full Text Available A mobile agent can sign a message in a remote server on behalf of a customer without exposing its secret key; it can be used not only to search for special products or services, but also to make a contract with a remote server. Hence a mobile agent system can be used for electronic commerce as an important key technology. In order to realize such a system, Lee et al. showed that a secure mobile agent can be constructed using proxy signatures. Intuitively, a proxy signature permits an entity (delegator to delegate its signing right to another entity (proxy to sign some specified messages on behalf of the delegator. However, the proxy signatures are often used in scenarios where the signing is done in an insecure environment, for example, the remote server of a mobile agent system. In such setting, an adversary could launch side-channel attacks to exploit some leakage information about the proxy key or even other secret states. The proxy signatures which are secure in the traditional security models obviously cannot provide such security. Based on this consideration, in this paper, we design a leakage-resilient proxy signature scheme for the secure mobile agent systems.

  17. Connection adaption for control of networked mobile chaotic agents.

    Science.gov (United States)

    Zhou, Jie; Zou, Yong; Guan, Shuguang; Liu, Zonghua; Xiao, Gaoxi; Boccaletti, S

    2017-11-22

    In this paper, we propose a strategy for the control of mobile chaotic oscillators by adaptively rewiring connections between nearby agents with local information. In contrast to the dominant adaptive control schemes where coupling strength is adjusted continuously according to the states of the oscillators, our method does not request adaption of coupling strength. As the resulting interaction structure generated by this proposed strategy is strongly related to unidirectional chains, by investigating synchronization property of unidirectional chains, we reveal that there exists a certain coupling range in which the agents could be controlled regardless of the length of the chain. This feature enables the adaptive strategy to control the mobile oscillators regardless of their moving speed. Compared with existing adaptive control strategies for networked mobile agents, our proposed strategy is simpler for implementation where the resulting interaction networks are kept unweighted at all time.

  18. Cost-Effective Location Management for Mobile Agents on the Internet

    OpenAIRE

    Chien-Sheng Chen; Jiing-Dong Hwang; Chyuan-Der Lu; Ting-Yuan Yeh

    2015-01-01

    Many mobile agent system-related services and applications require interacting with a mobile agent by passing messages. However, an agent’s mobility raises several challenges in delivering messages to a mobile agent accurately. Consisting of tracking and message delivery phases, most mobile agent location management schemes create or receive many update messages and interaction messages to ensure the effectiveness of the schemes. In addition to downgrading the overall performance of a mobile ...

  19. The Geographic Information Grid System Based on Mobile Agent

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    We analyze the deficiencies of current application systems, and discuss the key requirements of distributed Geographic Information service (GIS). We construct the distributed GIS on grid platform. Considering the flexibility and efficiency, we integrate the mobile agent technology into the system. We propose a new prototype system, the Geographic Information Grid System (GIGS) based on mobile agent. This system has flexible services and high performance, and improves the sharing of distributed resources. The service strategy of the system and the examples are also presented.

  20. On the opinion formation of mobile agents with memory

    Science.gov (United States)

    Zhang, Yunhong; Liu, Qipeng; Wang, Zhenling; Zhang, Siying

    2018-02-01

    This paper studies the opinion formation problem in a group of mobile agents using a multi-agent modeling method. Suppose that all agents move in a two-dimensional space following a certain rule. The interaction range of each agent is determined by its physical location and its opinion similarity with other agents. Moreover, agents have memory of the opinions of their previous interactive neighbors. We investigate the influence of three factors on the formation of group opinion: moving probability, interactive radius, and population density. Using simulations, we find that an opinion consensus can be achieved easily under a small moving probability and a small interactive radius, which is a relatively counterintuitive phenomenon. We also find that a large interactive radius or the model with memory can facilitate the convergence of opinions in a group to either consensus or clusters.

  1. Network flow of mobile agents enhances the evolution of cooperation

    Science.gov (United States)

    Ichinose, G.; Satotani, Y.; Nagatani, T.

    2018-01-01

    We study the effect of contingent movement on the persistence of cooperation on complex networks with empty nodes. Each agent plays the Prisoner's Dilemma game with its neighbors and then it either updates the strategy depending on the payoff difference with neighbors or it moves to another empty node if not satisfied with its own payoff. If no neighboring node is empty, each agent stays at the same site. By extensive evolutionary simulations, we show that the medium density of agents enhances cooperation where the network flow of mobile agents is also medium. Moreover, if the movements of agents are more frequent than the strategy updating, cooperation is further promoted. In scale-free networks, the optimal density for cooperation is lower than other networks because agents get stuck at hubs. Our study suggests that keeping a smooth network flow is significant for the persistence of cooperation in ever-changing societies.

  2. Protecting Dynamic Mobile Agent against Denial of Service Attacks

    Science.gov (United States)

    Aggarwal, Mayank; Nipur, Pallavi

    2010-11-01

    Mobile Agents are softwares migrating from one node to another to fulfill the task of its owner. The introduction of mobile agents has reduced network latency, network traffic a lot but at the same time it has increased the vulnerability for attacks by malicious hosts. One such attack is `Denial of Service', once the agent is launched it is free to roam without any control of its owner, this on one hand decreases the cost of agent—owner interaction and on the other hand increases the chances of `Denial Of Service'. In Denial Of Service attack the malicious host may deny resources required by the agent and kill the agent, thus the result computed so far is lost and this may happen every time the agent visits any malicious host. In this paper we continued the work done in [10] in which the authors proposed techniques by which owner can detect the malicious host for `Denial Of Service' but they did not covered technique for dynamic routes i.e. where the host or agent initiate migrations to hosts which were not contained in the route composed by the owner. We introduced an algorithm and a model which can be useful for the above purpose.

  3. Smart Agent Based Mobile Tutoring and Querying System

    Directory of Open Access Journals (Sweden)

    Suresh Sankaranarayanan

    2012-08-01

    Full Text Available With our busy schedules today and the rising cost of education there is a need to find a convenient and cost effective means of maximizing our educational/training experiences. New trends in the delivery/access of information are becoming more technology based in all areas of society with education being no exception. The ubiquitous use of mobile devices has led to a boom in m-commerce. Mobile devices provide many services in commercial environments such as mobile banking, mobile purchasing, mobile learning, etc. It is therefore fitting that we seek to use mobile devices as a platform in delivering our convenient and cost effective solution. The proposed agent based Mobile tutoring system seeks to provide a student with a rich learning experience that will provide them with the relevant reading material based on their stage of development which allows them to move at their own pace. The system will allow the user to be able to ask certain questions and get explanations as if they were interacting with a human tutor but with the added benefit of being able to do this anytime in any location via their mobile phone.

  4. Use of agents to optimize traffic over wireless mobile connections

    Science.gov (United States)

    Helin, Mikko; Jarvinen, Jari; Kalliokorpi, Janne; Kolehmainen, Jari; Narikka, Jorma

    2002-08-01

    Wireless mobile connections have some well known disadvantages, like slow data rate, high and variable error-rate. In addition to that there are possible (and probable) inefficiencies when connecting different types of protocols stacks, like running TCP over GPRS. On the other hand mobile and portable devices have some limitations, which are based on their size and cannot therefore be removed totally. Potential users are so-called common people and they would like to have very simple-to-use applications solving their daily problems, not causing new ones. One approach to make this situation better is to use agents. They could operate on many different levels, like connecting different physical servers to produce the service needed, connecting different services together, optimizing for different types of user devices, connecting different message types (like audio, animation etc.) to produce the service, making transformations (like reading e-mails as voice mail etc.). This paper will discuss these various aspects of agent technology in the context of mobile services provided to consumers. Discussion and conclusions are partly based on the ZanderMail project. Although it is a mail agent project its results can easily be extended to various message types and various other services, like those based on the location of mobile device. The paper will cover widely these different ideas and ZanderMail is just used as an example and a tool for testing various issues. The idea is to utilize agents many ways to fade away at least partly those known problems mentioned in the beginning. An agent could operate in the network quite near the mobile device to overcome the problem caused by different protocol stacks. It could make logical decisions based on location and other local information, like weather, and it could handle priority issues on various levels of application(s).

  5. Efficient priority queueing routing strategy on networks of mobile agents

    Science.gov (United States)

    Wu, Gan-Hua; Yang, Hui-Jie; Pan, Jia-Hui

    2018-03-01

    As a consequence of their practical implications for communications networks, traffic dynamics on complex networks have recently captivated researchers. Previous routing strategies for improving transport efficiency have paid little attention to the orders in which the packets should be forwarded, just simply used first-in-first-out queue discipline. Here, we apply a priority queuing discipline and propose a shortest-distance-first routing strategy on networks of mobile agents. Numerical experiments reveal that the proposed scheme remarkably improves both the network throughput and the packet arrival rate and reduces both the average traveling time and the rate of waiting time to traveling time. Moreover, we find that the network capacity increases with an increase in both the communication radius and the number of agents. Our work may be helpful for the design of routing strategies on networks of mobile agents.

  6. Integrity protection for code-on-demand mobile agents in e-commerce

    OpenAIRE

    Wang, TH; Guan, SU; Chan, TK

    2002-01-01

    The mobile agent paradigm has been proposed as a promising solution to facilitate distributed computing over open and heterogeneous networks. Mobility, autonomy, and intelligence are identified as key features of mobile agent systems and enabling characteristics for the next-generation smart electronic commerce on the Internet. However, security-related issues, especially integrity protection in mobile agent technology, still hinder the widespread use of software agents: from the agent’s pers...

  7. Securing DSR with mobile agents in wireless ad hoc networks

    Directory of Open Access Journals (Sweden)

    Ahmed Abosamra

    2011-03-01

    Full Text Available Ad hoc wireless network consists of a set of wireless nodes communicating with each other without a pre-defined infrastructure. They communicate by forwarding packets which can reach wireless nodes that do not exist in the range of the direct radio transmission. Designing ad hoc network routing protocols is a challenging task because of its decentralized infrastructure which makes securing ad hoc networks more and more challenging. Dynamic Source Routing (DSR protocol is a popular routing protocol designed for use in wireless ad hoc networks. Mobile agent is a promising technology used in diverse fields of network applications. In this paper, we try to implement DSR using mobile agents for securing this type of wireless network. Hybrid encryption technique (symmetric key encryption/public key encryption is used to improve performance; where symmetric keys are used to encrypt routing data to authenticate and authorize node sending data, while, public keys are used for the exchange of symmetric keys between nodes. We found that DSR may be secured using mobile agents with competitive performance.

  8. Employ a Mobile Agent for Making a Payment

    Directory of Open Access Journals (Sweden)

    Yan Wang

    2008-01-01

    Full Text Available The mobile agent paradigm offers flexibility and autonomy to e-commerce applications. But it is challenging to employ a mobile agent to make a payment due to the security consideration. In this paper, we propose a new agent-assisted secure payment protocol, which is based on SET payment protocol and aims at enabling the dispatched consumer-agent to autonomously sign contracts and make the payment on behalf of the cardholder after having found the best merchant, without the possibility of disclosing any secret to any participant. This is realized by adopting the Signature-Share scheme, and employing a Trusted Third Party (TTP. In the proposed protocol, the principle that each participant knows what is strictly necessary for his/her role is followed as in SET. In addition, mechanisms have been devised for preventing and detecting double payment, overspending and overpayment attacks. Finally the security properties of the proposed protocol are studied analytically. In comparison with other existing models, the proposed protocol is more efficient and can detect more attacks.

  9. Privacy-aware mobile agent: Protecting privacy in open systems by modelling social behaviour of software agents

    NARCIS (Netherlands)

    Meyer, A.P.

    2004-01-01

    In distributed problem solving with multi-agent systems it is assumed that collective behaviour emerges from interaction among rational agents. The dissemination of mobile agents will lead to open systems. Emergent behaviour in open systems must fulfil common goals based on goals of individual

  10. Percolation and cooperation with mobile agents: geometric and strategy clusters.

    Science.gov (United States)

    Vainstein, Mendeli H; Brito, Carolina; Arenzon, Jeferson J

    2014-08-01

    We study the conditions for persistent cooperation in an off-lattice model of mobile agents playing the Prisoner's Dilemma game with pure, unconditional strategies. Each agent has an exclusion radius r(P), which accounts for the population viscosity, and an interaction radius r(int), which defines the instantaneous contact network for the game dynamics. We show that, differently from the r(P)=0 case, the model with finite-sized agents presents a coexistence phase with both cooperators and defectors, besides the two absorbing phases, in which either cooperators or defectors dominate. We provide, in addition, a geometric interpretation of the transitions between phases. In analogy with lattice models, the geometric percolation of the contact network (i.e., irrespective of the strategy) enhances cooperation. More importantly, we show that the percolation of defectors is an essential condition for their survival. Differently from compact clusters of cooperators, isolated groups of defectors will eventually become extinct if not percolating, independently of their size.

  11. Cost-Effective Location Management for Mobile Agents on the Internet

    Directory of Open Access Journals (Sweden)

    Chien-Sheng Chen

    2015-01-01

    Full Text Available Many mobile agent system-related services and applications require interacting with a mobile agent by passing messages. However, an agent’s mobility raises several challenges in delivering messages to a mobile agent accurately. Consisting of tracking and message delivery phases, most mobile agent location management schemes create or receive many update messages and interaction messages to ensure the effectiveness of the schemes. In addition to downgrading the overall performance of a mobile agent location management scheme, excessive transmission of messages increases the network load. The migration locality of a mobile agent and the interaction rate between mobile agents significantly affect the performance of a mobile agent location management scheme with respect to location management cost. This work presents a novel Dual Home based Scheme (DHS that can lower the location management costs in terms of migration locality and interaction rate. While the DHS scheme uniquely adopts dual home location management architecture, a selective update strategy based on that architecture is also designed for cost-effective location management of mobile agents. Moreover, DHS is compared with available schemes based on formulations and simulation experiments from the perspective of location management costs. Simulation results demonstrate that the proposed DHS scheme performs satisfactorily in terms of migration locality and interaction rate.

  12. A Skeleton Based Programming Paradigm for Mobile Multi-Agents on Distributed Systems and Its Realization within the MAGDA Mobile Agents Platform

    Directory of Open Access Journals (Sweden)

    R. Aversa

    2008-01-01

    Full Text Available Parallel programming effort can be reduced by using high level constructs such as algorithmic skeletons. Within the MAGDA toolset, supporting programming and execution of mobile agent based distributed applications, we provide a skeleton-based parallel programming environment, based on specialization of Algorithmic Skeleton Java interfaces and classes. Their implementation include mobile agent features for execution on heterogeneous systems, such as clusters of WSs and PCs, and support reliability and dynamic workload balancing. The user can thus develop a parallel, mobile agent based application by simply specialising a given set of classes and methods and using a set of added functionalities.

  13. BROSMAP: A Novel Broadcast Based Secure Mobile Agent Protocol for Distributed Service Applications

    Directory of Open Access Journals (Sweden)

    Dina Shehada

    2017-01-01

    Full Text Available Mobile agents are smart programs that migrate from one platform to another to perform the user task. Mobile agents offer flexibility and performance enhancements to systems and service real-time applications. However, security in mobile agent systems is a great concern. In this paper, we propose a novel Broadcast based Secure Mobile Agent Protocol (BROSMAP for distributed service applications that provides mutual authentication, authorization, accountability, nonrepudiation, integrity, and confidentiality. The proposed system also provides protection from man in the middle, replay, repudiation, and modification attacks. We proved the efficiency of the proposed protocol through formal verification with Scyther verification tool.

  14. A Skeleton Based Programming Paradigm for Mobile Multi-Agents on Distributed Systems and Its Realization within the MAGDA Mobile Agents Platform

    OpenAIRE

    R. Aversa; B. Di Martino; N. Mazzocca; S. Venticinque

    2008-01-01

    Parallel programming effort can be reduced by using high level constructs such as algorithmic skeletons. Within the MAGDA toolset, supporting programming and execution of mobile agent based distributed applications, we provide a skeleton-based parallel programming environment, based on specialization of Algorithmic Skeleton Java interfaces and classes. Their implementation include mobile agent features for execution on heterogeneous systems, such as clusters of WSs and PCs, and support reliab...

  15. Modeling Multi-Mobile Agents System Based on Coalition Signature Mechanism Using UML

    Institute of Scientific and Technical Information of China (English)

    SUNZhixin; HUANGHaiping; WANGRuchuan

    2004-01-01

    With the development of electronic commerce and agent techniques, multi-mobile agents cooperation can not only improve the efficiency of electronic business trade, but more importantly, it has a comprehensive applicative value in solving the security issues of mobile agent system. This paper firstly describes the mechanism of multi-mobile agents coalition signature aiming at the system security. Subsequently it brings forward a basic architecture of Multi-mobile agents system (MMAS) based on the design pattern of multi-mobile agents. The paper uses the diagrs_rn of UML, such as use case diagram, class diagram and sequence diagram to build the detailed model of the coalition signature and multi-mobile agents cooperation results. Through security analysis, we find that multimobile agents cooperation and interaction can solve some security problems of mobile agents in transfer, and also it can improve the efficiency of business trade. These results indicate that MMAS has a high security performance and can be widely used in E-commerce trade.

  16. Adaptive Remote-Sensing Techniques Implementing Swarms of Mobile Agents

    Energy Technology Data Exchange (ETDEWEB)

    Asher, R.B.; Cameron, S.M.; Loubriel, G.M.; Robinett, R.D.; Stantz, K.M.; Trahan, M.W.; Wagner, J.S.

    1998-11-25

    In many situations, stand-off remote-sensing and hazard-interdiction techniques over realistic operational areas are often impractical "and difficult to characterize. An alternative approach is to implement an adap- tively deployable array of sensitive agent-specific devices. Our group has been studying the collective be- havior of an autonomous, multi-agent system applied to chedbio detection and related emerging threat applications, The current physics-based models we are using coordinate a sensor array for mukivanate sig- nal optimization and coverage as re,alized by a swarm of robots or mobile vehicles. These intelligent control systems integrate'glob"ally operating decision-making systems and locally cooperative learning neural net- works to enhance re+-timp operational responses to dynarnical environments examples of which include obstacle avoidance, res~onding to prevailing wind patterns, and overcoming other natural obscurants or in- terferences. Collectively',tkensor nefirons with simple properties, interacting according to basic community rules, can accomplish complex interconnecting functions such as generalization, error correction, pattern recognition, sensor fusion, and localization. Neural nets provide a greater degree of robusmess and fault tolerance than conventional systems in that minor variations or imperfections do not impair performance. The robotic platforms would be equipped with sensor devices that perform opticaI detection of biologicais in combination with multivariate chemical analysis tools based on genetic and neural network algorithms, laser-diode LIDAR analysis, ultra-wideband short-pulsed transmitting and receiving antennas, thermal im- a:ing sensors, and optical Communication technology providing robust data throughput pathways. Mission scenarios under consideration include ground penetrating radar (GPR) for detection of underground struc- tures, airborne systems, and plume migration and mitigation. We will describe our

  17. Epidemic spreading on dual-structure networks with mobile agents

    Science.gov (United States)

    Yao, Yiyang; Zhou, Yinzuo

    2017-02-01

    The rapid development of modern society continually transforms the social structure which leads to an increasingly distinct dual structure of higher population density in urban areas and lower density in rural areas. Such structure may induce distinctive spreading behavior of epidemics which does not happen in a single type structure. In this paper, we study the epidemic spreading of mobile agents on dual structure networks based on SIRS model. First, beyond the well known epidemic threshold for generic epidemic model that when the infection rate is below the threshold a pertinent infectious disease will die out, we find the other epidemic threshold which appears when the infection rate of a disease is relatively high. This feature of two thresholds for the SIRS model may lead to the elimination of infectious disease when social network has either high population density or low population density. Interestingly, however, we find that when a high density area is connected to a low density may cause persistent spreading of the infectious disease, even though the same disease will die out when it spreads in each single area. This phenomenon indicates the critical role of the connection between the two areas which could radically change the behavior of spreading dynamics. Our findings, therefore, provide new understanding of epidemiology pertinent to the characteristic modern social structure and have potential to develop controlling strategies accordingly.

  18. MAST – A Mobile Agent-based Security Tool

    Directory of Open Access Journals (Sweden)

    Marco Carvalho

    2004-08-01

    Full Text Available One of the chief computer security problems is not the long list of viruses and other potential vulnerabilities, but the vast number of systems that continue to be easy prey, as their system administrators or owners simply are not able to keep up with all of the available patches, updates, or needed configuration changes in order to protect them from those known vulnerabilities. Even up-to-date systems could become vulnerable to attacks, due to inappropriate configuration or combined used of applications and services. Our mobile agent-based security tool (MAST is designed to bridge this gap, and provide automated methods to make sure that all of the systems in a specific domain or network are secured and up-to-date with all patches and updates. The tool is also designed to check systems for misconfigurations that make them vulnerable. Additionally, this user interface is presented in a domain knowledge model known as a Concept Map that provides a continuous learning experience for the system administrator.

  19. Trust Level and Routing Selection for Mobile Agents in a Smart Home

    NARCIS (Netherlands)

    Nasution, Sandy; Hartel, Pieter H.; Suryana, Nanna; Azman, Nur; Shahib, Shahrin

    The central security concern for systems where agents roam is how to establish trust in the agent. We present a Fuzzy Logic mechanism to calculate a level of trust and an optimal route for a mobile agent system in a smart home. The mechanism consists of two parts. The first part calculates a trust

  20. Trust Level and Routing Selection for Mobile Agents in a Smart Home (Extended version)

    NARCIS (Netherlands)

    Nasution, S.; Hartel, Pieter H.; Suryana, N.; Azman, N.; Shahib, S.

    The central security concern for systems where agents roam is how to establish trust in the agent. We present a Fuzzy Logic mechanism to calculate a level of trust and an optimal route for a mobile agent system in a smart home. The mechanism consists of two parts. The first part calculates a trust

  1. Adaptive Remote-Sensing Techniques Implementing Swarms of Mobile Agents

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, S.M.; Loubriel, G.M.; Rbinett, R.D. III; Stantz, K.M.; Trahan, M.W.; Wagner, J.S.

    1999-04-01

    This paper focuses on our recent work at Sandia National Laboratories toward engineering a physics-based swarm of mobile vehicles for distributed sensing applications. Our goal is to coordinate a sensor array that optimizes sensor coverage and multivariate signal analysis by implementing artificial intelligence and evolutionary computational techniques. These intelligent control systems integrate both globally operating decision-making systems and locally cooperative information-sharing modes using genetically-trained neural networks. Once trained, neural networks have the ability to enhance real-time operational responses to dynamical environments, such as obstacle avoidance, responding to prevailing wind patterns, and overcoming other natural obscurants or interferences (jammers). The swarm realizes a collective set of sensor neurons with simple properties incorporating interactions based on basic community rules (potential fields) and complex interconnecting functions based on various neural network architectures, Therefore, the swarm is capable of redundant heterogeneous measurements which furnishes an additional degree of robustness and fault tolerance not afforded by conventional systems, while accomplishing such cognitive tasks as generalization, error correction, pattern recognition, and sensor fission. The robotic platforms could be equipped with specialized sensor devices including transmit/receive dipole antennas, chemical or biological sniffers in combination with recognition analysis tools, communication modulators, and laser diodes. Our group has been studying the collective behavior of an autonomous, multi-agent system applied to emerging threat applications. To accomplish such tasks, research in the fields of robotics, sensor technology, and swarms are being conducted within an integrated program. Mission scenarios under consideration include ground penetrating impulse radar (GPR) for detection of under-ground structures, airborne systems, and plume

  2. Agent Based Framework Architecture for Supporting Content Adaptation for Mobile Government

    Directory of Open Access Journals (Sweden)

    Hasan Omar Al-Sakran

    2013-01-01

    Full Text Available Rapid spread of smart mobile technology that supports internet access is transforming the way governments provide services to their citizens. Mobile devices have different capabilities based on the manufacturers and models. This paper proposes a new framework for adapting the content of M-government services using mobile agent technology. The framework is based on a mediation architecture that uses multiple mobile agents and XML as semi-structure mediation language. The flexibility of the mediation and XML provide an adaptive environment to stream data based on the capabilities of the device sending the query to the system.

  3. TinyMAPS : a lightweight Java-based mobile agent system for wireless sensor networks

    NARCIS (Netherlands)

    Aiello, F.; Fortino, G.; Galzarano, S.; Vittorioso, A.; Brazier, F.M.T.; Nieuwenhuis, K.; Pavlin, G.; Warnier, M.; Badica, C.

    2012-01-01

    In the context of the development of wireless sensor network (WSN) applications, effective programming frameworks and middlewares for rapid and efficient prototyping of resource-constrained applications are highly required. Mobile agents are an effective distributed programming paradigm that is

  4. A Mechanism to Avoid Collusion Attacks Based on Code Passing in Mobile Agent Systems

    Science.gov (United States)

    Jaimez, Marc; Esparza, Oscar; Muñoz, Jose L.; Alins-Delgado, Juan J.; Mata-Díaz, Jorge

    Mobile agents are software entities consisting of code, data, state and itinerary that can migrate autonomously from host to host executing their code. Despite its benefits, security issues strongly restrict the use of code mobility. The protection of mobile agents against the attacks of malicious hosts is considered the most difficult security problem to solve in mobile agent systems. In particular, collusion attacks have been barely studied in the literature. This paper presents a mechanism that avoids collusion attacks based on code passing. Our proposal is based on a Multi-Code agent, which contains a different variant of the code for each host. A Trusted Third Party is responsible for providing the information to extract its own variant to the hosts, and for taking trusted timestamps that will be used to verify time coherence.

  5. Research of using mobile agents for information discovery in P2P networks

    International Nuclear Information System (INIS)

    Lan Yan; Yao Qing

    2003-01-01

    The technology of P2P is a new network-computing model that has great value of commerce and technology. After analyzing the current information discovery technology in P2P network, a new solution that is based on mobile agent is proposed. The mobile agent solution can reduce the need of bandwidth, be adapt to the dynamic of P2P network, and be asynchronous and be very fault tolerant. (authors)

  6. A Public-key based Information Management Model for Mobile Agents

    OpenAIRE

    Rodriguez, Diego; Sobrado, Igor

    2000-01-01

    Mobile code based computing requires development of protection schemes that allow digital signature and encryption of data collected by the agents in untrusted hosts. These algorithms could not rely on carrying encryption keys if these keys could be stolen or used to counterfeit data by hostile hosts and agents. As a consequence, both information and keys must be protected in a way that only authorized hosts, that is the host that provides information and the server that has sent the mobile a...

  7. Secure Route Structures for Parallel Mobile Agents Based Systems Using Fast Binary Dispatch

    Directory of Open Access Journals (Sweden)

    Yan Wang

    2005-01-01

    Full Text Available In a distributed environment, where a large number of computers are connected together to enable the large-scale sharing of data and computing resources, agents, especially mobile agents, are the tools for autonomously completing tasks on behalf of their owners. For applications of large-scale mobile agents, security and efficiency are of great concern. In this paper, we present a fast binary dispatch model and corresponding secure route structures for mobile agents dispatched in parallel to protect the dispatch routes of agents while ensuring the dispatch efficiency. The fast binary dispatch model is simple but efficient with a dispatch complexity of O(log2n. The secure route structures adopt the combination of public-key encryption and digital signature schemes and expose minimal route information to hosts. The nested structure can help detect attacks as early as possible. We evaluated the various models both analytically and empirically.

  8. Mobile Agent based Market Basket Analysis on Cloud

    OpenAIRE

    Waghmare, Vijayata; Mukhopadhyay, Debajyoti

    2014-01-01

    This paper describes the design and development of a location-based mobile shopping application for bakery product shops. Whole application is deployed on cloud. The three-tier architecture consists of, front-end, middle-ware and back-end. The front-end level is a location-based mobile shopping application for android mobile devices, for purchasing bakery products of nearby places. Front-end level also displays association among the purchased products. The middle-ware level provides a web ser...

  9. Effect of two mobilizing agents on the elimination of 147Pm from rats

    International Nuclear Information System (INIS)

    Su Kunyuan; Gao Xianhua; Lao Qinhua

    1984-01-01

    A study was performed to determine the effect of two new mobilizing agents: N,N-bis-carboxymethyl amino acetylcysteine and hyaluronidase on the elimination of intracheally-injected 147 Pm from rats. The results showed that both the two agents could promote the elimination of 147 Pm from rats and decrease the body retention of rats. The former agent is much more effective in elimination than the other

  10. Cooperative mobile agents search using beehive partitioned structure and Tabu Random search algorithm

    Science.gov (United States)

    Ramazani, Saba; Jackson, Delvin L.; Selmic, Rastko R.

    2013-05-01

    In search and surveillance operations, deploying a team of mobile agents provides a robust solution that has multiple advantages over using a single agent in efficiency and minimizing exploration time. This paper addresses the challenge of identifying a target in a given environment when using a team of mobile agents by proposing a novel method of mapping and movement of agent teams in a cooperative manner. The approach consists of two parts. First, the region is partitioned into a hexagonal beehive structure in order to provide equidistant movements in every direction and to allow for more natural and flexible environment mapping. Additionally, in search environments that are partitioned into hexagons, mobile agents have an efficient travel path while performing searches due to this partitioning approach. Second, we use a team of mobile agents that move in a cooperative manner and utilize the Tabu Random algorithm to search for the target. Due to the ever-increasing use of robotics and Unmanned Aerial Vehicle (UAV) platforms, the field of cooperative multi-agent search has developed many applications recently that would benefit from the use of the approach presented in this work, including: search and rescue operations, surveillance, data collection, and border patrol. In this paper, the increased efficiency of the Tabu Random Search algorithm method in combination with hexagonal partitioning is simulated, analyzed, and advantages of this approach are presented and discussed.

  11. An efficient communication strategy for mobile agent based distributed spatial data mining application

    Science.gov (United States)

    Han, Guodong; Wang, Jiazhen

    2005-11-01

    An efficient communication strategy is proposed in this paper, which aims to improve the response time and availability of mobile agent based distributed spatial data mining applications. When dealing with decomposed complex data mining tasks or On-Line Analytical Processing (OLAP), mobile agents authorized by the specified user need to coordinate and cooperate with each other by employing given communication method to fulfill the subtasks delegated to them. Agent interactive behavior, e.g. messages passing, intermediate results exchanging and final results merging, must happen after the specified path is determined by executing given routing selection algorithm. Most of algorithms exploited currently run in time that grows approximately quadratic with the size of the input nodes where mobile agents migrate between. In order to gain enhanced communication performance by reducing the execution time of the decision algorithm, we propose an approach to reduce the number of nodes involved in the computation. In practice, hosts in the system are reorganized into groups in terms of the bandwidth between adjacent nodes. Then, we find an optimal node for each group with high bandwidth and powerful computing resources, which is managed by an agent dispatched by agent home node. With that, the communication pattern can be implemented at a higher level of abstraction and contribute to improving the overall performance of mobile agent based distributed spatial data mining applications.

  12. Darboux transformation for two-level system

    Energy Technology Data Exchange (ETDEWEB)

    Bagrov, V.; Baldiotti, M.; Gitman, D.; Shamshutdinova, V. [Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318-CEP, 05315-970 Sao Paulo, S.P. (Brazil)

    2005-06-01

    We develop the Darboux procedure for the case of the two-level system. In particular, it is demonstrated that one can construct the Darboux intertwining operator that does not violate the specific structure of the equations of the two-level system, transforming only one real potential into another real potential. We apply the obtained Darboux transformation to known exact solutions of the two-level system. Thus, we find three classes of new solutions for the two-level system and the corresponding new potentials that allow such solutions. (Abstract Copyright [2005], Wiley Periodicals, Inc.)

  13. Brain Computer Interfaces for Enhanced Interaction with Mobile Robot Agents

    Science.gov (United States)

    2016-07-27

    SECURITY CLASSIFICATION OF: Brain Computer Interfaces (BCIs) show great potential in allowing humans to interact with computational environments in a...Distribution Unlimited UU UU UU UU 27-07-2016 17-Sep-2013 16-Sep-2014 Final Report: Brain Computer Interfaces for Enhanced Interactions with Mobile Robot...published in peer-reviewed journals: Number of Papers published in non peer-reviewed journals: Final Report: Brain Computer Interfaces for Enhanced

  14. Control of group of mobile autonomous agents via local strategies

    Institute of Scientific and Technical Information of China (English)

    Lixin GAO; Daizhan CHENG; Yiguang HONG

    2008-01-01

    This paper considers the formation control problem of multi-agent systems in a distributed fashion.Two cases of the information propagating topologies among multiple agents,characterized by graphics model,are considered.One is fixed topology.The other is switching topology which represents the limited and less reliable information exchange.The local formation control strategies established in this paper are based on a simple modification of the existing consensus control strategies.Moreover,some existing convergence conditions ale shown to be a special case of our model even in the continuous-time consensus case.Therefore.the results of this paper extend the existing results about the consensus problem.

  15. A mobile-agent-based wireless sensing network for structural monitoring applications

    International Nuclear Information System (INIS)

    Taylor, Stuart G; Farinholt, Kevin M; Figueiredo, Eloi; Moro, Erik A; Park, Gyuhae; Farrar, Charles R; Flynn, Eric B; Mascarenas, David L; Todd, Michael D

    2009-01-01

    A new wireless sensing network paradigm is presented for structural monitoring applications. In this approach, both power and data interrogation commands are conveyed via a mobile agent that is sent to sensor nodes to perform intended interrogations, which can alleviate several limitations of the traditional sensing networks. Furthermore, the mobile agent provides computational power to make near real-time assessments on the structural conditions. This paper will discuss such prototype systems, which are used to interrogate impedance-based sensors for structural health monitoring applications. Our wireless sensor node is specifically designed to accept various energy sources, including wireless energy transmission, and to be wirelessly triggered on an as-needed basis by the mobile agent or other sensor nodes. The capabilities of this proposed sensing network paradigm are demonstrated in the laboratory and the field

  16. Mobile Agent-Based Software Systems Modeling Approaches: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Aissam Belghiat

    2016-06-01

    Full Text Available Mobile agent-based applications are special type of software systems which take the advantages of mobile agents in order to provide a new beneficial paradigm to solve multiple complex problems in several fields and areas such as network management, e-commerce, e-learning, etc. Likewise, we notice lack of real applications based on this paradigm and lack of serious evaluations of their modeling approaches. Hence, this paper provides a comparative study of modeling approaches of mobile agent-based software systems. The objective is to give the reader an overview and a thorough understanding of the work that has been done and where the gaps in the research are.

  17. Mobile agent-enabled framework for structuring and building distributed systems on the internet

    Institute of Scientific and Technical Information of China (English)

    CAO Jiannong; ZHOU Jingyang; ZHU Weiwei; LI Xuhui

    2006-01-01

    Mobile agent has shown its promise as a powerful means to complement and enhance existing technology in various application areas. In particular, existing work has demonstrated that MA can simplify the development and improve the performance of certain classes of distributed applications, especially for those running on a wide-area, heterogeneous, and dynamic networking environment like the Internet. In our previous work, we extended the application of MA to the design of distributed control functions, which require the maintenance of logical relationship among and/or coordination of processing entities in a distributed system. A novel framework is presented for structuring and building distributed systems, which use cooperating mobile agents as an aid to carry out coordination and cooperation tasks in distributed systems. The framework has been used for designing various distributed control functions such as load balancing and mutual exclusion in our previous work. In this paper, we use the framework to propose a novel approach to detecting deadlocks in distributed system by using mobile agents, which demonstrates the advantage of being adaptive and flexible of mobile agents. We first describe the MAEDD (Mobile Agent Enabled Deadlock Detection) scheme, in which mobile agents are dispatched to collect and analyze deadlock information distributed across the network sites and, based on the analysis, to detect and resolve deadlocks. Then the design of an adaptive hybrid algorithm derived from the framework is presented. The algorithm can dynamically adapt itself to the changes in system state by using different deadlock detection strategies. The performance of the proposed algorithm has been evaluated using simulations. The results show that the algorithm can outperform existing algorithms that use a fixed deadlock detection strategy.

  18. Programming secure mobile agents in healthcare environments using role-based permissions.

    Science.gov (United States)

    Georgiadis, C K; Baltatzis, J; Pangalos, G I

    2003-01-01

    The healthcare environment consists of vast amounts of dynamic and unstructured information, distributed over a large number of information systems. Mobile agent technology is having an ever-growing impact on the delivery of medical information. It supports acquiring and manipulating information distributed in a large number of information systems. Moreover is suitable for the computer untrained medical stuff. But the introduction of mobile agents generates advanced threads to the sensitive healthcare information, unless the proper countermeasures are taken. By applying the role-based approach to the authorization problem, we ease the sharing of information between hospital information systems and we reduce the administering part. The different initiative of the agent's migration method, results in different methods of assigning roles to the agent.

  19. Flocking Control of Multiple Mobile Agents with the Rules of Avoiding Collision

    Directory of Open Access Journals (Sweden)

    Hongtao Zhou

    2015-01-01

    Full Text Available This paper investigates the flocking and the coordinative control problems of multiple mobile agents with the rules of avoiding collision. We propose a set of control laws using hysteresis in adding new links and applying new potential function to guarantee that the fragmentation of the network can be avoided, under which all agents approach a common velocity vector, and asymptotically converge to a fixed value of interagent distances and collisions between agents can be avoided throughout the motion. Furthermore, we extend the flocking algorithm to solve the flocking situation of the group with a virtual leader agent. The laws can make all agents asymptotically approach the virtual leader and collisions can be avoided between agents in the motion evolution. Finally, some numerical simulations are showed to illustrate the theoretical results.

  20. Radiation resistant polypropylene blended with mobilizer,. antioxidants and nucleating agent

    Science.gov (United States)

    Shamshad, A.; Basfar, A. A.

    2000-03-01

    Post-irradiation storage of medical disposables prepared from isotactic polypropylene renders them brittle due to degradation. To avoid this, isotactic polypropylene [(is)PP] was blended with a mobilizer, dioctyl pthallate (DOP), three antioxidants (hindered amines and a secondary antioxidant) and benzoic acid to obtain radiation-resistant, thermally-stable and transparent material. Different formulations prepared were subjected to gamma radiation to doses of 25 and 50 kGy. Tests of breakage on bending after ageing in an oven at 70°C up to 12 months have shown that the addition of DOP and the antioxidants imparts improved radiation and thermal stability as compared to (is)PP alone or its blend with DOP. All the formulations irradiated or otherwise demonstrated excellent colour stability even after accelerated ageing at 70°C for prolonged periods.

  1. Running mobile agent code over simulated inter-networks : an extra gear towards distributed system evaluation

    NARCIS (Netherlands)

    Liotta, A.; Ragusa, C.; Pavlou, G.

    2002-01-01

    Mobile Agent (MA) systems are complex software entities whose behavior, performance and effectiveness cannot always be anticipated by the designer. Their evaluation often presents various aspects that require a careful, methodological approach as well as the adoption of suitable tools, needed to

  2. Modelling network and system monitoring over the Internet with mobile agents

    NARCIS (Netherlands)

    Liotta, A.; Knight, G.; Pavlou, G.

    1998-01-01

    Distributed Network Management is gaining importance due to the explosive growth of the size of computer networks. New management paradigms are being proposed as an alternative to the centralised one, and new technologies and programming languages are making them feasible. The use of Mobile Agents

  3. An enhanced performance through agent-based secure approach for mobile ad hoc networks

    Science.gov (United States)

    Bisen, Dhananjay; Sharma, Sanjeev

    2018-01-01

    This paper proposes an agent-based secure enhanced performance approach (AB-SEP) for mobile ad hoc network. In this approach, agent nodes are selected through optimal node reliability as a factor. This factor is calculated on the basis of node performance features such as degree difference, normalised distance value, energy level, mobility and optimal hello interval of node. After selection of agent nodes, a procedure of malicious behaviour detection is performed using fuzzy-based secure architecture (FBSA). To evaluate the performance of the proposed approach, comparative analysis is done with conventional schemes using performance parameters such as packet delivery ratio, throughput, total packet forwarding, network overhead, end-to-end delay and percentage of malicious detection.

  4. Agent-based model of the effect of globalization on inequality and class mobility

    Science.gov (United States)

    Evers, Joep H. M.; Iron, David; Kolokolnikov, Theodore; Rumsey, John

    2017-12-01

    We consider a variant of the Bouchaud-Mézard model for wealth distribution in a society which incorporates the interaction radius between the agents, to model the extent of globalization in a society. The wealth distribution depends critically on the extent of this interaction. When interaction is relatively local, a small cluster of individuals emerges which accumulate most of the society's wealth. In this regime, the society is highly stratified with little or no class mobility. As the interaction is increased, the number of wealthy agents decreases, but the overall inequality rises as the freed-up wealth is transferred to the remaining wealthy agents. However when the interaction exceeds a certain critical threshold, the society becomes highly mobile resulting in a much lower economic inequality (low Gini index). This is consistent with the Kuznets upside-down U shaped inequality curve hypothesis.

  5. Design and Analysis of a Data Fusion Scheme in Mobile Wireless Sensor Networks Based on Multi-Protocol Mobile Agents

    Directory of Open Access Journals (Sweden)

    Chunxue Wu

    2017-11-01

    Full Text Available Sensors are increasingly used in mobile environments with wireless network connections. Multiple sensor types measure distinct aspects of the same event. Their measurements are then combined to produce integrated, reliable results. As the number of sensors in networks increases, low energy requirements and changing network connections complicate event detection and measurement. We present a data fusion scheme for use in mobile wireless sensor networks with high energy efficiency and low network delays, that still produces reliable results. In the first phase, we used a network simulation where mobile agents dynamically select the next hop migration node based on the stability parameter of the link, and perform the data fusion at the migration node. Agents use the fusion results to decide if it should return the fusion results to the processing center or continue to collect more data. In the second phase. The feasibility of data fusion at the node level is confirmed by an experimental design where fused data from color sensors show near-identical results to actual physical temperatures. These results are potentially important for new large-scale sensor network applications.

  6. Design and Analysis of a Data Fusion Scheme in Mobile Wireless Sensor Networks Based on Multi-Protocol Mobile Agents.

    Science.gov (United States)

    Wu, Chunxue; Wu, Wenliang; Wan, Caihua; Bekkering, Ernst; Xiong, Naixue

    2017-11-03

    Sensors are increasingly used in mobile environments with wireless network connections. Multiple sensor types measure distinct aspects of the same event. Their measurements are then combined to produce integrated, reliable results. As the number of sensors in networks increases, low energy requirements and changing network connections complicate event detection and measurement. We present a data fusion scheme for use in mobile wireless sensor networks with high energy efficiency and low network delays, that still produces reliable results. In the first phase, we used a network simulation where mobile agents dynamically select the next hop migration node based on the stability parameter of the link, and perform the data fusion at the migration node. Agents use the fusion results to decide if it should return the fusion results to the processing center or continue to collect more data. In the second phase. The feasibility of data fusion at the node level is confirmed by an experimental design where fused data from color sensors show near-identical results to actual physical temperatures. These results are potentially important for new large-scale sensor network applications.

  7. Novel agents and approaches for stem cell mobilization in normal donors and patients.

    Science.gov (United States)

    Bakanay, Ş M; Demirer, T

    2012-09-01

    In spite of the safety and efficiency of the classical mobilization protocols, recombinant human G-CSF±chemotherapy, there is still a considerable amount of mobilization failures (10-30%), which warrant novel agents and approaches both in an autologous and an allogeneic transplant setting. Attempts to improve CD34+ yields by using several cytokines and growth factors as adjuncts to G-CSF could not change the standard approaches during the last decade, either because of inefficiency or the adverse events encountered with these agents. As a long-acting G-CSF analog, pegfilgrastim has the advantages of an earlier start of apheresis, reduction in the number of apheresis procedures as well as a reduced number of injections as compared with unconjugated G-CSF. However, dosing and cost-effectiveness especially in cytokine-only mobilizations require further investigation. As interactions between hematopoietic stem cells and the BM microenvironment are better understood, new molecules targeting these interactions are emerging. Plerixafor, which started its journey as an anti-HIV drug, recently ended up being a popular stem cell mobilizer with the ability of rapid mobilization and gained approval as an adjunct to G-CSF for poor mobilizers. At present, it is challenging to search for the best approach by using the available drugs with appropriate timing to provide sufficient CD34+ yield after an initial mobilization attempt, and in a cost-effective manner thereby avoiding further mobilization attempts and exposure to chemotherapy. Approaches not only for increasing stem cell yield, but also aiming to improve the quality of graft content and the associated transplantation outcomes are promising areas of research.

  8. Electrophoretic mobilities of dissolved polyelectrolyte charging agent and suspended non-colloidal titanium during electrophoretic deposition

    International Nuclear Information System (INIS)

    Lau, Kok-Tee; Sorrell, C.C.

    2011-01-01

    Coarse (≤20 μm) titanium particles were deposited on low-carbon steel substrates by cathodic electrophoretic deposition (EPD) with ethanol as suspension medium and poly(diallyldimethylammonium chloride) (PDADMAC) as polymeric charging agent. Preliminary data on the electrophoretic mobilities and electrical conductivities on the suspensions of these soft particles as well as the solutions themselves as a function of PDADMAC level were used as the basis for the investigation of the EPD parameters in terms of the deposition yield as a function of five experimental parameters: (a) PDADMAC addition level, (b) solids loading, (c) deposition time, (d) applied voltage, and (e) electrode separation. These data were supported by particle sizing by laser diffraction and deposit surface morphology by scanning electron microscopy (SEM). The preceding data demonstrated that Ti particles of ∼1-12 μm size, electrosterically modified by the PDADMAC charging agent, acted effectively as colloidal particles during EPD. Owing to the non-colloidal nature of the particles and the stabilization of the Ti particles by electrosteric forces, the relevance of the zeta potential is questionable, so the more fundamental parameter of electrophoretic mobility was used. A key finding from the present work is the importance of assessing the electrophoretic mobilities of both the suspensions and solutions since the latter, which normally is overlooked, plays a critical role in the ability to interpret the results meaningfully. Further, algebraic uncoupling of these data plus determination of the deposit yield as a function of charging agent addition allow discrimination between the three main mechanistic stages of the electrokinetics of the process, which are: (1) surface saturation; (2) compression of the diffuse layer, growth of polymer-rich layer, and/or competition between the mobility of Ti and PDADMAC; and (3) little or no decrease in electrophoretic mobility of Ti, establishment of

  9. Electrophoretic mobilities of dissolved polyelectrolyte charging agent and suspended non-colloidal titanium during electrophoretic deposition

    Energy Technology Data Exchange (ETDEWEB)

    Lau, Kok-Tee [School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka, 76109 Durian Tunggal, Melaka (Malaysia); Sorrell, C.C., E-mail: C.Sorrell@unsw.edu.au [School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052 (Australia)

    2011-03-25

    Coarse ({<=}20 {mu}m) titanium particles were deposited on low-carbon steel substrates by cathodic electrophoretic deposition (EPD) with ethanol as suspension medium and poly(diallyldimethylammonium chloride) (PDADMAC) as polymeric charging agent. Preliminary data on the electrophoretic mobilities and electrical conductivities on the suspensions of these soft particles as well as the solutions themselves as a function of PDADMAC level were used as the basis for the investigation of the EPD parameters in terms of the deposition yield as a function of five experimental parameters: (a) PDADMAC addition level, (b) solids loading, (c) deposition time, (d) applied voltage, and (e) electrode separation. These data were supported by particle sizing by laser diffraction and deposit surface morphology by scanning electron microscopy (SEM). The preceding data demonstrated that Ti particles of {approx}1-12 {mu}m size, electrosterically modified by the PDADMAC charging agent, acted effectively as colloidal particles during EPD. Owing to the non-colloidal nature of the particles and the stabilization of the Ti particles by electrosteric forces, the relevance of the zeta potential is questionable, so the more fundamental parameter of electrophoretic mobility was used. A key finding from the present work is the importance of assessing the electrophoretic mobilities of both the suspensions and solutions since the latter, which normally is overlooked, plays a critical role in the ability to interpret the results meaningfully. Further, algebraic uncoupling of these data plus determination of the deposit yield as a function of charging agent addition allow discrimination between the three main mechanistic stages of the electrokinetics of the process, which are: (1) surface saturation; (2) compression of the diffuse layer, growth of polymer-rich layer, and/or competition between the mobility of Ti and PDADMAC; and (3) little or no decrease in electrophoretic mobility of Ti

  10. Performance Analysis of Untraceability Protocols for Mobile Agents Using an Adaptable Framework

    OpenAIRE

    LESZCZYNA RAFAL; GORSKI Janusz Kazimierz

    2006-01-01

    Recently we had proposed two untraceability protocols for mobile agents and began investigating their quality. We believe that quality evaluation of security protocols should extend a sole validation of their security and cover other quality aspects, primarily their efficiency. Thus after conducting a security analysis, we wanted to complement it with a performance analysis. For this purpose we developed a performance evaluation framework, which, as we realised, with certain adjustments, can ...

  11. Computational Research on Mobile Pastoralism Using Agent-Based Modeling and Satellite Imagery.

    Directory of Open Access Journals (Sweden)

    Takuto Sakamoto

    Full Text Available Dryland pastoralism has long attracted considerable attention from researchers in diverse fields. However, rigorous formal study is made difficult by the high level of mobility of pastoralists as well as by the sizable spatio-temporal variability of their environment. This article presents a new computational approach for studying mobile pastoralism that overcomes these issues. Combining multi-temporal satellite images and agent-based modeling allows a comprehensive examination of pastoral resource access over a realistic dryland landscape with unpredictable ecological dynamics. The article demonstrates the analytical potential of this approach through its application to mobile pastoralism in northeast Nigeria. Employing more than 100 satellite images of the area, extensive simulations are conducted under a wide array of circumstances, including different land-use constraints. The simulation results reveal complex dependencies of pastoral resource access on these circumstances along with persistent patterns of seasonal land use observed at the macro level.

  12. Mobility timing for agent communities, a cue for advanced connectionist systems.

    Science.gov (United States)

    Apolloni, Bruno; Bassis, Simone; Pagani, Elena; Rossi, Gian Paolo; Valerio, Lorenzo

    2011-12-01

    We introduce a wait-and-chase scheme that models the contact times between moving agents within a connectionist construct. The idea that elementary processors move within a network to get a proper position is borne out both by biological neurons in the brain morphogenesis and by agents within social networks. From the former, we take inspiration to devise a medium-term project for new artificial neural network training procedures where mobile neurons exchange data only when they are close to one another in a proper space (are in contact). From the latter, we accumulate mobility tracks experience. We focus on the preliminary step of characterizing the elapsed time between neuron contacts, which results from a spatial process fitting in the family of random processes with memory, where chasing neurons are stochastically driven by the goal of hitting target neurons. Thus, we add an unprecedented mobility model to the literature in the field, introducing a distribution law of the intercontact times that merges features of both negative exponential and Pareto distribution laws. We give a constructive description and implementation of our model, as well as a short analytical form whose parameters are suitably estimated in terms of confidence intervals from experimental data. Numerical experiments show the model and related inference tools to be sufficiently robust to cope with two main requisites for its exploitation in a neural network: the nonindependence of the observed intercontact times and the feasibility of the model inversion problem to infer suitable mobility parameters.

  13. Key-Insulated Undetachable Digital Signature Scheme and Solution for Secure Mobile Agents in Electronic Commerce

    Directory of Open Access Journals (Sweden)

    Yang Shi

    2016-01-01

    Full Text Available Considering the security of both the customers’ hosts and the eShops’ servers, we introduce the idea of a key-insulated undetachable digital signature, enabling mobile agents to generate undetachable digital signatures on remote hosts with the key-insulated property of the original signer’s signing key. From the theoretical perspective, we provide the formal definition and security notion of a key-insulated undetachable digital signature. From the practical perspective, we propose a concrete scheme to secure mobile agents in electronic commerce. The scheme is mainly focused on protecting the signing key from leakage and preventing the misuse of the signature algorithm on malicious servers. Agents do not carry the signing key when they generate digital signatures on behalf of the original signer, so the key is protected on remote servers. Furthermore, if a hacker gains the signing key of the original signer, the hacker is still unable to forge a signature for any time period other than the key being accessed. In addition, the encrypted function is combined with the original signer’s requirement to prevent the misuse of signing algorithm. The scheme is constructed on gap Diffie–Hellman groups with provable security, and the performance testing indicates that the scheme is efficient.

  14. Development of maintenance support system using portable device and mobile agent

    International Nuclear Information System (INIS)

    Sato, Hisashi; Ito, Yo; Takahashi, Makoto; Kitamura, Masaharu; Ohi, Tadashi; Wu, Wei

    2004-01-01

    The framework of intelligent support system for the maintenance of nuclear power plant is proposed in this paper with emphasis on the combined use of a portable device and intelligent information processing. The purpose of this system is the realization of flexible inspection process and effective diagnosis process to be performed on-site. The prototype system has been implemented for the experimental facility with mobile-agent technology and PDA (personal digital assistant) to show the basic functionality of the proposed framework. The results of the scenario-based and function-based evaluation showed that the proposed framework is effective for the data management for the maintenance activities. (author)

  15. Setting up a mobile Lidar (DIAL) system for detecting chemical warfare agents

    International Nuclear Information System (INIS)

    Tehrani, M Kavosh; Jaafari, E; Mobashery, A; Mohammad, M Malek

    2015-01-01

    The mobile light detection and ranging DIAL system of Malek Ashtar University of Technology has been developed for the detection of chemical warfare agents whose absorption wavelengths are in the range of 9.2–10.8 μm tunable CO 2 lasers of the system. In this paper, this system is first described and then ammonia detection is analyzed experimentally. Also, experimental results of detecting a sarin agent simulant, dimethyl–methyl phosphonate (DMMP), are presented. The power levels received from different ranges to detect specific concentrations of NH 3 and DMMP have been measured and debated. The primary test results with a 150 ns clipped pulse width by passive pinhole plasma shutter indicate that the system is capable of monitoring several species of pollutants in the range of about 1 km, with a 20 m spatial and 2 min temporal resolution. (paper)

  16. Design of a Mobile Agent-Based Adaptive Communication Middleware for Federations of Critical Infrastructure Simulations

    Science.gov (United States)

    Görbil, Gökçe; Gelenbe, Erol

    The simulation of critical infrastructures (CI) can involve the use of diverse domain specific simulators that run on geographically distant sites. These diverse simulators must then be coordinated to run concurrently in order to evaluate the performance of critical infrastructures which influence each other, especially in emergency or resource-critical situations. We therefore describe the design of an adaptive communication middleware that provides reliable and real-time one-to-one and group communications for federations of CI simulators over a wide-area network (WAN). The proposed middleware is composed of mobile agent-based peer-to-peer (P2P) overlays, called virtual networks (VNets), to enable resilient, adaptive and real-time communications over unreliable and dynamic physical networks (PNets). The autonomous software agents comprising the communication middleware monitor their performance and the underlying PNet, and dynamically adapt the P2P overlay and migrate over the PNet in order to optimize communications according to the requirements of the federation and the current conditions of the PNet. Reliable communications is provided via redundancy within the communication middleware and intelligent migration of agents over the PNet. The proposed middleware integrates security methods in order to protect the communication infrastructure against attacks and provide privacy and anonymity to the participants of the federation. Experiments with an initial version of the communication middleware over a real-life networking testbed show that promising improvements can be obtained for unicast and group communications via the agent migration capability of our middleware.

  17. Protection of Mobile Agents Execution Using a Modified Self-Validating Branch-Based Software Watermarking with External Sentinel

    Science.gov (United States)

    Tomàs-Buliart, Joan; Fernández, Marcel; Soriano, Miguel

    Critical infrastructures are usually controlled by software entities. To monitor the well-function of these entities, a solution based in the use of mobile agents is proposed. Some proposals to detect modifications of mobile agents, as digital signature of code, exist but they are oriented to protect software against modification or to verify that an agent have been executed correctly. The aim of our proposal is to guarantee that the software is being executed correctly by a non trusted host. The way proposed to achieve this objective is by the improvement of the Self-Validating Branch-Based Software Watermarking by Myles et al.. The proposed modification is the incorporation of an external element called sentinel which controls branch targets. This technique applied in mobile agents can guarantee the correct operation of an agent or, at least, can detect suspicious behaviours of a malicious host during the execution of the agent instead of detecting when the execution of the agent have finished.

  18. Smart caching based on mobile agent of power WebGIS platform.

    Science.gov (United States)

    Wang, Xiaohui; Wu, Kehe; Chen, Fei

    2013-01-01

    Power information construction is developing towards intensive, platform, distributed direction with the expansion of power grid and improvement of information technology. In order to meet the trend, power WebGIS was designed and developed. In this paper, we first discuss the architecture and functionality of power WebGIS, and then we study caching technology in detail, which contains dynamic display cache model, caching structure based on mobile agent, and cache data model. We have designed experiments of different data capacity to contrast performance between WebGIS with the proposed caching model and traditional WebGIS. The experimental results showed that, with the same hardware environment, the response time of WebGIS with and without caching model increased as data capacity growing, while the larger the data was, the higher the performance of WebGIS with proposed caching model improved.

  19. An Autonomous Mobile Agent-Based Distributed Learning Architecture-A Proposal and Analytical Analysis

    Directory of Open Access Journals (Sweden)

    I. Ahmed M. J. SADIIG

    2005-10-01

    Full Text Available An Autonomous Mobile Agent-Based Distributed Learning Architecture-A Proposal and Analytical Analysis Dr. I. Ahmed M. J. SADIIG Department of Electrical & Computer EngineeringInternational Islamic University GombakKuala Lumpur-MALAYSIA ABSTRACT The traditional learning paradigm invoving face-to-face interaction with students is shifting to highly data-intensive electronic learning with the advances in Information and Communication Technology. An important component of the e-learning process is the delivery of the learning contents to their intended audience over a network. A distributed learning system is dependent on the network for the efficient delivery of its contents to the user. However, as the demand of information provision and utilization increases on the Internet, the current information service provision and utilization methods are becoming increasingly inefficient. Although new technologies have been employed for efficient learning methodologies within the context of an e-learning environment, the overall efficiency of the learning system is dependent on the mode of distribution and utilization of its learning contents. It is therefore imperative to employ new techniques to meet the service demands of current and future e-learning systems. In this paper, an architecture based on autonomous mobile agents creating a Faded Information Field is proposed. Unlike the centralized information distribution in a conventional e-learning system, the information is decentralized in the proposed architecture resulting in increased efficiency of the overall system for distribution and utilization of system learning contents efficiently and fairly. This architecture holds the potential to address the heterogeneous user requirements as well as the changing conditions of the underlying network.

  20. Reversing resistance to vascular-disrupting agents by blocking late mobilization of circulating endothelial progenitor cells.

    Science.gov (United States)

    Taylor, Melissa; Billiot, Fanny; Marty, Virginie; Rouffiac, Valérie; Cohen, Patrick; Tournay, Elodie; Opolon, Paule; Louache, Fawzia; Vassal, Gilles; Laplace-Builhé, Corinne; Vielh, Philippe; Soria, Jean-Charles; Farace, Françoise

    2012-05-01

    The prevailing concept is that immediate mobilization of bone marrow-derived circulating endothelial progenitor cells (CEP) is a key mechanism mediating tumor resistance to vascular-disrupting agents (VDA). Here, we show that administration of VDA to tumor-bearing mice induces 2 distinct peaks in CEPs: an early, unspecific CEP efflux followed by a late yet more dramatic tumor-specific CEP burst that infiltrates tumors and is recruited to vessels. Combination with antiangiogenic drugs could not disrupt the early peak but completely abrogated the late VDA-induced CEP burst, blunted bone marrow-derived cell recruitment to tumors, and resulted in striking antitumor efficacy, indicating that the late CEP burst might be crucial to tumor recovery after VDA therapy. CEP and circulating endothelial cell kinetics in VDA-treated patients with cancer were remarkably consistent with our preclinical data. These findings expand the current understanding of vasculogenic "rebounds" that may be targeted to improve VDA-based strategies. Our findings suggest that resistance to VDA therapy may be strongly mediated by late, rather than early, tumor-specific recruitment of CEPs, the suppression of which resulted in increased VDA-mediated antitumor efficacy. VDA-based therapy might thus be significantly enhanced by combination strategies targeting late CEP mobilization. © 2012 AACR

  1. HH-MIP: An Enhancement of Mobile IP by Home Agent Handover

    Directory of Open Access Journals (Sweden)

    Yang Chun-Chuan

    2010-01-01

    Full Text Available We propose an enhancement of Mobile IP (MIP called MIP with Home Agent Handover (HH-MIP to enjoy most of the advantages of Route Optimization MIP (ROMIP but with only a small increase of signaling overhead. In HH-MIP, the concept of Temporary HA (THA is proposed and the mobile host (MH registers the new CoA with its THA rather than its original HA. Since the THA of an MH is selected to be close to the current location of MH, HH-MIP reduces the handoff latency and shortens the signaling path of registration as well. Moreover, HH-MIP adopts an aggressive approach in selecting THA for an MH, that is, whenever an MH is moving away from its HA or previous THA, the MH triggers the handover of THA. Theoretical analysis demonstrates that the proposed scheme enjoys small handoff latency as well as routing efficiency, and the signaling cost of the proposed scheme is significantly less than that in ROMIP.

  2. 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.

  3. 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)

  4. Two-Level Semantics and Code Generation

    DEFF Research Database (Denmark)

    Nielson, Flemming; Nielson, Hanne Riis

    1988-01-01

    A two-level denotational metalanguage that is suitable for defining the semantics of Pascal-like languages is presented. The two levels allow for an explicit distinction between computations taking place at compile-time and computations taking place at run-time. While this distinction is perhaps...... not absolutely necessary for describing the input-output semantics of programming languages, it is necessary when issues such as data flow analysis and code generation are considered. For an example stack-machine, the authors show how to generate code for the run-time computations and still perform the compile...

  5. Investigation of oil recovery improvement by coupling an interfacial tension agent and a mobility control agent in light oil reservoirs. Second annual report, October 1993--September 1994

    Energy Technology Data Exchange (ETDEWEB)

    Pitts, M.J.

    1995-04-01

    {open_quotes}Investigation of Oil Recovery Improvement by Coupling an Interfacial Tension Agent and a Mobility Control Agent in Light Oil Reservoirs{close_quotes} is studying two major areas concerning co-injecting an interfacial tension reduction agent(s) and a mobility control agent. The first area defines the interactions of alkaline agents, surfactants, and polymers on a fluid-fluid and a fluid-rock basis. The second area concerns the economic improvement of the combined technology. This report continues the fluid-fluid interaction evaluations and begins the fluid-rock studies. Fluid-fluid interfacial tension work determined that replacing sodium ion with either potassium or ammonium ion in solutions with interfacial tension reduction up to 19,600 fold was detrimental and had little or no effect on alkali-surfactant solutions with interfacial tension reduction of 100 to 200 fold. Reservoir brine increases interfacial tension between crude oil and alkaline-surfactant solutions. Na{sub 2}CO{sub 3}-surfactant solutions maintained ultra low and low interfacial tension values better than NaOH-surfactant solutions. The initial phase of the fluid-rock investigations was adsorption studies. Surfactant adsorption is reduced when co-dissolved with alkali. Na{sub 2}CO{sub 3} and Na{sub 3}PO{sub 4} are more efficient at reducing surfactant adsorption than NaOH. When polymer is added to the surfactant solution, surfactant adsorption is reduced as well. When both polymer and alkali are added, polymer is the dominate component, reducing the Na{sub 2}CO{sub 3} and NaOH effect on adsorption. Substituting sodium ion with potassium or ammonium ion increased or decreased surfactant adsorption depending on surfactant structure with alkali having a less significant effect. No consistent change of surfactant adsorption with increasing salinity was observed in the presence or absence of alkali or polymer.

  6. A Spawn Mobile Agent Itinerary Planning Approach for Energy-Efficient Data Gathering in Wireless Sensor Networks.

    Science.gov (United States)

    Qadori, Huthiafa Q; Zulkarnain, Zuriati A; Hanapi, Zurina Mohd; Subramaniam, Shamala

    2017-06-03

    Mobile agent (MA), a part of the mobile computing paradigm, was recently proposed for data gathering in Wireless Sensor Networks (WSNs). The MA-based approach employs two algorithms: Single-agent Itinerary Planning (SIP) and Multi-mobile agent Itinerary Planning (MIP) for energy-efficient data gathering. The MIP was proposed to outperform the weakness of SIP by introducing distributed multi MAs to perform the data gathering task. Despite the advantages of MIP, finding the optimal number of distributed MAs and their itineraries are still regarded as critical issues. The existing MIP algorithms assume that the itinerary of the MA has to start and return back to the sink node. Moreover, each distributed MA has to carry the processing code (data aggregation code) to collect the sensory data and return back to the sink with the accumulated data. However, these assumptions have resulted in an increase in the number of MA's migration hops, which subsequently leads to an increase in energy and time consumption. In this paper, a spawn multi-mobile agent itinerary planning (SMIP) approach is proposed to mitigate the substantial increase in cost of energy and time used in the data gathering processes. The proposed approach is based on the agent spawning such that the main MA is able to spawn other MAs with different tasks assigned from the main MA. Extensive simulation experiments have been conducted to test the performance of the proposed approach against some selected MIP algorithms. The results show that the proposed SMIP outperforms the counterpart algorithms in terms of energy consumption and task delay (time), and improves the integrated energy-delay performance.

  7. An Agent-Based Model for the Development of Intelligent Mobile Services

    NARCIS (Netherlands)

    Koch, F.L.

    2009-01-01

    The next generation of mobile services must invisible, convenient, and useful. It requires new techniques to design and develop mobile computing applications, based on user-centred, environment-aware, adaptive behaviour. I propose an alternative technology for the development of intelligent mobile

  8. Application of mobile agent technology with portable information device to the maintenance support of nuclear power plant

    International Nuclear Information System (INIS)

    Takahashi, Makoto; Ito, Yo; Sato, Hisashi; Kitamura, Masaharu

    2004-01-01

    A support system for trouble shooting activities has been developed based on the distributed DB and mobile agent technology. The main purpose of the proposed system is to provide field workers with effective functions for realizing trouble-shooting with the aid of the mobile agents, which performs data retrieval from DB and fault diagnosis. In the proposed scheme of trouble shooting support, a portable information device is utilized by the maintenance personnel, which is connected to the local data base (LDB) via wireless network. The important point is that these functions can be accessed by the field workers through wearable information device with the lower cognitive burden. The prototype system has been developed using the JAVA-based Aglets Framework SDK and applied to the actual objective system. It has been confirmed through the experiments that the developed prototype system is capable of performing the tasks to support diagnostic activities. (author)

  9. What is the role of biosimilar G-CSF agents in hematopoietic stem cell mobilization at present?

    Science.gov (United States)

    Korkmaz, Serdal; Altuntas, Fevzi

    2017-12-01

    Mobilization of hematopoietic stem cells, which has largely replaced bone marrow harvesting as a source of hematopoietic stem cells, using recombinant agents such as filgrastim or lenograstim has become a standard procedure in both patients and healthy donors prior to peripheral blood stem cell collection for autologous and allogeneic stem cell transplantation. Published literature data suggest that mobilization with recombinant granulocyte-colony stimulating factor (G-CSF) is safe and mobilization outcomes are satisfactory. In recent years, besides G-CSF originators, biosimilar G-CSF agents have been approved by the regulatory agencies for the same indications. Current data showed that by using the biosimilar G-CSF, similar results regarding safety and efficacy of hematopoietic stem cell mobilization may be achieved compared to the originator G-CSF. Although the issues such as the similarity to a licenced biological medicine, differences in manufacturing processes, the potential to cause immunogenicity, extrapolation and interchangeability of these biosimilar products are still being discussed by the scientific area, however, more experience with these agents now exists in approved endications and there seems to be no reason to expect significant differences between biosimilar G-CSF and originator G-CSF regarding their efficacy and safety in both patients and healthy donors. Also, the significant cost savings of biosimilars in real life setting may enhance the use of these agents in the future. Nonetheless, the collection of long-term follow-up data is mandatory for both patients and healthy donors, and multicentre randomized clinical trials that directly compare biosimilar G-CSF with the originator G-CSF are needed in order to allow the transplant community to make informed decisions regarding the choice of G-CSF. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Moderation analysis using a two-level regression model.

    Science.gov (United States)

    Yuan, Ke-Hai; Cheng, Ying; Maxwell, Scott

    2014-10-01

    Moderation analysis is widely used in social and behavioral research. The most commonly used model for moderation analysis is moderated multiple regression (MMR) in which the explanatory variables of the regression model include product terms, and the model is typically estimated by least squares (LS). This paper argues for a two-level regression model in which the regression coefficients of a criterion variable on predictors are further regressed on moderator variables. An algorithm for estimating the parameters of the two-level model by normal-distribution-based maximum likelihood (NML) is developed. Formulas for the standard errors (SEs) of the parameter estimates are provided and studied. Results indicate that, when heteroscedasticity exists, NML with the two-level model gives more efficient and more accurate parameter estimates than the LS analysis of the MMR model. When error variances are homoscedastic, NML with the two-level model leads to essentially the same results as LS with the MMR model. Most importantly, the two-level regression model permits estimating the percentage of variance of each regression coefficient that is due to moderator variables. When applied to data from General Social Surveys 1991, NML with the two-level model identified a significant moderation effect of race on the regression of job prestige on years of education while LS with the MMR model did not. An R package is also developed and documented to facilitate the application of the two-level model.

  11. The Implementation Strategy of the Hierarchical Mobile-Agent%层次化Mobile-Agent的策略与设计

    Institute of Scientific and Technical Information of China (English)

    李琛; 赵清滨; 高璧

    2003-01-01

    文章针对网络营运环境的新变化以及网络拓扑结构的复杂性给网管带来的新要求,指出了集中式网管存在的不足,提出了层次化Mobile-Agent的实现策略,设计了层次化M0bile-Agent的定位方法.

  12. Experimental Hamiltonian identification for controlled two-level systems

    International Nuclear Information System (INIS)

    Schirmer, S.G.; Kolli, A.; Oi, D.K.L.

    2004-01-01

    We present a strategy to empirically determine the internal and control Hamiltonians for an unknown two-level system (black box) subject to various (piecewise constant) control fields when direct readout by measurement is limited to a single, fixed observable

  13. Design of a Mobile Agents Based Solution to Distributional Management of Computer Networks, Taking into Account the Security Mechanisms

    Directory of Open Access Journals (Sweden)

    S. Bahrami

    2017-10-01

    Full Text Available Mobile agents (MAs is one of the technologies considered in the recent years to perform management processes. This technology provides the ability to move code in distributed environments and to connect with other resources and agents locally which makes it an appropriate technology in the development of software applications of distributed network, especially management systems. For using mobile agent technology, an infrastructure for the management of MAs is needed. In this project, an infrastructure called MCT management is introduced for network management. In this infrastructure, some protocols like SNMP are used to get management data for the network administrator. With respect to management ability, MAs can dynamically access the database SNMP (i.e. MIB and extract the data required by the managers. Most well-known methods are characterized by being static relative to code and location in which components cannot modify their location or code in a lifetime. However, the MAs method can dynamically increase communications, reduce costs and overcome certain limitations by changing location and components.

  14. A specialised architecture for embedding trust evaluation capabilities in intelligent mobile agents

    OpenAIRE

    2010-01-01

    M.Sc.(Computer Science) The dissertation investigates trust and reputation as a specialisation of agent technology. The research presented herein aims to establish and demonstrate how it is possible for one rational agent to trust another entity. Furthermore, the research presented herein aims to determine the extent of the limitations of trust and reputation models, and of the demonstrable solution in particular. To this end, the dissertation investigates theoretical aspects of trust. The...

  15. Mobilities

    DEFF Research Database (Denmark)

    to social networks, personal identities, and our relationship to the built environment. The omnipresence of mobilities within everyday life, high politics, technology, and tourism (to mention but a few) all point to a key insight harnessed by the ‘mobilities turn’. Namely that mobilities is much more than......The world is on the move. This is a widespread understanding by many inhabitants of contemporary society across the Globe. But what does it actually mean? During over one decade the ‘mobilities turn’ within the social sciences have provided a new set of insights into the repercussions of mobilities...... and environmental degradation. The spaces and territories marked by mobilities as well as the sites marked by the bypassing of such are explored. Moreover, the architectural and technological dimensions to infrastructures and sites of mobilities will be included as well as the issues of power, social exclusion...

  16. A Framework for Research in Gamified Mobile Guide Applications using Embodied Conversational Agents (ECAs

    Directory of Open Access Journals (Sweden)

    Ioannis Doumanis

    2015-09-01

    Full Text Available Mobile Guides are mobile applications that provide players with local and location-based services (LBS, such as navigation assistance, where and when they need them most. Advances in mobile technologies in recent years have enabled the gamification of these applications, opening up new opportunities to transfer education and culture through game play. However, adding traditional game elements such as PBLs (points, badges, and leaderboards alone cannot ensure that the intended learning outcomes will be met, as the player’s cognitive resources are shared between the application and the surrounding environment. This distribution of resources prevents players from easily immersing themselves into the educational scenario. Adding artificial conversational characters (ECAs that simulate the social norms found in real-life human-to-human guide scenarios has the potential to address this problem and improve the player’s experience and learning of cultural narratives [1]. Although significant progress has been made towards creating game-like mobile guides with ECAs ([2], [3], there is still a lack of a unified framework that enables researchers and practitioners to investigate the potential effects of such applications to players and how to approach the concepts of player experience, cognitive accessibility and usability in this context. This paper presents a theoretically-well supported research framework consisted of four key components: differences in players, different features of the gamified task, aspects of how the ECA looks, sound or behaves and different mobile environments. Furthermore, it provides based on this framework a working definition of what player experience, cognitive accessibility and usability are in the context of game-like mobile guide applications. Finally, a synthesis of the results of six empirical studies conducted within this research framework is discussed and a series of design guidelines for the effective gamification

  17. Scaling of the propagation of epidemics in a system of mobile agents

    OpenAIRE

    Gonzalez, M. C.; Herrmann, H. J.

    2004-01-01

    For a two-dimensional system of agents modeled by molecular dynamics, we simulate epidemics spreading, which was recently studied on complex networks. Our resulting network model is time-evolving. We study the transitions to spreading as function of density, temperature and infection time. In addition, we analyze the epidemic threshold associated to a power-law distribution of infection times.

  18. The geometric phase in two-level atomic systems

    International Nuclear Information System (INIS)

    Tian Mingzhen; Barber, Zeb W.; Fischer, Joe A.; Randall Babbitt, Wm.

    2004-01-01

    We report the observation of the geometric phase in a closed two-level atomic system using stimulated photon echoes. The two-level system studied consists of the two-electronic energy levels ( 3 H 4 and 3 H 6 ) of Tm 3+ doped in YAG crystal. When a two-level atom at an arbitrary superposition state is excited by a pair of specially designed laser pulses, the excited state component gains a relative phase with respect to the ground state component. We identified the phase shift to be of pure geometric nature. The dynamic phase associated to the driving Hamiltonian is unchanged. The experiment results of the phase change agree with the theory to the extent of the measurement limit

  19. Application of multiAgent technology to mobile and wireless network optimization

    OpenAIRE

    Longan Zarzoso, Idoia

    2006-01-01

    Multiagent systems arise in several domains of engineering and it seems that can be also efficiently used to optimise resources in present and future generation of wireless heterogeneous networks. In this context an agent is considered as a software entity with autonomous behaviour and objectives, embedded in an environment which perceives, and in which it acts. Autonomy means the ability to have control over its actions and its internal states, and therefore implies de-centralized control. K...

  20. Ionic liquid as a mobile phase additive in high-performance liquid chromatography for the simultaneous determination of eleven fluorescent whitening agents in paper materials.

    Science.gov (United States)

    Wang, Qing; Chen, Xianbo; Qiu, Bin; Zhou, Liang; Zhang, Hui; Xie, Juan; Luo, Yan; Wang, Bin

    2016-04-01

    In the present study, 11 4,4'-diaminostilbene-2,2'-disulfonic acid based fluorescent whitening agents with different numbers of sulfonic acid groups were separated by using an ionic liquid as a mobile phase additive in high-performance liquid chromatography with fluorescence detection. The effects of ionic liquid concentration, pH of mobile phase B, and composition of mobile phase A on the separation of fluorescent whitening agents were systematically investigated. The ionic liquid tetrabutylammonium tetrafluoroborate is superior to tetrabutylammomnium bromide for the separation of the fluorescent whitening agents. The optimal separation conditions were an ionic liquid concentration at 8 mM and the pH of mobile phase B at 8.5 with methanol as mobile phase A. The established method exhibited low limits of detection (0.04-0.07 ng/mL) and wide linearity ranges (0.30-20 ng/mL) with high linear correlation coefficients from 0.9994 to 0.9998. The optimized procedure was applied to analyze target analytes in paper samples with satisfactory results. Eleven target analytes were quantified, and the recoveries of spiked paper samples were in the range of 85-105% with the relative standard deviations from 2.1 to 5.1%. The obtained results indicated that the method was efficient for detection of 11 fluorescent whitening agents. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. 基于Mobile Agent技术的主动性网络管理策略的研究%The Study of Active Network Management Strategies Based on Mobile Agent

    Institute of Scientific and Technical Information of China (English)

    庄力可; 杜军平; 涂序彦; 赵敏哲

    2001-01-01

    在讨论集中式网管体系结构的基础上,探讨了一种新型的基于Mobile agent 技术的主动性网络管理策略,并通过对一个实例的分析,阐述了该机制的优点。%In this paper, we are exploiting a new strategy based on mobile agent applied in active network management. The advantages of the new mechanism are also introduced after compared with centralized architectures through a case.

  2. Performance comparison of novel WNN approach with RBFNN in navigation of autonomous mobile robotic agent

    Directory of Open Access Journals (Sweden)

    Ghosh Saradindu

    2016-01-01

    Full Text Available This paper addresses the performance comparison of Radial Basis Function Neural Network (RBFNN with novel Wavelet Neural Network (WNN of designing intelligent controllers for path planning of mobile robot in an unknown environment. In the proposed WNN, different types of activation functions such as Mexican Hat, Gaussian and Morlet wavelet functions are used in the hidden nodes. The neural networks are trained by an intelligent supervised learning technique so that the robot makes a collision-free path in the unknown environment during navigation from different starting points to targets/goals. The efficiency of two algorithms is compared using some MATLAB simulations and experimental setup with Arduino Mega 2560 microcontroller in terms of path length and time taken to reach the target as an indicator for the accuracy of the network models.

  3. Two-level convolution formula for nuclear structure function

    Science.gov (United States)

    Ma, Boqiang

    1990-05-01

    A two-level convolution formula for the nuclear structure function is derived in considering the nucleus as a composite system of baryon-mesons which are also composite systems of quark-gluons again. The results show that the European Muon Colaboration effect can not be explained by the nuclear effects as nucleon Fermi motion and nuclear binding contributions.

  4. Two-level convolution formula for nuclear structure function

    International Nuclear Information System (INIS)

    Ma Boqiang

    1990-01-01

    A two-level convolution formula for the nuclear structure function is derived in considering the nucleus as a composite system of baryon-mesons which are also composite systems of quark-gluons again. The results show that the European Muon Colaboration effect can not be explained by the nuclear effects as nucleon Fermi motion and nuclear binding contributions

  5. Stationary states of two-level open quantum systems

    International Nuclear Information System (INIS)

    Gardas, Bartlomiej; Puchala, Zbigniew

    2011-01-01

    A problem of finding stationary states of open quantum systems is addressed. We focus our attention on a generic type of open system: a qubit coupled to its environment. We apply the theory of block operator matrices and find stationary states of two-level open quantum systems under certain conditions applied on both the qubit and the surrounding.

  6. Hematopoietic stem cell mobilizing agents G-CSF, cyclophosphamide or AMD3100 have distinct mechanisms of action on bone marrow HSC niches and bone formation.

    Science.gov (United States)

    Winkler, I G; Pettit, A R; Raggatt, L J; Jacobsen, R N; Forristal, C E; Barbier, V; Nowlan, B; Cisterne, A; Bendall, L J; Sims, N A; Lévesque, J-P

    2012-07-01

    The CXCR4 antagonist AMD3100 is progressively replacing cyclophosphamide (CYP) as adjuvant to granulocyte colony-stimulating factor (G-CSF) to mobilize hematopoietic stem cells (HSC) for autologous transplants in patients who failed prior mobilization with G-CSF alone. It has recently emerged that G-CSF mediates HSC mobilization and inhibits bone formation via specific bone marrow (BM) macrophages. We compared the effect of these three mobilizing agents on BM macrophages, bone formation, osteoblasts, HSC niches and HSC reconstitution potential. Both G-CSF and CYP suppressed niche-supportive macrophages and osteoblasts, and inhibited expression of endosteal cytokines resulting in major impairment of HSC reconstitution potential remaining in the mobilized BM. In sharp contrast, although AMD3100 was effective at mobilizing HSC, it did not suppress osteoblasts, endosteal cytokine expression or reconstitution potential of HSC remaining in the mobilized BM. In conclusion, although G-CSF, CYP and AMD3100 efficiently mobilize HSC into the blood, their effects on HSC niches and bone formation are distinct with both G-CSF and CYP targeting HSC niche function and bone formation, whereas AMD3100 directly targets HSC without altering niche function or bone formation.

  7. Inexpensive CO2 Thickening Agents for Improved Mobility Control of CO2 Floods

    Energy Technology Data Exchange (ETDEWEB)

    Robert Enick; Eric Beckman; Andrew Hamilton

    2005-08-31

    The objective of this research was the design, synthesis and evaluation of inexpensive, non-fluorous carbon dioxide thickening agents. We followed the same strategy employed in the design of fluorinated CO{sub 2} polymeric thickeners. First, a highly CO{sub 2}-philic, hydrocarbon-based monomer was to be identified. Polymers or oligomers of this monomer were then synthesized. The second step was to design a CO{sub 2}-thickener based on these CO{sub 2}-philic polymers. Two types of thickeners were considered. The first was a copolymer in which the CO{sub 2}-philic monomer was combined with a small proportion of CO{sub 2}-phobic associating groups that could cause viscosity-enhancing intermolecular interactions to occur. The second was a small hydrogen-bonding compound with urea groups in the core to promote intermolecular interactions that would cause the molecules to 'stack' in solution while the arms were composed of the CO{sub 2}-philic oligomers. Although we were not able to develop a viable thickener that exhibited high enough CO{sub 2} solubility at EOR MMP conditions to induce a viscosity increase, we made significant progress in our understanding of CO{sub 2}-soluble compounds that can be used in subsequent studies to design CO{sub 2}-soluble thickeners or CO{sub 2}-soluble surfactant-based foaming agents. These findings are detailed in this final report. In summary, we assessed many polymers and verified that the most CO{sub 2}-soluble oxygenated hydrocarbon polymer is poly(vinyl acetate), PVAc. This is primarily due to the presence of both ether and carbonyl oxygens associated with acetate-rich compounds. In addition to polymers, we also made small acetate-rich molecules that were also capable of associating in solution via the inclusion of hydrogen-bonding groups in hopes of forming viscosity-enhancing macromolecules. Despite the presence of multiple acetate groups in these compounds, which can impart incredible CO{sub 2}-solubility to many

  8. Design and simulation of material-integrated distributed sensor processing with a code-based agent platform and mobile multi-agent systems.

    Science.gov (United States)

    Bosse, Stefan

    2015-02-16

    Multi-agent systems (MAS) can be used for decentralized and self-organizing data processing in a distributed system, like a resource-constrained sensor network, enabling distributed information extraction, for example, based on pattern recognition and self-organization, by decomposing complex tasks in simpler cooperative agents. Reliable MAS-based data processing approaches can aid the material-integration of structural-monitoring applications, with agent processing platforms scaled to the microchip level. The agent behavior, based on a dynamic activity-transition graph (ATG) model, is implemented with program code storing the control and the data state of an agent, which is novel. The program code can be modified by the agent itself using code morphing techniques and is capable of migrating in the network between nodes. The program code is a self-contained unit (a container) and embeds the agent data, the initialization instructions and the ATG behavior implementation. The microchip agent processing platform used for the execution of the agent code is a standalone multi-core stack machine with a zero-operand instruction format, leading to a small-sized agent program code, low system complexity and high system performance. The agent processing is token-queue-based, similar to Petri-nets. The agent platform can be implemented in software, too, offering compatibility at the operational and code level, supporting agent processing in strong heterogeneous networks. In this work, the agent platform embedded in a large-scale distributed sensor network is simulated at the architectural level by using agent-based simulation techniques.

  9. Design and Simulation of Material-Integrated Distributed Sensor Processing with a Code-Based Agent Platform and Mobile Multi-Agent Systems

    Directory of Open Access Journals (Sweden)

    Stefan Bosse

    2015-02-01

    Full Text Available Multi-agent systems (MAS can be used for decentralized and self-organizing data processing in a distributed system, like a resource-constrained sensor network, enabling distributed information extraction, for example, based on pattern recognition and self-organization, by decomposing complex tasks in simpler cooperative agents. Reliable MAS-based data processing approaches can aid the material-integration of structural-monitoring applications, with agent processing platforms scaled to the microchip level. The agent behavior, based on a dynamic activity-transition graph (ATG model, is implemented with program code storing the control and the data state of an agent, which is novel. The program code can be modified by the agent itself using code morphing techniques and is capable of migrating in the network between nodes. The program code is a self-contained unit (a container and embeds the agent data, the initialization instructions and the ATG behavior implementation. The microchip agent processing platform used for the execution of the agent code is a standalone multi-core stack machine with a zero-operand instruction format, leading to a small-sized agent program code, low system complexity and high system performance. The agent processing is token-queue-based, similar to Petri-nets. The agent platform can be implemented in software, too, offering compatibility at the operational and code level, supporting agent processing in strong heterogeneous networks. In this work, the agent platform embedded in a large-scale distributed sensor network is simulated at the architectural level by using agent-based simulation techniques.

  10. Memory Effects in the Two-Level Model for Glasses

    Science.gov (United States)

    Aquino, Gerardo; Allahverdyan, Armen; Nieuwenhuizen, Theo M.

    2008-07-01

    We study an ensemble of two-level systems interacting with a thermal bath. This is a well-known model for glasses. The origin of memory effects in this model is a quasistationary but nonequilibrium state of a single two-level system, which is realized due to a finite-rate cooling and slow thermally activated relaxation. We show that single-particle memory effects, such as negativity of the specific heat under reheating, vanish for a sufficiently disordered ensemble. In contrast, a disordered ensemble displays a collective memory effect [similar to the Kovacs effect], where nonequilibrium features of the ensemble are monitored via a macroscopic observable. An experimental realization of the effect can be used to further assess the consistency of the model.

  11. Two-level method with coarse space size independent convergence

    Energy Technology Data Exchange (ETDEWEB)

    Vanek, P.; Brezina, M. [Univ. of Colorado, Denver, CO (United States); Tezaur, R.; Krizkova, J. [UWB, Plzen (Czech Republic)

    1996-12-31

    The basic disadvantage of the standard two-level method is the strong dependence of its convergence rate on the size of the coarse-level problem. In order to obtain the optimal convergence result, one is limited to using a coarse space which is only a few times smaller than the size of the fine-level one. Consequently, the asymptotic cost of the resulting method is the same as in the case of using a coarse-level solver for the original problem. Today`s two-level domain decomposition methods typically offer an improvement by yielding a rate of convergence which depends on the ratio of fine and coarse level only polylogarithmically. However, these methods require the use of local subdomain solvers for which straightforward application of iterative methods is problematic, while the usual application of direct solvers is expensive. We suggest a method diminishing significantly these difficulties.

  12. Fragmentation of molecular ions in differential mobility spectrometry as a method for identification of chemical warfare agents.

    Science.gov (United States)

    Maziejuk, M; Puton, J; Szyposzyńska, M; Witkiewicz, Z

    2015-11-01

    The subject of the work is the use of differential mobility spectrometry (DMS) for the detection of chemical warfare agents (CWA). Studies were performed for mustard gas, i.e., bis(2-chloroethyl)sulfide (HD), sarin, i.e., O-isopropyl methylphosphonofluoridate (GB) and methyl salicylate (MS) used as test compounds. Measurements were conducted with two ceramic DMS analyzers of different constructions allowing the generation of an electric field with an intensity of more than 120 Td. Detector signals were measured for positive and negative modes of operation in a temperature range from 0 to 80 °C. Fragmentations of ions containing analyte molecules were observed for all tested compounds. The effective temperatures of fragmentation estimated on the basis of dispersion plots were equal from about 148 °C for GB to 178 °C for MS. It was found that values of separation voltage (SV) and compensation voltage (CV) at which the fragmentation of sample ions is observed may be the parameters improving the certainty of detection for different analytes. The DMS analyzers enabling the observation of ion fragmentation can be successfully used for effective CWA detection. Copyright © 2015. Published by Elsevier B.V.

  13. Franson Interference Generated by a Two-Level System

    Science.gov (United States)

    Peiris, M.; Konthasinghe, K.; Muller, A.

    2017-01-01

    We report a Franson interferometry experiment based on correlated photon pairs generated via frequency-filtered scattered light from a near-resonantly driven two-level semiconductor quantum dot. In contrast to spontaneous parametric down-conversion and four-wave mixing, this approach can produce single pairs of correlated photons. We have measured a Franson visibility as high as 66%, which goes beyond the classical limit of 50% and approaches the limit of violation of Bell's inequalities (70.7%).

  14. Mixing phases of unstable two-level systems

    International Nuclear Information System (INIS)

    Sokolov, V.V.; Brentano, P. von.

    1993-01-01

    An unstable two-level system decaying into an arbitrary number of channels is considered. It is shown that the mixing phases of the two overlapping resonances can be expressed in the terms of their partial widths and one additional universal mixing parameter. Some applications to a doublet of 2 + resonances in 8 Be and to the ρ-ω systems are considered. 18 refs

  15. Ion mobility spectrometric analysis of vaporous chemical warfare agents by the instrument with corona discharge ionization ammonia dopant ambient temperature operation.

    Science.gov (United States)

    Satoh, Takafumi; Kishi, Shintaro; Nagashima, Hisayuki; Tachikawa, Masumi; Kanamori-Kataoka, Mieko; Nakagawa, Takao; Kitagawa, Nobuyoshi; Tokita, Kenichi; Yamamoto, Soichiro; Seto, Yasuo

    2015-03-20

    The ion mobility behavior of nineteen chemical warfare agents (7 nerve gases, 5 blister agents, 2 lachrymators, 2 blood agents, 3 choking agents) and related compounds including simulants (8 agents) and organic solvents (39) was comparably investigated by the ion mobility spectrometry instrument utilizing weak electric field linear drift tube with corona discharge ionization, ammonia doping, purified inner air drift flow circulation operated at ambient temperature and pressure. Three alkyl methylphosphonofluoridates, tabun, and four organophosphorus simulants gave the intense characteristic positive monomer-derived ion peaks and small dimer-derived ion peaks, and the later ion peaks were increased with the vapor concentrations. VX, RVX and tabun gave both characteristic positive monomer-derived ions and degradation product ions. Nitrogen mustards gave the intense characteristic positive ion peaks, and in addition distinctive negative ion peak appeared from HN3. Mustard gas, lewisite 1, o-chlorobenzylidenemalononitrile and 2-mercaptoethanol gave the characteristic negative ion peaks. Methylphosphonyl difluoride, 2-chloroacetophenone and 1,4-thioxane gave the characteristic ion peaks both in the positive and negative ion mode. 2-Chloroethylethylsulfide and allylisothiocyanate gave weak ion peaks. The marker ion peaks derived from two blood agents and three choking agents were very close to the reactant ion peak in negative ion mode and the respective reduced ion mobility was fluctuated. The reduced ion mobility of the CWA monomer-derived peaks were positively correlated with molecular masses among structurally similar agents such as G-type nerve gases and organophosphorus simulants; V-type nerve gases and nitrogen mustards. The slope values of the calibration plots of the peak heights of the characteristic marker ions versus the vapor concentrations are related to the detection sensitivity, and within chemical warfare agents examined the slope values for sarin, soman

  16. Two-level systems driven by large-amplitude fields

    Science.gov (United States)

    Nori, F.; Ashhab, S.; Johansson, J. R.; Zagoskin, A. M.

    2009-03-01

    We analyze the dynamics of a two-level system subject to driving by large-amplitude external fields, focusing on the resonance properties in the case of driving around the region of avoided level crossing. In particular, we consider three main questions that characterize resonance dynamics: (1) the resonance condition, (2) the frequency of the resulting oscillations on resonance, and (3) the width of the resonance. We identify the regions of validity of different approximations. In a large region of the parameter space, we use a geometric picture in order to obtain both a simple understanding of the dynamics and quantitative results. The geometric approach is obtained by dividing the evolution into discrete time steps, with each time step described by either a phase shift on the basis states or a coherent mixing process corresponding to a Landau-Zener crossing. We compare the results of the geometric picture with those of a rotating wave approximation. We also comment briefly on the prospects of employing strong driving as a useful tool to manipulate two-level systems. S. Ashhab, J.R. Johansson, A.M. Zagoskin, F. Nori, Two-level systems driven by large-amplitude fields, Phys. Rev. A 75, 063414 (2007). S. Ashhab et al, unpublished.

  17. Handheld and mobile hyperspectral imaging sensors for wide-area standoff detection of explosives and chemical warfare agents

    Science.gov (United States)

    Gomer, Nathaniel R.; Gardner, Charles W.; Nelson, Matthew P.

    2016-05-01

    Hyperspectral imaging (HSI) is a valuable tool for the investigation and analysis of targets in complex background with a high degree of autonomy. HSI is beneficial for the detection of threat materials on environmental surfaces, where the concentration of the target of interest is often very low and is typically found within complex scenery. Two HSI techniques that have proven to be valuable are Raman and shortwave infrared (SWIR) HSI. Unfortunately, current generation HSI systems have numerous size, weight, and power (SWaP) limitations that make their potential integration onto a handheld or field portable platform difficult. The systems that are field-portable do so by sacrificing system performance, typically by providing an inefficient area search rate, requiring close proximity to the target for screening, and/or eliminating the potential to conduct real-time measurements. To address these shortcomings, ChemImage Sensor Systems (CISS) is developing a variety of wide-field hyperspectral imaging systems. Raman HSI sensors are being developed to overcome two obstacles present in standard Raman detection systems: slow area search rate (due to small laser spot sizes) and lack of eye-safety. SWIR HSI sensors have been integrated into mobile, robot based platforms and handheld variants for the detection of explosives and chemical warfare agents (CWAs). In addition, the fusion of these two technologies into a single system has shown the feasibility of using both techniques concurrently to provide higher probability of detection and lower false alarm rates. This paper will provide background on Raman and SWIR HSI, discuss the applications for these techniques, and provide an overview of novel CISS HSI sensors focused on sensor design and detection results.

  18. Application of Surfactant Micellar Solutions as Extractants and Mobile Phases for TLC-Determination of Purine Bases and Doping Agents in Biological Liquids

    Directory of Open Access Journals (Sweden)

    Daria Victorovna Yedamenko

    2015-04-01

    Full Text Available Separation of caffeine and its metabolites (theophylline and theobromine and doping agents (spironolactone, propranolol, and ephedrine and determination of caffeine in serum sample and propranolol and ephedrine in urine were studied on normal-phase thin layers (“Sorbfil-UV-254”. Aqueous organic solvents and aqueous micellar surfactant solutions were compared as the mobile phases for separation. The acceptable separation of purine bases and doping agents was achieved by micellar Thin Layer Chromatography and normal-phase Thin Layer Chromatography. Anionic surfactant solution with added 1-propanol was the best eluent as for caffeine, theophylline, and theobromine separation, as for doping agents. The best characteristics of caffeine extraction from serum, and propranolol and ephedrine from urine were achieved when micellar eluent based on non-ionic Tween-80 surfactant was used. DOI: http://dx.doi.org/10.17807/orbital.v7i1.632

  19. Perturbation Theory for Open Two-Level Nonlinear Quantum Systems

    International Nuclear Information System (INIS)

    Zhang Zhijie; Jiang Dongguang; Wang Wei

    2011-01-01

    Perturbation theory is an important tool in quantum mechanics. In this paper, we extend the traditional perturbation theory to open nonlinear two-level systems, treating decoherence parameter γ as a perturbation. By this virtue, we give a perturbative solution to the master equation, which describes a nonlinear open quantum system. The results show that for small decoherence rate γ, the ratio of the nonlinear rate C to the tunneling coefficient V (i.e., r = C/V) determines the validity of the perturbation theory. For small ratio r, the perturbation theory is valid, otherwise it yields wrong results. (general)

  20. Modal intersection types, two-level languages, and staged synthesis

    DEFF Research Database (Denmark)

    Henglein, Fritz; Rehof, Jakob

    2016-01-01

    -linguistic framework for staged program synthesis, where metaprograms are automatically synthesized which, when executed, generate code in a target language. We survey the basic theory of staged synthesis and illustrate by example how a two-level language theory specialized from λ∩ ⎕ can be used to understand......A typed λ-calculus, λ∩ ⎕, is introduced, combining intersection types and modal types. We develop the metatheory of λ∩ ⎕, with particular emphasis on the theory of subtyping and distributivity of the modal and intersection type operators. We describe how a stratification of λ∩ ⎕ leads to a multi...... the process of staged synthesis....

  1. Two-level schemes for the advection equation

    Science.gov (United States)

    Vabishchevich, Petr N.

    2018-06-01

    The advection equation is the basis for mathematical models of continuum mechanics. In the approximate solution of nonstationary problems it is necessary to inherit main properties of the conservatism and monotonicity of the solution. In this paper, the advection equation is written in the symmetric form, where the advection operator is the half-sum of advection operators in conservative (divergent) and non-conservative (characteristic) forms. The advection operator is skew-symmetric. Standard finite element approximations in space are used. The standard explicit two-level scheme for the advection equation is absolutely unstable. New conditionally stable regularized schemes are constructed, on the basis of the general theory of stability (well-posedness) of operator-difference schemes, the stability conditions of the explicit Lax-Wendroff scheme are established. Unconditionally stable and conservative schemes are implicit schemes of the second (Crank-Nicolson scheme) and fourth order. The conditionally stable implicit Lax-Wendroff scheme is constructed. The accuracy of the investigated explicit and implicit two-level schemes for an approximate solution of the advection equation is illustrated by the numerical results of a model two-dimensional problem.

  2. Two-level systems driven by large-amplitude fields

    International Nuclear Information System (INIS)

    Ashhab, S.; Johansson, J. R.; Zagoskin, A. M.; Nori, Franco

    2007-01-01

    We analyze the dynamics of a two-level system subject to driving by large-amplitude external fields, focusing on the resonance properties in the case of driving around the region of avoided level crossing. In particular, we consider three main questions that characterize resonance dynamics: (1) the resonance condition (2) the frequency of the resulting oscillations on resonance, and (3) the width of the resonance. We identify the regions of validity of different approximations. In a large region of the parameter space, we use a geometric picture in order to obtain both a simple understanding of the dynamics and quantitative results. The geometric approach is obtained by dividing the evolution into discrete time steps, with each time step described by either a phase shift on the basis states or a coherent mixing process corresponding to a Landau-Zener crossing. We compare the results of the geometric picture with those of a rotating wave approximation. We also comment briefly on the prospects of employing strong driving as a useful tool to manipulate two-level systems

  3. Two-step values for games with two-level communication structure

    NARCIS (Netherlands)

    Béal, Silvain; Khmelnitskaya, Anna Borisovna; Solal, Philippe

    TU games with two-level communication structure, in which a two-level communication structure relates fundamentally to the given coalition structure and consists of a communication graph on the collection of the a priori unions in the coalition structure, as well as a collection of communication

  4. Ultra high performance supercritical fluid chromatography coupled with tandem mass spectrometry for screening of doping agents. I: Investigation of mobile phase and MS conditions.

    Science.gov (United States)

    Nováková, Lucie; Grand-Guillaume Perrenoud, Alexandre; Nicoli, Raul; Saugy, Martial; Veuthey, Jean-Luc; Guillarme, Davy

    2015-01-01

    The conditions for the analysis of selected doping substances by UHPSFC-MS/MS were optimized to ensure suitable peak shapes and maximized MS responses. A representative mixture of 31 acidic and basic doping agents was analyzed, in both ESI+ and ESI- modes. The best compromise for all compounds in terms of MS sensitivity and chromatographic performance was obtained when adding 2% water and 10mM ammonium formate in the CO2/MeOH mobile phase. Beside mobile phase, the nature of the make-up solvent added for interfacing UHPSFC with MS was also evaluated. Ethanol was found to be the best candidate as it was able to compensate for the negative effect of 2% water addition in ESI- mode and provided a suitable MS response for all doping agents. Sensitivity of the optimized UHPSFC-MS/MS method was finally assessed and compared to the results obtained in conventional UHPLC-MS/MS. Sensitivity was improved by 5-100-fold in UHPSFC-MS/MS vs. UHPLC-MS/MS for 56% of compounds, while only one compound (bumetanide) offered a significantly higher MS response (4-fold) under UHPLC-MS/MS conditions. In the second paper of this series, the optimal conditions for UHPSFC-MS/MS analysis will be employed to screen >100 doping agents in urine matrix and results will be compared to those obtained by conventional UHPLC-MS/MS. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Construction of multi-agent mobile robots control system in the problem of persecution with using a modified reinforcement learning method based on neural networks

    Science.gov (United States)

    Patkin, M. L.; Rogachev, G. N.

    2018-02-01

    A method for constructing a multi-agent control system for mobile robots based on training with reinforcement using deep neural networks is considered. Synthesis of the management system is proposed to be carried out with reinforcement training and the modified Actor-Critic method, in which the Actor module is divided into Action Actor and Communication Actor in order to simultaneously manage mobile robots and communicate with partners. Communication is carried out by sending partners at each step a vector of real numbers that are added to the observation vector and affect the behaviour. Functions of Actors and Critic are approximated by deep neural networks. The Critics value function is trained by using the TD-error method and the Actor’s function by using DDPG. The Communication Actor’s neural network is trained through gradients received from partner agents. An environment in which a cooperative multi-agent interaction is present was developed, computer simulation of the application of this method in the control problem of two robots pursuing two goals was carried out.

  6. The Application of Fuzzy Logic Controller to Compute a Trust Level for Mobile Agents in a Smart Home

    NARCIS (Netherlands)

    Nasution, S.; Suryana, N.; Shahib, S.; Abu, N.A.; Hartel, Pieter H.; Gómez Chova, L.; Martí Belenguer, D.; Candel Torres, I.

    Agents that travel through many hosts may cause a threat on the security of the visited hosts. Assets, system resources, and the reputation of the host are few possible targets for such an attack. The possibility for multi-hop agents to be malicious is higher compared to the one-hop or two-hop

  7. Rapid characterization of microscopic two-level systems using Landau-Zener transitions in a superconducting qubit

    International Nuclear Information System (INIS)

    Tan, Xinsheng; Yu, Haifeng; Yu, Yang; Han, Siyuan

    2015-01-01

    We demonstrate a fast method to detect microscopic two-level systems in a superconducting phase qubit. By monitoring the population leak after sweeping the qubit bias flux, we are able to measure the two-level systems that are coupled with the qubit. Compared with the traditional method that detects two-level systems by energy spectroscopy, our method is faster and more sensitive. This method supplies a useful tool to investigate two-level systems in solid-state qubits

  8. Portable Solid Phase Micro-Extraction Coupled with Ion Mobility Spectrometry System for On-Site Analysis of Chemical Warfare Agents and Simulants in Water Samples

    Directory of Open Access Journals (Sweden)

    Liu Yang

    2014-11-01

    Full Text Available On-site analysis is an efficient approach to facilitate analysis at the location of the system under investigation as it can result in more accurate, more precise and quickly available analytical data. In our work, a novel self-made thermal desorption based interface was fabricated to couple solid-phase microextraction with ion mobility spectrometry for on-site water analysis. The portable interface can be connected with the front-end of an ion mobility spectrometer directly without other modifications. The analytical performance was evaluated via the extraction of chemical warfare agents and simulants in water samples. Several parameters including ionic strength and extraction time have been investigated in detail. The application of the developed method afforded satisfactory recoveries ranging from 72.9% to 114.4% when applied to the analysis of real water samples.

  9. Portable Solid Phase Micro-Extraction Coupled with Ion Mobility Spectrometry System for On-Site Analysis of Chemical Warfare Agents and Simulants in Water Samples

    Science.gov (United States)

    Yang, Liu; Han, Qiang; Cao, Shuya; Yang, Jie; Yang, Junchao; Ding, Mingyu

    2014-01-01

    On-site analysis is an efficient approach to facilitate analysis at the location of the system under investigation as it can result in more accurate, more precise and quickly available analytical data. In our work, a novel self-made thermal desorption based interface was fabricated to couple solid-phase microextraction with ion mobility spectrometry for on-site water analysis. The portable interface can be connected with the front-end of an ion mobility spectrometer directly without other modifications. The analytical performance was evaluated via the extraction of chemical warfare agents and simulants in water samples. Several parameters including ionic strength and extraction time have been investigated in detail. The application of the developed method afforded satisfactory recoveries ranging from 72.9% to 114.4% when applied to the analysis of real water samples. PMID:25384006

  10. Mobility and retention of micronutrients in soil : Part III. Investigation on the influence of various external factors, NPK-fertilizers and soil amending agents on the mobility and retention of manganese

    International Nuclear Information System (INIS)

    Das, S.K.; Santikari, A.K.; Banerji, K.C.

    1980-01-01

    Investigations on the mobility and retention of manganese through Sindri red sandy clay loam of pH 7.4 and Ranchi clay loam of pH 5.6 have been carried out using the radiotracer 54 Mn. The vertical distribution of manganese in these soils showed almost sharp fall upto a depth of 12 to 14 cm and thereafter it tended to attain the saturation. Variations have been marked in the degrees of manganese retention at the top surface layers of the concerned soils. Influence of various NPK fertilizers and soil amending agents, at various application levels, have been studied on the mobility, retention and leaching loss of manganese in the prementioned soils. Marked variations have been recorded and discussed. (author)

  11. Indoor Semantic Modelling for Routing: The Two-Level Routing Approach for Indoor Navigation

    Directory of Open Access Journals (Sweden)

    Liu Liu

    2017-11-01

    that a small increase of user size can largely change the accessible path; the second case shows different path segments for distinct sizes can be combined into one geometric path; the third case demonstrates a geometric network can be created ’on the fly’ for any specified spaces of a building. Therefore, the generation and routing of geometric networks are very flexible and fit to given users. To demonstrate the proposed two-level routing approach, this thesis designs five cases. The five cases are distinguished according to the method of model creation (pre-computed or ’on-the-fly’ and model storage (on the client or server. Two of them are realized in this thesis: 1 Case 1 just in the client pre-computes the logical network and derives geometric networks ’on the fly’; 2 Case 2 just in the client pre-computes and stores the logical and geometric networks for certain user sizes. Case 1 is implemented in a desktop application for building managers, and Case 2 is realized as a mobile mock-up for mobile users without an internet connection. As this thesis shows, two-level routing is powerful enough to effectively provide indicative logical paths and/or comprehensive geometric paths, according to different user requirements on path details. In the desktop application, three of the proposed routing options for two-level routing are tested for the simple OTB building and the complex Schiphol Airport building. These use cases demonstrate that the two-level routing approach includes the following merits: • It supports routing in different abstraction forms of a building. The INSM model can describe different subdivision results of a building, and it allows two types of routing network to be derived – pure logical and geometric ones. The logical network contains the topology and semantics of indoor spaces, and the geometric network provides accurate geometry for paths. A consistent navigation model is formed with the two networks, i.e., the conceptual and

  12. Analysis of chemical warfare agents in food products by atmospheric pressure ionization-high field asymmetric waveform ion mobility spectrometry-mass spectrometry.

    Science.gov (United States)

    Kolakowski, Beata M; D'Agostino, Paul A; Chenier, Claude; Mester, Zoltán

    2007-11-01

    Flow injection high field asymmetric waveform ion mobility spectrometry (FAIMS)-mass spectrometry (MS) methodology was developed for the detection and identification of chemical warfare (CW) agents in spiked food products. The CW agents, soman (GD), sarin (GB), tabun (GA), cyclohexyl sarin (GF), and four hydrolysis products, ethylphosphonic acid (EPA), methylphosphonic acid (MPA), pinacolyl methylphosphonic acid (Pin MPA), and isopropyl methylphosphonic acid (IMPA) were separated and detected by positive ion and negative ion atmospheric pressure ionization-FAIMS-MS. Under optimized conditions, the compensation voltages were 7.2 V for GD, 8.0 V for GA, 7.2 V for GF, 7.6 V for GB, 18.2 V for EPA, 25.9 V for MPA, -1.9 V for PinMPA, and +6.8 V for IMPA. Sample preparation was kept to a minimum, resulting in analysis times of 3 min or less per sample. The developed methodology was evaluated by spiking bottled water, canola oil, cornmeal, and honey samples at low microgram per gram (or microg/mL) levels with the CW agents or CW agent hydrolysis products. The detection limits observed for the CW agents in the spiked food samples ranged from 3 to 15 ng/mL in bottled water, 1-33 ng/mL in canola oil, 1-34 ng/g in cornmeal, and 13-18 ng/g in honey. Detection limits were much higher for the CW agent hydrolysis products, with only MPA being detected in spiked honey samples.

  13. Atomistic study of two-level systems in amorphous silica

    Science.gov (United States)

    Damart, T.; Rodney, D.

    2018-01-01

    Internal friction is analyzed in an atomic-scale model of amorphous silica. The potential energy landscape of more than 100 glasses is explored to identify a sample of about 700 two-level systems (TLSs). We discuss the properties of TLSs, particularly their energy asymmetry and barrier as well as their deformation potential, computed as longitudinal and transverse averages of the full deformation potential tensors. The discrete sampling is used to predict dissipation in the classical regime. Comparison with experimental data shows a better agreement with poorly relaxed thin films than well relaxed vitreous silica, as expected from the large quench rates used to produce numerical glasses. The TLSs are categorized in three types that are shown to affect dissipation in different temperature ranges. The sampling is also used to discuss critically the usual approximations employed in the literature to represent the statistical properties of TLSs.

  14. Two-level modelling of real estate taxtation

    DEFF Research Database (Denmark)

    Gall, Jaroslav; Stubkjær, Erik

    2006-01-01

    Real estate taxes recurrently attract attention, because they are a source of potentially increased revenue for local and national government. Most experts agree that it is necessary to switch from using normative values for taxation to a market-value-based taxation of real property with computer......-assisted mass valuation, witch benefit from use of value maps. In Czech Republic, efforts have been made to adopt current tax policy goals, but improvements are still needed. The paper aims at supporting the current improvement process towards a market based system. It presents models, which describe aspects...... of the present Czech property tax system. A proposal for the future system focuses on the value map component. The described change depends on political involvement. This political activity is modelled as well. The hypothesis is that the two-level modelling effort enhances the change process by providing...

  15. Mobile Probes in Mobile Learning

    DEFF Research Database (Denmark)

    Ørngreen, Rikke; Blomhøj, Ulla; Duvaa, Uffe

    In this paper experiences from using mobile probes in educational design of a mobile learning application is presented. The probing process stems from the cultural probe method, and was influenced by qualitative interview and inquiry approaches. In the project, the mobile phone was not only acting...... as an agent for acquiring empirical data (as the situation in hitherto mobile probe settings) but was also the technological medium for which data should say something about (mobile learning). Consequently, not only the content of the data but also the ways in which data was delivered and handled, provided...... a valuable dimension for investigating mobile use. The data was collected at the same time as design activities took place and the collective data was analysed based on user experience goals and cognitive processes from interaction design and mobile learning. The mobile probe increased the knowledge base...

  16. Bargaining Agents in Wireless Contexts: An Alternating-Offers Protocol for Multi-issue Bilateral Negotiation in Mobile Marketplaces

    Science.gov (United States)

    Ragone, Azzurra; Ruta, Michele; di Sciascio, Eugenio; Donini, Francesco M.

    We present an approach to multi-issue bilateral negotiation for mobile commerce scenarios. The negotiation mechanism has been integrated in a semantic-based application layer enhancing both RFID and Bluetooth wireless standards. OWL DL has been used to model advertisements and relationships among issues within a shared common ontology. Finally, non standard inference services integrated with utility theory help in finding suitable agreements. We illustrate and motivate the provided theoretical framework in a wireless commerce case study.

  17. Agent-based simulation of reactions in the crowded and structured intracellular environment: Influence of mobility and location of the reactants

    Directory of Open Access Journals (Sweden)

    Lapin Alexei

    2011-05-01

    Full Text Available Abstract Background In this paper we apply a novel agent-based simulation method in order to model intracellular reactions in detail. The simulations are performed within a virtual cytoskeleton enriched with further crowding elements, which allows the analysis of molecular crowding effects on intracellular diffusion and reaction rates. The cytoskeleton network leads to a reduction in the mobility of molecules. Molecules can also unspecifically bind to membranes or the cytoskeleton affecting (i the fraction of unbound molecules in the cytosol and (ii furthermore reducing the mobility. Binding of molecules to intracellular structures or scaffolds can in turn lead to a microcompartmentalization of the cell. Especially the formation of enzyme complexes promoting metabolic channeling, e.g. in glycolysis, depends on the co-localization of the proteins. Results While the co-localization of enzymes leads to faster reaction rates, the reduced mobility decreases the collision rate of reactants, hence reducing the reaction rate, as expected. This effect is most prominent in diffusion limited reactions. Furthermore, anomalous diffusion can occur due to molecular crowding in the cell. In the context of diffusion controlled reactions, anomalous diffusion leads to fractal reaction kinetics. The simulation framework is used to quantify and separate the effects originating from molecular crowding or the reduced mobility of the reactants. We were able to define three factors which describe the effective reaction rate, namely f diff for the diffusion effect, f volume for the crowding, and f access for the reduced accessibility of the molecules. Conclusions Molecule distributions, reaction rate constants and structural parameters can be adjusted separately in the simulation allowing a comprehensive study of individual effects in the context of a realistic cell environment. As such, the present simulation can help to bridge the gap between in vivo and in vitro

  18. Dynamical properties of a two-level system with arbitrary nonlinearities

    Indian Academy of Sciences (India)

    nication, information processing and quantum computing, such as in the investigation of quantum teleportation ... They con- sidered a two-level atom interacting with an undamped cavity initially in a coherent state. ... Because concurrence pro-.

  19. Describing the processes of propagation and eliminating wildfires with the use of agent models

    Directory of Open Access Journals (Sweden)

    G. A. Dorrer

    2017-10-01

    Full Text Available A new method of describing the processes of propagation and elimination of wildfires on the basis of agent-based modeling is proposed. The main structural units of the creation of such models are the classes of active objects (agents. Agent approach, combined with Geographic Information Systems (GIS can effectively describe the interaction of a large number of participants in the process to combat wildfires: fire spreading, fire crews, mechanization, aerial means and other. In this paper we propose a multi-agent model to predict the spread of wildfire edge and simulate the direct method of extinguishing a ground fire with non-mechanized crews. The model consist with two classes of agents, designated A and B. The burning fire edge is represented as a chain of A-agents, each of which simulates the burning of an elementary portion of vegetation fuel. Fire front movement (moving the A-agent described by the Hamilton-Jacobi equation with using the indicatrises of normal front rate of spread (figurotris. The configuration of the front calculated on basis the algorithm of mobile grids. Agents other type, B-agents, described extinguishing process; they move to the agents of A type and act on them, reducing the combustion intensity to zero. Modeling system presented as two-level coloured nested Petri Net, which describes the agents’ interaction semantics. This model is implemented as a GIS-oriented software system that can be useful both in the fire fighting management as well as in staff training tactics to fighting wildfires. Some examples of modeling decision making on а ground fire extinguishing are presented.

  20. Controlling the optical bistability and multistability in a two-level pumped-probe system

    International Nuclear Information System (INIS)

    Mahmoudi, Mohammad; Sahrai, Mostafa; Masoumeh Mousavi, Seyede

    2010-01-01

    We study the behavior of the optical bistability (OB) and multistability (OM) in a two-level pumped-probe atomic system by means of a unidirectional ring cavity. We show that the optical bistability in a two-level atomic system can be controlled by adjusting the intensity of the pump field and the detuning between two fields. We find that applying the pumping field decreases the threshold of the optical bistability.

  1. Excitation transfer in two two-level systems coupled to an oscillator

    International Nuclear Information System (INIS)

    Hagelstein, P L; Chaudhary, I U

    2008-01-01

    We consider a generalization of the spin-boson model in which two different two-level systems are coupled to an oscillator, under conditions where the oscillator energy is much less than the two-level system energies, and where the oscillator is highly excited. We find that the two-level system transition energy is shifted, producing a Bloch-Siegert shift in each two-level system similar to what would be obtained if the other were absent. At resonances associated with energy exchange between a two-level system and the oscillator, the level splitting is about the same as would be obtained in the spin-boson model at a Bloch-Siegert resonance. However, there occur resonances associated with the transfer of excitation between one two-level system and the other, an effect not present in the spin-boson model. We use a unitary transformation leading to a rotated system in which terms responsible for the shift and splittings can be identified. The level splittings at the anticrossings associated with both energy exchange and excitation transfer resonances are accounted for with simple two-state models and degenerate perturbation theory using operators that appear in the rotated Hamiltonian

  2. Two-level tunneling systems in amorphous alumina

    Science.gov (United States)

    Lebedeva, Irina V.; Paz, Alejandro P.; Tokatly, Ilya V.; Rubio, Angel

    2014-03-01

    The decades of research on thermal properties of amorphous solids at temperatures below 1 K suggest that their anomalous behaviour can be related to quantum mechanical tunneling of atoms between two nearly equivalent states that can be described as a two-level system (TLS). This theory is also supported by recent studies on microwave spectroscopy of superconducting qubits. However, the microscopic nature of the TLS remains unknown. To identify structural motifs for TLSs in amorphous alumina we have performed extensive classical molecular dynamics simulations. Several bistable motifs with only one or two atoms jumping by considerable distance ~ 0.5 Å were found at T=25 K. Accounting for the surrounding environment relaxation was shown to be important up to distances ~ 7 Å. The energy asymmetry and barrier for the detected motifs lied in the ranges 0.5 - 2 meV and 4 - 15 meV, respectively, while their density was about 1 motif per 10 000 atoms. Tuning of motif asymmetry by strain was demonstrated with the coupling coefficient below 1 eV. The tunnel splitting for the symmetrized motifs was estimated on the order of 0.1 meV. The discovered motifs are in good agreement with the available experimental data. The financial support from the Marie Curie Fellowship PIIF-GA-2012-326435 (RespSpatDisp) is gratefully acknowledged.

  3. INEXPENSIVE CO{sub 2} THICKENING AGENTS FOR IMPROVED MOBILITY CONTROL OF CO{sub 2} FLOODS

    Energy Technology Data Exchange (ETDEWEB)

    Robert M. Enick; Eric J. Beckman; Andrew Hamilton

    2004-10-01

    The objective of this research was the design, synthesis and evaluation of inexpensive, nonfluorous carbon dioxide thickening agents. We followed the same strategy employed in the design of fluorinated CO{sub 2} polymeric thickeners. First, a highly CO{sub 2}-philic, hydrocarbon-based monomer was to be identified. Polymers or oligomers of this monomer were then synthesized. The second step was to be completed only when a CO{sub 2}-soluble polymer that was soluble in CO{sub 2} at pressures comparable to the MMP was identified. In the second step, viscosity-enhancing associating groups were to be incorporated into the polymer to make it a viable thickener that exhibited high CO{sub 2} solubility at EOR MMP conditions. This final report documents the CO{sub 2} solubility of a series of commercial and novel polymers composed of carbon, hydrogen, oxygen and, in some cases, nitrogen.

  4. Venoconstrictor agents mobilize blood from different sources and increase intrathoracic filling during epidural anesthesia in supine humans

    International Nuclear Information System (INIS)

    Stanton-Hicks, M.; Hoeck, A.S.; Stuehmeier, K.D.A.; Arndt, J.O.

    1987-01-01

    The authors studied the effects of dihydroergotamine (DHE) and etilefrine hydrochloride (E) on the regional distribution of /sup 99m/Tc-marked erythrocytes during epidural anesthesia in eight supine men to determine if vasoactive agents with venoconstrictor action would enhance cardiac filling during epidural anesthesia. Radioactivity was recorded with a gamma camera, and its distribution determined in the thorax, abdomen, and limbs. Arterial and central venous pressure, heart rate, and calf volume by plethysmography were measured. During epidural anesthesia with a sensory block up to T4/5, DHE (7.5 micrograms/kg) reduced the radioactivity, i.e., blood volume, in both the innervated (-5.9 +/- 3.5%) and denervated muscle/skin (-16.9 +/- 7%) regions, and increased it in both the intrathoracic (+7.0 +/- 2.3%), and splanchnic vasculature (+4.2 +/- 3.2). In contrast, E (6 micrograms X kg-1 X min-1) decreased the blood volume most markedly in the splanchnic region (-5.4 +/- 0.7%) and increased it in the thorax (+2 +/- 0.6%). All these changes were statistically significant. The combined effects were estimated to be equivalent to a transfusion of nearly 1.01 of blood. Both drugs reversed the hypotensive action of epidural anesthesia. During epidural anesthesia, DHE preferentially constricted the capacitance vessels in skeletal muscle and skin irrespective of the state of innervation, whereas E preferentially constricted the splanchnic vasculature. In the doses used, the two agents replenished in an additive fashion the central circulation during epidural anesthesia

  5. Pixel detector readout electronics with two-level discriminator scheme

    International Nuclear Information System (INIS)

    Pengg, F.

    1998-01-01

    In preparation for a silicon pixel detector with more than 3,000 readout channels per chip for operation at the future large hadron collider (LHC) at CERN the analog front end of the readout electronics has been designed and measured on several test-arrays with 16 by 4 cells. They are implemented in the HP 0.8 microm process but compatible with the design rules of the radiation hard Honeywell 0.8 microm bulk process. Each cell contains bump bonding pad, preamplifier, discriminator and control logic for masking and testing within a layout area of only 50 microm by 140 microm. A new two-level discriminator scheme has been implemented to cope with the problems of time-walk and interpixel cross-coupling. The measured gain of the preamplifier is 900 mV for a minimum ionizing particle (MIP, about 24,000 e - for a 300 microm thick Si-detector) with a return to baseline within 750 ns for a 1 MIP input signal. The full readout chain (without detector) shows an equivalent noise charge to 60e - r.m.s. The time-walk, a function of the separation between the two threshold levels, is measured to be 22 ns at a separation of 1,500 e - , which is adequate for the 40 MHz beam-crossing frequency at the LHC. The interpixel cross-coupling, measured with a 40fF coupling capacitance, is less than 3%. A single cell consumes 35 microW at 3.5 V supply voltage

  6. Mobilities Mobilities

    Directory of Open Access Journals (Sweden)

    César Pompeyo

    2011-12-01

    Full Text Available Urry, John (2007 Mobilities.Oxford: Polity Press.Urry, John (2007 Mobilities.Oxford: Polity Press.John Urry (1946-, profesor en la Universidad de Lancaster, es un sociólogo de sobra conocido y altamente reputado en el panorama internacional de las ciencias sociales. Su dilatada carrera, aparentemente dispersa y diversificada, ha seguido senderos bastante bien definidos dejando tras de sí un catálogo extenso de obras sociológicas de primer nivel. Sus primeros trabajos se centraban en el campo de la teoría social y la filosofía de las ciencias sociales o de la sociología del poder [...

  7. Performance of a Two-Level Call Admission Control Scheme for DS-CDMA Wireless Networks

    Directory of Open Access Journals (Sweden)

    Fapojuwo Abraham O

    2007-01-01

    Full Text Available We propose a two-level call admission control (CAC scheme for direct sequence code division multiple access (DS-CDMA wireless networks supporting multimedia traffic and evaluate its performance. The first-level admission control assigns higher priority to real-time calls (also referred to as class 0 calls in gaining access to the system resources. The second level admits nonreal-time calls (or class 1 calls based on the resources remaining after meeting the resource needs for real-time calls. However, to ensure some minimum level of performance for nonreal-time calls, the scheme reserves some resources for such calls. The proposed two-level CAC scheme utilizes the delay-tolerant characteristic of non-real-time calls by incorporating a queue to temporarily store those that cannot be assigned resources at the time of initial access. We analyze and evaluate the call blocking, outage probability, throughput, and average queuing delay performance of the proposed two-level CAC scheme using Markov chain theory. The analytic results are validated by simulation results. The numerical results show that the proposed two-level CAC scheme provides better performance than the single-level CAC scheme. Based on these results, it is concluded that the proposed two-level CAC scheme serves as a good solution for supporting multimedia applications in DS-CDMA wireless communication systems.

  8. Performance of a Two-Level Call Admission Control Scheme for DS-CDMA Wireless Networks

    Directory of Open Access Journals (Sweden)

    Abraham O. Fapojuwo

    2007-11-01

    Full Text Available We propose a two-level call admission control (CAC scheme for direct sequence code division multiple access (DS-CDMA wireless networks supporting multimedia traffic and evaluate its performance. The first-level admission control assigns higher priority to real-time calls (also referred to as class 0 calls in gaining access to the system resources. The second level admits nonreal-time calls (or class 1 calls based on the resources remaining after meeting the resource needs for real-time calls. However, to ensure some minimum level of performance for nonreal-time calls, the scheme reserves some resources for such calls. The proposed two-level CAC scheme utilizes the delay-tolerant characteristic of non-real-time calls by incorporating a queue to temporarily store those that cannot be assigned resources at the time of initial access. We analyze and evaluate the call blocking, outage probability, throughput, and average queuing delay performance of the proposed two-level CAC scheme using Markov chain theory. The analytic results are validated by simulation results. The numerical results show that the proposed two-level CAC scheme provides better performance than the single-level CAC scheme. Based on these results, it is concluded that the proposed two-level CAC scheme serves as a good solution for supporting multimedia applications in DS-CDMA wireless communication systems.

  9. Solutions of the two-level problem in terms of biconfluent Heun functions

    Energy Technology Data Exchange (ETDEWEB)

    Ishkhanyan, Artur [Engineering Center of Armenian National Academy of Sciences, Ashtarak (Armenia)]. E-mail: artur@ec.sci.am; Suominen, Kalle-Antti [Helsinki Institute of Physics, Helsinki (Finland); Department of Applied Physics, University of Turku, Turku (Finland)

    2001-08-17

    Five four-parametric classes of quantum mechanical two-level models permitting solutions in terms of the biconfluent Heun function are derived. Three of these classes are generalizations of the well known classes of Landau-Zener, Nikitin and Crothers. It is shown that two other classes describe super- and sublinear and essentially nonlinear level crossings, as well as processes with three crossing points. In particular, these classes include two-level models where the field amplitude is constant and the detuning varies as {delta}{sub 0}t+{delta}{sub 2}t{sup 3} or {approx}t{sup 1/3}. For the essentially nonlinear cubic-crossing model, {delta}{sub t}{approx}{delta}{sub 2}t{sup 3}, the general solution of the two-level problem is shown to be expressed as series of confluent hypergeometric functions. (author)

  10. Two-Level Solutions to Exponentially Complex Problems in Glass Science

    DEFF Research Database (Denmark)

    Mauro, John C.; Smedskjær, Morten Mattrup

    Glass poses an especially challenging problem for physicists. The key to making progress in theoretical glass science is to extract the key physics governing properties of practical interest. In this spirit, we discuss several two-level solutions to exponentially complex problems in glass science....... Topological constraint theory, originally developed by J.C. Phillips, is based on a two-level description of rigid and floppy modes in a glass network and can be used to derive quantitatively accurate and analytically solvable models for a variety of macroscopic properties. The temperature dependence...... that captures both primary and secondary relaxation modes. Such a model also offers the ability to calculate the distinguishability of particles during glass transition and relaxation processes. Two-level models can also be used to capture the distribution of various network-forming species in mixed...

  11. Efficiency analysis on a two-level three-phase quasi-soft-switching inverter

    DEFF Research Database (Denmark)

    Geng, Pan; Wu, Weimin; Huang, Min

    2013-01-01

    When designing an inverter, an engineer often needs to select and predict the efficiency beforehand. For the standard inverters, plenty of researches are analyzing the power losses and also many software tools are being used for efficiency calculation. In this paper, the efficiency calculation...... for non-conventional inverters with special shoot-through state is introduced and illustrated through the analysis on a special two-level three-phase quasi-soft-switching inverter. Efficiency comparison between the classical two-stage two-level three-phase inverter and the two-level three-phase quasi......-soft-switching inverter is carried out. A 10 kW/380 V prototype is constructed to verify the analysis. The experimental results show that the efficiency of the new inverter is higher than that of the traditional two-stage two- level three-phase inverter....

  12. MOBILE COMMERCE APPROACH BASED ON MOBILE AGENT

    OpenAIRE

    Oussama Zerdoumi; Okba Kazar; Saber Benharzallah

    2011-01-01

    Telecommunications technologies are advanced; they introduced new technologies to meet the needs of individuals and organizations to make commercial transactions, where we find the birth of e-commerce after the emergence of the Internet. But this approach has limits like the use of a client / server model, which limit the use of these transactions in anytime and anywhere. Recently and after the emergence of the wireless networking, the commerce increase the range of the E-commerce application...

  13. A Two-Level Cache for Distributed Information Retrieval in Search Engines

    Directory of Open Access Journals (Sweden)

    Weizhe Zhang

    2013-01-01

    Full Text Available To improve the performance of distributed information retrieval in search engines, we propose a two-level cache structure based on the queries of the users’ logs. We extract the highest rank queries of users from the static cache, in which the queries are the most popular. We adopt the dynamic cache as an auxiliary to optimize the distribution of the cache data. We propose a distribution strategy of the cache data. The experiments prove that the hit rate, the efficiency, and the time consumption of the two-level cache have advantages compared with other structures of cache.

  14. A two-level cache for distributed information retrieval in search engines.

    Science.gov (United States)

    Zhang, Weizhe; He, Hui; Ye, Jianwei

    2013-01-01

    To improve the performance of distributed information retrieval in search engines, we propose a two-level cache structure based on the queries of the users' logs. We extract the highest rank queries of users from the static cache, in which the queries are the most popular. We adopt the dynamic cache as an auxiliary to optimize the distribution of the cache data. We propose a distribution strategy of the cache data. The experiments prove that the hit rate, the efficiency, and the time consumption of the two-level cache have advantages compared with other structures of cache.

  15. Strong nonlinearity-induced correlations for counterpropagating photons scattering on a two-level emitter

    DEFF Research Database (Denmark)

    Nysteen, Anders; McCutcheon, Dara; Mørk, Jesper

    2015-01-01

    We analytically treat the scattering of two counterpropagating photons on a two-level emitter embedded in an optical waveguide. We find that the nonlinearity of the emitter can give rise to significant pulse-dependent directional correlations in the scattered photonic state, which could be quanti......We analytically treat the scattering of two counterpropagating photons on a two-level emitter embedded in an optical waveguide. We find that the nonlinearity of the emitter can give rise to significant pulse-dependent directional correlations in the scattered photonic state, which could...

  16. Contract Monitoring in Agent-Based Systems: Case Study

    Science.gov (United States)

    Hodík, Jiří; Vokřínek, Jiří; Jakob, Michal

    Monitoring of fulfilment of obligations defined by electronic contracts in distributed domains is presented in this paper. A two-level model of contract-based systems and the types of observations needed for contract monitoring are introduced. The observations (inter-agent communication and agents’ actions) are collected and processed by the contract observation and analysis pipeline. The presented approach has been utilized in a multi-agent system for electronic contracting in a modular certification testing domain.

  17. Polynomial pseudosupersymmetry underlying a two-level atom in an external electromagnetic field

    International Nuclear Information System (INIS)

    Samsonov, B.F.; Shamshutdinova, V.V.; Gitman, D.M.

    2005-01-01

    Chains of transformations introduced previously were studied in order to obtain electric fields with a time-dependent frequency for which the equation of motion of a two-level atom in the presence of these fields can be solved exactly. It is shown that a polynomial pseudosupersymmetry may be associated to such chains

  18. Ultimate temperature for laser cooling of two-level neutral atoms

    International Nuclear Information System (INIS)

    Bagnato, V.S.; Zilio, S.C.

    1989-01-01

    We present a simple pedagogical method to evaluate the minimum attainable temperature for laser cooling of two-level neutral atoms. Results are given as a function of the laser detuning and intensity. We also discuss the use of this approach to predict the minimum temperature of neutral atoms confined in magnetic traps. (author) [pt

  19. Resonant retuning of Rabi oscillations in a two-level system

    International Nuclear Information System (INIS)

    Leonov, A.V.; Feranchuk, I.D.

    2009-01-01

    The evolution of a two-level system in a single-mode quantum field is considered beyond the rotating wave approximation. The existence of quasi-degenerate energy levels is shown to influence the essential characteristics of temporal and amplitude Rabi oscillations of the system in a resonant manner. (authors)

  20. An Owen-type value for games with two-level communication structures

    NARCIS (Netherlands)

    van den Brink, René; Khmelnitskaya, Anna Borisovna; van der Laan, Gerard

    We introduce an Owen-type value for games with two-level communication structure, which is a structure where the players are partitioned into a coalition structure such that there exists restricted communication between as well as within the a priori unions of the coalition structure. Both types of

  1. Reactive Power Impact on Lifetime Prediction of Two-level Wind Power Converter

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede; Lau, M.

    2013-01-01

    The influence of reactive power injection on the dominating two-level wind power converter is investigated and compared in terms of power loss and thermal behavior. Then the lifetime of both the partial-scale and full-scale power converter is estimated based on the widely used Coffin-Manson model...

  2. A two-level strategy to realize life-cycle production optimization in an operational setting

    NARCIS (Netherlands)

    Essen, van G.M.; Hof, Van den P.M.J.; Jansen, J.D.

    2012-01-01

    We present a two-level strategy to improve robustness against uncertainty and model errors in life-cycle flooding optimization. At the upper level, a physics-based large-scale reservoir model is used to determine optimal life-cycle injection and production profiles. At the lower level these profiles

  3. Random model of two-level atoms interacting with electromagnetic field

    International Nuclear Information System (INIS)

    Kireev, A.N.; Meleshko, A.N.

    1983-12-01

    A phase transition has been studied in a random system of two-level atoms interacting with an electromagnetic field. It is shown that superradiation can arise when there is short-range order in a spin-subsystem. The existence of long-range order is irrelevant for this phase transition

  4. Excitation of graphene plasmons as an analogy with the two-level system

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Jiahui [Microwave and Electromagnetic Laboratory, Harbin Institute of Technology, No. 92, Xidazhi Street, Nangang District, Harbin City, Heilongjiang Province (China); Lv, Bo, E-mail: lb19840313@126.com [Microwave and Electromagnetic Laboratory, Harbin Institute of Technology, No. 92, Xidazhi Street, Nangang District, Harbin City, Heilongjiang Province (China); Li, Rujiang [College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027 (China); Ma, Ruyu; Chen, Wan; Meng, Fanyi [Microwave and Electromagnetic Laboratory, Harbin Institute of Technology, No. 92, Xidazhi Street, Nangang District, Harbin City, Heilongjiang Province (China)

    2016-02-15

    The excitation of graphene plasmons (GPs) is presented as an interaction between the GPs and the incident electromagnetic field. In this Letter, the excitation of GPs in a plasmonic system is interpreted as an analogy with the two-level system by taking the two-coupled graphene-covered gratings as an example. Based on the equivalent circuit theory, the excitation of GPs in the graphene-covered grating is equivalent to the resonance of an oscillator. Thus, according to the governing equation, the electric currents at the resonant frequencies for two-coupled graphene-covered gratings correspond to the energy states in a two-level system. In addition, the excitation of GPs in different two-coupled graphene-covered gratings is numerically studied to validate our theoretical model. Our work provides an intuitive understanding of the excitation of GPs using an analogy with the two-level system. - Highlights: • The excitation of graphene plasmons (GPs) in graphene-covered grating is equivalent to the resonance of an oscillator. • We establish the equivalent circuit of two-level system to analyze the resonant character. • The excitation of GPs in different two-coupled graphene-covered gratings are numerically studied to validate our theoretical model.

  5. Excitation of graphene plasmons as an analogy with the two-level system

    International Nuclear Information System (INIS)

    Fu, Jiahui; Lv, Bo; Li, Rujiang; Ma, Ruyu; Chen, Wan; Meng, Fanyi

    2016-01-01

    The excitation of graphene plasmons (GPs) is presented as an interaction between the GPs and the incident electromagnetic field. In this Letter, the excitation of GPs in a plasmonic system is interpreted as an analogy with the two-level system by taking the two-coupled graphene-covered gratings as an example. Based on the equivalent circuit theory, the excitation of GPs in the graphene-covered grating is equivalent to the resonance of an oscillator. Thus, according to the governing equation, the electric currents at the resonant frequencies for two-coupled graphene-covered gratings correspond to the energy states in a two-level system. In addition, the excitation of GPs in different two-coupled graphene-covered gratings is numerically studied to validate our theoretical model. Our work provides an intuitive understanding of the excitation of GPs using an analogy with the two-level system. - Highlights: • The excitation of graphene plasmons (GPs) in graphene-covered grating is equivalent to the resonance of an oscillator. • We establish the equivalent circuit of two-level system to analyze the resonant character. • The excitation of GPs in different two-coupled graphene-covered gratings are numerically studied to validate our theoretical model.

  6. A two-level strategy to realize life-cycle production optimization in an operational setting

    NARCIS (Netherlands)

    Essen, van G.M.; Hof, Van den P.M.J.; Jansen, J.D.

    2013-01-01

    We present a two-level strategy to improve robustness against uncertainty and model errors in life-cycle flooding optimization. At the upper level, a physics-based large-scale reservoir model is used to determine optimal life-cycle injection and production profiles. At the lower level these profiles

  7. Localization of a two-level atom via the absorption spectrum

    International Nuclear Information System (INIS)

    Xu, Jun; Hu, Xiang-Ming

    2007-01-01

    We show that it is possible to localize a two-level atom as it passes through a standing-wave field by measuring the probe-field absorption. There is 50% detecting probability of the atom at the nodes of the standing-wave field in the subwavelength domain when the probe field is tuned resonant with the atomic transition

  8. Efficient two-level preconditionined conjugate gradient method on the GPU

    NARCIS (Netherlands)

    Gupta, R.; Van Gijzen, M.B.; Vuik, K.

    2011-01-01

    We present an implementation of Two-Level Preconditioned Conjugate Gradient Method for the GPU. We investigate a Truncated Neumann Series based preconditioner in combination with deflation and compare it with Block Incomplete Cholesky schemes. This combination exhibits fine-grain parallelism and

  9. A spatial scan statistic for nonisotropic two-level risk cluster.

    Science.gov (United States)

    Li, Xiao-Zhou; Wang, Jin-Feng; Yang, Wei-Zhong; Li, Zhong-Jie; Lai, Sheng-Jie

    2012-01-30

    Spatial scan statistic methods are commonly used for geographical disease surveillance and cluster detection. The standard spatial scan statistic does not model any variability in the underlying risks of subregions belonging to a detected cluster. For a multilevel risk cluster, the isotonic spatial scan statistic could model a centralized high-risk kernel in the cluster. Because variations in disease risks are anisotropic owing to different social, economical, or transport factors, the real high-risk kernel will not necessarily take the central place in a whole cluster area. We propose a spatial scan statistic for a nonisotropic two-level risk cluster, which could be used to detect a whole cluster and a noncentralized high-risk kernel within the cluster simultaneously. The performance of the three methods was evaluated through an intensive simulation study. Our proposed nonisotropic two-level method showed better power and geographical precision with two-level risk cluster scenarios, especially for a noncentralized high-risk kernel. Our proposed method is illustrated using the hand-foot-mouth disease data in Pingdu City, Shandong, China in May 2009, compared with two other methods. In this practical study, the nonisotropic two-level method is the only way to precisely detect a high-risk area in a detected whole cluster. Copyright © 2011 John Wiley & Sons, Ltd.

  10. Two-Level Designs to Estimate All Main Effects and Two-Factor Interactions

    NARCIS (Netherlands)

    Eendebak, P.T.; Schoen, E.D.

    2017-01-01

    We study the design of two-level experiments with N runs and n factors large enough to estimate the interaction model, which contains all the main effects and all the two-factor interactions. Yet, an effect hierarchy assumption suggests that main effect estimation should be given more prominence

  11. Exact Solution of the Two-Level System and the Einstein Solid in the Microcanonical Formalism

    Science.gov (United States)

    Bertoldi, Dalia S.; Bringa, Eduardo M.; Miranda, E. N.

    2011-01-01

    The two-level system and the Einstein model of a crystalline solid are taught in every course of statistical mechanics and they are solved in the microcanonical formalism because the number of accessible microstates can be easily evaluated. However, their solutions are usually presented using the Stirling approximation to deal with factorials. In…

  12. Mobile code security

    Science.gov (United States)

    Ramalingam, Srikumar

    2001-11-01

    A highly secure mobile agent system is very important for a mobile computing environment. The security issues in mobile agent system comprise protecting mobile hosts from malicious agents, protecting agents from other malicious agents, protecting hosts from other malicious hosts and protecting agents from malicious hosts. Using traditional security mechanisms the first three security problems can be solved. Apart from using trusted hardware, very few approaches exist to protect mobile code from malicious hosts. Some of the approaches to solve this problem are the use of trusted computing, computing with encrypted function, steganography, cryptographic traces, Seal Calculas, etc. This paper focuses on the simulation of some of these existing techniques in the designed mobile language. Some new approaches to solve malicious network problem and agent tampering problem are developed using public key encryption system and steganographic concepts. The approaches are based on encrypting and hiding the partial solutions of the mobile agents. The partial results are stored and the address of the storage is destroyed as the agent moves from one host to another host. This allows only the originator to make use of the partial results. Through these approaches some of the existing problems are solved.

  13. Pyrosequencing reveals the effect of mobilizing agents and lignocellulosic substrate amendment on microbial community composition in a real industrial PAH-polluted soil

    Energy Technology Data Exchange (ETDEWEB)

    Lladó, S., E-mail: llado@biomed.cas.cz [Department of Microbiology, University of Barcelona, Diagonal 645, E-08028 Barcelona (Spain); Institute of Microbiology, Academy of Sciences of the Czech Republic, Vídenská 1083, 142 20 Prague 4 (Czech Republic); Covino, S., E-mail: covino@biomed.cas.cz [Institute of Microbiology, Academy of Sciences of the Czech Republic, Vídenská 1083, 142 20 Prague 4 (Czech Republic); Solanas, A.M., E-mail: asolanas@ub.edu [Department of Microbiology, University of Barcelona, Diagonal 645, E-08028 Barcelona (Spain); Petruccioli, M., E-mail: petrucci@unitus.it [Department for Innovation in Biological, Agro-Food and Forest Systems [DIBAF], University of Tuscia, Via S. Camillo de Lellis snc, 01100 Viterbo (Italy); D’annibale, A., E-mail: dannib@unitus.it [Department for Innovation in Biological, Agro-Food and Forest Systems [DIBAF], University of Tuscia, Via S. Camillo de Lellis snc, 01100 Viterbo (Italy); Viñas, M., E-mail: marc.vinas@irta.cat [GIRO Joint Research Unit IRTA-UPC, Institute of Research and Technology Food and Agriculture [IRTA], Torre Marimon, E-08140 Caldes de Montbui (Spain)

    2015-02-11

    Highlights: • Soil microbial community assessment through classical (MPN) and molecular tools (DGGE and pyrosequencing) is provided. • A failure of exogenous white rot fungi to colonize the polluted soil is shown by DGGE and pyrosequencing. • Surfactant Brij 30 hampers 4-ring PAHs degradation due to toxicity over Actinobacteria and Bacteroidetes populations. • A high prevalence of Fusarium and Scedosporium populations is revealed during soil bioremediation. • Cupriavidus, Mycobacterium and Chithinophagaceae are potential HMW–PAH degraders in the soil. - Abstract: Bacterial and fungal biodiversity throughout different biostimulation and bioaugmentation treatments applied to an industrial creosote-polluted soil were analyzed by means of polyphasic approach in order to gain insight into the microbial community structure and dynamics. Pyrosequencing data obtained from initial creosote polluted soil (after a biopiling step) revealed that Alpha and Gammaproteobacteria were the most abundant bacterial groups, whereas Fusarium and Scedosporium were the main fungal genera in the contaminated soil. At the end of 60-days laboratory scale bioremediation assays, pyrosequencing and DGGE data showed that (i) major bacterial community shifts were caused by the type of mobilizing agent added to the soil and, to a lesser extent, by the addition of lignocellulosic substrate; and (ii) the presence of the non-ionic surfactant (Brij 30) hampered the proliferation of Actinobacteria (Mycobacteriaceae) and Bacteroidetes (Chitinophagaceae) and, in the absence of lignocellulosic substrate, also impeded polycyclic aromatic hydrocarbons (PAHs) degradation. The results show the importance of implementing bioremediation experiments combined with microbiome assessment to gain insight on the effect of crucial parameters (e.g. use of additives) over the potential functions of complex microbial communities harbored in polluted soils, essential for bioremediation success.

  14. Pyrosequencing reveals the effect of mobilizing agents and lignocellulosic substrate amendment on microbial community composition in a real industrial PAH-polluted soil

    International Nuclear Information System (INIS)

    Lladó, S.; Covino, S.; Solanas, A.M.; Petruccioli, M.; D’annibale, A.; Viñas, M.

    2015-01-01

    Highlights: • Soil microbial community assessment through classical (MPN) and molecular tools (DGGE and pyrosequencing) is provided. • A failure of exogenous white rot fungi to colonize the polluted soil is shown by DGGE and pyrosequencing. • Surfactant Brij 30 hampers 4-ring PAHs degradation due to toxicity over Actinobacteria and Bacteroidetes populations. • A high prevalence of Fusarium and Scedosporium populations is revealed during soil bioremediation. • Cupriavidus, Mycobacterium and Chithinophagaceae are potential HMW–PAH degraders in the soil. - Abstract: Bacterial and fungal biodiversity throughout different biostimulation and bioaugmentation treatments applied to an industrial creosote-polluted soil were analyzed by means of polyphasic approach in order to gain insight into the microbial community structure and dynamics. Pyrosequencing data obtained from initial creosote polluted soil (after a biopiling step) revealed that Alpha and Gammaproteobacteria were the most abundant bacterial groups, whereas Fusarium and Scedosporium were the main fungal genera in the contaminated soil. At the end of 60-days laboratory scale bioremediation assays, pyrosequencing and DGGE data showed that (i) major bacterial community shifts were caused by the type of mobilizing agent added to the soil and, to a lesser extent, by the addition of lignocellulosic substrate; and (ii) the presence of the non-ionic surfactant (Brij 30) hampered the proliferation of Actinobacteria (Mycobacteriaceae) and Bacteroidetes (Chitinophagaceae) and, in the absence of lignocellulosic substrate, also impeded polycyclic aromatic hydrocarbons (PAHs) degradation. The results show the importance of implementing bioremediation experiments combined with microbiome assessment to gain insight on the effect of crucial parameters (e.g. use of additives) over the potential functions of complex microbial communities harbored in polluted soils, essential for bioremediation success

  15. Marketing mobile imaging services.

    Science.gov (United States)

    McCue, P

    1987-09-01

    Competition in the mobile imaging arena has put radiologists, radiology directors, and other health care professionals in the unfamiliar position of being marketing agents for their services. Mobile imaging is being promoted through consumer advertising as well as through the traditional route of physician referral. This article offers some of the marketing lessons being learned in the mobile arena.

  16. Ion mobility spectrometry

    CERN Document Server

    Eiceman, GA

    2005-01-01

    Key Developments for Faster, More Precise Detection Capabilities Driven by the demand for the rapid and advanced detection of explosives, chemical and biological warfare agents, and narcotics, ion mobility spectrometry (IMS) undergone significant refinements in technology, computational capabilities, and understanding of the principles of gas phase ion chemistry and mobility. Beginning with a thorough discussion of the fundamental theories and physics of ion mobility, Ion Mobility Spectrometry, Second Edition describes the recent advances in instrumentation and newly

  17. Analysis of stationary availability factor of two-level backbone computer networks with arbitrary topology

    Science.gov (United States)

    Rahman, P. A.

    2018-05-01

    This scientific paper deals with the two-level backbone computer networks with arbitrary topology. A specialized method, offered by the author for calculation of the stationary availability factor of the two-level backbone computer networks, based on the Markov reliability models for the set of the independent repairable elements with the given failure and repair rates and the methods of the discrete mathematics, is also discussed. A specialized algorithm, offered by the author for analysis of the network connectivity, taking into account different kinds of the network equipment failures, is also observed. Finally, this paper presents an example of calculation of the stationary availability factor for the backbone computer network with the given topology.

  18. Two-Level Iteration Penalty Methods for the Navier-Stokes Equations with Friction Boundary Conditions

    Directory of Open Access Journals (Sweden)

    Yuan Li

    2013-01-01

    Full Text Available This paper presents two-level iteration penalty finite element methods to approximate the solution of the Navier-Stokes equations with friction boundary conditions. The basic idea is to solve the Navier-Stokes type variational inequality problem on a coarse mesh with mesh size H in combining with solving a Stokes, Oseen, or linearized Navier-Stokes type variational inequality problem for Stokes, Oseen, or Newton iteration on a fine mesh with mesh size h. The error estimate obtained in this paper shows that if H, h, and ε can be chosen appropriately, then these two-level iteration penalty methods are of the same convergence orders as the usual one-level iteration penalty method.

  19. Dynamics of quantum Fisher information in a two-level system coupled to multiple bosonic reservoirs

    Science.gov (United States)

    Wang, Guo-You; Guo, You-Neng; Zeng, Ke

    2015-11-01

    We consider the optimal parameter estimation for a two-level system coupled to multiple bosonic reservoirs. By using quantum Fisher information (QFI), we investigate the effect of the Markovian reservoirs’ number N on QFI in both weak and strong coupling regimes for a two-level system surrounded by N zero-temperature reservoirs of field modes initially in the vacua. The results show that the dynamics of QFI non-monotonically decays to zero with revival oscillations at some time in the weak coupling regime depending on the reservoirs’ parameters. Furthermore, we also present the relations between the QFI flow, the flows of energy and information, and the sign of the decay rate to gain insight into the physical processes characterizing the dynamics. Project supported by the Hunan Provincial Innovation Foundation for Postgraduate, China (Grant No. CX2014B194) and the Scientific Research Foundation of Hunan Provincial Education Department, China (Grant No. 13C039).

  20. A modified two-level three-phase quasi-soft-switching inverter

    DEFF Research Database (Denmark)

    Liu, Yusheng; Wu, Weimin; Blaabjerg, Frede

    2014-01-01

    A traditional Voltage Source Inverter (VSI) has higher efficiency than a Current Voltage Source (CSI) due to the less conduction power loss. However, the reverse recovery of the free-wheeling diode limits the efficiency improvement for the silicon devices based hard-switching VSI. The traditional...... quasi-soft-switching inverter can alternate between VSI and CSI by using a proper control scheme and thereby reduce the power losses caused by the reverse recovery of the free-wheeling diode. Nevertheless, slightly extra conduction power loss of the auxiliary switch is also introduced. In order...... to reduce the extra conduction power loss and the voltage stress across the DC-link capacitor, a modified two-level three-phase quasi-soft-switching inverter is proposed by using a SiC MOSFET instead of an IGBT. The principle of the modified two-level three-phase quasi-soft-switching inverter is analyzed...

  1. Non-zero temperature two-mode squeezing for time-dependent two-level systems

    International Nuclear Information System (INIS)

    Aliaga, J.; Gruver, J.L.; Proto, A.N.; Cerdeira, H.A.

    1994-01-01

    A Maximum Entropy Principle density matrix method, valid for systems with temperature different from zero, is presented making it possible two-mode squeezed states in two-level systems with relevant operators and Hamiltonian connected with O(3,2). A method which allows one to relate the appearance of squeezing to the relevant operators, included in order to define the density matrix of the system is given. (author). 14 refs, 1 fig

  2. Experiences of building a medical data acquisition system based on two-level modeling.

    Science.gov (United States)

    Li, Bei; Li, Jianbin; Lan, Xiaoyun; An, Ying; Gao, Wuqiang; Jiang, Yuqiao

    2018-04-01

    Compared to traditional software development strategies, the two-level modeling approach is more flexible and applicable to build an information system in the medical domain. However, the standards of two-level modeling such as openEHR appear complex to medical professionals. This study aims to investigate, implement, and improve the two-level modeling approach, and discusses the experience of building a unified data acquisition system for four affiliated university hospitals based on this approach. After the investigation, we simplified the approach of archetype modeling and developed a medical data acquisition system where medical experts can define the metadata for their own specialties by using a visual easy-to-use tool. The medical data acquisition system for multiple centers, clinical specialties, and diseases has been developed, and integrates the functions of metadata modeling, form design, and data acquisition. To date, 93,353 data items and 6,017 categories for 285 specific diseases have been created by medical experts, and over 25,000 patients' information has been collected. OpenEHR is an advanced two-level modeling method for medical data, but its idea to separate domain knowledge and technical concern is not easy to realize. Moreover, it is difficult to reach an agreement on archetype definition. Therefore, we adopted simpler metadata modeling, and employed What-You-See-Is-What-You-Get (WYSIWYG) tools to further improve the usability of the system. Compared with the archetype definition, our approach lowers the difficulty. Nevertheless, to build such a system, every participant should have some knowledge in both medicine and information technology domains, as these interdisciplinary talents are necessary. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Feedback controlled dephasing and population relaxation in a two-level system

    International Nuclear Information System (INIS)

    Wang Jin

    2009-01-01

    This Letter presents the maximum achievable stability and purity that can be obtained in a two-level system with both dephasing and population relaxation processes by using homodyne-mediated feedback control. An analytic formula giving the optimal amplitudes of the driving and feedback for the steady-state is also presented. Experimental examples are used to show the importance of controlling the dephasing process.

  4. Understanding of phase modulation in two-level systems through inverse scattering

    International Nuclear Information System (INIS)

    Hasenfeld, A.; Hammes, S.L.; Warren, W.S.

    1988-01-01

    Analytical and numerical calculations describe the effects of shaped radiation pulses on two-level systems in terms of quantum-mechanical scattering. Previous results obtained in the reduced case of amplitude modulation are extended to the general case of simultaneous amplitude and phase modulation. We show that an infinite family of phase- and amplitude-modulated pulses all generate rectangular inversion profiles. Experimental measurements also verify the theoretical analysis

  5. The simulation of the non-Markovian behaviour of a two-level system

    Science.gov (United States)

    Semina, I.; Petruccione, F.

    2016-05-01

    Non-Markovian relaxation dynamics of a two-level system is studied with the help of the non-linear stochastic Schrödinger equation with coloured Ornstein-Uhlenbeck noise. This stochastic Schrödinger equation is investigated numerically with an adapted Platen scheme. It is shown, that the memory effects have a significant impact to the dynamics of the system.

  6. Minimum time control of a pair of two-level quantum systems with opposite drifts

    International Nuclear Information System (INIS)

    Romano, Raffaele; D’Alessandro, Domenico

    2016-01-01

    In this paper we solve two equivalent time optimal control problems. On one hand, we design the control field to implement in minimum time the SWAP (or equivalent) operator on a two-level system, assuming that it interacts with an additional, uncontrollable, two-level system. On the other hand, we synthesize the SWAP operator simultaneously, in minimum time, on a pair of two-level systems subject to opposite drifts. We assume that it is possible to perform three independent control actions, and that the total control strength is bounded. These controls either affect the dynamics of the target system, under the first perspective, or, simultaneously, the dynamics of both systems, in the second view. We obtain our results by using techniques of geometric control theory on Lie groups. In particular, we apply the Pontryagin maximum principle, and provide a complete characterization of singular and nonsingular extremals. Our analysis shows that the problem can be formulated as the motion of a material point in a central force, a well known system in classical mechanics. Although we focus on obtaining the SWAP operator, many of the ideas and techniques developed in this work apply to the time optimal implementation of an arbitrary unitary operator. (paper)

  7. Two-Level Micro-to-Nanoscale Hierarchical TiO2 Nanolayers on Titanium Surface

    Directory of Open Access Journals (Sweden)

    Elena G. Zemtsova

    2016-12-01

    Full Text Available Joint replacement is being actively developed within modern orthopedics. One novel material providing fast implantation is bioactive coatings. The synthesis of targeted nanocoatings on metallic nanotitanium surface is reported in this paper. TiO2-based micro- and nanocoatings were produced by sol-gel synthesis using dip-coating technology with subsequent fast (shock drying in hot plate mode at 400 °C. As a result of shock drying, the two-level hierarchical TiO2 nanolayer on the nanotitanium was obtained. This two-level hierarchy includes nanorelief of porous xerogel and microrelief of the micron-sized “defect” network (a crack network. The thickness of TiO2 nanolayers was controlled by repeating dip-coating process the necessary number of times after the first layer deposition. The state of the MS3T3-E1 osteoblast cell line (young cells that form bone tissue on the two-level hierarchical surface has been studied. Particularly, adhesion character, adhesion time and morphology have been studied. The reported results may serve the starting point for the development of novel bioactive coatings for bone and teeth implants.

  8. Lipid Raft Size and Lipid Mobility in Non-raft Domains Increase during Aging and Are Exacerbated in APP/PS1 Mice Model of Alzheimer's Disease. Predictions from an Agent-Based Mathematical Model

    Science.gov (United States)

    Santos, Guido; Díaz, Mario; Torres, Néstor V.

    2016-01-01

    A connection between lipid rafts and Alzheimer's disease has been studied during the last decades. Mathematical modeling approaches have recently been used to correlate the effects of lipid composition changes in the physicochemical properties of raft-like membranes. Here we propose an agent based model to assess the effect of lipid changes in lipid rafts on the evolution and progression of Alzheimer's disease using lipid profile data obtained in an established model of familial Alzheimer's disease. We have observed that lipid raft size and lipid mobility in non-raft domains are two main factors that increase during age and are accelerated in the transgenic Alzheimer's disease mouse model. The consequences of these changes are discussed in the context of neurotoxic amyloid β production. Our agent based model predicts that increasing sterols (mainly cholesterol) and long-chain polyunsaturated fatty acids (LCPUFA) (mainly DHA, docosahexaenoic acid) proportions in the membrane composition might delay the onset and progression of the disease. PMID:27014089

  9. EVALUACIÓN DEL DESEMPEÑO EN REDES INALÁMBRICAS DE SENSORES MEJORADAS CON AGENTES MÓVILES AVALIAÇÃO DO DESEMPENHO EN REDES DE SENSORES SEM FIO MELHORADAS COM AGENTES MÓVEIS PERFORMANCE EVALUATION OF WIRELESS SENSOR NETWORKS IMPROVED WITH MOBILE AGENTS

    Directory of Open Access Journals (Sweden)

    Alcides Montoya

    2012-06-01

    retardo durante a mudança do tempo de amostragem para toda a rede. A solução mais eficiente, que foi provada e avaliada em uma rede sem fio formada por 40 nós que detectam fugas de amoníaco em tempo real, determinou que o ponto-chave consiste em diminuir o consumo de energia, produto das confirmações e retransmissões desnecessárias de dados e procedimentos, desde os nós sensores até a estação base. Este fato representa, além da diminuição no consumo energético, uma poupança significativa no tempo de convergência da rede.The reconfiguration, reprogramming, and deployment of new computational tasks in wireless sensor networks are complex and represent a problem satisfactorily unresolved at present. The aim of this paper is to propose the performance evaluation of the use of mobile intelligent agents as autonomous rescheduling mechanism in such networks. The method used for performance evaluation is done by measuring the energy consumption in the migration of mobile intelligent agents among the sensor nodes of the system and calculating the convergence time of the network, defined as the time it takes for the network to move from one state to another; in experiments it refers to the delay in changing the sampling time for the entire network. The most efficient solution, which was tested and evaluated in a network is composed of 40 nodes that detect in real time ammonia leaks, determined that the key issue is to reduce the expenditure of unnecessary energy in transmission from the wireless sensors to the base station, while avoiding unnecessary confirmations and transmissions of data and procedures among sensor nodes. This fact represents besides the reduction in the network energy consumption, a very significant saving for convergence time of the network.

  10. Renormalization of correlations in a quasiperiodically forced two-level system: quadratic irrationals

    International Nuclear Information System (INIS)

    Mestel, B D; Osbaldestin, A H

    2004-01-01

    Generalizing from the case of golden mean frequency to a wider class of quadratic irrationals, we extend our renormalization analysis of the self-similarity of correlation functions in a quasiperiodically forced two-level system. We give a description of all piecewise-constant periodic orbits of an additive functional recurrence generalizing that present in the golden mean case. We establish a criterion for periodic orbits to be globally bounded, and also calculate the asymptotic height of the main peaks in the correlation function

  11. Quantum averaging and resonances: two-level atom in a one-mode classical laser field

    Directory of Open Access Journals (Sweden)

    M. Amniat-Talab

    2007-06-01

    Full Text Available   We use a nonperturbative method based on quantum averaging and an adapted from of resonant transformations to treat the resonances of the Hamiltonian of a two-level atom interacting with a one-mode classical field in Floquet formalism. We illustrate this method by extraction of effective Hamiltonians of the system in two regimes of weak and strong coupling. The results obtained in the strong-coupling regime, are valid in the whole range of the coupling constant for the one-photon zero-field resonance.

  12. Aspects of two-level systems under external time-dependent fields

    Energy Technology Data Exchange (ETDEWEB)

    Bagrov, V.G.; Wreszinski, W.F. [Tomsk State University and Tomsk Institute of High Current Electronics (Russian Federation); Barata, J.C.A.; Gitman D.M. [Universidade de Sao Paulo, Instituto de Fisica (Brazil)]. E-mails: jbarata@fma.if.usp.br; gitman@fma.if.usp.br

    2001-12-14

    The dynamics of two-level systems in time-dependent backgrounds is under consideration. We present some new exact solutions in special backgrounds decaying in time. On the other hand, following ideas of Feynman et al, we discuss in detail the possibility of reducing the quantum dynamics to a classical Hamiltonian system. This, in particular, opens the possibility of directly applying powerful methods of classical mechanics (e.g. KAM methods) to study the quantum system. Following such an approach, we draw conclusions of relevance for 'quantum chaos' when the external background is periodic or quasi-periodic in time. (author)

  13. Teleporting the one-qubit state via two-level atoms with spontaneous emission

    Energy Technology Data Exchange (ETDEWEB)

    Hu Mingliang, E-mail: mingliang0301@xupt.edu.cn, E-mail: mingliang0301@163.com [School of Science, Xi' an University of Posts and Telecommunications, Xi' an 710061 (China)

    2011-05-14

    We study quantum teleportation via two two-level atoms coupled collectively to a multimode vacuum field and prepared initially in different atomic states. We concentrated on the influence of the spontaneous emission, collective damping and dipole-dipole interaction of the atoms on fidelity dynamics of quantum teleportation and obtained the region of spatial distance between the two atoms over which the state can be teleported nonclassically. Moreover, we showed through concrete examples that entanglement of the channel state is the prerequisite but not the only essential quantity for predicting the teleportation fidelity.

  14. A January angular momentum balance in the OSU two-level atmospheric general circulation model

    Science.gov (United States)

    Kim, J.-W.; Grady, W.

    1982-01-01

    The present investigation is concerned with an analysis of the atmospheric angular momentum balance, based on the simulation data of the Oregon State University two-level atmospheric general circulation model (AGCM). An attempt is also made to gain an understanding of the involved processes. Preliminary results on the angular momentum and mass balance in the AGCM are shown. The basic equations are examined, and questions of turbulent momentum transfer are investigated. The methods of analysis are discussed, taking into account time-averaged balance equations, time and longitude-averaged balance equations, mean meridional circulation, the mean meridional balance of relative angular momentum, and standing and transient components of motion.

  15. Thermal analysis of two-level wind power converter under symmetrical grid fault

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede

    2013-01-01

    In this paper, the case of symmetrical grid fault when using the multi-MW wind turbine of partial-scale and full-scale two-level power converter are designed and investigated. Firstly, the different operation behaviors of the relevant power converters under the voltage dip will be described......) condition as well as the junction temperature. For the full-scale wind turbine system, the most thermal stressed power device in the grid-side converter will appear at the grid voltage below 0.5 pu, and for the partial-scale wind turbine system, the most thermal stressed power device in the rotor...

  16. Geometric manipulation of the quantum states of two-level atoms

    International Nuclear Information System (INIS)

    Tian, Mingzhen; Barber, Zeb W.; Fischer, Joe A.; Babbitt, Wm. Randall

    2004-01-01

    Manipulation of the quantum states of two-level atoms has been investigated using laser-controlled geometric phase change, which has the potential to build robust quantum logic gates for quantum computing. For a qubit based on two electronic transition levels of an atom, two basic quantum operations that can make any universal single qubit gate have been designed employing resonant laser pulses. An operation equivalent to a phase gate has been demonstrated using Tm 3+ doped in a yttrium aluminum garnet crystal

  17. Probe transparency in a two-level medium embedded by a squeezed vacuum

    International Nuclear Information System (INIS)

    Swain, S.; Zhou, P.

    1994-08-01

    Effect of the detuning on the probe absorption spectra of a two-level system with and without a classically driven field in a squeezed vacuum is investigated. For a strong squeezing, there is a threshold which determines the positions and widths of the absorption peaks, for the squeezed parameter M. In a large detuning, the spectra exhibit some resemblance to the Fano spectrum. The squeezing-induced transparency occurs at the frequency 2ω L - ω A in the minimum-uncertainty squeezed vacuum. This effect is not phase-sensitive. (author). 15 refs, 8 figs

  18. Experimental Research into the Two-Level Cylindrical Cyclone with a Different Number of Channels

    Directory of Open Access Journals (Sweden)

    Egidijus Baliukas

    2014-10-01

    Full Text Available The multichannel two-level cyclone has been designed for separating solid particles from airflow and built at the Laboratory of Environmental Protection Technologies of Vilnius Gediminas Technical University. The conducted research is aimed at determining air flow distribution at two levels and channels of the multichannel cyclone. The multifunctional meter Testo-400 and the dynamic Pitot tube have been used form easuring air flow rates in the channels. The obtained results show that the equal volume of air gets into two levels installed inside the cyclone, and rates are distributed equally in the channels of these levels. The maximum air flow rate is recorded in the first channel and occurs when half-rings are set in such positions so that 75% of air flow returns to the previous channel. The biggest aerodynamic resistance is 1660 Pa and has been recorded in the cyclone having eight channels under air flow distribution ratio 75/25. The highest air purification efficiency has been observed in the two-level six-channel cyclone under air flow distribution ratio 75/25. The effectiveness of separating granite particles is 92.1% and that of wood particles – 91.1 when the particles are up to 20 μm in diameter.

  19. SCREENING OF MEDIUM COMPOUNDS USING A TWO-LEVEL FACTORIAL DESIGN FOR SACCHAROMYCES BOULARDII

    Directory of Open Access Journals (Sweden)

    GUOWEI SHU

    2016-04-01

    Full Text Available Even if the probiotic effect of Saccharomyces boulardii is has been reported, this yeast is rarely used in medium composition. Based on single factor experiment, two-level factorial design was employed to evaluate the effect of carbon sources (sucrose, glucose, nitrogen sources (soy peptone, beef extract, yeast extract, calf serum, malt extract and salts (K2HPO4, KH2PO4, MgSO4, Na2HPO4, NaH2PO4, CaCl2, sodium citrate, sodium glutamate on the growth of S. boulardii. At the same time, the optical density (OD in the medium was measured at 560 nm after 36 h of incubation. The result of two-level factorial design experiment showed that calf serum (p = 0.0214 and sodium citrate (p = 0.0045 are the significant growth factors of S. boulardii, sucrose (p = 0.0861 and malt extract (p = 0.0763 are important factors. In addition, sucrose and sodium citrate showed positive effect on the growth of S. boulardii. However, calf serum and malt extract showed negative effect on the growth. And we determined that the optimum medium composition for S. boulardii was as follow: 37.5 g·L-1 sucrose, 6 g·L-1 calf serum, 6 g·L-1 malt extract, 5 g·L-1 sodium citrate.

  20. Improved Genetic Algorithm with Two-Level Approximation for Truss Optimization by Using Discrete Shape Variables

    Directory of Open Access Journals (Sweden)

    Shen-yan Chen

    2015-01-01

    Full Text Available This paper presents an Improved Genetic Algorithm with Two-Level Approximation (IGATA to minimize truss weight by simultaneously optimizing size, shape, and topology variables. On the basis of a previously presented truss sizing/topology optimization method based on two-level approximation and genetic algorithm (GA, a new method for adding shape variables is presented, in which the nodal positions are corresponding to a set of coordinate lists. A uniform optimization model including size/shape/topology variables is established. First, a first-level approximate problem is constructed to transform the original implicit problem to an explicit problem. To solve this explicit problem which involves size/shape/topology variables, GA is used to optimize individuals which include discrete topology variables and shape variables. When calculating the fitness value of each member in the current generation, a second-level approximation method is used to optimize the continuous size variables. With the introduction of shape variables, the original optimization algorithm was improved in individual coding strategy as well as GA execution techniques. Meanwhile, the update strategy of the first-level approximation problem was also improved. The results of numerical examples show that the proposed method is effective in dealing with the three kinds of design variables simultaneously, and the required computational cost for structural analysis is quite small.

  1. Two-level method for unsteady Navier-Stokes equations based on a new projection

    International Nuclear Information System (INIS)

    Hou Yanren; Li Kaitai

    2004-12-01

    A two-level algorithm for the two dimensional unsteady Navier-Stokes equations based on a new projection is proposed and investigated. The approximate solution is solved as a sum of a large eddy component and a small eddy component, which are in the sense of the new projection, constructed in this paper. These two terms advance in time explicitly. Actually, the new algorithm proposed here can be regarded as a sort of postprocessing algorithm for the standard Galerkin method (SGM). The large eddy part is solved by SGM in the usual L 2 -based large eddy subspace while the small eddy part (the correction part) is obtained in its complement subspace in the sense of the new projection. The stability analysis indicates the improvement of the stability comparing with SGM of the same scale, and the L 2 -error estimate shows that the scheme can improve the accuracy of SGM approximation for half order. We also propose a numerical implementation based on Lagrange multiplier for this two-level algorithm. (author)

  2. Two-level Robust Measurement Fusion Kalman Filter for Clustering Sensor Networks

    Institute of Scientific and Technical Information of China (English)

    ZHANG Peng; QI Wen-Juan; DENG Zi-Li

    2014-01-01

    This paper investigates the distributed fusion Kalman filtering over clustering sensor networks. The sensor network is partitioned as clusters by the nearest neighbor rule and each cluster consists of sensing nodes and cluster-head. Using the minimax robust estimation principle, based on the worst-case conservative system with the conservative upper bounds of noise variances, two-level robust measurement fusion Kalman filter is presented for the clustering sensor network systems with uncertain noise variances. It can significantly reduce the communication load and save energy when the number of sensors is very large. A Lyapunov equation approach for the robustness analysis is presented, by which the robustness of the local and fused Kalman filters is proved. The concept of the robust accuracy is presented, and the robust accuracy relations among the local and fused robust Kalman filters are proved. It is proved that the robust accuracy of the two-level weighted measurement fuser is equal to that of the global centralized robust fuser and is higher than those of each local robust filter and each local weighted measurement fuser. A simulation example shows the correctness and effectiveness of the proposed results.

  3. Protecting quantum coherence of two-level atoms from vacuum fluctuations of electromagnetic field

    International Nuclear Information System (INIS)

    Liu, Xiaobao; Tian, Zehua; Wang, Jieci; Jing, Jiliang

    2016-01-01

    In the framework of open quantum systems, we study the dynamics of a static polarizable two-level atom interacting with a bath of fluctuating vacuum electromagnetic field and explore under which conditions the coherence of the open quantum system is unaffected by the environment. For both a single-qubit and two-qubit systems, we find that the quantum coherence cannot be protected from noise when the atom interacts with a non-boundary electromagnetic field. However, with the presence of a boundary, the dynamical conditions for the insusceptible of quantum coherence are fulfilled only when the atom is close to the boundary and is transversely polarizable. Otherwise, the quantum coherence can only be protected in some degree in other polarizable direction. -- Highlights: •We study the dynamics of a two-level atom interacting with a bath of fluctuating vacuum electromagnetic field. •For both a single and two-qubit systems, the quantum coherence cannot be protected from noise without a boundary. •The insusceptible of the quantum coherence can be fulfilled only when the atom is close to the boundary and is transversely polarizable. •Otherwise, the quantum coherence can only be protected in some degree in other polarizable direction.

  4. Ramsey interferometry with a two-level generalized Tonks-Girardeau gas

    International Nuclear Information System (INIS)

    Mousavi, S. V.; Campo, A. del; Lizuain, I.; Muga, J. G.

    2007-01-01

    We propose a solvable generalization of the Tonks-Girardeau model that describes a coherent one-dimensional (1D) gas of cold two-level bosons which interact with two external fields in a Ramsey interferometer. They also interact among themselves by idealized, infinitely strong contact potentials, with interchange of momentum and internal state. We study the corresponding Ramsey fringes and the quantum projection noise which, essentially unaffected by the interactions, remains that for ideal bosons. The dual system of this gas, an ideal gas of two-level fermions coupled by the interaction with the separated fields, produces the same fringes and noise fluctuations. The cases of time-separated and spatially separated fields are studied. For spatially separated fields the fringes may be broadened slightly by increasing the number of particles, but only for large particle numbers far from present experiments with Tonks-Girardeau gases. The uncertainty in the determination of the atomic transition frequency diminishes, essentially with the inverse root of the particle number. The difficulties to implement the model experimentally and possible shortcomings of strongly interacting 1D gases for frequency standards and atomic clocks are discussed

  5. A Weighted Two-Level Bregman Method with Dictionary Updating for Nonconvex MR Image Reconstruction

    Directory of Open Access Journals (Sweden)

    Qiegen Liu

    2014-01-01

    Full Text Available Nonconvex optimization has shown that it needs substantially fewer measurements than l1 minimization for exact recovery under fixed transform/overcomplete dictionary. In this work, two efficient numerical algorithms which are unified by the method named weighted two-level Bregman method with dictionary updating (WTBMDU are proposed for solving lp optimization under the dictionary learning model and subjecting the fidelity to the partial measurements. By incorporating the iteratively reweighted norm into the two-level Bregman iteration method with dictionary updating scheme (TBMDU, the modified alternating direction method (ADM solves the model of pursuing the approximated lp-norm penalty efficiently. Specifically, the algorithms converge after a relatively small number of iterations, under the formulation of iteratively reweighted l1 and l2 minimization. Experimental results on MR image simulations and real MR data, under a variety of sampling trajectories and acceleration factors, consistently demonstrate that the proposed method can efficiently reconstruct MR images from highly undersampled k-space data and presents advantages over the current state-of-the-art reconstruction approaches, in terms of higher PSNR and lower HFEN values.

  6. Detuning-induced stimulated Raman adiabatic passage in dense two-level systems

    Science.gov (United States)

    Deng, Li; Lin, Gongwei; Niu, Yueping; Gong, Shangqing

    2018-05-01

    We investigate the coherence generation in dense two-level systems under detuning-induced stimulated Raman adiabatic passage (D-STIRAP). In the dense two-level system, the near dipole-dipole (NDD) interaction should be taken into consideration. With the increase in the strength of the NDD interaction, it is found that a switchlike transition of the generated coherence from maximum value to zero appears. Meanwhile, the adiabatic condition of the D-STIRAP is destroyed in the presence of the NDD interaction. In order to avoid the sudden decrease in the generated coherence and maintain the maximum value, we can use stronger detuning pulse or pump pulse, between which increasing the intensity of the detuning pulse is of more efficiency. Except for taking advantage of such maximum coherence in the high density case into areas like enhancing the four-wave mixing process, we also point out that the phenomenon of the coherence transition can be applied as an optical switch.

  7. A novel two-level dynamic parallel data scheme for large 3-D SN calculations

    International Nuclear Information System (INIS)

    Sjoden, G.E.; Shedlock, D.; Haghighat, A.; Yi, C.

    2005-01-01

    We introduce a new dynamic parallel memory optimization scheme for executing large scale 3-D discrete ordinates (Sn) simulations on distributed memory parallel computers. In order for parallel transport codes to be truly scalable, they must use parallel data storage, where only the variables that are locally computed are locally stored. Even with parallel data storage for the angular variables, cumulative storage requirements for large discrete ordinates calculations can be prohibitive. To address this problem, Memory Tuning has been implemented into the PENTRAN 3-D parallel discrete ordinates code as an optimized, two-level ('large' array, 'small' array) parallel data storage scheme. Memory Tuning can be described as the process of parallel data memory optimization. Memory Tuning dynamically minimizes the amount of required parallel data in allocated memory on each processor using a statistical sampling algorithm. This algorithm is based on the integral average and standard deviation of the number of fine meshes contained in each coarse mesh in the global problem. Because PENTRAN only stores the locally computed problem phase space, optimal two-level memory assignments can be unique on each node, depending upon the parallel decomposition used (hybrid combinations of angular, energy, or spatial). As demonstrated in the two large discrete ordinates models presented (a storage cask and an OECD MOX Benchmark), Memory Tuning can save a substantial amount of memory per parallel processor, allowing one to accomplish very large scale Sn computations. (authors)

  8. Dynamical model of coherent circularly polarized optical pulse interactions with two-level quantum systems

    International Nuclear Information System (INIS)

    Slavcheva, G.; Hess, O.

    2005-01-01

    We propose and develop a method for theoretical description of circularly (elliptically) polarized optical pulse resonant coherent interactions with two-level atoms. The method is based on the time-evolution equations of a two-level quantum system in the presence of a time-dependent dipole perturbation for electric dipole transitions between states with total angular-momentum projection difference (ΔJ z =±1) excited by a circularly polarized electromagnetic field [Feynman et al., J. Appl. Phys. 28, 49 (1957)]. The adopted real-vector representation approach allows for coupling with the vectorial Maxwell's equations for the optical wave propagation and thus the resulting Maxwell pseudospin equations can be numerically solved in the time domain without any approximations. The model permits a more exact study of the ultrafast coherent pulse propagation effects taking into account the vector nature of the electromagnetic field and hence the polarization state of the optical excitation. We demonstrate self-induced transparency effects and formation of polarized solitons. The model represents a qualitative extension of the well-known optical Maxwell-Bloch equations valid for linearly polarized light and a tool for studying coherent quantum control mechanisms

  9. Direct Power Control for Three-Phase Two-Level Voltage-Source Rectifiers Based on Extended-State Observation

    DEFF Research Database (Denmark)

    Song, Zhanfeng; Tian, Yanjun; Yan, Zhuo

    2016-01-01

    This paper proposed a direct power control strategy for three-phase two-level voltage-source rectifiers based on extended-state observation. Active and reactive powers are directly regulated in the stationary reference frame. Similar to the family of predictive controllers whose inherent characte......This paper proposed a direct power control strategy for three-phase two-level voltage-source rectifiers based on extended-state observation. Active and reactive powers are directly regulated in the stationary reference frame. Similar to the family of predictive controllers whose inherent...

  10. The Population Inversion and the Entropy of a Moving Two-Level Atom in Interaction with a Quantized Field

    Science.gov (United States)

    Abo-Kahla, D. A. M.; Abdel-Aty, M.; Farouk, A.

    2018-05-01

    An atom with only two energy eigenvalues is described by a two-dimensional state space spanned by the two energy eigenstates is called a two-level atom. We consider the interaction between a two-level atom system with a constant velocity. An analytic solution of the systems which interacts with a quantized field is provided. Furthermore, the significant effect of the temperature on the atomic inversion, the purity and the information entropy are discussed in case of the initial state either an exited state or a maximally mixed state. Additionally, the effect of the half wavelengths number of the field-mode is investigated.

  11. Mobile marketing for mobile games

    OpenAIRE

    Vu, Giang

    2016-01-01

    Highly developed mobile technology and devices enable the rise of mobile game industry and mobile marketing. Hence mobile marketing for mobile game is an essential key for a mobile game success. Even though there are many articles on marketing for mobile games, there is a need of highly understanding mobile marketing strategies, how to launch a mobile campaign for a mobile game. Besides that, it is essential to understand the relationship between mobile advertising and users behaviours. There...

  12. Assessing the impacts of deploying a shared self-driving urban mobility system: An agent-based model applied to the city of Lisbon, Portugal

    Directory of Open Access Journals (Sweden)

    Luis M. Martinez

    2017-06-01

    Full Text Available This paper examines the changes that might result from the large-scale uptake of a shared and self-driving fleet of vehicles in a mid-sized European city. The work explores two different self-driving vehicle concepts – a ridesharing system (Shared Taxi, which emulates a taxi-like system where customers accept small detours from their original direct path and share part of their ride with others and a dynamic bus-like service with minibuses (Taxi-Bus, where customers pre-book their service at least 30 min in advance (permanent bookings for regular trips should represent most requests and walk short distances to a designated stop. Under the premise that the “upgraded” system should as much as possible deliver the same trips as today in terms of origin, destination and timing, and that it should also replace all car and bus trips, it looks at impacts on car fleet size, volume of travel and parking requirements. Mobility output and CO2 emissions are also detailed in two different time scales (24 h. average and peak-hour only. The obtained results suggest that a full implementation scenario where the existing metro service is kept and private car, bus and taxi mobility would be replaced by shared modes would significantly reduce travelled vehicle.kilometres and CO2 emissions.

  13. Computer simulation of two-level pedicle subtraction osteotomy for severe thoracolumbar kyphosis in ankylosing spondylitis

    Directory of Open Access Journals (Sweden)

    Ning Zhang

    2017-01-01

    Full Text Available Background: Advanced ankylosing spondylitis is often associated with thoracolumbar kyphosis, resulting in an abnormal spinopelvic balance and pelvic morphology. Different osteotomy techniques have been used to correct AS deformities, unfortunnaly, not all AS patients can gain spinal sagittal balance and good horizontal vision after osteotomy. Materials and Methods: Fourteen consecutive AS patients with severe thoracolumbar kyphosis who were treated with two-level PSO were studied retrospectively. All were male with a mean age of 34.9 ± 9.6 years. The followup ranged from 1–5 years. Preoperative computer simulations using the Surgimap Spinal software were performed for all patients, and the osteotomy level and angle determined from the computer simulation were used surgically. Spinal sagittal parameters were measured preoperatively, after the computer simulation, and postoperatively and included thoracic kyphosis (TK, lumbar lordosis (LL, sagittal vertical axis (SVA, pelvic incidence, pelvic tilt (PT, and sacral slope (SS. The level of correlation between the computer simulation and postoperative parameters was evaluated, and the differences between preoperative and postoperative parameters were compared. The visual analog scale (VAS for back pain and clinical outcome was also assessed. Results: Six cases underwent PSO at L1 and L3, five cases at L2 and T12, and three cases at L3 and T12. TK was corrected from 57.8 ± 15.2° preoperatively to 45.3 ± 7.7° postoperatively (P < 0.05, LL from 9.3 ± 17.5° to −52.3 ± 3.9° (P < 0.001, SVA from 154.5 ± 36.7 to 37.8 ± 8.4 mm (P < 0.001, PT from 43.3 ± 6.1° to 18.0 ± 0.9° (P < 0.001, and SS from 0.8 ± 7.0° to 26.5 ± 10.6° (P < 0.001. The LL, VAS, and PT of the simulated two-level PSO were highly consistent with, or almost the same as, the postoperative parameters. The correlations between the computer simulations and postoperative parameters were significant. The VAS decreased

  14. Comprehensive solutions to the Bloch equations and dynamical models for open two-level systems

    Science.gov (United States)

    Skinner, Thomas E.

    2018-01-01

    The Bloch equation and its variants constitute the fundamental dynamical model for arbitrary two-level systems. Many important processes, including those in more complicated systems, can be modeled and understood through the two-level approximation. It is therefore of widespread relevance, especially as it relates to understanding dissipative processes in current cutting-edge applications of quantum mechanics. Although the Bloch equation has been the subject of considerable analysis in the 70 years since its inception, there is still, perhaps surprisingly, significant work that can be done. This paper extends the scope of previous analyses. It provides a framework for more fully understanding the dynamics of dissipative two-level systems. A solution is derived that is compact, tractable, and completely general, in contrast to previous results. Any solution of the Bloch equation depends on three roots of a cubic polynomial that are crucial to the time dependence of the system. The roots are typically only sketched out qualitatively, with no indication of their dependence on the physical parameters of the problem. Degenerate roots, which modify the solutions, have been ignored altogether. Here the roots are obtained explicitly in terms of a single real-valued root that is expressed as a simple function of the system parameters. For the conventional Bloch equation, a simple graphical representation of this root is presented that makes evident the explicit time dependence of the system for each point in the parameter space. Several intuitive, visual models of system dynamics are developed. A Euclidean coordinate system is identified in which any generalized Bloch equation is separable, i.e., the sum of commuting rotation and relaxation operators. The time evolution in this frame is simply a rotation followed by relaxation at modified rates that play a role similar to the standard longitudinal and transverse rates. These rates are functions of the applied field, which

  15. Open quantum systems and the two-level atom interacting with a single mode of the electromagnetic field

    International Nuclear Information System (INIS)

    Sandulescu, A.; Stefanescu, E.

    1987-07-01

    On the basis of Lindblad theory of open quantum systems we obtain new optical equations for the system of two-level atom interacting with a single mode of the electromagnetic field. The conventional Block equations in a generalized form with field phases are obtained in the hypothesis that all the terms are slowly varying in the rotating frame.(authors)

  16. Analytical Design of Passive LCL Filter for Three-phase Two-level Power Factor Correction Rectifiers

    DEFF Research Database (Denmark)

    Kouchaki, Alireza; Nymand, Morten

    2017-01-01

    This paper proposes a comprehensive analytical LCL filter design method for three-phase two-level power factor correction rectifiers (PFCs). The high frequency converter current ripple generates the high frequency current harmonics that need to be attenuated with respect to the grid standards...

  17. Quantum driving protocols for a two-level system: From generalized Landau-Zener sweeps to transitionless control

    DEFF Research Database (Denmark)

    Malossi, Nicola; Bason, Mark George; Viteau, Matthieu

    2013-01-01

    We present experimental results on the preparation of a desired quantum state in a two-level system with the maximum possible fidelity using driving protocols ranging from generalizations of the linear Landau-Zener protocol to transitionless driving protocols that ensure perfect following of the ...

  18. Biological Agents

    Science.gov (United States)

    ... E-Tools Safety and Health Topics / Biological Agents Biological Agents This page requires that javascript be enabled ... 202) 693-2300 if additional assistance is required. Biological Agents Menu Overview In Focus: Ebola Frederick A. ...

  19. Canyon of current suppression in an interacting two-level quantum dot

    DEFF Research Database (Denmark)

    Karlström, O; Pedersen, Jonas Nyvold; Samuelsson, P

    2011-01-01

    Motivated by the recent discovery of a canyon of conductance suppression in a two-level equal-spin quantum dot system [Phys. Rev. Lett. 104, 186804 (2010)], the transport through this system is studied in detail. At low bias and low temperature a strong current suppression is found around...... the electron-hole symmetry point independent of the couplings, in agreement with previous results. By means of a Schrieffer–Wolff transformation we are able to give an intuitive explanation to this suppression in the low-energy regime. In the general situation, numerical simulations are carried out using...... for the current suppression. It is also shown how broadening, interference, and a finite interaction energy cause a shift of the current minimum away from degeneracy. Finally we see how an increased population of the upper level leads to current peaks on each side of the suppression line. At sufficiently high...

  20. Propagation of an attosecond pulse in a dense two-level medium

    International Nuclear Information System (INIS)

    Song Xiaohong; Gong Shangqing; Yang Weifeng; Xu Zhizhan

    2004-01-01

    We investigate the propagation of attosecond pulse in a dense two-level medium by using an iterative predictor-corrector finite-difference time-domain method. We find when attosecond pulse is considered, that the standard area theorem will break down even for small area pulses: ideal self-induced transparency cannot occur even for a 2π pulse, while the pulses whose areas are not integer multiples of 2π, such as 1.8π and 2.2π pulses, cannot evolve to 2π pulses as predicted by the standard area theorem. Significantly higher spectra components can occur on all these small area propagating pulses due to strong carrier reshaping. Furthermore, these higher spectral components dependent sensitively on the pulse area: the larger the pulse area is, the more evident are these higher spectral components

  1. Information Entropy Squeezing of a Two-Level Atom Interacting with Two-Mode Coherent Fields

    Institute of Scientific and Technical Information of China (English)

    LIU Xiao-Juan; FANG Mao-Fa

    2004-01-01

    From a quantum information point of view we investigate the entropy squeezing properties for a two-level atom interacting with the two-mode coherent fields via the two-photon transition. We discuss the influences of the initial state of the system on the atomic information entropy squeezing. Our results show that the squeezed component number,squeezed direction, and time of the information entropy squeezing can be controlled by choosing atomic distribution angle,the relative phase between the atom and the two-mode field, and the difference of the average photon number of the two field modes, respectively. Quantum information entropy is a remarkable precision measure for the atomic squeezing.

  2. Transmission-line resonators for the study of individual two-level tunneling systems

    Science.gov (United States)

    Brehm, Jan David; Bilmes, Alexander; Weiss, Georg; Ustinov, Alexey V.; Lisenfeld, Jürgen

    2017-09-01

    Parasitic two-level tunneling systems (TLS) emerge in amorphous dielectrics and constitute a serious nuisance for various microfabricated devices, where they act as a source of noise and decoherence. Here, we demonstrate a new test bed for the study of TLS in various materials which provides access to properties of individual TLS as well as their ensemble response. We terminate a superconducting transmission-line resonator with a capacitor that hosts TLS in its dielectric. By tuning TLS via applied mechanical strain, we observe the signatures of individual TLS strongly coupled to the resonator in its transmission characteristics and extract the coupling components of their dipole moments and energy relaxation rates. The strong and well-defined coupling to the TLS bath results in pronounced resonator frequency fluctuations and excess phase noise, through which we can study TLS ensemble effects such as spectral diffusion, and probe theoretical models of TLS interactions.

  3. Entanglement for a Bimodal Cavity Field Interacting with a Two-Level Atom

    International Nuclear Information System (INIS)

    Liu Jia; Chen Ziyu; Bu Shenping; Zhang Guofeng

    2009-01-01

    Negativity has been adopted to investigate the entanglement in a system composed of a two-level atom and a two-mode cavity field. Effects of Kerr-like medium and the number of photon inside the cavity on the entanglement are studied. Our results show that atomic initial state must be superposed, so that the two cavity field modes can be entangled. Moreover, we also conclude that the number of photon in the two cavity mode should be equal. The interaction between modes, namely, the Kerr effect, has a significant negative contribution. Note that the atom frequency and the cavity frequency have an indistinguishable effect, so a corresponding approximation has been made in this article. These results may be useful for quantum information in optics systems.

  4. Organization of the two-level memory in the image processing system on scanning measuring projectors

    International Nuclear Information System (INIS)

    Sychev, A.Yu.

    1977-01-01

    Discussed are the problems of improving the efficiency of the system for processing pictures taken in bubble chambers with the use of scanning measuring projectors. The system comprises 20 to 30 pro ectors linked with the ICL-1903A computer provided with a mainframe memory, 64 kilobytes in size. Because of the insufficient size of a mainframe memory, a part of the programs and data is located in a second-level memory, i.e. in an external memory. The analytical model described herein is used to analyze the effect of the memory organization on the characteristics of the system. It is shown that organization of pure procedures and introduction of the centralized control of the tWo-leVel memory result in substantial improvement of the efficiency of the picture processing system

  5. Interacting two-level defects as sources of fluctuating high-frequency noise in superconducting circuits

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Clemens [ARC Centre of Excellence for Engineered Quantum Systems, The University of Queensland, Brisbane (Australia); Lisenfeld, Juergen [Physikalisches Institut, Karlsruhe Institute of Technology, Karlsruhe (Germany); Shnirman, Alexander [Institut fuer Theory der Kondensierten Materie, Karlsruhe Institute of Technology, Karlsruhe (Germany); LD Landau Institute for Theoretical Physics, Moscow (Russian Federation); Poletto, Stefano [IBM TJ Watson Research Centre, Yorktown Heights (United States)

    2016-07-01

    Since the very first experiments, superconducting circuits have suffered from strong coupling to environmental noise, destroying quantum coherence and degrading performance. In state-of-the-art experiments, it is found that the relaxation time of superconducting qubits fluctuates as a function of time. We present measurements of such fluctuations in a 3D-transmon circuit and develop a qualitative model based on interactions within a bath of background two-level systems (TLS) which emerge from defects in the device material. In our model, the time-dependent noise density acting on the qubit emerges from its near-resonant coupling to high-frequency TLS which experience energy fluctuations due to their interaction with thermally fluctuating TLS at low frequencies. We support the model by providing experimental evidence of such energy fluctuations observed in a single TLS in a phase qubit circuit.

  6. Estimation of Missing Observations in Two-Level Split-Plot Designs

    DEFF Research Database (Denmark)

    Almimi, Ashraf A.; Kulahci, Murat; Montgomery, Douglas C.

    2008-01-01

    Inserting estimates for the missing observations from split-plot designs restores their balanced or orthogonal structure and alleviates the difficulties in the statistical analysis. In this article, we extend a method due to Draper and Stoneman to estimate the missing observations from unreplicated...... two-level factorial and fractional factorial split-plot (FSP and FFSP) designs. The missing observations, which can either be from the same whole plot, from different whole plots, or comprise entire whole plots, are estimated by equating to zero a number of specific contrast columns equal...... to the number of the missing observations. These estimates are inserted into the design table and the estimates for the remaining effects (or alias chains of effects as the case with FFSP designs) are plotted on two half-normal plots: one for the whole-plot effects and the other for the subplot effects...

  7. Thermal analysis of multi-MW two-level wind power converter

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede; Mogens, Lau

    2012-01-01

    In this paper, the multi-MW wind turbine of partial-scale and full-scale two-level power converter with DFIG and direct-drive PMSG are designed and compared in terms of their thermal performance. Simulations of different configurations regarding loss distribution and junction temperature...... in the power device in the whole range of wind speed are presented and analyzed. It is concluded that in both partial-scale and full-scale power converter the most thermal stressed power device in the generator-side converter will have higher mean junction temperature and larger junction temperature...... fluctuation compared to grid-side converter at the rated wind speed. Moreover, the thermal performance of the generator-side converter in the partial-scale power converter becomes crucial around the synchronous operating point and should be considered carefully....

  8. Two-Level Verification of Data Integrity for Data Storage in Cloud Computing

    Science.gov (United States)

    Xu, Guangwei; Chen, Chunlin; Wang, Hongya; Zang, Zhuping; Pang, Mugen; Jiang, Ping

    Data storage in cloud computing can save capital expenditure and relive burden of storage management for users. As the lose or corruption of files stored may happen, many researchers focus on the verification of data integrity. However, massive users often bring large numbers of verifying tasks for the auditor. Moreover, users also need to pay extra fee for these verifying tasks beyond storage fee. Therefore, we propose a two-level verification of data integrity to alleviate these problems. The key idea is to routinely verify the data integrity by users and arbitrate the challenge between the user and cloud provider by the auditor according to the MACs and ϕ values. The extensive performance simulations show that the proposed scheme obviously decreases auditor's verifying tasks and the ratio of wrong arbitration.

  9. Nonlinear Jaynes–Cummings model for two interacting two-level atoms

    International Nuclear Information System (INIS)

    Santos-Sánchez, O de los; González-Gutiérrez, C; Récamier, J

    2016-01-01

    In this work we examine a nonlinear version of the Jaynes–Cummings model for two identical two-level atoms allowing for Ising-like and dipole–dipole interplays between them. The model is said to be nonlinear in the sense that it can incorporate both a general intensity-dependent interaction between the atomic system and the cavity field and/or the presence of a nonlinear medium inside the cavity. As an example, we consider a particular type of atom-field coupling based upon the so-called Buck–Sukumar model and a lossless Kerr-like cavity. We describe the possible effects of such features on the evolution of some quantities of current interest, such as atomic excitation, purity, concurrence, the entropy of the field and the evolution of the latter in phase space. (paper)

  10. Minimax terminal approach problem in two-level hierarchical nonlinear discrete-time dynamical system

    Energy Technology Data Exchange (ETDEWEB)

    Shorikov, A. F., E-mail: afshorikov@mail.ru [Ural Federal University, 19 S. Mira, Ekaterinburg, 620002, Russia Institute of Mathematics and Mechanics, Ural Branch of Russian Academy of Sciences, 16 S. Kovalevskaya, Ekaterinburg, 620990 (Russian Federation)

    2015-11-30

    We consider a discrete–time dynamical system consisting of three controllable objects. The motions of all objects are given by the corresponding vector nonlinear or linear discrete–time recurrent vector relations, and control system for its has two levels: basic (first or I level) that is dominating and subordinate level (second or II level) and both have different criterions of functioning and united a priori by determined informational and control connections defined in advance. For the dynamical system in question, we propose a mathematical formalization in the form of solving a multistep problem of two-level hierarchical minimax program control over the terminal approach process with incomplete information and give a general scheme for its solving.

  11. TWO-LEVEL HIERARCHICAL COORDINATION QUEUING METHOD FOR TELECOMMUNICATION NETWORK NODES

    Directory of Open Access Journals (Sweden)

    M. V. Semenyaka

    2014-07-01

    Full Text Available The paper presents hierarchical coordination queuing method. Within the proposed method a queuing problem has been reduced to optimization problem solving that was presented as two-level hierarchical structure. The required distribution of flows and bandwidth allocation was calculated at the first level independently for each macro-queue; at the second level solutions obtained on lower level for each queue were coordinated in order to prevent probable network link overload. The method of goal coordination has been determined for multilevel structure managing, which makes it possible to define the order for consideration of queue cooperation restrictions and calculation tasks distribution between levels of hierarchy. Decisions coordination was performed by the method of Lagrange multipliers. The study of method convergence has been carried out by analytical modeling.

  12. On Two-Level State-Dependent Routing Polling Systems with Mixed Service

    Directory of Open Access Journals (Sweden)

    Guan Zheng

    2015-01-01

    Full Text Available Based on priority differentiation and efficiency of the system, we consider an N+1 queues’ single-server two-level polling system which consists of one key queue and N normal queues. The novel contribution of the present paper is that we consider that the server just polls active queues with customers waiting in the queue. Furthermore, key queue is served with exhaustive service and normal queues are served with 1-limited service in a parallel scheduling. For this model, we derive an expression for the probability generating function of the joint queue length distribution at polling epochs. Based on these results, we derive the explicit closed-form expressions for the mean waiting time. Numerical examples demonstrate that theoretical and simulation results are identical and the new system is efficient both at key queue and normal queues.

  13. Intensity profiles of superdeformed bands in Pb isotopes in a two-level mixing model

    International Nuclear Information System (INIS)

    Wilson, A. N.; Szigeti, S. S.; Rogers, J. I.; Davidson, P. M.; Cardamone, D. M.

    2009-01-01

    A recently developed two-level mixing model of the decay out of superdeformed bands is applied to examine the loss of flux from the yrast superdeformed bands in 192 Pb, 194 Pb, and 196 Pb. Probability distributions for decay to states at normal deformations are calculated at each level. The sensitivity of the results to parameters describing the levels at normal deformation and their coupling to levels in the superdeformed well is explored. It is found that except for narrow ranges of the interaction strength coupling the states, the amount of intensity lost is primarily determined by the ratio of γ decay widths in the normal and superdeformed wells. It is also found that while the model can accommodate the observed fractional intensity loss profiles for decay from bands at relatively high excitation, it cannot accommodate the similarly abrupt decay from bands at lower energies if standard estimates of the properties of the states in the first minimum are employed

  14. Crossing rule for a PT-symmetric two-level time-periodic system

    International Nuclear Information System (INIS)

    Moiseyev, Nimrod

    2011-01-01

    For a two-level system in a time-periodic field we show that in the non-Hermitian PT case the level crossing is of two quasistationary states that have the same dynamical symmetry property. At the field's parameters where the two levels which have the same dynamical symmetry cross, the corresponding quasienergy states coalesce and a self-orthogonal state is obtained. This situation is very different from the Hermitian case where a crossing of two quasienergy levels happens only when the corresponding two quasistationary states have different dynamical symmetry properties and, unlike the situation in the non-Hermitian case, the spectrum remains complete also when the two levels cross.

  15. Photon echo with a few photons in two-level atoms

    International Nuclear Information System (INIS)

    Bonarota, M; Dajczgewand, J; Louchet-Chauvet, A; Le Gouët, J-L; Chanelière, T

    2014-01-01

    To store and retrieve signals at the single photon level, various photon echo schemes have resorted to complex preparation steps involving ancillary shelving states in multi-level atoms. For the first time, we experimentally demonstrate photon echo operation at such a low signal intensity without any preparation step, which allows us to work with mere two-level atoms. This simplified approach relies on the so-coined ‘revival of silenced echo’ (ROSE) scheme. Low noise conditions are obtained by returning the atoms to the ground state before the echo emission. In the present paper we manage ROSE in photon counting conditions, showing that very strong control fields can be compatible with extremely weak signals, making ROSE consistent with quantum memory requirements. (paper)

  16. Dynamical Evolution of an Effective Two-Level System with {\\mathscr{P}}{\\mathscr{T}} Symmetry

    Science.gov (United States)

    Du, Lei; Xu, Zhihao; Yin, Chuanhao; Guo, Liping

    2018-05-01

    We investigate the dynamics of parity- and time-reversal (PT ) symmetric two-energy-level atoms in the presence of two optical and a radio-frequency (rf) fields. The strength and relative phase of fields can drive the system from unbroken to broken PT symmetric regions. Compared with the Hermitian model, Rabi-type oscillation is still observed, and the oscillation characteristics are also adjusted by the strength and relative phase in the region of unbroken PT symmetry. At exception point (EP), the oscillation breaks down. To better understand the underlying properties we study the effective Bloch dynamics and find the emergence of the z components of the fixed points is the feature of the PT symmetry breaking and the projections in x-y plane can be controlled with high flexibility compared with the standard two-level system with PT symmetry. It helps to study the dynamic behavior of the complex PT symmetric model.

  17. Faithful state transfer between two-level systems via an actively cooled finite-temperature cavity

    Science.gov (United States)

    Sárkány, Lőrinc; Fortágh, József; Petrosyan, David

    2018-03-01

    We consider state transfer between two qubits—effective two-level systems represented by Rydberg atoms—via a common mode of a microwave cavity at finite temperature. We find that when both qubits have the same coupling strength to the cavity field, at large enough detuning from the cavity mode frequency, quantum interference between the transition paths makes the swap of the excitation between the qubits largely insensitive to the number of thermal photons in the cavity. When, however, the coupling strengths are different, the photon-number-dependent differential Stark shift of the transition frequencies precludes efficient transfer. Nevertheless, using an auxiliary cooling system to continuously extract the cavity photons, we can still achieve a high-fidelity state transfer between the qubits.

  18. Segmental and global lordosis changes with two-level axial lumbar interbody fusion and posterior instrumentation

    Science.gov (United States)

    Melgar, Miguel A; Tobler, William D; Ernst, Robert J; Raley, Thomas J; Anand, Neel; Miller, Larry E; Nasca, Richard J

    2014-01-01

    Background Loss of lumbar lordosis has been reported after lumbar interbody fusion surgery and may portend poor clinical and radiographic outcome. The objective of this research was to measure changes in segmental and global lumbar lordosis in patients treated with presacral axial L4-S1 interbody fusion and posterior instrumentation and to determine if these changes influenced patient outcomes. Methods We performed a retrospective, multi-center review of prospectively collected data in 58 consecutive patients with disabling lumbar pain and radiculopathy unresponsive to nonsurgical treatment who underwent L4-S1 interbody fusion with the AxiaLIF two-level system (Baxano Surgical, Raleigh NC). Main outcomes included back pain severity, Oswestry Disability Index (ODI), Odom's outcome criteria, and fusion status using flexion and extension radiographs and computed tomography scans. Segmental (L4-S1) and global (L1-S1) lumbar lordosis measurements were made using standing lateral radiographs. All patients were followed for at least 24 months (mean: 29 months, range 24-56 months). Results There was no bowel injury, vascular injury, deep infection, neurologic complication or implant failure. Mean back pain severity improved from 7.8±1.7 at baseline to 3.3±2.6 at 2 years (p lordosis, defined as a change in Cobb angle ≤ 5°, was identified in 84% of patients at L4-S1 and 81% of patients at L1-S1. Patients with loss or gain in segmental or global lordosis experienced similar 2-year outcomes versus those with less than a 5° change. Conclusions/Clinical Relevance Two-level axial interbody fusion supplemented with posterior fixation does not alter segmental or global lordosis in most patients. Patients with postoperative change in lordosis greater than 5° have similarly favorable long-term clinical outcomes and fusion rates compared to patients with less than 5° lordosis change. PMID:25694920

  19. Embodied Cultures of Mobilities

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    2010-01-01

    and material artifacts. The paper target the complex relationship between the moving, sensing body and the material and built environment of infrastructures and mobility modes in order to explore what norms, and meanings, and everyday life mobility cultures are being produced and re-produced in this process....... A particular emphasis is put on how mobilities produce and re-produce norms, meanings and cultures in relation to the Everyday life perspective. By looking into walking, running, cycling, driving and mass transit mobilities different modes of embodied mobility is identified. The theoretical framework is based...... and interaction (Lynch). The argument is thus that understanding embodied cultures of mobilities from the vantage point of this paper lend is self to new interpretations, explorations and understandings of what it means to move within and between other social agents in particular material and physical...

  20. Critical evaluation of the use of the hydroxyapatite as a stabilizing agent to reduce the mobility of Zn and Ni in sewage sludge amended soils.

    Science.gov (United States)

    Zupancic, Marija; Bukovec, Peter; Milacic, Radmila; Scancar, Janez

    2006-01-01

    The leachability of zinc (Zn) and nickel (Ni) was investigated in various soil types amended with sewage sludge and sewage sludge treated with hydroxyapatite. Sandy, clay and peat soils were investigated. For leachability tests, plastic columns (diameter 9 cm, height 50 cm) were filled with moist samples up to a height of 25 cm. Sewage sludge (1 kg) was mixed with 4.6 kg of clay and sandy soils and with 6.7 kg of peat soil. For sewage sludge mixtures treated with hydroxyapatite, 0.5 kg of the hydroxyapatite was added to 1 kg of the sewage sludge. Neutral (pH 7) and acid precipitation (pH 3.5) were applied. Acid precipitation was prepared from concentrated HNO(3), H(2)SO(4) and fresh doubly distilled water. The amount of precipitation corresponded to the average annual precipitation for the city of Ljubljana, Slovenia. It was divided into eight equal portions and applied sequentially on the top of the columns. The results indicated that the leachabilities of Zn in sewage sludge amended peat and clay soils were low (below 0.3% of total Zn content) and of Ni in sewage sludge amended sandy, clay and peat soil below 1.9% of total Ni content. In sewage sludge amended sandy soil, the leachability of Zn was higher (11% of Zn content). The pH of precipitation had no influence on the leachability of either metal. Treatment of sewage sludge with hydroxyapatite efficiently reduced the leachability of Zn in sewage sludge amended sandy soil (from 11% to 0.2% of total Zn content). In clay and peat sewage sludge amended soils, soil characteristics rather than hydroxyapatite treatment dominate Zn mobility.

  1. DNCON2: improved protein contact prediction using two-level deep convolutional neural networks.

    Science.gov (United States)

    Adhikari, Badri; Hou, Jie; Cheng, Jianlin

    2018-05-01

    Significant improvements in the prediction of protein residue-residue contacts are observed in the recent years. These contacts, predicted using a variety of coevolution-based and machine learning methods, are the key contributors to the recent progress in ab initio protein structure prediction, as demonstrated in the recent CASP experiments. Continuing the development of new methods to reliably predict contact maps is essential to further improve ab initio structure prediction. In this paper we discuss DNCON2, an improved protein contact map predictor based on two-level deep convolutional neural networks. It consists of six convolutional neural networks-the first five predict contacts at 6, 7.5, 8, 8.5 and 10 Å distance thresholds, and the last one uses these five predictions as additional features to predict final contact maps. On the free-modeling datasets in CASP10, 11 and 12 experiments, DNCON2 achieves mean precisions of 35, 50 and 53.4%, respectively, higher than 30.6% by MetaPSICOV on CASP10 dataset, 34% by MetaPSICOV on CASP11 dataset and 46.3% by Raptor-X on CASP12 dataset, when top L/5 long-range contacts are evaluated. We attribute the improved performance of DNCON2 to the inclusion of short- and medium-range contacts into training, two-level approach to prediction, use of the state-of-the-art optimization and activation functions, and a novel deep learning architecture that allows each filter in a convolutional layer to access all the input features of a protein of arbitrary length. The web server of DNCON2 is at http://sysbio.rnet.missouri.edu/dncon2/ where training and testing datasets as well as the predictions for CASP10, 11 and 12 free-modeling datasets can also be downloaded. Its source code is available at https://github.com/multicom-toolbox/DNCON2/. chengji@missouri.edu. Supplementary data are available at Bioinformatics online.

  2. PSCAD modeling of a two-level space vector pulse width modulation algorithm for power electronics education

    Directory of Open Access Journals (Sweden)

    Ahmet Mete Vural

    2016-09-01

    Full Text Available This paper presents the design details of a two-level space vector pulse width modulation algorithm in PSCAD that is able to generate pulses for three-phase two-level DC/AC converters with two different switching patterns. The presented FORTRAN code is generic and can be easily modified to meet many other kinds of space vector modulation strategies. The code is also editable for hardware programming. The new component is tested and verified by comparing its output as six gating signals with those of a similar component in MATLAB library. Moreover the component is used to generate digital signals for closed-loop control of STATCOM for reactive power compensation in PSCAD. This add-on can be an effective tool to give students better understanding of the space vector modulation algorithm for different control tasks in power electronics area, and can motivate them for learning.

  3. Non-Hermitian wave packet approximation for coupled two-level systems in weak and intense fields

    Energy Technology Data Exchange (ETDEWEB)

    Puthumpally-Joseph, Raiju; Charron, Eric [Institut des Sciences Moléculaires d’Orsay (ISMO), CNRS, Univ. Paris-Sud, Université Paris-Saclay, F-91405 Orsay (France); Sukharev, Maxim [Science and Mathematics Faculty, College of Letters and Sciences, Arizona State University, Mesa, Arizona 85212 (United States)

    2016-04-21

    We introduce a non-Hermitian Schrödinger-type approximation of optical Bloch equations for two-level systems. This approximation provides a complete and accurate description of the coherence and decoherence dynamics in both weak and strong laser fields at the cost of losing accuracy in the description of populations. In this approach, it is sufficient to propagate the wave function of the quantum system instead of the density matrix, providing that relaxation and dephasing are taken into account via automatically adjusted time-dependent gain and decay rates. The developed formalism is applied to the problem of scattering and absorption of electromagnetic radiation by a thin layer comprised of interacting two-level emitters.

  4. Adiabatic interpretation of a two-level atom diode, a laser device for unidirectional transmission of ground-state atoms

    International Nuclear Information System (INIS)

    Ruschhaupt, A.; Muga, J. G.

    2006-01-01

    We present a generalized two-level scheme for an 'atom diode', namely, a laser device that lets a two-level ground-state atom pass in one direction, say from left to right, but not in the opposite direction. The laser field is composed of two lateral state-selective mirror regions and a central pumping region. We demonstrate the robustness of the scheme and propose a physical realization. It is shown that the inclusion of a counterintuitive laser field blocking the excited atoms on the left side of the device is essential for a perfect diode effect. The reason for this, the diodic behavior, and the robustness may be understood with an adiabatic approximation. The conditions to break down the approximation, which imply also the diode failure, are analyzed

  5. Two-level MOC calculation scheme in APOLLO2 for cross-section library generation for LWR hexagonal assemblies

    International Nuclear Information System (INIS)

    Petrov, Nikolay; Todorova, Galina; Kolev, Nikola; Damian, Frederic

    2011-01-01

    The accurate and efficient MOC calculation scheme in APOLLO2, developed by CEA for generating multi-parameterized cross-section libraries for PWR assemblies, has been adapted to hexagonal assemblies. The neutronic part of this scheme is based on a two-level calculation methodology. At the first level, a multi-cell method is used in 281 energy groups for cross-section definition and self-shielding. At the second level, precise MOC calculations are performed in a collapsed energy mesh (30-40 groups). In this paper, the application and validation of the two-level scheme for hexagonal assemblies is described. Solutions for a VVER assembly are compared with TRIPOLI4® calculations and direct 281g MOC solutions. The results show that the accuracy is close to that of the 281g MOC calculation while the CPU time is substantially reduced. Compared to the multi-cell method, the accuracy is markedly improved. (author)

  6. Enforcing Integrity of Agent Migration Paths by Distribution of Trust

    NARCIS (Netherlands)

    Warnier, M.E.; Oey, M.A.; Timmer, R.J.; Overeinder, B.J.; Brazier, F.M.

    2008-01-01

    Agent mobility is the ability of an agent to migrate from one location to another across a network. Though conceptually relatively straightforward, in practice security of mobile agents is a challenge: from transport layer security to preservation of integrity in open environments. This paper

  7. Mobile Router Developed and Tested

    Science.gov (United States)

    Ivancic, William D.

    2002-01-01

    subnetworks. This is essential in many wireless networks. A mobile router, unlike a mobile IP node, allows entire networks to roam. Hence, a device connected to the mobile router does not need to be a mobile node because the mobile router provides the roaming capabilities. There are three basic elements in the mobile IP: the home agent, the foreign agent, and the mobile node. The home agent is a router on a mobile node's home network that tunnels datagrams for delivery to the mobile node when it is away from home. The foreign agent is a router on a remote network that provides routing services to a registered mobile node. The mobile node is a host or router that changes its point of attachment from one network or subnetwork to another. In mobile routing, virtual communications are maintained by the home agent, which forwards all packets for the mobile networks to the foreign agent. The foreign agent passes the packets to the mobile router, which then forwards the packets to the devices on its networks. As the mobile router moves, it will register with its home agent on its whereabouts via the foreign agent to assure continuous connectivity.

  8. Coherent control of the group velocity in a dielectric slab doped with duplicated two-level atoms

    Science.gov (United States)

    Ziauddin; Chuang, You-Lin; Lee, Ray-Kuang; Qamar, Sajid

    2016-01-01

    Coherent control of reflected and transmitted pulses is investigated theoretically through a slab doped with atoms in a duplicated two-level configuration. When a strong control field and a relatively weak probe field are employed, coherent control of the group velocity is achieved via changing the phase shift ϕ between control and probe fields. Furthermore, the peak values in the delay time of the reflected and transmitted pulses are also studied by varying the phase shift ϕ.

  9. Entropy squeezing for a two-level atom in two-mode Raman coupled model with intrinsic decoherence

    Institute of Scientific and Technical Information of China (English)

    Zhang Jian; Shao Bin; Zou Jian

    2009-01-01

    In this paper,we investigate the entropy squeezing for a two-level atom interacting with two quantized fields through Raman coupling.We obtain the dynamical evolution of the total system under the influence of intrinsic decoherence when the two quantized fields are prepared in a two-mode squeezing vacuum state initially.The effects of the field squeezing factor,the two-level atomic transition frequency,the second field frequency and the intrinsic decoherence on the entropy squeezing are discussed.Without intrinsic decoherence,the increase of field squeezing factor can break the entropy squeezing.The two-level atomic transition frequency changes only the period of oscillation but not the strength of entropy squeezing.The influence of the second field frequency is complicated.With the intrinsic decoherence taken into consideration,the results show that the stronger the intrinsic decoherence is,the more quickly the entropy squeezing will disappear.The increase of the atomic transition frequency can hasten the disappearance of entropy squeezing.

  10. Asynchronous Two-Level Checkpointing Scheme for Large-Scale Adjoints in the Spectral-Element Solver Nek5000

    Energy Technology Data Exchange (ETDEWEB)

    Schanen, Michel; Marin, Oana; Zhang, Hong; Anitescu, Mihai

    2016-01-01

    Adjoints are an important computational tool for large-scale sensitivity evaluation, uncertainty quantification, and derivative-based optimization. An essential component of their performance is the storage/recomputation balance in which efficient checkpointing methods play a key role. We introduce a novel asynchronous two-level adjoint checkpointing scheme for multistep numerical time discretizations targeted at large-scale numerical simulations. The checkpointing scheme combines bandwidth-limited disk checkpointing and binomial memory checkpointing. Based on assumptions about the target petascale systems, which we later demonstrate to be realistic on the IBM Blue Gene/Q system Mira, we create a model of the expected performance of our checkpointing approach and validate it using the highly scalable Navier-Stokes spectralelement solver Nek5000 on small to moderate subsystems of the Mira supercomputer. In turn, this allows us to predict optimal algorithmic choices when using all of Mira. We also demonstrate that two-level checkpointing is significantly superior to single-level checkpointing when adjoining a large number of time integration steps. To our knowledge, this is the first time two-level checkpointing had been designed, implemented, tuned, and demonstrated on fluid dynamics codes at large scale of 50k+ cores.

  11. Entropy squeezing for a two-level atom in two-mode Raman coupled model with intrinsic decoherence

    International Nuclear Information System (INIS)

    Jian, Zhang; Bin, Shao; Jian, Zou

    2009-01-01

    In this paper, we investigate the entropy squeezing for a two-level atom interacting with two quantized fields through Raman coupling. We obtain the dynamical evolution of the total system under the influence of intrinsic decoherence when the two quantized fields are prepared in a two-mode squeezing vacuum state initially. The effects of the field squeezing factor, the two-level atomic transition frequency, the second field frequency and the intrinsic decoherence on the entropy squeezing are discussed. Without intrinsic decoherence, the increase of field squeezing factor can break the entropy squeezing. The two-level atomic transition frequency changes only the period of oscillation but not the strength of entropy squeezing. The influence of the second field frequency is complicated. With the intrinsic decoherence taken into consideration, the results show that the stronger the intrinsic decoherence is, the more quickly the entropy squeezing will disappear. The increase of the atomic transition frequency can hasten the disappearance of entropy squeezing. (classical areas of phenomenology)

  12. Induced absorption and stimulated emission in a driven two-level atom

    International Nuclear Information System (INIS)

    Mavroyannis, C.

    1992-01-01

    We have considered the induced processes that occur in a driven two-level atom, where a laser photon is absorbed and emitted by the ground and by the excited states of the atom, respectively. In the low-intensity limit of the laser field, the induced spectra arising when a laser photon is absorbed by the ground state of the atom consist of two peaks describing induced absorption and stimulated-emission processes, respectively, where the former prevails over the latter. Asymmetry of the spectral lines occurs at off-resonance and its extent depends on the detuning of the laser field. The physical. process where a laser photon is emitted by the excited state is the reverse of that arising from the absorption of a laser photon by the ground state of the atom. The former differs from the latter in that the emission of a laser photon by the excited state occurs in the low frequency regime and that the stimulated-emission process prevails over that of the induced absorption. In this case, amplification of ultrashort pulses is likely to occur without the need of population inversion between the optical transitions. The computed spectra are graphically presented and discussed. (author)

  13. A distributed monitoring system for photovoltaic arrays based on a two-level wireless sensor network

    Science.gov (United States)

    Su, F. P.; Chen, Z. C.; Zhou, H. F.; Wu, L. J.; Lin, P. J.; Cheng, S. Y.; Li, Y. F.

    2017-11-01

    In this paper, a distributed on-line monitoring system based on a two-level wireless sensor network (WSN) is proposed for real time status monitoring of photovoltaic (PV) arrays to support the fine management and maintenance of PV power plants. The system includes the sensing nodes installed on PV modules (PVM), sensing and routing nodes installed on combiner boxes of PV sub-arrays (PVA), a sink node and a data management centre (DMC) running on a host computer. The first level WSN is implemented by the low-cost wireless transceiver nRF24L01, and it is used to achieve single hop communication between the PVM nodes and their corresponding PVA nodes. The second level WSN is realized by the CC2530 based ZigBee network for multi-hop communication among PVA nodes and the sink node. The PVM nodes are used to monitor the PVM working voltage and backplane temperature, and they send the acquired data to their PVA node via the nRF24L01 based first level WSN. The PVA nodes are used to monitor the array voltage, PV string current and environment irradiance, and they send the acquired and received data to the DMC via the ZigBee based second level WSN. The DMC is designed using the MATLAB GUIDE and MySQL database. Laboratory experiment results show that the system can effectively acquire, display, store and manage the operating and environment parameters of PVA in real time.

  14. Domain decomposition method of stochastic PDEs: a two-level scalable preconditioner

    International Nuclear Information System (INIS)

    Subber, Waad; Sarkar, Abhijit

    2012-01-01

    For uncertainty quantification in many practical engineering problems, the stochastic finite element method (SFEM) may be computationally challenging. In SFEM, the size of the algebraic linear system grows rapidly with the spatial mesh resolution and the order of the stochastic dimension. In this paper, we describe a non-overlapping domain decomposition method, namely the iterative substructuring method to tackle the large-scale linear system arising in the SFEM. The SFEM is based on domain decomposition in the geometric space and a polynomial chaos expansion in the probabilistic space. In particular, a two-level scalable preconditioner is proposed for the iterative solver of the interface problem for the stochastic systems. The preconditioner is equipped with a coarse problem which globally connects the subdomains both in the geometric and probabilistic spaces via their corner nodes. This coarse problem propagates the information quickly across the subdomains leading to a scalable preconditioner. For numerical illustrations, a two-dimensional stochastic elliptic partial differential equation (SPDE) with spatially varying non-Gaussian random coefficients is considered. The numerical scalability of the the preconditioner is investigated with respect to the mesh size, subdomain size, fixed problem size per subdomain and order of polynomial chaos expansion. The numerical experiments are performed on a Linux cluster using MPI and PETSc parallel libraries.

  15. Vorticity, backscatter and counter-gradient transport predictions using two-level simulation of turbulent flows

    Science.gov (United States)

    Ranjan, R.; Menon, S.

    2018-04-01

    The two-level simulation (TLS) method evolves both the large-and the small-scale fields in a two-scale approach and has shown good predictive capabilities in both isotropic and wall-bounded high Reynolds number (Re) turbulent flows in the past. Sensitivity and ability of this modelling approach to predict fundamental features (such as backscatter, counter-gradient turbulent transport, small-scale vorticity, etc.) seen in high Re turbulent flows is assessed here by using two direct numerical simulation (DNS) datasets corresponding to a forced isotropic turbulence at Taylor's microscale-based Reynolds number Reλ ≈ 433 and a fully developed turbulent flow in a periodic channel at friction Reynolds number Reτ ≈ 1000. It is shown that TLS captures the dynamics of local co-/counter-gradient transport and backscatter at the requisite scales of interest. These observations are further confirmed through a posteriori investigation of the flow in a periodic channel at Reτ = 2000. The results reveal that the TLS method can capture both the large- and the small-scale flow physics in a consistent manner, and at a reduced overall cost when compared to the estimated DNS or wall-resolved LES cost.

  16. Robust Methods for Moderation Analysis with a Two-Level Regression Model.

    Science.gov (United States)

    Yang, Miao; Yuan, Ke-Hai

    2016-01-01

    Moderation analysis has many applications in social sciences. Most widely used estimation methods for moderation analysis assume that errors are normally distributed and homoscedastic. When these assumptions are not met, the results from a classical moderation analysis can be misleading. For more reliable moderation analysis, this article proposes two robust methods with a two-level regression model when the predictors do not contain measurement error. One method is based on maximum likelihood with Student's t distribution and the other is based on M-estimators with Huber-type weights. An algorithm for obtaining the robust estimators is developed. Consistent estimates of standard errors of the robust estimators are provided. The robust approaches are compared against normal-distribution-based maximum likelihood (NML) with respect to power and accuracy of parameter estimates through a simulation study. Results show that the robust approaches outperform NML under various distributional conditions. Application of the robust methods is illustrated through a real data example. An R program is developed and documented to facilitate the application of the robust methods.

  17. Entanglement Criteria of Two Two-Level Atoms Interacting with Two Coupled Modes

    Science.gov (United States)

    Baghshahi, Hamid Reza; Tavassoly, Mohammad Kazem; Faghihi, Mohammad Javad

    2015-08-01

    In this paper, we study the interaction between two two-level atoms and two coupled modes of a quantized radiation field in the form of parametric frequency converter injecting within an optical cavity enclosed by a medium with Kerr nonlinearity. It is demonstrated that, by applying the Bogoliubov-Valatin canonical transformation, the introduced model is reduced to a well-known form of the generalized Jaynes-Cummings model. Then, under particular initial conditions for the atoms (in a coherent superposition of its ground and upper states) and the fields (in a standard coherent state) which may be prepared, the time evolution of state vector of the entire system is analytically evaluated. In order to understand the degree of entanglement between subsystems (atom-field and atom-atom), the dynamics of entanglement through different measures, namely, von Neumann reduced entropy, concurrence and negativity is evaluated. In each case, the effects of Kerr nonlinearity and detuning parameter on the above measures are numerically analyzed, in detail. It is illustrated that the amount of entanglement can be tuned by choosing the evolved parameters, appropriately.

  18. Multilevel Converter by Cascading Two-Level Three-Phase Voltage Source Converter

    Directory of Open Access Journals (Sweden)

    Abdullrahman A. Al-Shamma’a

    2018-04-01

    Full Text Available This paper proposes a topology using isolated, cascaded multilevel voltage source converters (VSCs and employing two-winding magnetic elements for high-power applications. The proposed topology synthesizes 6 two-level, three-phase VSCs, so the power capability of the presented converter is six times the capability of each VSC module. The characteristics of the proposed topology are demonstrated through analyzing its current relationships, voltage relationships and power capability in detail. The power rating is equally shared among the VSC modules without the need for a sharing algorithm; thus, the converter operates as a single three-phase VSC. The comparative analysis with classical neutral-point clamped, flying capacitor and cascaded H-bridge exhibits the superior features of fewer insulated gate bipolar transistors (IGBTs, capacitor requirement and fewer diodes. To validate the theoretical performance of the proposed converter, it is simulated in a MATLAB/Simulink environment and the results are experimentally demonstrated using a laboratory prototype.

  19. Acoustic interactions between inversion symmetric and asymmetric two-level systems

    International Nuclear Information System (INIS)

    Churkin, A; Schechter, M; Barash, D

    2014-01-01

    Amorphous solids, as well as many disordered lattices, display remarkable universality in their low temperature acoustic properties. This universality is attributed to the attenuation of phonons by tunneling two-level systems (TLSs), facilitated by the interaction of the TLSs with the phonon field. TLS-phonon interaction also mediates effective TLS–TLS interactions, which dictates the existence of a glassy phase and its low energy properties. Here we consider KBr:CN, the archetypal disordered lattice showing universality. We calculate numerically, using conjugate gradients method, the effective TLS–TLS interactions for inversion symmetric (CN flips) and asymmetric (CN rotations) TLSs, in the absence and presence of disorder, in two and three dimensions. The observed dependence of the magnitude and spatial power law of the interaction on TLS symmetry, and its change with disorder, characterizes TLS–TLS interactions in disordered lattices in both extreme and moderate dilutions. Our results are in good agreement with the two-TLS model, recently introduced to explain long-standing questions regarding the quantitative universality of phonon attenuation and the energy scale of ≈1–3 K below which universality is observed. (paper)

  20. Generalized Heine–Stieltjes and Van Vleck polynomials associated with two-level, integrable BCS models

    International Nuclear Information System (INIS)

    Marquette, Ian; Links, Jon

    2012-01-01

    We study the Bethe ansatz/ordinary differential equation (BA/ODE) correspondence for Bethe ansatz equations that belong to a certain class of coupled, nonlinear, algebraic equations. Through this approach we numerically obtain the generalized Heine–Stieltjes and Van Vleck polynomials in the degenerate, two-level limit for four cases of integrable Bardeen–Cooper–Schrieffer (BCS) pairing models. These are the s-wave pairing model, the p + ip-wave pairing model, the p + ip pairing model coupled to a bosonic molecular pair degree of freedom, and a newly introduced extended d + id-wave pairing model with additional interactions. The zeros of the generalized Heine–Stieltjes polynomials provide solutions of the corresponding Bethe ansatz equations. We compare the roots of the ground states with curves obtained from the solution of a singular integral equation approximation, which allows for a characterization of ground-state phases in these systems. Our techniques also permit the computation of the roots of the excited states. These results illustrate how the BA/ODE correspondence can be used to provide new numerical methods to study a variety of integrable systems. (paper)

  1. Two-Level Evaluation on Sensor Interoperability of Features in Fingerprint Image Segmentation

    Directory of Open Access Journals (Sweden)

    Ya-Shuo Li

    2012-03-01

    Full Text Available Features used in fingerprint segmentation significantly affect the segmentation performance. Various features exhibit different discriminating abilities on fingerprint images derived from different sensors. One feature which has better discriminating ability on images derived from a certain sensor may not adapt to segment images derived from other sensors. This degrades the segmentation performance. This paper empirically analyzes the sensor interoperability problem of segmentation feature, which refers to the feature’s ability to adapt to the raw fingerprints captured by different sensors. To address this issue, this paper presents a two-level feature evaluation method, including the first level feature evaluation based on segmentation error rate and the second level feature evaluation based on decision tree. The proposed method is performed on a number of fingerprint databases which are obtained from various sensors. Experimental results show that the proposed method can effectively evaluate the sensor interoperability of features, and the features with good evaluation results acquire better segmentation accuracies of images originating from different sensors.

  2. Amplification without inversion, fast light and optical bistability in a duplicated two-level system

    International Nuclear Information System (INIS)

    Ebrahimi Zohravi, Lida; Vafafard, Azar; Mahmoudi, Mohammad

    2014-01-01

    The optical properties of a weak probe field in a duplicated two-level system are investigated in multi-photon resonance (MPR) condition and beyond it. It is shown that by changing the relative phase of applied fields, the absorption switches to the amplification without inversion in MPR condition. By applying the Floquet decomposition to the equations of motion beyond MPR condition, it is shown that the phase-dependent behavior is valid only in MPR condition. Moreover, it is demonstrated that the group velocity of light pulse can be controlled by the intensity of the applied fields and the gain-assisted superluminal light propagation (fast light) is obtained in this system. In addition, the optical bistability (OB) behavior of the system is studied beyond MPR condition. We apply an indirect incoherent pumping field to the system and it is found that the group velocity and OB behavior of the system can be controlled by the incoherent pumping rate. - Highlights: • We studied the optical properties of DTL system under MPR condition and beyond it. • By changing the relative phase, the absorption switches to the amplification without inversion in MPR condition. • The gain-assisted superluminal light propagation (fast light) is obtained in this system. • The optical bistability (OB) behavior of the system is studied beyond MPR condition. • The incoherent pumping rate has a major role in controlling the group velocity and OB behavior of the system

  3. Automatic QRS complex detection using two-level convolutional neural network.

    Science.gov (United States)

    Xiang, Yande; Lin, Zhitao; Meng, Jianyi

    2018-01-29

    The QRS complex is the most noticeable feature in the electrocardiogram (ECG) signal, therefore, its detection is critical for ECG signal analysis. The existing detection methods largely depend on hand-crafted manual features and parameters, which may introduce significant computational complexity, especially in the transform domains. In addition, fixed features and parameters are not suitable for detecting various kinds of QRS complexes under different circumstances. In this study, based on 1-D convolutional neural network (CNN), an accurate method for QRS complex detection is proposed. The CNN consists of object-level and part-level CNNs for extracting different grained ECG morphological features automatically. All the extracted morphological features are used by multi-layer perceptron (MLP) for QRS complex detection. Additionally, a simple ECG signal preprocessing technique which only contains difference operation in temporal domain is adopted. Based on the MIT-BIH arrhythmia (MIT-BIH-AR) database, the proposed detection method achieves overall sensitivity Sen = 99.77%, positive predictivity rate PPR = 99.91%, and detection error rate DER = 0.32%. In addition, the performance variation is performed according to different signal-to-noise ratio (SNR) values. An automatic QRS detection method using two-level 1-D CNN and simple signal preprocessing technique is proposed for QRS complex detection. Compared with the state-of-the-art QRS complex detection approaches, experimental results show that the proposed method acquires comparable accuracy.

  4. A Two-Level Task Scheduler on Multiple DSP System for OpenCL

    Directory of Open Access Journals (Sweden)

    Li Tian

    2014-04-01

    Full Text Available This paper addresses the problem that multiple DSP system does not support OpenCL programming. With the compiler, runtime, and the kernel scheduler proposed, an OpenCL application becomes portable not only between multiple CPU and GPU, but also between embedded multiple DSP systems. Firstly, the LLVM compiler was imported for source-to-source translation in which the translated source was supported by CCS. Secondly, two-level schedulers were proposed to support efficient OpenCL kernel execution. The DSP/BIOS is used to schedule system level tasks such as interrupts and drivers; however, the synchronization mechanism resulted in heavy overhead during task switching. So we designed an efficient second level scheduler especially for OpenCL kernel work-item scheduling. The context switch process utilizes the 8 functional units and cross path links which was superior to DSP/BIOS in the aspect of task switching. Finally, dynamic loading and software managed CACHE were redesigned for OpenCL running on multiple DSP system. We evaluated the performance using some common OpenCL kernels from NVIDIA, AMD, NAS, and Parboil benchmarks. Experimental results show that the DSP OpenCL can efficiently exploit the computing resource of multiple cores.

  5. Two-level image authentication by two-step phase-shifting interferometry and compressive sensing

    Science.gov (United States)

    Zhang, Xue; Meng, Xiangfeng; Yin, Yongkai; Yang, Xiulun; Wang, Yurong; Li, Xianye; Peng, Xiang; He, Wenqi; Dong, Guoyan; Chen, Hongyi

    2018-01-01

    A two-level image authentication method is proposed; the method is based on two-step phase-shifting interferometry, double random phase encoding, and compressive sensing (CS) theory, by which the certification image can be encoded into two interferograms. Through discrete wavelet transform (DWT), sparseness processing, Arnold transform, and data compression, two compressed signals can be generated and delivered to two different participants of the authentication system. Only the participant who possesses the first compressed signal attempts to pass the low-level authentication. The application of Orthogonal Match Pursuit CS algorithm reconstruction, inverse Arnold transform, inverse DWT, two-step phase-shifting wavefront reconstruction, and inverse Fresnel transform can result in the output of a remarkable peak in the central location of the nonlinear correlation coefficient distributions of the recovered image and the standard certification image. Then, the other participant, who possesses the second compressed signal, is authorized to carry out the high-level authentication. Therefore, both compressed signals are collected to reconstruct the original meaningful certification image with a high correlation coefficient. Theoretical analysis and numerical simulations verify the feasibility of the proposed method.

  6. Crises-induced intermittencies in a coherently driven system of two-level atoms

    International Nuclear Information System (INIS)

    Pando L, C.L.; Perez, G.; Cerdeira, H.A.

    1993-04-01

    We study the coherent dynamics of a thin layer of two-level atoms driven by an external coherent field and a phase conjugated mirror (PCM). Since the variables of the system are defined on the Bloch sphere, the third dimension is provided by the temporal modulation of the Rabi frequencies, which are induced by a PCM which reflects an electric field with a carrier frequency different from the incident one. We show that as the PCM gain coefficient is changed period doubling leading to chaos occurs. We find crises of attractor merging and attractor widening types related to homoclinic and heteroclinic tangencies respectively. For the attractor merging crises we find the critical exponent for the characteristic time of intermittency versus the control parameter which is given by the gain coefficient of the PCM. We show that during the crises of attractor widening type, another crisis due to attractor destruction occurs as the control parameter is changed. The latter is due to the collision of the old attractor with its basin boundary when a new attractor is created. This new attractor is stable only in a very small interval in the neighborhood of this second crisis. (author). 31 refs, 15 figs

  7. Dynamics of a quantum two-level system under the action of phase-diffusion field

    Energy Technology Data Exchange (ETDEWEB)

    Sobakinskaya, E.A. [Institute for Physics of Microstructures of RAS, Nizhny Novgorod, 603950 (Russian Federation); Pankratov, A.L., E-mail: alp@ipm.sci-nnov.ru [Institute for Physics of Microstructures of RAS, Nizhny Novgorod, 603950 (Russian Federation); Vaks, V.L. [Institute for Physics of Microstructures of RAS, Nizhny Novgorod, 603950 (Russian Federation)

    2012-01-09

    We study a behavior of quantum two-level system, interacting with noisy phase-diffusion field. The dynamics is shown to split into two regimes, determined by the coherence time of the phase-diffusion field. For both regimes we present a model of quantum system behavior and discuss possible applications of the obtained effect for spectroscopy. In particular, the obtained analytical formula for the macroscopic polarization demonstrates that the phase-diffusion field does not affect the absorption line shape, which opens up an intriguing possibility of noisy spectroscopy, based on broadband sources with Lorentzian line shape. -- Highlights: ► We study dynamics of quantum system interacting with noisy phase-diffusion field. ► At short times the phase-diffusion field induces polarization in the quantum system. ► At long times the noise leads to polarization decay and heating of a quantum system. ► Simple model of interaction is derived. ► Application of the described effects for spectroscopy is discussed.

  8. Bayesian feedback versus Markovian feedback in a two-level atom

    International Nuclear Information System (INIS)

    Wiseman, H.M.; Mancini, Stefano; Wang Jin

    2002-01-01

    We compare two different approaches to the control of the dynamics of a continuously monitored open quantum system. The first is Markovian feedback, as introduced in quantum optics by Wiseman and Milburn [Phys. Rev. Lett. 70, 548 (1993)]. The second is feedback based on an estimate of the system state, developed recently by Doherty and Jacobs [Phys. Rev. A 60, 2700 (1999)]. Here we choose to call it, for brevity, Bayesian feedback. For systems with nonlinear dynamics, we expect these two methods of feedback control to give markedly different results. The simplest possible nonlinear system is a driven and damped two-level atom, so we choose this as our model system. The monitoring is taken to be homodyne detection of the atomic fluorescence, and the control is by modulating the driving. The aim of the feedback in both cases is to stabilize the internal state of the atom as close as possible to an arbitrarily chosen pure state, in the presence of inefficient detection and other forms of decoherence. Our results (obtained without recourse to stochastic simulations) prove that Bayesian feedback is never inferior, and is usually superior, to Markovian feedback. However, it would be far more difficult to implement than Markovian feedback and it loses its superiority when obvious simplifying approximations are made. It is thus not clear which form of feedback would be better in the face of inevitable experimental imperfections

  9. Risk Analysis of a Two-Level Supply Chain Subject to Misplaced Inventory

    Directory of Open Access Journals (Sweden)

    Lijing Zhu

    2017-06-01

    Full Text Available Misplaced inventory is prevalent in retail stores and may lead to the overall poor performance of the supply chain. We explore the impact of misplaced inventory on a two-level supply chain, which consists of a risk-neutral supplier and a risk-averse retailer. The supplier decides the wholesale price to maximize her profit, whereas the retailer decides the order quantity to maximize his utility. Under the Conditional Value-at-Risk (CVaR criterion, we formulate the problem as a Stackelberg game model and obtain the equilibrium solutions in three cases: (i information asymmetry about inventory errors exists; (ii the retailer shares information about inventory errors with the supplier; and (iii in order to reduce misplaced inventory, the supply chain deploys Radio-Frequency Identification (RFID technology. The benefits of information sharing and RFID implementation are explored. A revenue and cost sharing contract is proposed to coordinate the supply chain and to allocate the cost savings from RFID implementation among supply chain participants. Finally, we provide managerial insights for risk-averse decision makers that are considering investing in the RFID technology.

  10. Testing a Quantum Heat Pump with a Two-Level Spin

    Directory of Open Access Journals (Sweden)

    Luis A. Correa

    2016-04-01

    Full Text Available Once in its non-equilibrium steady state, a nanoscale system coupled to several heat baths may be thought of as a “quantum heat pump”. Depending on the direction of its stationary heat flows, it may function as, e.g., a refrigerator or a heat transformer. These continuous heat devices can be arbitrarily complex multipartite systems, and yet, their working principle is always the same: they are made up of several elementary three-level stages operating in parallel. As a result, it is possible to devise external “black-box” testing strategies to learn about their functionality and performance regardless of any internal details. In particular, one such heat pump can be tested by coupling a two-level spin to one of its “contact transitions”. The steady state of this external probe contains information about the presence of heat leaks and internal dissipation in the device and, also, about the direction of its steady-state heat currents. Provided that the irreversibility of the heat pump is low, one can further estimate its coefficient of performance. These techniques may find applications in the emerging field of quantum thermal engineering, as they facilitate the diagnosis and design optimization of complex thermodynamic cycles.

  11. Seamless handoff in Mobile IP

    NARCIS (Netherlands)

    Karagiannis, Georgios; Heijenk, Geert; El Malki, Karim; Soliman, Hesham

    2001-01-01

    In a system and method for handing off a mobile node in a seamless manner in a wireless access network, procedures are implemented for allowing the mobile node to synchronize the handoff with a base node (e.g., a home agent) and a correspondent node. In this way, a seamless handoff may be achieved,

  12. Service fusion in mobile contexts

    OpenAIRE

    Shen, J. M.; O'Grady, Michael J.; O'Hare, G. M. P. (Greg M. P.)

    2010-01-01

    Service provision for mobile users poses several challenges for those managing enterprise information systems. Some of these are ubiquitous, for example, privacy and security. Others give rise to integration and interoperability issues. The agent paradigm, though offering potential in fixed networked scenarios, has not been seriously considered as a mechanism for incorporating mobile clients, primarily to their computational intractability on mobile devices. However, recent developments in ag...

  13. Comparison of Cervical Kinematics, Pain, and Functional Disability Between Single- and Two-level Anterior Cervical Discectomy and Fusion.

    Science.gov (United States)

    Chien, Andy; Lai, Dar-Ming; Wang, Shwu-Fen; Hsu, Wei-Li; Cheng, Chih-Hsiu; Wang, Jaw-Lin

    2016-08-01

    A prospective, time series design. The purpose of this study is two-fold: firstly, to investigate the impact of altered cervical alignment and range of motion (ROM) on patients' self-reported outcomes after anterior cervical discectomy and fusion (ACDF), and secondly, to comparatively differentiate the influence of single- and two-level ACDF on the cervical ROM and adjacent segmental kinematics up to 12-month postoperatively. ACDF is one of the most commonly employed surgical interventions to treat degenerative disc disease. However, there are limited in vivo data on the impact of ACDF on the cervical kinematics and its association with patient-reported clinical outcomes. Sixty-two patients (36 males; 55.63 ± 11.6 yrs) undergoing either a single- or consecutive two-level ACDF were recruited. The clinical outcomes were assessed with the Pain Visual Analogue Scale (VAS) and the Neck Disability Index (NDI). Radiological results included cervical lordosis, global C2-C7 ROM, ROM of the Functional Spinal Unit (FSU), and its adjacent segments. The outcome measures were collected preoperatively and then at 3, 6, and 12-month postoperatively. A significant reduction of both VAS and NDI was found for both groups from the preoperative to 3-month period (P < 0.01). Pearson correlation revealed no significant correlation between global ROM with neither VAS (P = 0.667) nor NDI (P = 0.531). A significant reduction of global ROM was identified for the two-level ACDF group at 12 months (P = 0.017) but not for the single-level group. A significant interaction effect was identified for the upper adjacent segment ROM (P = 0.024) but not at the lower adjacent segment. Current study utilized dynamic radiographs to comparatively evaluate the biomechanical impact of single- and two-level ACDF. The results highlighted that the two-level group demonstrated a greater reduction of global ROM coupled with an increased upper adjacent segmental compensatory motions that

  14. Mobile Learning Using Mobile Phones

    Science.gov (United States)

    Vicente, Paula

    2013-01-01

    The participation in mobile learning programs is conditioned by having/using mobile communication technology. Those who do not have or use such technology cannot participate in mobile learning programs. This study evaluates who are the most likely participants of mobile learning programs by examining the demographic profile and mobile phone usage…

  15. Scalable Fault-Tolerant Location Management Scheme for Mobile IP

    Directory of Open Access Journals (Sweden)

    JinHo Ahn

    2001-11-01

    Full Text Available As the number of mobile nodes registering with a network rapidly increases in Mobile IP, multiple mobility (home of foreign agents can be allocated to a network in order to improve performance and availability. Previous fault tolerant schemes (denoted by PRT schemes to mask failures of the mobility agents use passive replication techniques. However, they result in high failure-free latency during registration process if the number of mobility agents in the same network increases, and force each mobility agent to manage bindings of all the mobile nodes registering with its network. In this paper, we present a new fault-tolerant scheme (denoted by CML scheme using checkpointing and message logging techniques. The CML scheme achieves low failure-free latency even if the number of mobility agents in a network increases, and improves scalability to a large number of mobile nodes registering with each network compared with the PRT schemes. Additionally, the CML scheme allows each failed mobility agent to recover bindings of the mobile nodes registering with the mobility agent when it is repaired even if all the other mobility agents in the same network concurrently fail.

  16. Staging Mobilities / Designing Mobilities

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    2015-01-01

    , and systems 'hosting' these multiple and complex mobilities are designed and how they are staging these in terms of their physical layout. By analysing specific cases of ‘mobilities design’ related to the four modes of moving; Walk, Bike, Train, and Car, the book uncover important and until now neglected...... is more than movement between point A and B. It explores how the movement of people, goods, information, and signs influences human understandings of self, other and the built environment. Moving towards a new understanding of the relationship between movement, interaction and environments, the project...

  17. Mobile Code: The Future of the Internet

    Science.gov (United States)

    1999-01-01

    code ( mobile agents) to multiple proxies or servers " Customization " (e.g., re-formatting, filtering, metasearch) Information overload Diversified... Mobile code is necessary, rather than client-side code, since many customization features (such as information monitoring) do not work if the...economic foundation for Web sites, many Web sites earn money solely from advertisements . If these sites allow mobile agents to easily access the content

  18. Lambda-Based Data Processing Architecture for Two-Level Load Forecasting in Residential Buildings

    Directory of Open Access Journals (Sweden)

    Gde Dharma Nugraha

    2018-03-01

    Full Text Available Building energy management systems (BEMS have been intensively used to manage the electricity consumption of residential buildings more efficiently. However, the dynamic behavior of the occupants introduces uncertainty problems that affect the performance of the BEMS. To address this uncertainty problem, the BEMS may implement load forecasting as one of the BEMS modules. Load forecasting utilizes historical load data to compute model predictions for a specific time in the future. Recently, smart meters have been introduced to collect electricity consumption data. Smart meters not only capture aggregation data, but also individual data that is more frequently close to real-time. The processing of both smart meter data types for load forecasting can enhance the performance of the BEMS when confronted with uncertainty problems. The collection of smart meter data can be processed using a batch approach for short-term load forecasting, while the real-time smart meter data can be processed for very short-term load forecasting, which adjusts the short-term load forecasting to adapt to the dynamic behavior of the occupants. This approach requires different data processing techniques for aggregation and individual of smart meter data. In this paper, we propose Lambda-based data processing architecture to process the different types of smart meter data and implement the two-level load forecasting approach, which combines short-term and very short-term load forecasting techniques on top of our proposed data processing architecture. The proposed approach is expected to enhance the BEMS to address the uncertainty problem in order to process data in less time. Our experiment showed that the proposed approaches improved the accuracy by 7% compared to a typical BEMS with only one load forecasting technique, and had the lowest computation time when processing the smart meter data.

  19. Absorption spectrum of a two-level atom in a bad cavity with injected squeezed vacuum

    Science.gov (United States)

    Zhou, Peng; Swain, S.

    1996-02-01

    We study the absorption spectrum of a coherently driven two-level atom interacting with a resonant cavity mode which is coupled to a broadband squeezed vacuum through its input-output mirror in the bad cavity limit. We study the modification of the two-photon correlation strength of the injected squeezed vacuum inside the cavity, and show that the equations describing probe absorption in the cavity environment are formally identical to these in free space, but with modified parameters describing the squeezed vacuum. The two photon correlations induced by the squeezed vacuum are always weaker than in free space. We pay particular attention to the spectral behaviour at line centre in the region of intermediate trength driving intensities, where anomalous spectral features such as hole-burning and dispersive profiles are displayed. These unusual spectral features are very sensitive to the squeezing phase and the Rabi frequency of the driving field. We also derive the threshold value of the Rabi frequency which gives rise to the transparency of the probe beam at the driving frequency. When the Rabi frequency is less than the threshold value, the probe beam is absorbed, whilst the probe beam is amplified (without population inversion under certain conditions) when the Rabi frequency is larger than this threshold. The anomalous spectral features all take place in the vicinity of the critical point dividing the different dynamical regimes, probe absorption and amplification, of the atomic radiation. The physical origin of the strong amplification without population inversion, and the feasibility of observing it, are discussed.

  20. 14th International Conference on Practical Applications of Agents and Multi-Agent Systems : Special Sessions

    CERN Document Server

    Escalona, María; Corchuelo, Rafael; Mathieu, Philippe; Vale, Zita; Campbell, Andrew; Rossi, Silvia; Adam, Emmanuel; Jiménez-López, María; Navarro, Elena; Moreno, María

    2016-01-01

    PAAMS, the International Conference on Practical Applications of Agents and Multi-Agent Systems is an evolution of the International Workshop on Practical Applications of Agents and Multi-Agent Systems. PAAMS is an international yearly tribune to present, to discuss, and to disseminate the latest developments and the most important outcomes related to real-world applications. It provides a unique opportunity to bring multi-disciplinary experts, academics and practitioners together to exchange their experience in the development of Agents and Multi-Agent Systems. This volume presents the papers that have been accepted for the 2016 in the special sessions: Agents Behaviours and Artificial Markets (ABAM); Advances on Demand Response and Renewable Energy Sources in Agent Based Smart Grids (ADRESS); Agents and Mobile Devices (AM); Agent Methodologies for Intelligent Robotics Applications (AMIRA); Learning, Agents and Formal Languages (LAFLang); Multi-Agent Systems and Ambient Intelligence (MASMAI); Web Mining and ...

  1. Mobility management in mobile IP

    Science.gov (United States)

    Medidi, Sirisha; Golshani, Forouzan

    2002-07-01

    There is an emerging interest in integrating mobile wireless communication with the Internet based on the Ipv6 technology. Many issues introduced by the mobility of users arise when such an integration is attempted. This paper addresses the problem of mobility management, i.e., that of tracking the current IP addresses of mobile terminals and sustaining active IP connections as mobiles move. The paper presents some architectural and mobility management options for integrating wireless access to the Internet. We then present performance results for Mobile IPv4, route optimization and Mobile IPv6.

  2. Two-level cervical corpectomy-long-term follow-up reveals the high rate of material failure in patients, who received an anterior approach only.

    Science.gov (United States)

    Bayerl, Simon Heinrich; Pöhlmann, Florian; Finger, Tobias; Prinz, Vincent; Vajkoczy, Peter

    2018-06-18

    In contrast to a one-level cervical corpectomy, a multilevel corpectomy without posterior fusion is accompanied by a high material failure rate. So far, the adequate surgical technique for patients, who receive a two-level corpectomy, remains to be elucidated. The aim of this study was to determine the long-term clinical outcome of patients with cervical myelopathy, who underwent a two-level corpectomy. Outcome parameters of 21 patients, who received a two-level cervical corpectomy, were retrospectively analyzed concerning reoperations and outcome scores (VAS, Neck Disability Index (NDI), Nurick scale, modified Japanese Orthopaedic Association score (mJOAS), Short Form 36-item Health Survey Questionnaire (SF-36)). The failure rate was determined using postoperative radiographs. The choice over the surgical procedures was exercised by every surgeon individually. Therefore, a distinction between two groups was possible: (1) anterior group (ANT group) with a two-level corpectomy and a cervical plate, (2) anterior/posterior group (A/P group) with two-level corpectomy, cervical plate, and additional posterior fusion. Both groups benefitted from surgery concerning pain, disability, and myelopathy. While all patients of the A/P group showed no postoperative instability, one third of the patients of the ANT group exhibited instability and clinical deterioration. Thus, a revision surgery with secondary posterior fusion was needed. Furthermore, the ANT group had worse myelopathy scores (mJOAS ANT group  = 13.5 ± 2.5, mJOAS A/P group  = 15.7 ± 2.2). Patients with myelopathy, who receive a two-level cervical corpectomy, benefitted from surgical decompression. However, patients with a sole anterior approach demonstrated a very high rate of instability (33%) and clinical deterioration in a long-term follow-up. Therefore, we recommend to routinely perform an additional posterior fusion after two-level cervical corpectomy.

  3. [Alkylating agents].

    Science.gov (United States)

    Pourquier, Philippe

    2011-11-01

    With the approval of mechlorethamine by the FDA in 1949 for the treatment of hematologic malignancies, alkylating agents are the oldest class of anticancer agents. Even though their clinical use is far beyond the use of new targeted therapies, they still occupy a major place in specific indications and sometimes represent the unique option for the treatment of refractory diseases. Here, we are reviewing the major classes of alkylating agents and their mechanism of action, with a particular emphasis for the new generations of alkylating agents. As for most of the chemotherapeutic agents used in the clinic, these compounds are derived from natural sources. With a complex but original mechanism of action, they represent new interesting alternatives for the clinicians, especially for tumors that are resistant to conventional DNA damaging agents. We also briefly describe the different strategies that have been or are currently developed to potentiate the use of classical alkylating agents, especially the inhibition of pathways that are involved in the repair of DNA lesions induced by these agents. In this line, the development of PARP inhibitors is a striking example of the recent regain of interest towards the "old" alkylating agents.

  4. [Social mobilization].

    Science.gov (United States)

    Bop, C

    1990-04-01

    One of the principal recommendations from Alma Ata and the Bamako Initiative was the need for communities to take responsibility for their own health--a recommendation that still remains unmet and in need of reform in Africa because of the severe economic recession and lack of resources allocated for health care in the region. The mobilization of communities "is the opposite of passivity and submission." People must demystify the notion that health care is the exclusive right of health professionals and should realize that they themselves can bring about changes from the household to the village levels; community mobilization is an integral component of development planning. African societies have developed very centralized structures requiring changes that only their own communities can bring about. Because women remain the principal agents for the family's health they should be informed, about the multiple dimensions leading to good health care to enable them to provide the rest of the family with good nourishment and health care follow-up. Children are a vulnerable and important group that require preventive care. A UNICEF experiment in Senegal is training 10-13 year old school children to visit the parents of 5 children, inform them about vaccinating their children, and to follow-up on their activities with these "adopted families." The need for short and long-term IEC interventions in Africa are a priority and effective strategies must be found to reach the majority of the rural populations where all obstacles such as the lack of infrastructure and illiteracy exist. Mali has used traditional theatre "Koteba" to reach the rural populations on a variety of health issues such as oral rehydration and diarrhea as well as the Rural Audio Library (it used cassettes rather than books) to reach villagers in their own languages. The worst obstacle facing Africa today is the refusal of officials in power to allow people to manage their own lives, of which health is a

  5. Optimizing Water Exchange Rates and Rotational Mobility for High-Relaxivity of a Novel Gd-DO3A Derivative Complex Conjugated to Inulin as Macromolecular Contrast Agents for MRI.

    Science.gov (United States)

    Granato, Luigi; Vander Elst, Luce; Henoumont, Celine; Muller, Robert N; Laurent, Sophie

    2018-02-01

    Thanks to the understanding of the relationships between the residence lifetime τ M of the coordinated water molecules to macrocyclic Gd-complexes and the rotational mobility τ R of these structures, and according to the theory for paramagnetic relaxation, it is now possible to design macromolecular contrast agents with enhanced relaxivities by optimizing these two parameters through ligand structural modification. We succeeded in accelerating the water exchange rate by inducing steric compression around the water binding site, and by removing the amide function from the DOTA-AA ligand [1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid mono(p-aminoanilide)] (L) previously designed. This new ligand 10[2(1-oxo-1-p-propylthioureidophenylpropyl]-1,4,7,10-tetraazacyclodecane-1,4,7-tetraacetic acid (L 1 ) was then covalently conjugated to API [O-(aminopropyl)inulin] to get the complex API-(GdL 1 )x with intent to slow down the rotational correlation time (τ R ) of the macromolecular complex. The evaluation of the longitudinal relaxivity at different magnetic fields and the study of the 17 O-NMR at variable temperature of the low-molecular-weight compound (GdL 1 ) showed a slight decrease of the τ M value (τM310 = 331 ns vs. τM310 = 450 ns for the GdL complex). Consequently to the increase of the size of the API-(GdL 1 )x complex, the rotational correlation time becomes about 360 times longer compared to the monomeric GdL 1 complex (τ R  = 33,700 ps), which results in an enhanced proton relaxivity. © 2018 Wiley-VHCA AG, Zurich, Switzerland.

  6. Behavioural domain knowledge transfer for autonomous agents

    CSIR Research Space (South Africa)

    Rosman, Benjamin S

    2014-11-01

    Full Text Available , and Behavior Transfer in Autonomous Robots, AAAI 2014 Fall Symposium Series, 13-15 November 2014 Behavioural Domain Knowledge Transfer for Autonomous Agents Benjamin Rosman Mobile Intelligent Autonomous Systems Modelling and Digital Science Council...

  7. Mobile Election

    OpenAIRE

    Long, Elena; Lovitskii, Vladimir; Thrasher, Michael; Traynor, David

    2009-01-01

    Mobile phones have the potential of fostering political mobilisation. There is a significant political power in mobile technology. Like the Internet, mobile phones facilitate communication and rapid access to information. Compared to the Internet, however, mobile phone diffusion has reached a larger proportion of the population in most countries, and thus the impact of this new medium is conceivably greater. There are now more mobile phones in the UK than there are people (ave...

  8. Mobile Advertising

    OpenAIRE

    Alamuri, Lavanya

    2009-01-01

    The aim of this project was to get an understanding of how companies adopt mobile as an advertising medium. The literature review aided in framing a draft of the factors that affect mobile advertising adoption and possible forms of mobile advertising. Considering the scope of the thesis work, branding strategy, service costs, personalization and privacy and platform were considered to be the factors that could affect the mobile advertising adoption. A few possible forms on mobile device we...

  9. Entropy squeezing for a two-level atom in the Jaynes-Cummings model with an intensity-depend coupling

    Institute of Scientific and Technical Information of China (English)

    李春先; 方卯发

    2003-01-01

    We study the squeezing for a two-level atom in the Jaynes-Cummings model with intensity-dependent coupling using quantum information entropy, and examine the influences of the initial state of the system on the squeezed component number and direction of the information entropy squeezing. Our results show that, the squeezed component number depends on the atomic initial distribution angle, while the squeezed direction is determined by both the phases of the atom and the field for the information entropy squeezing. Quantum information entropy is shown to be a remarkable precision measure for atomic squeezing.

  10. Entropy as a measure of the noise extent in a two-level quantum feedback controlled system

    Institute of Scientific and Technical Information of China (English)

    Wang Tao-Bo; Fang Mao-Fa; Hu Yao-Hua

    2007-01-01

    By introducing the von Neumann entropy as a measure of the extent of noise, this paper discusses the entropy evolution in a two-level quantum feedback controlled system. The results show that the feedback control can induce the reduction of the degree of noise, and different control schemes exhibit different noise controlling ability, the extent of the reduction also related with the position of the target state on the Bloch sphere. It is shown that the evolution of entropy can provide a real time noise observation and a systematic guideline to make reasonable choice of control strategy.

  11. Comparison of PI and PR current controllers applied on two-level VSC-HVDC transmission system

    DEFF Research Database (Denmark)

    Manoloiu, A.; Pereria, H.A.; Teodorescu, Remus

    2015-01-01

    This paper analyzes differences between αβ and dq reference frames regarding the control of two-level VSC-HVDC current loop and dc-link voltage outer loop. In the first part, voltage feedforward effect is considered with PI and PR controllers. In the second part, the feedforward effect is removed...... and the PR gains are tuned to keep the dynamic performance. Also, the power feedforward is removed and the outer loop PI controller is tuned in order to maintain the system dynamic performance. The paper is completed with simulation results, which highlight the advantages of using PR controller....

  12. On the deviation from the sech2 superradiant emission law in a two-level atomic system

    International Nuclear Information System (INIS)

    Goncalves, A.E.

    1990-01-01

    The atomic superradiant emission is treated in the single particle mean field approximation. A single particle Hamiltonian, which represents a dressed two-level atom in a radiation field, can be obtained and it is verified that it describes the transient regime of the emission process. While the line shape emission for a bare atom follows the sech 2 law, for the dressed atom the line shape deviates appreciably from this law and it is verified that the deviation depends crucially on the ratio of the dynamic frequency shift to the transition frequency. This kind of deviation is observed in experimental results. (Author) [pt

  13. 2L-PCA: a two-level principal component analyzer for quantitative drug design and its applications.

    Science.gov (United States)

    Du, Qi-Shi; Wang, Shu-Qing; Xie, Neng-Zhong; Wang, Qing-Yan; Huang, Ri-Bo; Chou, Kuo-Chen

    2017-09-19

    A two-level principal component predictor (2L-PCA) was proposed based on the principal component analysis (PCA) approach. It can be used to quantitatively analyze various compounds and peptides about their functions or potentials to become useful drugs. One level is for dealing with the physicochemical properties of drug molecules, while the other level is for dealing with their structural fragments. The predictor has the self-learning and feedback features to automatically improve its accuracy. It is anticipated that 2L-PCA will become a very useful tool for timely providing various useful clues during the process of drug development.

  14. Mobility-induced persistent chimera states

    Science.gov (United States)

    Petrungaro, Gabriela; Uriu, Koichiro; Morelli, Luis G.

    2017-12-01

    We study the dynamics of mobile, locally coupled identical oscillators in the presence of coupling delays. We find different kinds of chimera states in which coherent in-phase and antiphase domains coexist with incoherent domains. These chimera states are dynamic and can persist for long times for intermediate mobility values. We discuss the mechanisms leading to the formation of these chimera states in different mobility regimes. This finding could be relevant for natural and technological systems composed of mobile communicating agents.

  15. Mobilities Design

    DEFF Research Database (Denmark)

    Lanng, Ditte Bendix; Wind, Simon; Jensen, Ole B.

    2017-01-01

    Mobilities comprise a large part of our world and everyday lives, and the mobilities spaces in which we travel are ubiquitous. Yet, ordinary mobilities spaces – such as parking lots, pedestrian tunnels, and road lay-bys – tend to be criticized as typologies that lack consideration for the people...... who use them and for their wider social, aesthetic, cultural, and ecological agency in the city. This is clearly not an unambiguous characterization. But from it follows an urgency to re-examine unheeded mobilities spaces and extend demands of their agency beyond standards of technical efficiency....... This article draws on the recent “mobilities turn” in social science to support such re-examination of mobilities spaces. In social-scientific mobilities research, mobilities are considered the departure point for understanding the socio-material world in which we live. Mobilities are regarded as far more than...

  16. SUBJECT «NUMBER SYSTEMS» IN TWO-LEVELED FORMAT PREPARATION TEACHERS OF MATHEMATICS

    Directory of Open Access Journals (Sweden)

    V. I. Igoshin

    2017-01-01

    Full Text Available The aim of this article is to analyze the format of a two-leveled training – bachelor and master – future teachers of mathematics from the point of view of the content of mathematical material, which is to develop prospective teachers of mathematics at those two levels, shaping their professional competence.Methods. The study involves the theoretical methods: the analysis of pedagogical and methodical literature, normative documents; historical, comparative and logical analysis of the content of pedagogical mathematical education; forecasting, planning and designing of two-leveled methodical system of training of future teachers of mathematics.Results and scientific novelty. The level differentiation of the higher education system requires developing the appropriate curricula for undergraduate and graduate programs. The fundamental principle must be the principle of continuity – the magister must continue to deepen and broaden knowledge and skills, along with competences acquired, developed and formed on the undergraduate level. From these positions, this paper examines the course «Number Systems» – the most important in terms of methodology course for future mathematics teachers, and shows what content should be filled with this course at the undergraduate level and the graduate level. At the undergraduate level it is proposed to study classical number systems – natural, integer, rational, real and complex. Further extensions of the number systems are studied at the graduate level. The theory of numeric systems is presented as a theory of algebraic systems, arising at the intersection of algebra and mathematical logic. Here we study algebras over a field, division algebra over a field, an alternative algebra with division over the field, Jordan algebra, Lie algebra. Comprehension of bases of the theory of algebras by the master of the «mathematical education» profile will promote more conscious

  17. Chemical Agents

    Science.gov (United States)

    ... CR) see Riot Control Agents Digitalis Distilled mustard (HD) see Sulfur mustard E Ethylene glycol F Fentanyls and other opioids H Hydrazine Hydrofluoric acid (hydrogen fluoride) Hydrogen chloride Hydrogen cyanide (AC) Hydrogen ...

  18. Mobile Workforce, Mobile Technology, Mobile Threats

    International Nuclear Information System (INIS)

    Garcia, J.

    2015-01-01

    Mobile technologies' introduction into the world of safeguards business processes such as inspection creates tremendous opportunity for novel approaches and could result in a number of improvements to such processes. Mobile applications are certainly the wave of the future. The success of the application ecosystems has shown that users want full fidelity, highly-usable, simple purpose applications with simple installation, quick responses and, of course, access to network resources at all times. But the counterpart to opportunity is risk, and the widespread adoption of mobile technologies requires a deep understanding of the threats and vulnerabilities inherent in mobile technologies. Modern mobile devices can be characterized as small computers. As such, the threats against computing infrastructure apply to mobile devices. Meanwhile, the attributes of mobile technology that make it such an obvious benefit over traditional computing platforms all have elements of risk: pervasive, always-on networking; diverse ecosystems; lack of centralized control; constantly shifting technological foundations; intense competition among competitors in the marketplace; the scale of the installation base (from millions to billions); and many more. This paper will explore the diverse and massive environment of mobile, the number of attackers and vast opportunities for compromise. The paper will explain how mobile devices prove valuable targets to both advanced and persistent attackers as well as less-skilled casual hackers. Organized crime, national intelligence agencies, corporate espionage are all part of the landscape. (author)

  19. Multi-Agent Software Engineering

    International Nuclear Information System (INIS)

    Mohamed, A.H.

    2014-01-01

    This paper proposed an alarm-monitoring system for people based on multi-agent using maps. The system monitors the users physical context using their mobile phone. The agents on the mobile phones are responsible for collecting, processing and sending data to the server. They can determine the parameters of their environment by sensors. The data are processed and sent to the server. On the other side, a set of agents on server can store this data and check the preconditions of the restrictions associated with the user, in order to trigger the appropriate alarms. These alarms are sent not only to the user who is alarmed to avoid the appeared restriction, but also to his supervisor. The proposed system is a general purpose alarm system that can be used in different critical application areas. It has been applied for monitoring the workers of radiation sites. However, these workers can do their activity tasks in the radiation environments safely

  20. A game theoretical approach for cooperative green mobile operators under roaming price consideration

    KAUST Repository

    Ghazzai, Hakim

    2015-09-11

    In this paper, we investigate the performance of a green mobile operator collaborating with other traditional mobile operators. Its goal is to minimize its CO2 emissions, maximize its profit or achieve or tradeoff between both objectives by offloading its users to neighbor networks and exploiting renewable energies. On the other hand, traditional mobile operators aim to maximize their profits by attracting the maximum number of roamed users. The problem is modeled as a two-level Stackelberg game and its equilibrium is derived. A green mobile operator level that determines how many users per each base station to offload to each neighbor network, and a non-green mobile operator level where operators focus on finding the optimal roaming price. Our simulation results show a significant saving in terms of CO2 emissions compared to the non-cooperation case and that roaming decision depends essentially on the availability of renewable energy in base station sites. © 2015 IEEE.

  1. Transverse magnetic field effect on the giant Goos–Hänchen shifts based on a degenerate two-level system

    Science.gov (United States)

    Nasehi, R.

    2018-06-01

    We study the effect of the Goos–Hänchen (GH) shifts through a cavity with degenerate two-level systems in the line of . For this purpose, we focus on the transverse magnetic field (TMF) in a Floquet frame to obtain the giant GH shifts. Physically, the collisional effects of TMF lead to increasing the population trapping in the ground state. However, we demonstrate that the population trapping generates the large negative or positive GH shifts and simultaneously switches from superluminal to subluminal (or vice versa). Also, we investigate the other optical properties such as the longitudinal magnetic field (LMF), which plays an important role in the control of the GH shifts and leads to the generation of new subsystems. In the next step, we evaluate the GH shifts beyond the multi-photon resonance condition by the control of TMF. Moreover, we compute the appearance of negative and positive GH shifts by setting the width of the incident Gaussian beams in the presence of a multi-photon resonance condition. Our results show that superluminal or subluminal light propagation can be simultaneously controlled by adjusting the rates of the TMF and LMF. The significant effects of these factors on the degenerate two-level systems provide different applications such as slow light, optical switches and quantum information storage.

  2. Political legitimacy and European monetary union: contracts, constitutionalism and the normative logic of two-level games

    Science.gov (United States)

    Bellamy, Richard; Weale, Albert

    2015-01-01

    ABSTRACT The crisis of the euro area has severely tested the political authority of the European Union (EU). The crisis raises questions of normative legitimacy both because the EU is a normative order and because the construction of economic and monetary union (EMU) rested upon a theory that stressed the normative value of the depoliticization of money. However, this theory neglected the normative logic of the two-level game implicit in EMU. It also neglected the need for an impartial and publically acceptable constitutional order to acknowledge reasonable disagreements. By contrast, we contend that any reconstruction of the EU's economic constitution has to pay attention to reconciling a European monetary order with the legitimacy of member state governance. The EU requires a two-level contract to meet this standard. Member states must treat each other as equals and be representative of and accountable to their citizens on an equitable basis. These criteria entail that the EU's political legitimacy requires a form of demoicracy that we call ‘republican intergovernmentalism’. Only rules that could be acceptable as the product of a political constitution among the peoples of Europe can ultimately meet the required standards of political legitimacy. Such a political constitution could be brought about through empowering national parliaments in EU decision-making. PMID:26924935

  3. Experimental study of magnetocaloric effect in the two-level quantum system KTm(MoO4)2

    Science.gov (United States)

    Tarasenko, R.; Tkáč, V.; Orendáčová, A.; Orendáč, M.; Valenta, J.; Sechovský, V.; Feher, A.

    2018-05-01

    KTm(MoO4)2 belongs to the family of binary alkaline rare-earth molybdates. This compound can be considered to be an almost ideal quantum two-level system at low temperatures. Magnetocaloric properties of KTm(MoO4)2 single crystals were investigated using specific heat and magnetization measurement in the magnetic field applied along the easy axis. Large conventional magnetocaloric effect (-ΔSM ≈ 10.3 J/(kg K)) was observed in the magnetic field of 5 T in a relatively wide temperature interval. The isothermal magnetic entropy change of about 8 J/(kgK) has been achieved already for the magnetic field of 2 T. Temperature dependence of the isothermal entropy change under different magnetic fields is in good agreement with theoretical predictions for a quantum two-level system with Δ ≈ 2.82 cm-1. Investigation of magnetocaloric properties of KTm(MoO4)2 suggests that the studied system can be considered as a good material for magnetic cooling at low temperatures.

  4. Optimal control of quantum gates and suppression of decoherence in a system of interacting two-level particles

    International Nuclear Information System (INIS)

    Grace, Matthew; Brif, Constantin; Rabitz, Herschel; Walmsley, Ian A; Kosut, Robert L; Lidar, Daniel A

    2007-01-01

    Methods of optimal control are applied to a model system of interacting two-level particles (e.g., spin-half atomic nuclei or electrons or two-level atoms) to produce high-fidelity quantum gates while simultaneously negating the detrimental effect of decoherence. One set of particles functions as the quantum information processor, whose evolution is controlled by a time-dependent external field. The other particles are not directly controlled and serve as an effective environment, coupling to which is the source of decoherence. The control objective is to generate target one- and two-qubit unitary gates in the presence of strong environmentally-induced decoherence and under physically motivated restrictions on the control field. The quantum-gate fidelity, expressed in terms of a novel state-independent distance measure, is maximized with respect to the control field using combined genetic and gradient algorithms. The resulting high-fidelity gates demonstrate the feasibility of precisely guiding the quantum evolution via optimal control, even when the system complexity is exacerbated by environmental coupling. It is found that the gate duration has an important effect on the control mechanism and resulting fidelity. An analysis of the sensitivity of the gate performance to random variations in the system parameters reveals a significant degree of robustness attained by the optimal control solutions

  5. Can centralized sanctioning promote trust in social dilemmas? A two-level trust game with incomplete information.

    Science.gov (United States)

    Wang, Raymond Yu; Ng, Cho Nam

    2015-01-01

    The problem of trust is a paradigmatic social dilemma. Previous literature has paid much academic attention on effects of peer punishment and altruistic third-party punishment on trust and human cooperation in dyadic interactions. However, the effects of centralized sanctioning institutions on decentralized reciprocity in hierarchical interactions remain to be further explored. This paper presents a formal two-level trust game with incomplete information which adds an authority as a strategic purposive actor into the traditional trust game. This model allows scholars to examine the problem of trust in more complex game theoretic configurations. The analysis demonstrates how the centralized institutions might change the dynamics of reciprocity between the trustor and the trustee. Findings suggest that the sequential equilibria of the newly proposed two-level model simultaneously include the risk of placing trust for the trustor and the temptation of short-term defection for the trustee. Moreover, they have shown that even a slight uncertainty about the type of the newly introduced authority might facilitate the establishment of trust and reciprocity in social dilemmas.

  6. Can centralized sanctioning promote trust in social dilemmas? A two-level trust game with incomplete information.

    Directory of Open Access Journals (Sweden)

    Raymond Yu Wang

    Full Text Available The problem of trust is a paradigmatic social dilemma. Previous literature has paid much academic attention on effects of peer punishment and altruistic third-party punishment on trust and human cooperation in dyadic interactions. However, the effects of centralized sanctioning institutions on decentralized reciprocity in hierarchical interactions remain to be further explored. This paper presents a formal two-level trust game with incomplete information which adds an authority as a strategic purposive actor into the traditional trust game. This model allows scholars to examine the problem of trust in more complex game theoretic configurations. The analysis demonstrates how the centralized institutions might change the dynamics of reciprocity between the trustor and the trustee. Findings suggest that the sequential equilibria of the newly proposed two-level model simultaneously include the risk of placing trust for the trustor and the temptation of short-term defection for the trustee. Moreover, they have shown that even a slight uncertainty about the type of the newly introduced authority might facilitate the establishment of trust and reciprocity in social dilemmas.

  7. An Economic Order Quantity Model with Completely Backordering and Nondecreasing Demand under Two-Level Trade Credit

    Directory of Open Access Journals (Sweden)

    Zohreh Molamohamadi

    2014-01-01

    Full Text Available In the traditional inventory system, it was implicitly assumed that the buyer pays to the seller as soon as he receives the items. In today’s competitive industry, however, the seller usually offers the buyer a delay period to settle the account of the goods. Not only the seller but also the buyer may apply trade credit as a strategic tool to stimulate his customers’ demands. This paper investigates the effects of the latter policy, two-level trade credit, on a retailer’s optimal ordering decisions within the economic order quantity framework and allowable shortages. Unlike most of the previous studies, the demand function of the customers is considered to increase with time. The objective of the retailer’s inventory model is to maximize the profit. The replenishment decisions optimally are obtained using genetic algorithm. Two special cases of the proposed model are discussed and the impacts of parameters on the decision variables are finally investigated. Numerical examples demonstrate the profitability of the developed two-level supply chain with backorder.

  8. Political legitimacy and European monetary union: contracts, constitutionalism and the normative logic of two-level games.

    Science.gov (United States)

    Bellamy, Richard; Weale, Albert

    2015-02-07

    The crisis of the euro area has severely tested the political authority of the European Union (EU). The crisis raises questions of normative legitimacy both because the EU is a normative order and because the construction of economic and monetary union (EMU) rested upon a theory that stressed the normative value of the depoliticization of money. However, this theory neglected the normative logic of the two-level game implicit in EMU. It also neglected the need for an impartial and publically acceptable constitutional order to acknowledge reasonable disagreements. By contrast, we contend that any reconstruction of the EU's economic constitution has to pay attention to reconciling a European monetary order with the legitimacy of member state governance. The EU requires a two-level contract to meet this standard. Member states must treat each other as equals and be representative of and accountable to their citizens on an equitable basis. These criteria entail that the EU's political legitimacy requires a form of demoi cracy that we call 'republican intergovernmentalism'. Only rules that could be acceptable as the product of a political constitution among the peoples of Europe can ultimately meet the required standards of political legitimacy. Such a political constitution could be brought about through empowering national parliaments in EU decision-making.

  9. Mobilities Design

    DEFF Research Database (Denmark)

    Jensen, Ole B.; Lanng, Ditte Bendix

    Contemporary society is marked and defined by the ways in which mobile goods, bodies, vehicles, objects, and data are organized, moved and staged. On the background of the ‘mobilities turn’ (e.g. Cresswell 2006, Urry 2007) this book articulates a new and emerging research field, namely that of ‘m......Contemporary society is marked and defined by the ways in which mobile goods, bodies, vehicles, objects, and data are organized, moved and staged. On the background of the ‘mobilities turn’ (e.g. Cresswell 2006, Urry 2007) this book articulates a new and emerging research field, namely...... that of ‘mobilities design’. The book revolves around the following research question: How are design decisions and interventions staging mobilities? It builds upon the Staging Mobilities model (Jensen 2013) in an explorative inquiry into the problems and potentials of the design of mobilities. The exchange value...

  10. Mobile economy

    OpenAIRE

    Turowski, Klaus

    2004-01-01

    Mobile economy : Transaktionen, Prozesse, Anwendungen und Dienste ; 4. Workshop Mobile Commerce, 02.-03. Februar 2004, Univ. Augsburg / K. Turowski ... (Hrsg.). - Bonn : Ges. für Informatik, 2004. - 189 S. : Ill., graph. Darst. - (GI-Edition : Proceedings ; 42)

  11. Mansion, A Distributed Multi-Agent System

    NARCIS (Netherlands)

    van t Noordende, G.; Brazier, F.M.; Tanenbaum, A.S.

    2001-01-01

    In this position summary we present work in progress on a worldwide, scalable multi-agent system, based on a paradigm of hyperlinked rooms. The framework offers facilities for managing distribution, security and mobility aspects for both active elements (agents) and passive elements (objects) in the

  12. Mobile marketing

    OpenAIRE

    Gause, Matěj

    2012-01-01

    The goal of bachelor's thesis on the theme "Mobile marketing" is to outline its development and why is this new phenomen so important for all modern companies around the world. The work is not about simple description of mobile marketing media but it vividly informs about the latest trends and news from the world of mobile apps and games. It presents the most successful mobile apps which registered more than billion downloads and from their unique characteristics it unveils great potential of...

  13. Mobile marketing

    OpenAIRE

    KLEČKOVÁ, Zuzana

    2013-01-01

    The main aim of this thesis was to provide a comprehensive overview of the mobile marketing and analyze selected campaigns of Czech mobile marketing in comparison to world successful campaigns. The research contained studying of available literature about the theme to gain general knowledge about the issue. The theoretical part of the thesis contains predominantly various definitions of mobile marketing and its tools, advantages of these tools and some information about Mobile Marketing Assoc...

  14. Staging Mobilities

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    and lived as people are “staging themselves” (from below). Staging mobilities is a dynamic process between “being staged” (for example, being stopped at traffic lights) and the “mobile staging” of interacting individuals (negotiating a passage on the pavement). Staging Mobilities is about the fact...

  15. Subversive Mobilities

    DEFF Research Database (Denmark)

    Thelle, Mikkel

    2013-01-01

    The article approaches mobility through a cultural history of urban conflict. Using a case of “The Copenhagen Trouble,“ a series of riots in the Danish capital around 1900, a space of subversive mobilities is delineated. These turn-of-the-century riots points to a new pattern of mobile gathering...

  16. Mobile Semiotics

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    2013-01-01

    This chapter aims to understand the mobile condition of contemporary life with a particular view to the signifying dimension of the environment and its ‘readability’. The chapter explores the potentials of semiotics and its relationship to the new mobilities literature. What takes place...... is a ‘mobile sense making’ where signs and materially situated meanings connect to the moving human body and thus create particular challenges and complexities of making sense of the world. The chapter includes notions of mobility systems and socio-technical networks in order to show how a ‘semiotic layer’ may...... work to afford or restrict mobile practices....

  17. The off-resonant aspects of decoherence and a critique of the two-level approximation

    International Nuclear Information System (INIS)

    Savran, Kerim; Hakioglu, T; Mese, E; Sevincli, Haldun

    2006-01-01

    Conditions in favour of a realistic multilevelled description of a decohering quantum system are examined. In this regard the first crucial observation is that the thermal effects, contrary to the conventional belief, play a minor role at low temperatures in the decoherence properties. The system-environment coupling and the environmental energy spectrum dominantly affect the decoherence. In particular, zero temperature quantum fluctuations or non-equilibrium sources can be present and influential on the decoherence rates in a wide energy range allowed by the spectrum of the environment. A crucial observation against the validity of the two-level approximation is that the decoherence rates are found to be dominated not by the long time resonant but the short time off-resonant processes. This observation is demonstrated in two stages. Firstly, our zero temperature numerical results reveal that the calculated short time decoherence rates are Gaussian-like (the time dependence of the density matrix is led by the second time derivative at t = 0). Exact analytical results are also permitted in the short time limit, which, consistent with our numerical results, reveal that this specific Gaussian-like behaviour is a property of the non-Markovian correlations in the environment. These Gaussian-like rates have no dependence on any spectral parameter (position and the width of the spectrum) except, in totality, the spectral area itself. The dependence on the spectral area is a power law. Furthermore, the Gaussian-like character at short times is independent of the number of levels (N), but the numerical value of the decoherence rates is a monotonic function of N. In this context, we demonstrate that leakage, as a characteristic multilevel effect, is dominated by the non-resonant processes. The long time behaviour of decoherence is also examined. Since our spectral model allows Markovian environmental correlations at long times, the decoherence rates in this regime become

  18. Mobile Lexicography

    DEFF Research Database (Denmark)

    Køhler Simonsen, Henrik

    2014-01-01

    Users are already mobile, but the question is to which extent knowledge-based dictionary apps are designed for the mobile user situation. The objective of this article is to analyse the characteristics of the mobile user situation and to look further into the stationary user situation and the mob......Users are already mobile, but the question is to which extent knowledge-based dictionary apps are designed for the mobile user situation. The objective of this article is to analyse the characteristics of the mobile user situation and to look further into the stationary user situation...... and the mobile user situation. The analysis is based on an empirical survey involving ten medical doctors and a monolingual app designed to support cognitive lexicographic functions, cf. (Tarp 2006:61-64). In test A the doctors looked up five medical terms while sitting down at a desk and in test B the doctors...

  19. Mobility Divides

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    Contemporary mobilities are cultural and social manifestations, and the mobile practices in the everyday life of billions of humans are re-configuring senses of place, self, other and relationships to the built environment. The way ‘mobile situations’ are staged in designed and built environments......’ in the everyday life and cast light on how design and ‘materialities of mobilites’ are creating differential mobilities across societies, social networks, and communities of practices.......Contemporary mobilities are cultural and social manifestations, and the mobile practices in the everyday life of billions of humans are re-configuring senses of place, self, other and relationships to the built environment. The way ‘mobile situations’ are staged in designed and built environments...

  20. Mobile Semiotics - signs and mobilities

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    a potential for mobilities studies if the awareness of seeing the environment as a semiotic layer and system can be sensitized to the insights of the ‘mobilities turn’. Empirically the paper tentatively explores the usefulness of a mobile semiotics approach to cases such as street signage, airport design...

  1. Analysis of Two-Level Support Systems with Time-Dependent Overflow - A Banking Application

    DEFF Research Database (Denmark)

    Barth, Wolfgang; Manitz, Michael; Stolletz, Raik

    2010-01-01

    In this paper, we analyze the performance of call centers of financial service providers with two levels of support and a time-dependent overflow mechanism. Waiting calls from the front-office queue flow over to the back office if a waiting-time limit is reached and at least one back-office agent...

  2. Cooperative Localization for Mobile Networks

    DEFF Research Database (Denmark)

    Cakmak, Burak; Urup, Daniel Nygaard; Meyer, Florian

    2016-01-01

    We propose a hybrid message passing method for distributed cooperative localization and tracking of mobile agents. Belief propagation and mean field message passing are employed for, respectively, the motion-related and measurementrelated part of the factor graph. Using a Gaussian belief approxim......We propose a hybrid message passing method for distributed cooperative localization and tracking of mobile agents. Belief propagation and mean field message passing are employed for, respectively, the motion-related and measurementrelated part of the factor graph. Using a Gaussian belief...

  3. School Emphasis on Academic Success: Exploring Changes in Science Performance in Norway between 2007 and 2011 Employing Two-Level SEM

    Science.gov (United States)

    Nilsen, Trude; Gustafsson, Jan-Eric

    2014-01-01

    We study whether changes in school emphasis on academic success (SEAS) and safe schools (SAFE) may explain the increased science performance in Norway between TIMSS 2007 and 2011. Two-level structural equation modelling (SEM) of merged TIMSS data was used to investigate whether changes in levels of SEAS and SAFE mediate the changes in science…

  4. Maintaining Limited-Range Connectivity Among Second-Order Agents

    Science.gov (United States)

    2016-07-07

    we consider ad-hoc networks of robotic agents with double integrator dynamics. For such networks, the connectivity maintenance problems are: (i) do...connectivity-maintaining controls in a distributed fashion? The proposed solution is based on three contributions. First, we define and characterize...hoc networks of mobile autonomous agents. This loose ter- minology refers to groups of robotic agents with limited mobility and communica- tion

  5. The Mobi-C cervical disc for one-level and two-level cervical disc replacement: a review of the literature

    Directory of Open Access Journals (Sweden)

    Alvin MD

    2014-11-01

    Full Text Available Matthew D Alvin,1,2 Thomas E Mroz1,3,41Cleveland Clinic Center for Spine Health, Cleveland Clinic, Cleveland, OH, USA; 2Case Western Reserve University School of Medicine, Cleveland, OH, USA; 3Cleveland Clinic Lerner College of Medicine, Cleveland, OH, USA; 4Department of Neurological Surgery, Cleveland Clinic, Cleveland, OH, USABackground: Cervical disc arthroplasty (CDA is a novel motion-preserving procedure that is an alternative to fusion. The Mobi-C disc prosthesis, one of many Food and Drug Administration (FDA-approved devices for CDA, is the only FDA-approved prosthesis for two-level CDA. Hence, it may allow for improved outcomes compared with multilevel fusion procedures.Purpose: To critically assess the available literature on CDA with the Mobi-C prosthesis, with a focus on two-level CDA.Methods: All clinical articles involving the Mobi-C disc prosthesis for CDA through September 1, 2014 were identified on Medline. Any paper that presented Mobi-C CDA clinical results was included. Study design, sample size, length of follow-up, use of statistical analysis, quality of life outcome scores, conflict of interest, and complications were recorded.Results: Fifteen studies were included that investigated Mobi-C CDA, only one of which was a level Ib randomized control trial. All studies included showed non-inferiority of one-level Mobi-C CDA to one-level anterior cervical discectomy and fusion (ACDF. Only one study analyzed outcomes of one-level versus two-level Mobi-C CDA, and only one study analyzed two-level Mobi-C CDA versus two-level ACDF. In comparison with other cervical disc prostheses, the Mobi-C prosthesis is associated with higher rates of heterotopic ossification (HO. Studies with conflicts of interest reported lower rates of HO. Adjacent segment degeneration or disease, along with other complications, were not assessed in most studies.Conclusion: One-level Mobi-C CDA is non-inferior, but not superior, to one-level ACDF for patients

  6. Lymphocyte mobilization by dextran sulfate in beagles

    International Nuclear Information System (INIS)

    Ragan, H.A.; Debban, K.H.

    1978-01-01

    Dogs manifesting 239 Pu-induced lymphopenia responded to the lymphocyte-mobilizing agent, dextran sulfate, to a degree similar to that observed in control dogs. No life-threatening increase in prothrombin times or hemorrhagic tendencies were observed

  7. Mobile Clouds

    DEFF Research Database (Denmark)

    Fitzek, Frank; Katz, Marcos

    A mobile cloud is a cooperative arrangement of dynamically connected communication nodes sharing opportunistic resources. In this book, authors provide a comprehensive and motivating overview of this rapidly emerging technology. The book explores how distributed resources can be shared by mobile...... users in very different ways and for various purposes. The book provides many stimulating examples of resource-sharing applications. Enabling technologies for mobile clouds are also discussed, highlighting the key role of network coding. Mobile clouds have the potential to enhance communications...... performance, improve utilization of resources and create flexible platforms to share resources in very novel ways. Energy efficient aspects of mobile clouds are discussed in detail, showing how being cooperative can bring mobile users significant energy saving. The book presents and discusses multiple...

  8. Mobilities Design

    DEFF Research Database (Denmark)

    Jensen, Ole B.; Lanng, Ditte Bendix; Wind, Simon

    2016-01-01

    In this paper, we identify the nexus between design (architecture, urban design, service design, etc.) and mobilities as a new and emerging research field. In this paper, we apply a “situational mobilities” perspective and take point of departure in the pragmatist question: “What design decisions...... and interventions affords this particular mobile situation?” The paper presents the contours of an emerging research agenda within mobilities research. The advent of “mobilities design” as an emerging research field points towards a critical interest in the material as well as practical consequences of contemporary......-making. The paper proposes that increased understanding of the material affordances facilitated through design provides important insight to planning and policymaking that at times might be in risk of becoming too detached from the everyday life of the mobile subject within contemporary mobilities landscapes....

  9. Supply chain model with price- and trade credit-sensitive demand under two-level permissible delay in payments

    Science.gov (United States)

    Giri, B. C.; Maiti, T.

    2013-05-01

    This article develops a single-manufacturer and single-retailer supply chain model under two-level permissible delay in payments when the manufacturer follows a lot-for-lot policy in response to the retailer's demand. The manufacturer offers a trade credit period to the retailer with the contract that the retailer must share a fraction of the profit earned during the trade credit period. On the other hand, the retailer provides his customer a partial trade credit which is less than that of the manufacturer. The demand at the retailer is assumed to be dependent on the selling price and the trade credit period offered to the customers. The average net profit of the supply chain is derived and an algorithm for finding the optimal solution is developed. Numerical examples are given to demonstrate the coordination policy of the supply chain and examine the sensitivity of key model-parameters.

  10. Inverse problem for a two-level medium with an inhomgeneously broadened transition in the field of a periodic wave

    International Nuclear Information System (INIS)

    Zabolotskii, A.A.

    1995-01-01

    The inverse problem is considered for a spectral problem, which is formally equivalent to a system of Bloch equations for an inhomogeneously broadened transition interacting with the electric field. Two cases are considered to demonstrate that, for any given frequency interval, one can determine the pulse of the shape which corresponds to the interaction with only this frequency interval. In the general case, the pulse shape is described by a nonlinear periodic wave. The first example is the resonance interaction of light with a gas of two-level atoms. The second example is interaction of a linearly polarized light with the molecular J-J transition, where J much-gt 1. In the latter case, the role of inhomogeneous broadening belongs to the frequency shift induced by the applied magnetic field. 10 refs

  11. Quantum correlations between each two-level system in a pair of atoms and general coherent fields

    Directory of Open Access Journals (Sweden)

    S. Abdel-Khalek

    Full Text Available The quantitative description of the quantum correlations between each two-level system in a two-atom system and the coherent fields initially defined in a coherent state in the framework of power-law potentials (PLPCSs is considered. Specifically, we consider two atoms locally interacting with PLPCSs and take into account the different terms of interactions, the entanglement and quantum discord are studied including the time-dependent coupling and photon transition effects. Using the monogamic relation between the entanglement of formation and quantum discord in tripartite systems, we show that the control and preservation of the different kinds of quantum correlations greatly benefit from the combination of the choice of the physical quantities. Finally, we explore the link between the dynamical behavior of quantum correlations and nonclassicality of the fields with and without atomic motion effect. Keywords: Quantum correlations, Monogamic relation, Coherent states, Power-law potentials, Wehrl entropy

  12. Cascaded two-photon nonlinearity in a one-dimensional waveguide with multiple two-level emitters

    Science.gov (United States)

    Roy, Dibyendu

    2013-01-01

    We propose and theoretically investigate a model to realize cascaded optical nonlinearity with few atoms and photons in one-dimension (1D). The optical nonlinearity in our system is mediated by resonant interactions of photons with two-level emitters, such as atoms or quantum dots in a 1D photonic waveguide. Multi-photon transmission in the waveguide is nonreciprocal when the emitters have different transition energies. Our theory provides a clear physical understanding of the origin of nonreciprocity in the presence of cascaded nonlinearity. We show how various two-photon nonlinear effects including spatial attraction and repulsion between photons, background fluorescence can be tuned by changing the number of emitters and the coupling between emitters (controlled by the separation). PMID:23948782

  13. Temporal Bell-type inequalities for two-level Rydberg atoms coupled to a high-Q resonator

    International Nuclear Information System (INIS)

    Huelga, S.F.; Marshall, T.W.; Santos, E.

    1996-01-01

    Following the strategy of showing specific quantum effects by means of the violation of a classical inequality, a pair of Bell-type inequalities is derived on the basis of certain additional assumptions, whose plausibility is discussed in detail. Such inequalities are violated by the quantum mechanical predictions for the interaction of a two-level Rydberg atom with a single mode sustained by a high-Q resonator. The experimental conditions required in order to show the existence of forbidden values, according to a hidden variables formalism, in a real experiment are analyzed for various initial field statistics. In particular, the revival dynamics expected for the interaction with a coherent field leads to classically forbidden values, which would indicate a purely quantum effect. copyright 1996 The American Physical Society

  14. Dynamics of a trapped two-level and three-level atom interacting with classical electromagnetic field

    International Nuclear Information System (INIS)

    Ray, Aditi

    2004-01-01

    The dynamics of a two-level atom driven by a single laser beam and three-level atom (Lambda configuration) irradiated by two laser beams are studied taking into account of the quantized center-of-mass motion of the atom. It is shown that the trapped atom system under appropriate resonance condition exhibits the large time-scale revivals when the index of the vibrational sideband responsible for the atomic electronic transition is greater than unity. The revival times are shown to be dependent on the initial number of vibrational excitations and the magnitude of the Lamb-Dicke parameter. The sub-Poissonian statistics in vibrational quantum number is observed at certain time intervals. The minimum time of interaction for which the squeezed states of motional quadrature are generated is found to be decreasing with the increase in the Lamb-Dicke parameter

  15. LCL filter design for three-phase two-level power factor correction using line impedance stabilization network

    DEFF Research Database (Denmark)

    Kouchaki, Alireza; Nymand, Morten

    2016-01-01

    This paper presents LCL filter design method for three-phase two-level power factor correction (PFC) using line impedance stabilization network (LISN). A straightforward LCL filter design along with variation in grid impedance is not simply achievable and inevitably lead to an iterative solution...... for filter. By introducing of fast power switches for PFC applications such as silicon-carbide, major current harmonics around the switching frequency drops in the region that LISN can actively provide well-defined impedance for measuring the harmonics (i.e. 9 kHz- 30MHz). Therefore, LISN can be replaced...... is derived using the current ripple behavior of converter-side inductor. The grid-side inductor is achieved as a function of LISN impedance to fulfill the grid regulation. To verify the analyses, an LCL filter is designed for a 5 kW SiC-based PFC. The simulation and experimental results support the validity...

  16. Loschmidt echo of a two-level qubit coupled to nonuniform anisotropic XY chains in a transverse field

    International Nuclear Information System (INIS)

    Zhong Ming; Tong Peiqing

    2011-01-01

    The Loschmidt echo (LE) of a central two-level qubit coupled to nonuniform anisotropic XY chains in a transverse field is studied. A general formula for LE is derived, which we use to discuss the influence of the criticality of the environment on LE. It is found that for the periodic XY chain the behaviors of LE in the vicinity of the critical points are similar to those of the uniform case. It is different for the disordered transverse Ising chains. For the aperiodic chains, if the surrounding systems are bounded chains, the behaviors of LE are similar to those of the uniform case, while if the surrounding systems are unbounded chains, they are similar to those of the disordered case.

  17. Dynamics of a Landau-Zener transitions in a two-level system driven by a dissipative environment

    Science.gov (United States)

    Ateuafack, M. E.; Diffo, J. T.; Fai, L. C.

    2016-02-01

    The paper investigates the effects of a two-level quantum system coupled to transversal and longitudinal dissipative environment. The time-dependent phase accumulation, LZ transition probability and entropy in the presence of fast-ohmic, sub-ohmic and super-ohmic quantum noise are derived. Analytical results are obtained in terms of temperature, dissipation strength, LZ parameter and bath cutoff frequency. The bath is observed to modify the standard occupation difference by a decaying random phase factor and also produces dephasing during the transfer of population. The dephasing characteristics or the initial non-zero decoherence rate are observed to increase in time with the bath temperature and depend on the system-bath coupling strength and cutoff frequency. These parameters are found to strongly affect the memory and thus tailor the coherence process of the system.

  18. Dynamics of a Landau–Zener transitions in a two-level system driven by a dissipative environment

    Energy Technology Data Exchange (ETDEWEB)

    Ateuafack, M.E., E-mail: esouamath@yahoo.fr [Mesoscopic and Multilayer Structures Laboratory, Department of Physics, Faculty of Science, University of Dschang (Cameroon); Diffo, J.T., E-mail: diffojaures@yahoo.com [Mesoscopic and Multilayer Structures Laboratory, Department of Physics, Faculty of Science, University of Dschang (Cameroon); Department of Physics, Higher Teachers' Training College, The University of Maroua, PO Box 55 Maroua (Cameroon); Fai, L.C., E-mail: corneliusfai@yahoo.fr [Mesoscopic and Multilayer Structures Laboratory, Department of Physics, Faculty of Science, University of Dschang (Cameroon)

    2016-02-15

    The paper investigates the effects of a two-level quantum system coupled to transversal and longitudinal dissipative environment. The time-dependent phase accumulation, LZ transition probability and entropy in the presence of fast-ohmic, sub-ohmic and super-ohmic quantum noise are derived. Analytical results are obtained in terms of temperature, dissipation strength, LZ parameter and bath cutoff frequency. The bath is observed to modify the standard occupation difference by a decaying random phase factor and also produces dephasing during the transfer of population. The dephasing characteristics or the initial non-zero decoherence rate are observed to increase in time with the bath temperature and depend on the system-bath coupling strength and cutoff frequency. These parameters are found to strongly affect the memory and thus tailor the coherence process of the system.

  19. Minimax approach problem with incomplete information for the two-level hierarchical discrete-time dynamical system

    Energy Technology Data Exchange (ETDEWEB)

    Shorikov, A. F. [Ural Federal University, 19 S. Mira, Ekaterinburg, 620002, Russia and Institute of Mathematics and Mechanics, Ural Division of Russian Academy of Sciences, 16 S. Kovalevskaya, Ekaterinburg, 620990 (Russian Federation)

    2014-11-18

    We consider a discrete-time dynamical system consisting of three controllable objects. The motions of all objects are given by the corresponding vector linear or convex discrete-time recurrent vector relations, and control system for its has two levels: basic (first or I level) that is dominating and subordinate level (second or II level) and both have different criterions of functioning and united a priori by determined informational and control connections defined in advance. For the dynamical system in question, we propose a mathematical formalization in the form of solving a multistep problem of two-level hierarchical minimax program control over the terminal approach process with incomplete information and give a general scheme for its solution.

  20. An acceleration of the characteristics by a space-angle two-level method using surface discontinuity factors

    Energy Technology Data Exchange (ETDEWEB)

    Grassi, G. [Commissariat a l' Energie Atomique, CEA de Saclay, DM2S/SERMA/LENR, 91191, Gif-sur-Yvette (France)

    2006-07-01

    We present a non-linear space-angle two-level acceleration scheme for the method of the characteristics (MOC). To the fine level on which the MOC transport calculation is performed, we associate a more coarsely discretized phase space in which a low-order problem is solved as an acceleration step. Cross sections on the coarse level are obtained by a flux-volume homogenisation technique, which entails the non-linearity of the acceleration. Discontinuity factors per surface are introduced as additional degrees of freedom on the coarse level in order to ensure the equivalence of the heterogeneous and the homogenised problem. After each fine transport iteration, a low-order transport problem is iteratively solved on the homogenised grid. The solution of this problem is then used to correct the angular moments of the flux resulting from the previous free transport sweep. Numerical tests for a given benchmark have been performed. Results are discussed. (authors)

  1. An acceleration of the characteristics by a space-angle two-level method using surface discontinuity factors

    International Nuclear Information System (INIS)

    Grassi, G.

    2006-01-01

    We present a non-linear space-angle two-level acceleration scheme for the method of the characteristics (MOC). To the fine level on which the MOC transport calculation is performed, we associate a more coarsely discretized phase space in which a low-order problem is solved as an acceleration step. Cross sections on the coarse level are obtained by a flux-volume homogenisation technique, which entails the non-linearity of the acceleration. Discontinuity factors per surface are introduced as additional degrees of freedom on the coarse level in order to ensure the equivalence of the heterogeneous and the homogenised problem. After each fine transport iteration, a low-order transport problem is iteratively solved on the homogenised grid. The solution of this problem is then used to correct the angular moments of the flux resulting from the previous free transport sweep. Numerical tests for a given benchmark have been performed. Results are discussed. (authors)

  2. Mobiles Robotersystem

    OpenAIRE

    Schmierer, G.; Wolf, A.

    1999-01-01

    DE 19816893 A UPAB: 20000203 NOVELTY - An optical and or acoustic noticeable advertising and or information carrier (10) is fixed permitting detachment in such a manner at the mobile platform (8), that the advertising and or information carrier does not impair the movability of the mobile platform. The advertising is provided at an exposed place on the mobile platform. USE - Advertising or information communication. ADVANTAGE - Advertising or information is imparted in prominent positioning w...

  3. Two-level anterior lumbar interbody fusion with percutaneous pedicle screw fixation. A minimum 3-year follow-up study

    International Nuclear Information System (INIS)

    Lee, Dong-Yeob; Lee, Sang-Ho; Maeng, Dae-Hyeon

    2010-01-01

    The clinical and radiological outcomes of two-level anterior lumbar interbody fusion (ALIF) with percutaneous pedicle screw fixation (PSF) were evaluated in 24 consecutive patients who underwent two level ALIF with percutaneous PSF for segmental instability and were followed up for more than 3 years. Clinical outcomes were assessed using a visual analogue scale (VAS) score and the Oswestry Disability Index (ODI). Sagittal alignment, bone union, and adjacent segment degeneration (ASD) were assessed using radiography and magnetic resonance imaging. The mean age of the patients at the time of operation was 56.3 years (range 39-70 years). Minor complications occurred in 2 patients in the perioperative period. At a mean follow-up duration of 39.4 months (range 36-42 months), VAS scores for back pain and leg pain, and ODI score decreased significantly (from 6.5, 6.8, and 46.9% to 3.0, 1.9, and 16.3%, respectively). Clinical success was achieved in 22 of the 24 patients. The mean segmental lordosis, whole lumbar lordosis, and sacral tilt significantly increased after surgery (from 25.1deg, 39.2deg, and 32.6deg to 32.9deg, 44.5deg, and 36.6deg, respectively). Solid fusion was achieved in 21 patients. ASD was found in 8 of the 24 patients. No patient underwent revision surgery due to nonunion or ASD. Two-level ALIF with percutaneous PSF yielded satisfactory clinical and radiological outcomes and could be a useful alternative to posterior fusion surgery. (author)

  4. Two-level anterior lumbar interbody fusion with percutaneous pedicle screw fixation. A minimum 3-year follow-up study

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong-Yeob; Lee, Sang-Ho; Maeng, Dae-Hyeon [Wooridul Spine Hospital, Seoul (Korea, Republic of)

    2010-08-15

    The clinical and radiological outcomes of two-level anterior lumbar interbody fusion (ALIF) with percutaneous pedicle screw fixation (PSF) were evaluated in 24 consecutive patients who underwent two level ALIF with percutaneous PSF for segmental instability and were followed up for more than 3 years. Clinical outcomes were assessed using a visual analogue scale (VAS) score and the Oswestry Disability Index (ODI). Sagittal alignment, bone union, and adjacent segment degeneration (ASD) were assessed using radiography and magnetic resonance imaging. The mean age of the patients at the time of operation was 56.3 years (range 39-70 years). Minor complications occurred in 2 patients in the perioperative period. At a mean follow-up duration of 39.4 months (range 36-42 months), VAS scores for back pain and leg pain, and ODI score decreased significantly (from 6.5, 6.8, and 46.9% to 3.0, 1.9, and 16.3%, respectively). Clinical success was achieved in 22 of the 24 patients. The mean segmental lordosis, whole lumbar lordosis, and sacral tilt significantly increased after surgery (from 25.1deg, 39.2deg, and 32.6deg to 32.9deg, 44.5deg, and 36.6deg, respectively). Solid fusion was achieved in 21 patients. ASD was found in 8 of the 24 patients. No patient underwent revision surgery due to nonunion or ASD. Two-level ALIF with percutaneous PSF yielded satisfactory clinical and radiological outcomes and could be a useful alternative to posterior fusion surgery. (author)

  5. Mobil marketing

    OpenAIRE

    Engelová, Kateřina

    2006-01-01

    Mobil marketing - reklama a podpora prodeje prostřednictvím mobilních telefonů. Technologické a kulturní předpoklady vzniku tohoto odvětví. Mobil marketing a marketingový mix, možnosti synergie. Nástroje mobil marketingu - reklamní SMS a MMS, lokační služby, soutěže, ankety a hlasování, věrnostní systémy, mobilní obsah. Subjekty mobil marketingu. M-komerce. Využití pro podnikové aplikace.

  6. [Biological agents].

    Science.gov (United States)

    Amano, Koichi

    2009-03-01

    There are two types of biological agents for the treatment of rheumatoid arthritis (RA); monoclonal antibodies and recombinant proteins. Among the latter, etanercept, a recombinant fusion protein of soluble TNF receptor and IgG was approved in 2005 in Japan. The post-marketing surveillance of 13,894 RA patients revealed the efficacy and safety profiles of etanercept in the Japanese population, as well as overseas studies. Abatacept, a recombinant fusion protein of CTLA4 and IgG, is another biological agent for RA. Two clinical trials disclosed the efficacy of abatacept for difficult-to-treat patients: the AIM for MTX-resistant cases and the ATTAIN for patients who are resistant to anti-TNF. The ATTEST trial suggested abatacept might have more acceptable safety profile than infliximab. These biologics are also promising for the treatment of RA for not only relieving clinical symptoms and signs but retarding structural damage.

  7. Mobile phones and mobile communication

    DEFF Research Database (Denmark)

    Ling, Richard; Donner, Jonathan

    With staggering swiftness, the mobile phone has become a fixture of daily life in almost every society on earth. In 2007, the world had over 3 billion mobile subscriptions. Prosperous nations boast of having more subscriptions than people. In the developing world, hundreds of millions of people who...... could never afford a landline telephone now have a mobile number of their own. With a mobile in our hand many of us feel safer, more productive, and more connected to loved ones, but perhaps also more distracted and less involved with things happening immediately around us. Written by two leading...... researchers in the field, this volume presents an overview of the mobile telephone as a social and cultural phenomenon. Research is summarized and made accessible though detailed descriptions of ten mobile users from around the world. These illustrate popular debates, as well as deeper social forces at work...

  8. Elckerlyc goes mobile - Enabling natural interaction in mobile user interfaces

    NARCIS (Netherlands)

    Klaassen, Randy; Hendrix, Jordi; Reidsma, Dennis; op den Akker, Hendrikus J.A.; van Dijk, Elisabeth M.A.G.; op den Akker, Harm

    The fast growth of computational resources and speech technology available on mobile devices makes it possible to entertain users of these devices in having a natural dialogue with service systems. These systems are sometimes perceived as social agents and this can be supported by presenting them on

  9. Elckerlyc goes mobile: enabling technology for ECAs in mobile applications

    NARCIS (Netherlands)

    Klaassen, Randy; Hendrix, J.; Reidsma, Dennis; op den Akker, Hendrikus J.A.

    2012-01-01

    The fast growth of computational resources and speech technology available on mobile devices makes it pos- sible for users of these devices to interact with service sys- tems through natural dialogue. These systems are sometimes perceived as social agents and presented by means of an animated

  10. An Agent Framework of Tourism Recommender System

    Directory of Open Access Journals (Sweden)

    Jia Zhi Yang

    2016-01-01

    Full Text Available This paper proposes the development of an Agent framework for tourism recommender system. The recommender system can be featured as an online web application which is capable of generating a personalized list of preference attractions for tourists. Traditional technologies of classical recommender system application domains, such as collaborative filtering, content-based filtering and content-based filtering are effectively adopted in the framework. In the framework they are constructed as Agents that can generate recommendations respectively. Recommender Agent can generate recommender information by integrating the recommendations of Content-based Agent, collaborative filtering-based Agent and constraint-based Agent. In order to make the performance more effective, linear combination method of data fusion is applied. User interface is provided by the tourist Agent in form of webpages and mobile app.

  11. 2015 Special Sessions of the 13th International Conference on Practical Applications of Agents and Multi-Agent Systems

    CERN Document Server

    Hernández, Josefa; Mathieu, Philippe; Campbell, Andrew; Fernández-Caballero, Antonio; Moreno, María; Julián, Vicente; Alonso-Betanzos, Amparo; Jiménez-López, María; Botti, Vicente; Trends in Practical Applications of Agents, Multi-Agent Systems and Sustainability : the PAAMS Collection

    2015-01-01

    This volume presents the papers that have been accepted for the 2015 special sessions of the 13th International Conference on Practical Applications of Agents and Multi-Agent Systems, held at University of Salamanca, Spain, at 3rd-5th June, 2015: Agents Behaviours and Artificial Markets (ABAM); Agents and Mobile Devices (AM); Multi-Agent Systems and Ambient Intelligence (MASMAI); Web Mining and Recommender systems (WebMiRes); Learning, Agents and Formal Languages (LAFLang); Agent-based Modeling of Sustainable Behavior and Green Economies (AMSBGE); Emotional Software Agents (SSESA) and Intelligent Educational Systems (SSIES). The volume also includes the paper accepted for the Doctoral Consortium in PAAMS 2015. PAAMS, the International Conference on Practical Applications of Agents and Multi-Agent Systems is an evolution of the International Workshop on Practical Applications of Agents and Multi-Agent Systems. PAAMS is an international yearly tribune to present, to discuss, and to disseminate the latest develo...

  12. Urban Mobility

    DEFF Research Database (Denmark)

    2017-01-01

    This anthology is the proceedings publication from the 2015 NAF Symposium in Malmö, Sweden. The aim of the 2015 NAF Symposium “Urban Mobility – Architectures, Geographies and Social Space” was to facilitate a cross-disciplinary discussion on urban mobility in which the juxtaposition of different...

  13. Urban Mobility

    DEFF Research Database (Denmark)

    2017-01-01

    This anthology is the proceedings publication from the 2015 NAF Symposium in Malmö, Sweden. The aim of the 2015 NAF Symposium “Urban Mobility – Architectures, Geographies and Social Space” was to facilitate a cross-disciplinary discussion on urban mobility in which the juxtaposition of different ...

  14. Mobile phone

    International Nuclear Information System (INIS)

    2009-01-01

    Almost the entire Norwegian population has cell phone. The usefulness of the cell phone is great, but can use a mobile phone to health or discomfort? How can exposure be reduced? NRPA follows research and provides advice on mobile phone use. (AG)

  15. Intensive mobilities

    DEFF Research Database (Denmark)

    Vannini, Phillip; Bissell, David; Jensen, Ole B.

    with fieldwork conducted in Canada, Denmark and Australia to develop our understanding of the experiential politics of long distance workers. Rather than focusing on the extensive dimensions of mobilities that are implicated in patterns and trends, our paper turns to the intensive dimensions of this experience......This paper explores the intensities of long distance commuting journeys as a way of exploring how bodily sensibilities are being changed by the mobilities that they undertake. The context of this paper is that many people are travelling further to work than ever before owing to a variety of factors...... which relate to transport, housing and employment. Yet we argue that the experiential dimensions of long distance mobilities have not received the attention that they deserve within geographical research on mobilities. This paper combines ideas from mobilities research and contemporary social theory...

  16. Designing Mobilities

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    are often still not engaged with in a sufficiently manner. Often social sciences keep distance to the physical and material as if the social was still to be understood as a realm separate of technology, architecture, and design (for a critique of this see; Latour 2005 and Urry 2000). This paper takes point......Within the so-called ‘mobilities turn’ (Adey 2010; Cresswell 2006; Urry 2007) much research has taken place during the last decade bringing mobilities into the centre of sociological analysis. However, the materiality and spatiality of artefacts, infrastructures, and sites hosting mobilities...... of departure in the sociological perspective termed ‘Staging Mobilities’ (Jensen 2013a) and utilizes this as an analytical frame for exploring cases of mobility design. The paper put focus on how the material shape, design and architectures of technologies, spaces and sites influence mobilities practices...

  17. Mobile probes

    DEFF Research Database (Denmark)

    Ørngreen, Rikke; Jørgensen, Anna Neustrup; Noesgaard, Signe Schack

    2016-01-01

    A project investigating the effectiveness of a collection of online resources for teachers' professional development used mobile probes as a data collection method. Teachers received questions and tasks on their mobile in a dialogic manner while in their everyday context as opposed...... to in an interview. This method provided valuable insight into the contextual use, i.e. how did the online resource transfer to the work practice. However, the research team also found that mobile probes may provide the scaffolding necessary for individual and peer learning at a very local (intra-school) community...... level. This paper is an initial investigation of how the mobile probes process proved to engage teachers in their efforts to improve teaching. It also highlights some of the barriers emerging when applying mobile probes as a scaffold for learning....

  18. Mobilities Design

    DEFF Research Database (Denmark)

    Jensen, Ole B.; Lanng, Ditte Bendix

    2016-01-01

    of life’ for billions of people in the everyday life. This paper is structured in three parts. After the general introduction we present the mobilities theory perspective of ‘staging mobilities’ and connects this to the empirical phenomenon of parking lots and their design. The paper ends in section three......Contemporary society is marked and defined by the ways in which mobile goods, bodies, vehicles, objects, and data are organized, moved and staged. On the backgound of the ‘mobilities turn’ (for short review paper on this see; Sheller 2011, Vannini 2010) this paper proposes a further development...... of the perspective in the direction of a material and design oriented turn. In order to fulfill this purpose we articulate a new and emerging research field, namely that of ‘mobilities design’. In our understanding time has come to articulate ‘Mobilities Design’ as a dedicated research field in and of its own...

  19. Mobile Lexicography

    DEFF Research Database (Denmark)

    Køhler Simonsen, Henrik

    2015-01-01

    are already mobile – but lexicography is not yet fully ready for the mobile challenge, mobile users and mobile user situations. The article is based on empirical data from two surveys comprising 10 medical doctors, who were asked to look up five medical substances with the medical dictionary app Medicin.......dk and five students, who were asked to look up five terms with the dictionary app Gyldendal Engelsk-Dansk. The empirical data comprise approximately 15 hours of recordings of user behavior, think-aloud data and interview data. The data indicate that there is still much to be done in this area...... and that lexicographic innovation is needed. A new type of users, new user situations and new access methods call for new lexicographic solutions, and this article proposes a six-pointed hexagram model, which can be used during dictionary app design to lexicographically calibrate the six dimensions in mobile...

  20. Restricted Mobilities

    DEFF Research Database (Denmark)

    Nielsen, Mette; Lassen, Claus

    2012-01-01

    communities and shopping centres through mobility lenses. The article shows how different mobility systems enable and restrict the public access to private-public spaces, and it points out that proprietary communities create an unequal potential for human movement and access in the city. The main argument......Privatisation of public spaces in the contemporary city has increased during the last decades but only few studies have approached this field from a mobility perspective. Therefore the article seeks to rectify this by exploring two Australian examples of private spaces in the city; gated...... and stratification mechanisms. In conclusion the article therefore suggests that future urban research and planning also needs a mobile understanding of spaces in the cities and how different mobility systems play an important role to sustain the exclusiveness that often characterises the private/public spaces...

  1. Mobility Work

    DEFF Research Database (Denmark)

    Bardram, Jakob Eyvind; Bossen, Claus

    2005-01-01

    We posit the concept of Mobility Work to describe efforts of moving about people and things as part of accomplishing tasks. Mobility work can be seen as a spatial parallel to the concept of articulation work proposed by the sociologist Anselm Strauss. Articulation work describes efforts of coordi....../or resources. To accomplish their work, actors have to make the right configuration of these four aspects emerge.......We posit the concept of Mobility Work to describe efforts of moving about people and things as part of accomplishing tasks. Mobility work can be seen as a spatial parallel to the concept of articulation work proposed by the sociologist Anselm Strauss. Articulation work describes efforts...... of coordination necessary in cooperative work, but focuses, we argue, mainly on the temporal aspects of cooperative work. As a supplement, the concept of mobility work focuses on the spatial aspects of cooperative work. Whereas actors seek to diminish the amount of articulation work needed in collaboration...

  2. Mobility Challenges

    DEFF Research Database (Denmark)

    Jensen, Ole B.; Lassen, Claus

    2011-01-01

    This article takes point of departure in the challenges to understand the importance of contemporary mobility. The approach advocated is a cross-disciplinary one drawing on sociology, geography, urban planning and design, and cultural studies. As such the perspective is to be seen as a part...... of the so-called ‘mobility turn’ within social science. The perspective is illustrative for the research efforts at the Centre for Mobility and Urban Studies (C-MUS), Aalborg University. The article presents the contours of a theoretical perspective meeting the challenges to research into contemporary urban...... mobilities. In particular the article discusses 1) the physical city, its infrastructures and technological hardware/software, 2) policies and planning strategies for urban mobility and 3) the lived everyday life in the city and the region....

  3. Trading Agents

    CERN Document Server

    Wellman, Michael

    2011-01-01

    Automated trading in electronic markets is one of the most common and consequential applications of autonomous software agents. Design of effective trading strategies requires thorough understanding of how market mechanisms operate, and appreciation of strategic issues that commonly manifest in trading scenarios. Drawing on research in auction theory and artificial intelligence, this book presents core principles of strategic reasoning that apply to market situations. The author illustrates trading strategy choices through examples of concrete market environments, such as eBay, as well as abst

  4. An agent architecture with on-line learning of both procedural and declarative knowledge

    Energy Technology Data Exchange (ETDEWEB)

    Sun, R.; Peterson, T.; Merrill, E. [Univ. of Alabama, Tuscaloosa, AL (United States)

    1996-12-31

    In order to develop versatile cognitive agents that learn in situated contexts and generalize resulting knowledge to different environments, we explore the possibility of learning both declarative and procedural knowledge in a hybrid connectionist architecture. The architecture is based on the two-level idea proposed earlier by the author. Declarative knowledge is represented symbolically, while procedural knowledge is represented subsymbolically. The architecture integrates reactive procedures, rules, learning, and decision-making in a unified framework, and structures different learning components (including Q-learning and rule induction) in a synergistic way to perform on-line and integrated learning.

  5. The 5-year cost-effectiveness of two-level anterior cervical discectomy and fusion or cervical disc replacement: a Markov analysis.

    Science.gov (United States)

    Overley, Samuel C; McAnany, Steven J; Brochin, Robert L; Kim, Jun S; Merrill, Robert K; Qureshi, Sheeraz A

    2018-01-01

    Anterior cervical discectomy and fusion (ACDF) and cervical disc replacement (CDR) are both acceptable surgical options for the treatment of cervical myelopathy and radiculopathy. To date, there are limited economic analyses assessing the relative cost-effectiveness of two-level ACDF versus CDR. The purpose of this study was to determine the 5-year cost-effectiveness of two-level ACDF versus CDR. The study design is a secondary analysis of prospectively collected data. Patients in the Prestige cervical disc investigational device exemption (IDE) study who underwent either a two-level CDR or a two-level ACDF were included in the study. The outcome measures were cost and quality-adjusted life years (QALYs). A Markov state-transition model was used to evaluate data from the two-level Prestige cervical disc IDE study. Data from the 36-item Short Form Health Survey were converted into utilities using the short form (SF)-6D algorithm. Costs were calculated from the payer perspective. QALYs were used to represent effectiveness. A probabilistic sensitivity analysis (PSA) was performed using a Monte Carlo simulation. The base-case analysis, assuming a 40-year-old person who failed appropriate conservative care, generated a 5-year cost of $130,417 for CDR and $116,717 for ACDF. Cervical disc replacement and ACDF generated 3.45 and 3.23 QALYs, respectively. The incremental cost-effectiveness ratio (ICER) was calculated to be $62,337/QALY for CDR. The Monte Carlo simulation validated the base-case scenario. Cervical disc replacement had an average cost of $130,445 (confidence interval [CI]: $108,395-$152,761) with an average effectiveness of 3.46 (CI: 3.05-3.83). Anterior cervical discectomy and fusion had an average cost of $116,595 (CI: $95,439-$137,937) and an average effectiveness of 3.23 (CI: 2.84-3.59). The ICER was calculated at $62,133/QALY with respect to CDR. Using a $100,000/QALY willingness to pay (WTP), CDR is the more cost-effective strategy and would be selected

  6. Sustainable Mobility

    DEFF Research Database (Denmark)

    Kjærulff, Aslak Aamot

    This paper combines strands of mobilities theory and planning theory, and develops a qualitative approach to look across emerging planning practices. By actively following 8 Danish urban and transport planners, over the course of 2 years, we learn how their practices have changed, inspired...... by mobility management, a concept aiming to reduce carbon emissions from transportation in western societies. The article focuses on how municipal planners formulate the role of mobility management activities organized around private companies, and how their practices are connected to wider ideas on planning....

  7. Monitoring presence of chemical agents

    International Nuclear Information System (INIS)

    Preston, J.M.

    1984-01-01

    The specification describes a case for use with a hand-portable chemical agent detector for continuously monitoring an atmosphere for the presence of predetermined chemical agents. The detector having means for ionizing air samples and providing at an output terminal electrical signals representative of the mobility spectrum of ionized chemical vapours produced by the ionizing means. The case comprises means for defining a chamber in the case for supporting and removably enclosing the detector, means for communicating ambient atmosphere to the chamber, electrical circuit means in the case, the circuit means being adapted to be detachably connected to the detector output terminal when the detector is positioned in the chamber and being responsive to the electrical signals for producing an alarm signal when the signals detect a chemical agent concentration in the atmosphere exceeding a predetermined concentration level, and alarm means responsive to the alarm signal. (author)

  8. Radioprotective Agents

    Directory of Open Access Journals (Sweden)

    Ilker Kelle

    2008-01-01

    Full Text Available Since1949, a great deal of research has been carried out on the radioprotective activity of various chemical substances. Thiol compounds, compounds which contain –SH radical, different classes of pharmacological agents and other compounds such as vitamine C and WR-2721 have been shown to reduce mortality when administered prior to exposure to a lethal dose of radiation. Recently, honey bee venom as well as that of its components melittin and histamine have shown to be valuable in reduction of radiation-induced damage and also provide prophylactic alternative treatment for serious side effects related with radiotherapy. It has been suggested that the radioprotective activity of bee venom components is related with the stimulation of the hematopoetic system.

  9. Agentes de software móviles

    Directory of Open Access Journals (Sweden)

    Crisman Martínez Barrera

    2001-10-01

    Full Text Available Los agentes móviles son programas de software inteligentes que realizan un objetivo que involucran desarrollos soportados en técnicas de Inteligencia Artificial, los cuales pretenden facilitar la interoperabilidad de sistemas. Este artículo define las disciplinas, plataformas y herramientas necesarias para el desarrollo de agentes móviles, sus características principales y las arquitecturas predominantes de éstas; presenta además una evaluación de sus perspectivas futuras.Mobile agents are intelligent software programs that can obtain an objective that involucrates developments supported in Artificial Intelligence techniques. These pretend to facilitate the interoperability of systems. This article defines disciplines, platforms and tools necessary for the development of mobile agents, their principal characteristics and the predominant architectures of these. A final evaluation and future perspectives are offered.

  10. Two-Level Adaptive Algebraic Multigrid for a Sequence of Problems with Slowly Varying Random Coefficients [Adaptive Algebraic Multigrid for Sequence of Problems with Slowly Varying Random Coefficients

    Energy Technology Data Exchange (ETDEWEB)

    Kalchev, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ketelsen, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vassilevski, P. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2013-11-07

    Our paper proposes an adaptive strategy for reusing a previously constructed coarse space by algebraic multigrid to construct a two-level solver for a problem with nearby characteristics. Furthermore, a main target application is the solution of the linear problems that appear throughout a sequence of Markov chain Monte Carlo simulations of subsurface flow with uncertain permeability field. We demonstrate the efficacy of the method with extensive set of numerical experiments.

  11. Controlled ultrafast transfer and stability degree of generalized coherent states of a kicked two-level ion

    Science.gov (United States)

    Chen, Hao; Kong, Chao; Hai, Wenhua

    2018-06-01

    We investigate quantum dynamics of a two-level ion trapped in the Lamb-Dicke regime of a δ -kicked optical lattice, based on the exact generalized coherent states rotated by a π / 2 pulse of Ramsey type experiment. The spatiotemporal evolutions of the spin-motion entangled states in different parameter regions are illustrated, and the parameter regions of different degrees of quantum stability described by the quantum fidelity are found. Time evolutions of the probability for the ion being in different pseudospin states reveal that the ultrafast entanglement generation and population transfers of the system can be analytically controlled by managing the laser pulses. The probability in an initially disentangled state shows periodic collapses (entanglement) and revivals (de-entanglement). Reduction of the stability degree results in enlarging the period of de-entanglement, while the instability and potential chaos will cause the sustained entanglement. The results could be justified experimentally in the existing setups and may be useful in engineering quantum dynamics for quantum information processing.

  12. A Two-Level Sensorless MPPT Strategy Using SRF-PLL on a PMSG Wind Energy Conversion System

    Directory of Open Access Journals (Sweden)

    Amina Echchaachouai

    2017-01-01

    Full Text Available In this paper, a two-level sensorless Maximum Power Point Tracking (MPPT strategy is presented for a variable speed Wind Energy Conversion System (WECS. The proposed system is composed of a wind turbine, a direct-drive Permanent Magnet Synchronous Generator (PMSG and a three phase controlled rectifier connected to a DC load. The realised generator output power maximization analysis justifies the use of the Field Oriented Control (FOC giving the six Pulse Width Modulation (PWM signals to the active rectifier. The generator rotor speed and position required by the FOC and the sensorless MPPT are estimated using a Synchronous Reference Frame Phase Locked Loop (SRF-PLL. The MPPT strategy used consists of two levels, the first level is a power regulation loop and the second level is an extremum seeking bloc generating the coefficient gathering the turbine characteristics. Experimental results validated on a hardware test setup using a DSP digital board (dSPACE 1104 are presented. Figures illustrating the estimated speed and angle confirm that the SRF-PLL is able to give an estimated speed and angle which closely follow the real ones. Also, the power at the DC load and the power at the generator output indicate that the MPPT gives optimum extracted power. Finally, other results show the effectiveness of the adopted approach in real time applications.

  13. A two-level discount model for coordinating a decentralized supply chain considering stochastic price-sensitive demand

    Science.gov (United States)

    Heydari, Jafar; Norouzinasab, Yousef

    2015-12-01

    In this paper, a discount model is proposed to coordinate pricing and ordering decisions in a two-echelon supply chain (SC). Demand is stochastic and price sensitive while lead times are fixed. Decentralized decision making where downstream decides on selling price and order size is investigated. Then, joint pricing and ordering decisions are extracted where both members act as a single entity aim to maximize whole SC profit. Finally, a coordination mechanism based on quantity discount is proposed to coordinate both pricing and ordering decisions simultaneously. The proposed two-level discount policy can be characterized from two aspects: (1) marketing viewpoint: a retail price discount to increase the demand, and (2) operations management viewpoint: a wholesale price discount to induce the retailer to adjust its order quantity and selling price jointly. Results of numerical experiments demonstrate that the proposed policy is suitable to coordinate SC and improve the profitability of SC as well as all SC members in comparison with decentralized decision making.

  14. Statistical Analysis of the Figure of Merit of a Two-Level Thermoelectric System: A Random Matrix Approach

    KAUST Repository

    Abbout, Adel

    2016-08-05

    Using the tools of random matrix theory we develop a statistical analysis of the transport properties of thermoelectric low-dimensional systems made of two electron reservoirs set at different temperatures and chemical potentials, and connected through a low-density-of-states two-level quantum dot that acts as a conducting chaotic cavity. Our exact treatment of the chaotic behavior in such devices lies on the scattering matrix formalism and yields analytical expressions for the joint probability distribution functions of the Seebeck coefficient and the transmission profile, as well as the marginal distributions, at arbitrary Fermi energy. The scattering matrices belong to circular ensembles which we sample to numerically compute the transmission function, the Seebeck coefficient, and their relationship. The exact transport coefficients probability distributions are found to be highly non-Gaussian for small numbers of conduction modes, and the analytical and numerical results are in excellent agreement. The system performance is also studied, and we find that the optimum performance is obtained for half-transparent quantum dots; further, this optimum may be enhanced for systems with few conduction modes.

  15. Optomechanically induced transparency in multi-cavity optomechanical system with and without one two-level atom.

    Science.gov (United States)

    Sohail, Amjad; Zhang, Yang; Zhang, Jun; Yu, Chang-Shui

    2016-06-28

    We analytically study the optomechanically induced transparency (OMIT) in the N-cavity system with the Nth cavity driven by pump, probing laser fields and the 1st cavity coupled to mechanical oscillator. We also consider that one atom could be trapped in the ith cavity. Instead of only illustrating the OMIT in such a system, we are interested in how the number of OMIT windows is influenced by the cavities and the atom and what roles the atom could play in different cavities. In the resolved sideband regime, we find that, the number of cavities precisely determines the maximal number of OMIT windows. It is interesting that, when the two-level atom is trapped in the even-labeled cavity, the central absorptive peak (odd N) or dip (even N) is split and forms an extra OMIT window, but if the atom is trapped in the odd-labeled cavity, the central absorptive peak (odd N) or dip (even N) is only broadened and thus changes the width of the OMIT windows rather than induces an extra window.

  16. Cavity quantum electrodynamics using a near-resonance two-level system: Emergence of the Glauber state

    Energy Technology Data Exchange (ETDEWEB)

    Sarabi, B.; Ramanayaka, A. N. [Laboratory for Physical Sciences, College Park, Maryland 20740 (United States); Department of Physics, University of Maryland, College Park, Maryland 20742 (United States); Burin, A. L. [Department of Chemistry, Tulane University, New Orleans, Louisiana 70118 (United States); Wellstood, F. C. [Department of Physics, University of Maryland, College Park, Maryland 20742 (United States); Joint Quantum Institute, University of Maryland, College Park, Maryland 20742 (United States); Osborn, K. D. [Laboratory for Physical Sciences, College Park, Maryland 20740 (United States); Joint Quantum Institute, University of Maryland, College Park, Maryland 20742 (United States)

    2015-04-27

    Random tunneling two-level systems (TLSs) in dielectrics have been of interest recently because they adversely affect the performance of superconducting qubits. The coupling of TLSs to qubits has allowed individual TLS characterization, which has previously been limited to TLSs within (thin) Josephson tunneling barriers made from aluminum oxide. Here, we report on the measurement of an individual TLS within the capacitor of a lumped-element LC microwave resonator, which forms a cavity quantum electrodynamics (CQED) system and allows for individual TLS characterization in a different structure and material than demonstrated with qubits. Due to the reduced volume of the dielectric (80 μm{sup 3}), even with a moderate dielectric thickness (250 nm), we achieve the strong coupling regime as evidenced by the vacuum Rabi splitting observed in the cavity spectrum. A TLS with a coherence time of 3.2 μs was observed in a film of silicon nitride as analyzed with a Jaynes-Cummings spectral model, which is larger than seen from superconducting qubits. As the drive power is increased, we observe an unusual but explicable set of continuous and discrete crossovers from the vacuum Rabi split transitions to the Glauber (coherent) state.

  17. Statistical Analysis of the Figure of Merit of a Two-Level Thermoelectric System: A Random Matrix Approach

    KAUST Repository

    Abbout, Adel; Ouerdane, Henni; Goupil, Christophe

    2016-01-01

    Using the tools of random matrix theory we develop a statistical analysis of the transport properties of thermoelectric low-dimensional systems made of two electron reservoirs set at different temperatures and chemical potentials, and connected through a low-density-of-states two-level quantum dot that acts as a conducting chaotic cavity. Our exact treatment of the chaotic behavior in such devices lies on the scattering matrix formalism and yields analytical expressions for the joint probability distribution functions of the Seebeck coefficient and the transmission profile, as well as the marginal distributions, at arbitrary Fermi energy. The scattering matrices belong to circular ensembles which we sample to numerically compute the transmission function, the Seebeck coefficient, and their relationship. The exact transport coefficients probability distributions are found to be highly non-Gaussian for small numbers of conduction modes, and the analytical and numerical results are in excellent agreement. The system performance is also studied, and we find that the optimum performance is obtained for half-transparent quantum dots; further, this optimum may be enhanced for systems with few conduction modes.

  18. Quantum phase transition in a coupled two-level system embedded in anisotropic three-dimensional photonic crystals.

    Science.gov (United States)

    Shen, H Z; Shao, X Q; Wang, G C; Zhao, X L; Yi, X X

    2016-01-01

    The quantum phase transition (QPT) describes a sudden qualitative change of the macroscopic properties mapped from the eigenspectrum of a quantum many-body system. It has been studied intensively in quantum systems with the spin-boson model, but it has barely been explored for systems in coupled spin-boson models. In this paper, we study the QPT with coupled spin-boson models consisting of coupled two-level atoms embedded in three-dimensional anisotropic photonic crystals. The dynamics of the system is derived exactly by means of the Laplace transform method, which has been proven to be equivalent to the dissipationless non-Markovian dynamics. Drawing on methods for analyzing the ground state, we obtain the phase diagrams through two exact critical equations and two QPTs are found: one QPT is that from the phase without one bound state to the phase with one bound state and another is that from one phase with the bound state having one eigenvalue to another phase where the bound state has two eigenvalues. Our analytical results also suggest a way of control to overcome the effect of decoherence by engineering the spectrum of the reservoirs to approach the non-Markovian regime and to form the bound state of the whole system for quantum devices and quantum statistics.

  19. Phase-controlled all-optical switching based on coherent population oscillation in a two-level system

    International Nuclear Information System (INIS)

    Liao, Ping; Yu, Song; Luo, Bin; Shen, Jing; Gu, Wanyi; Guo, Hong

    2011-01-01

    We theoretically propose a scheme of phase-controlled all-optical switching due to the effect of degenerate four-wave mixing (FWM) and coherent population oscillation (CPO) in a two-level system driven by a strong coupling field and two weak symmetrically detuned fields. The results show that the phase of the FWM field can be utilized to switch between constructive and destructive interference, which can lead to the transmission or attenuation of the probe field and thus switch the field on or off. We also find the intensity of the coupling field and the propagation distance have great influence on the performance of the switching. In our scheme, due to the quick response in semiconductor systems, a fast all-optical switching can be realized at low light level. -- Highlights: ► We study a new all-optical switching based on coherent population oscillation. ► The phase of the FWM field can be utilized to switch the probe field on or off. ► A fast and low-light-level switching can be realized in semiconductors.

  20. Dissipative two-level system under strong ac driving: A combination of Floquet and Van Vleck perturbation theory

    International Nuclear Information System (INIS)

    Hausinger, Johannes; Grifoni, Milena

    2010-01-01

    We study the dissipative dynamics of a two-level system (TLS) exposed to strong ac driving. By combining Floquet theory with Van Vleck perturbation theory in the TLS tunneling matrix element, we diagonalize the time-dependent Hamiltonian and provide corrections to the renormalized Rabi frequency of the TLS, which are valid for both a biased and unbiased TLS and go beyond the known high-frequency and rotating-wave results. In order to mimic environmental influences on the TLS, we couple the system weakly to a thermal bath and solve analytically the corresponding Floquet-Bloch-Redfield master equation. We give a closed expression for the relaxation and dephasing rates of the TLS and discuss their behavior under variation of the driving amplitude. Further, we examine the robustness of coherent destruction of tunneling (CDT) and driving-induced tunneling oscillations (DITO). We show that also for a moderate driving frequency an almost complete suppression of tunneling can be achieved for short times and demonstrate the sensitiveness of DITO to a change of the external parameters.

  1. Ordering policies of a deteriorating item in an EOQ model with backorder under two-level partial trade credit

    Science.gov (United States)

    Molamohamadi, Zohreh; Arshizadeh, Rahman; Ismail, Napsiah

    2015-05-01

    In the classical inventory model, it was assumed that the retailer must settle the accounts of the purchased items as soon as they are received. In practice, however, the supplier usually offers a full or partial delay period to the retailer to pay for the amount of the purchasing costs. In the partial trade credit contract, which is mostly applied to avoid non-payment risks, the retailer must pay for a portion of the purchased goods at the time of ordering and may delay settling the rest until the end of the predefined agreed upon period, so-called credit period. This paper assumes a two-level partial trade credit where both supplier and retailer offer a partial trade credit to their downstream members. The objective here is to determine the retailer's ordering policy of a deteriorating item by formulating his economic order quantity (EOQ) inventory system with backorder as a cost minimization problem. The sensitivity of the variables on different parameters has been also analyzed by applying numerical examples.

  2. A SEMI-LAGRANGIAN TWO-LEVEL PRECONDITIONED NEWTON-KRYLOV SOLVER FOR CONSTRAINED DIFFEOMORPHIC IMAGE REGISTRATION.

    Science.gov (United States)

    Mang, Andreas; Biros, George

    2017-01-01

    We propose an efficient numerical algorithm for the solution of diffeomorphic image registration problems. We use a variational formulation constrained by a partial differential equation (PDE), where the constraints are a scalar transport equation. We use a pseudospectral discretization in space and second-order accurate semi-Lagrangian time stepping scheme for the transport equations. We solve for a stationary velocity field using a preconditioned, globalized, matrix-free Newton-Krylov scheme. We propose and test a two-level Hessian preconditioner. We consider two strategies for inverting the preconditioner on the coarse grid: a nested preconditioned conjugate gradient method (exact solve) and a nested Chebyshev iterative method (inexact solve) with a fixed number of iterations. We test the performance of our solver in different synthetic and real-world two-dimensional application scenarios. We study grid convergence and computational efficiency of our new scheme. We compare the performance of our solver against our initial implementation that uses the same spatial discretization but a standard, explicit, second-order Runge-Kutta scheme for the numerical time integration of the transport equations and a single-level preconditioner. Our improved scheme delivers significant speedups over our original implementation. As a highlight, we observe a 20 × speedup for a two dimensional, real world multi-subject medical image registration problem.

  3. A Novel Scheme to Minimize Hop Count for GAF in Wireless Sensor Networks: Two-Level GAF

    Directory of Open Access Journals (Sweden)

    Vaibhav Soni

    2015-01-01

    Full Text Available In wireless sensor networks, geographic adaptive fidelity (GAF is one of the most popular energy-aware routing protocols. It conserves energy by identifying equivalence between sensors from a routing perspective and then turning off unnecessary sensors, while maintaining the connectivity of the network. Nevertheless, the traditional GAF still cannot reach the optimum energy usage since it needs more number of hops to transmit data packets to the sink. As a result, it also leads to higher packet delay. In this paper, we propose a modified version of GAF to minimize hop count for data routing, called two-level GAF (T-GAF. Furthermore, we use a generalized version of GAF called Diagonal-GAF (DGAF where two diagonal adjacent grids can also directly communicate. It has an advantage of less overhead of coordinator election based on the residual energy of sensors. Analysis and simulation results show significant improvements of the proposed work comparing to traditional GAF in the aspect of total hop count, energy consumption, total distance covered by the data packet before reaching the sink, and packet delay. As a result, compared to traditional GAF, it needs 40% to 47% less hop count and consumes 27% to 35% less energy to extend the network lifetime.

  4. Introducing ALAS: A Novel Agent-Oriented Programming Language

    Science.gov (United States)

    Mitrović, Dejan; Ivanović, Mirjana; Vidaković, Milan

    2011-09-01

    Agent-oriented programming languages represent a family of programming languages that provide developers with high-level abstractions and constructs necessary for implementing and using agent-related concepts. In this paper a novel agent-oriented programming language for rapid and efficient development of reactive agents, named ALAS, is presented. The simple, but powerful set of language constructs is designed to support the execution of agents in heterogenous environments, and to enable easy employment of advanced agent features, such as mobility and web service integration.

  5. Relay tracking control for second-order multi-agent systems with damaged agents.

    Science.gov (United States)

    Dong, Lijing; Li, Jing; Liu, Qin

    2017-11-01

    This paper investigates a situation where smart agents capable of sensory and mobility are deployed to monitor a designated area. A preset number of agents start tracking when a target intrudes this area. Some of the tracking agents are possible to be out of order over the tracking course. Thus, we propose a cooperative relay tracking strategy to ensure the successful tracking with existence of damaged agents. Relay means that, when a tracking agent quits tracking due to malfunction, one of the near deployed agents replaces it to continue the tracking task. This results in jump of tracking errors and dynamic switching of topology of the multi-agent system. Switched system technique is employed to solve this specific problem. Finally, the effectiveness of proposed tracking strategy and validity of the theoretical results are verified by conducting a numerical simulation. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  6. Mobile Marketing

    OpenAIRE

    竹安, 数博; Takeyasu, Kazuhiro

    2005-01-01

    This article deals with one of the modern trends in marketing communication, which is mobile marketing. Towards the end of 2008, several projects which use mobile phones for target marketing communication were launched. Commercial SMS´s are sent on the base of agreement or registration of the consumers on special websites, for example hellomobil.cz. The benefit for the consumers is the bonus which can have more forms - not only sending money to the account, free SMS´s/MMS´s and minutes but al...

  7. Mobile Usability

    DEFF Research Database (Denmark)

    Aryana, Bijan; Clemmensen, Torkil

    2013-01-01

    In this article, a country specific comparative mobile usability study is presented, using Iran and Turkey as the two chosen emerging/emergent nation exemplars of smartphone usage and adoption. In a focus group study, three mobile applications were selected by first-time users of smartphones...... personal contacts. The results and analysis establish the existence of country specific issues and concerns, as well as reveal generic usability issues. The article concludes that the source of these issues is most likely due to a combination of certain contextual features endemic to both Iran and Turkey...

  8. An Agent Based Collaborative Simplification of 3D Mesh Model

    Science.gov (United States)

    Wang, Li-Rong; Yu, Bo; Hagiwara, Ichiro

    Large-volume mesh model faces the challenge in fast rendering and transmission by Internet. The current mesh models obtained by using three-dimensional (3D) scanning technology are usually very large in data volume. This paper develops a mobile agent based collaborative environment on the development platform of mobile-C. Communication among distributed agents includes grasping image of visualized mesh model, annotation to grasped image and instant message. Remote and collaborative simplification can be efficiently conducted by Internet.

  9. Designing Mobilities

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    How is the width of the pavement shaping the urban experience? How is the material design of transport infrastructure and mobile technology affording social interaction in everyday life spaces? How do people inhabit these spaces with their bodies and in accordance to social and cultural norms...

  10. Mobile IP

    NARCIS (Netherlands)

    Heijenk, Geert; Sallent, S.; Pras, Aiko

    1999-01-01

    The Internet is growing exponentially, both in the amount of traffic carried, and in the amount of hosts connected. IP technology is becoming more and more important, in company networks (Intranets), and also in the core networks for the next generation mobile networks. Further, wireless access to

  11. Mobile Misfortune

    DEFF Research Database (Denmark)

    Vigh, Henrik Erdman

    2015-01-01

    of the mobility it enables. This article, thus, looks at the motives and manners in which young men in Bissau become caught up in transnational flows of cocaine. It shows how motion is emotively anchored and affectively bound: tied to and directed toward a feeling of worth and realisation of being, and how...

  12. Going Mobile?

    DEFF Research Database (Denmark)

    Tallon, Loic; Froes, Isabel Cristina G.

    2011-01-01

    If the future is mobile, how is the museum community developing within that future? What are the challenges museums face within it? In which directions should we be seeking to evolve our collective knowledge share? It was to gain observations on questions such as these that the 2011 Museums & Mob...

  13. Resource Mobilization

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

    Annex 1: The Scoping Study on Donor Funding for. Development Research in ... publication of the Resource Mobilization: A Practical Guide for Research .... applied the concept or technique, which validates the practical application of ... some other staff member would write up a grant application addressed to one, two, or a ...

  14. Mobile Phone

    Institute of Scientific and Technical Information of China (English)

    籍万杰

    2004-01-01

    Your mobile phone rings.and instead of usual electronic signals,it's playing your favorite music.A friend sends your favorite song to cheer you up.One day,a record company might forward new records and music videos to your phone.

  15. 226Ra and 210Pb lixiviation sediments from the region of uranium mine and mill in Pocos de Caldas, contaminated in laboratory by river water and chemical agents, mobility and availability in soils

    International Nuclear Information System (INIS)

    Oliveira, A.E. de.

    1982-01-01

    Leaching experiments of river bottom sediments, contaminated in the laboratory with 226 Ra or 210 Pb, by river waters or solutions of inorganic salts and mobility experiments of these radionuclides added to soil columns and leached by a volume of distilled or river water, equivalent to the average annual rain precipitation in the region, are performed. The determination of 226 Ra and 210 Pb exchangeable fractions in soils contaminated in the laboratory are studied too. The results, as a whole, lead to the conclusion that 226 Ra should be considered, potentially, the radionuclide most able to increase the population radiation dose, through the ingestion of contaminated water and foodstuff. (M.A.C.) [pt

  16. Identification of immiscible NAPL contaminant sources in aquifers by a modified two-level saturation based imperialist competitive algorithm

    Science.gov (United States)

    Ghafouri, H. R.; Mosharaf-Dehkordi, M.; Afzalan, B.

    2017-07-01

    A simulation-optimization model is proposed for identifying the characteristics of local immiscible NAPL contaminant sources inside aquifers. This model employs the UTCHEM 9.0 software as its simulator for solving the governing equations associated with the multi-phase flow in porous media. As the optimization model, a novel two-level saturation based Imperialist Competitive Algorithm (ICA) is proposed to estimate the parameters of contaminant sources. The first level consists of three parallel independent ICAs and plays as a pre-conditioner for the second level which is a single modified ICA. The ICA in the second level is modified by dividing each country into a number of provinces (smaller parts). Similar to countries in the classical ICA, these provinces are optimized by the assimilation, competition, and revolution steps in the ICA. To increase the diversity of populations, a new approach named knock the base method is proposed. The performance and accuracy of the simulation-optimization model is assessed by solving a set of two and three-dimensional problems considering the effects of different parameters such as the grid size, rock heterogeneity and designated monitoring networks. The obtained numerical results indicate that using this simulation-optimization model provides accurate results at a less number of iterations when compared with the model employing the classical one-level ICA. A model is proposed to identify characteristics of immiscible NAPL contaminant sources. The contaminant is immiscible in water and multi-phase flow is simulated. The model is a multi-level saturation-based optimization algorithm based on ICA. Each answer string in second level is divided into a set of provinces. Each ICA is modified by incorporating a new knock the base model.

  17. A preventive maintenance model with a two-level inspection policy based on a three-stage failure process

    International Nuclear Information System (INIS)

    Wang, Wenbin; Zhao, Fei; Peng, Rui

    2014-01-01

    Inspection is always an important preventive maintenance (PM) activity and can have different depths and cover all or part of plant systems. This paper introduces a two-level inspection policy model for a single component plant system based on a three-stage failure process. Such a failure process divides the system′s life into three stages: good, minor defective and severe defective stages. The first level of inspection, the minor inspection, can only identify the minor defective stage with a certain probability, but can always reveal the severe defective stage. The major inspection can however identify both defective stages perfectly. Once the system is found to be in the minor defective stage, a shortened inspection interval is adopted. If however the system is found to be in the severe defective stage, we may delay the maintenance action if the time to the next planned PM window is less than a threshold level, but otherwise, replace immediately. This corresponds to the well adopted maintenance policy in practice such as periodic inspections with planned PMs. A numerical example is presented to demonstrate the proposed model by comparing with other models. - Highlights: • The system′s deterioration goes through a three-stage process, namely, normal, minor defective and severe defective. • Two levels of inspections are proposed, e.g., minor and major inspections. • Once the minor defective stage is found, instead of taking a maintenance action, a shortened inspection interval is recommended. • When the severe defective stage is found, we delay the maintenance according to the threshold to the next PM. • The decision variables are the inspection intervals and the threshold to PM

  18. On the Performance Optimization of Two-Level Three-Phase Grid-Feeding Voltage-Source Inverters

    Directory of Open Access Journals (Sweden)

    Issam A. Smadi

    2018-02-01

    Full Text Available The performance optimization of the two-level, three-phase, grid-feeding, voltage-source inverter (VSI is studied in this paper, which adopts an online adaptive switching frequency algorithm (OASF. A new degree of freedom has been added to the employed OASF algorithm for optimal selection of the weighting factor and overall system optimization design. Toward that end, a full mathematical formulation, including the impact of the coupling inductor and the controller response time, is presented. At first, the weighting factor is selected to favor the switching losses, and the controller gains are optimized by minimizing the integral time-weighted absolute error (ITAE of the output active and reactive power. Different loading and ambient temperature conditions are considered to validate the optimized controller and its fast response through online field programmable gate array (FPGA-in-the-loop. Then, the weighting factor is optimally selected to reduce the cost of the L-filter and the heat-sink. An optimization problem to minimize the cost design at the worst case of loading condition for grid-feeding VSI is formulated. The results from this optimization problem are the filter inductance, the thermal resistance of the heat-sink, and the optimal switching frequency with the optimal weighting factor. The VSI test-bed using the optimized parameters is used to verify the proposed work experimentally. Adopting the OASF algorithm that employs the optimal weighting factor for grid-feeding VSI, the percentages of the reductions in the slope of the steady state junction temperature profile compared to fixed frequencies of 10 kHz, 14.434 kHz, and 20 kHz are about 6%, 30%, and 18%, respectively.

  19. Two-Level Chebyshev Filter Based Complementary Subspace Method: Pushing the Envelope of Large-Scale Electronic Structure Calculations.

    Science.gov (United States)

    Banerjee, Amartya S; Lin, Lin; Suryanarayana, Phanish; Yang, Chao; Pask, John E

    2018-06-12

    We describe a novel iterative strategy for Kohn-Sham density functional theory calculations aimed at large systems (>1,000 electrons), applicable to metals and insulators alike. In lieu of explicit diagonalization of the Kohn-Sham Hamiltonian on every self-consistent field (SCF) iteration, we employ a two-level Chebyshev polynomial filter based complementary subspace strategy to (1) compute a set of vectors that span the occupied subspace of the Hamiltonian; (2) reduce subspace diagonalization to just partially occupied states; and (3) obtain those states in an efficient, scalable manner via an inner Chebyshev filter iteration. By reducing the necessary computation to just partially occupied states and obtaining these through an inner Chebyshev iteration, our approach reduces the cost of large metallic calculations significantly, while eliminating subspace diagonalization for insulating systems altogether. We describe the implementation of the method within the framework of the discontinuous Galerkin (DG) electronic structure method and show that this results in a computational scheme that can effectively tackle bulk and nano systems containing tens of thousands of electrons, with chemical accuracy, within a few minutes or less of wall clock time per SCF iteration on large-scale computing platforms. We anticipate that our method will be instrumental in pushing the envelope of large-scale ab initio molecular dynamics. As a demonstration of this, we simulate a bulk silicon system containing 8,000 atoms at finite temperature, and obtain an average SCF step wall time of 51 s on 34,560 processors; thus allowing us to carry out 1.0 ps of ab initio molecular dynamics in approximately 28 h (of wall time).

  20. Multi agent gathering waste system

    Directory of Open Access Journals (Sweden)

    Álvaro LOZANO MURCIEGO

    2016-07-01

    Full Text Available Along this paper, we present a new multi agent-based system to gather waste on cities and villages. We have developed a low cost wireless sensor prototype to measure the volume level of the containers. Furthermore a route system is developed to optimize the routes of the trucks and a mobile application has been developed to help drivers in their working days. In order to evaluate and validate the proposed system a practical case study in a real city environment is modeled using open data available and with the purpose of identifying limitations of the system.

  1. Mobile Customer Relationship Management and Mobile Security

    Science.gov (United States)

    Sanayei, Ali; Mirzaei, Abas

    The purpose of this study is twofold. First, in order to guarantee a coherent discussion about mobile customer relationship management (mCRM), this paper presents a conceptualization of mCRM delineating its unique characteristics because of Among the variety of mobile services, considerable attention has been devoted to mobile marketing and in particular to mobile customer relationship management services. Second, the authors discusses the security risks in mobile computing in different level(user, mobile device, wireless network,...) and finally we focus on enterprise mobile security and it's subgroups with a series of suggestion and solution for improve mobile computing security.

  2. The African Mobile Story

    DEFF Research Database (Denmark)

    This book identifies the factors that has enabled the growth of mobile telephony in Africa. The book covers the regulatory factors, the development and usage of mobile application, mobile security and sustainable power source for mobile networks...

  3. Interacting agents in finance

    NARCIS (Netherlands)

    Hommes, C.; Durlauf, S.N.; Blume, L.E.

    2008-01-01

    Interacting agents in finance represent a behavioural, agent-based approach in which financial markets are viewed as complex adaptive systems consisting of many boundedly rational agents interacting through simple heterogeneous investment strategies, constantly adapting their behaviour in response

  4. Riot Control Agents

    Science.gov (United States)

    ... Submit What's this? Submit Button Facts About Riot Control Agents Interim document Recommend on Facebook Tweet Share Compartir What riot control agents are Riot control agents (sometimes referred to ...

  5. Mobile weatherstation

    International Nuclear Information System (INIS)

    Hahn, H.; Koutny, P.; Schwabach, H.; Eisenwagner, H.

    1981-01-01

    A mobile weatherstation is described which allows to measure the following parameters: airtemperature, relative humidity, winddirection and windspeed. The station consists of three main units: the central station METEODAT, the multiplexer and the weather measure tower with the sensors. The measured data are displayed in digital form in the central unit and can be printed on a teletype. The power supply is either 220 Volt AC or 24 Volt DC. (author)

  6. Protecting software agents from malicious hosts using quantum computing

    Science.gov (United States)

    Reisner, John; Donkor, Eric

    2000-07-01

    We evaluate how quantum computing can be applied to security problems for software agents. Agent-based computing, which merges technological advances in artificial intelligence and mobile computing, is a rapidly growing domain, especially in applications such as electronic commerce, network management, information retrieval, and mission planning. System security is one of the more eminent research areas in agent-based computing, and the specific problem of protecting a mobile agent from a potentially hostile host is one of the most difficult of these challenges. In this work, we describe our agent model, and discuss the capabilities and limitations of classical solutions to the malicious host problem. Quantum computing may be extremely helpful in addressing the limitations of classical solutions to this problem. This paper highlights some of the areas where quantum computing could be applied to agent security.

  7. Structural Mobility, Exchange Mobility and Subgroup Consistent Mobility Measurement – US–German Mobility Measurements Revisited

    OpenAIRE

    C. SCHLUTER; D. VAN DE GAER

    2008-01-01

    We formalize the concept of structural mobility and use the framework of subgroup consistent mobility measurement to derive a relative and an absolute measure of mobility that is increasing both in upward structural mobility and exchange mobility. In our empirical illustration, we contribute substantively to the ongoing debate about mobility rankings between the USA and Germany.

  8. Bridging the Gap Between the Social and the Technical: The Enrolment of Socio-Technical Information Architects to Cope with the Two-Level Model of EPR Systems.

    Science.gov (United States)

    Pedersen, Rune

    2017-01-01

    This is a project proposal derived from an urge to re-define the governance of ICT in healthcare towards regional and national standardization of the patient pathways. The focus is on a two-levelled approach for governing EPR systems where the clinicians' model structured variables and patient pathways. The overall goal is a patient centric EPR portfolio. This paper define and enlighten the need for establishing the socio- technical architect role necessary to obtain the capabilities of a modern structured EPR system. Clinicians are not capable to moderate between the technical and the clinical.

  9. Effects of an applied low frequency field on the dynamics of a two-level atom interacting with a single-mode field

    International Nuclear Information System (INIS)

    Xun-Wei, Xu; Nian-Hua, Liu

    2010-01-01

    The effects of an applied low frequency field on the dynamics of a two-level atom interacting with a single-mode field are investigated. It is shown that the time evolution of the atomic population is mainly controlled by the coupling constants and the frequency of the low frequency field, which leads to a low frequency modulation function for the time evolution of the upper state population. The amplitude of the modulation function becomes larger as the coupling constants increase. The frequency of the modulation function is proportional to the frequency of the low frequency field, and decreases with increasing coupling constant. (classical areas of phenomenology)

  10. Prediction of intragranular strains in metallic polycrystals with a two-level homogenisation approach: Influence of dislocation microstructure on the mechanical behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Gloaguen, D. [GeM, Institut de Recherche en Genie Civil et Mecanique, Universite de Nantes, Ecole Centrale de Nantes, CNRS UMR 6183, 37 Boulevard de l' Universite, BP 406, 44 602 Saint-Nazaire (France); Francois, M. [Laboratoire des Systemes Mecaniques et d' Ingenierie Simultanee (LASMIS FRE CNRS 2719), Universite de Technologie de Troyes, 12 Rue Marie Curie, BP 2060, 10010 Troyes cedex (France)

    2006-06-15

    A two-level homogenisation approach is applied to the micro-mechanical modelling of the elasto-plasticity of polycrystalline materials during various strain-path changes. The model is tested by simulating the development of intragranular strains during different complex loads. Mechanical tests measurements are used as a reference in order to validate the model. The anisotropy of plastic deformation in relation to the evolution of the dislocation structure is analysed. The results demonstrate the relevance of this approach for FCC polycrystals. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. Mobile Termination and Mobile Penetration

    OpenAIRE

    Hurkens, Sjaak; Jeon, Doh-Shin

    2009-01-01

    In this paper, we study how access pricing affects network competition when subscription demand is elastic and each network uses non-linear prices and can apply termination-based price discrimination. In the case of a fixed per minute termination charge, we find that a reduction of the termination charge below cost has two oppos- ing effects: it softens competition but helps to internalize network externalities. The former reduces mobile penetration while the latter boosts it. We find that fi...

  12. Mobile termination and mobile penetration

    OpenAIRE

    Hurkens, Sjaak

    2009-01-01

    In this paper, we study how access pricing affects network competition when subscription demand is elastic and each network uses non-linear prices and can apply termination-based price discrimination. In the case of a fixed per minute termination charge, we find that a reduction of the termination charge below cost has two opposing effects: it softens competition but helps to internalize network externalities. The former reduces mobile penetration while the latter boosts it. We find that firm...

  13. Gesture Activated Mobile Edutainment (GAME)

    DEFF Research Database (Denmark)

    Rehm, Matthias; Leichtenstern, Karin; Plomer, Joerg

    2010-01-01

    An approach to intercultural training of nonverbal behavior is presented that draws from research on role-plays with virtual agents and ideas from situated learning. To this end, a mobile serious game is realized where the user acquires knowledge about German emblematic gestures and tries them out...... in role-plays with virtual agents. Gesture performance is evaluated making use of build-in acceleration sensors of smart phones. After an account of the theoretical background covering diverse areas like virtual agents, situated learning and intercultural training, the paper presents the GAME approach...... along with details on the gesture recognition and content authoring. By its experience-based role plays with virtual characters, GAME brings together ideas from situated learning and intercultural training in an integrated approach and paves the way for new m-learning concepts....

  14. Mobile Payments : Comparison of Mobile Wallet Concepts

    OpenAIRE

    Narayan, Srikant

    2013-01-01

    Mobile payments are an emerging trend and an alternative to traditional payment methods. Mobile payments involve the usage of the mobile phone to handle credit transfers during purchase of goods and peer to peer money transfers referred to as mobile wallet service, instead of depending on bank cards and cash. In this scenario, while the mobile wallet industry still being in its infancy there exist a few drivers of mobile wallet solutions aiming to create a de-facto standard in the mobile mark...

  15. Quantum theory of phonon-mediated decoherence and relaxation of two-level systems in a structured electromagnetic reservoir

    Science.gov (United States)

    Roy, Chiranjeeb

    In this thesis we study the role of nonradiative degrees of freedom on quantum optical properties of mesoscopic quantum dots placed in the structured electromagnetic reservoir of a photonic crystal. We derive a quantum theory of the role of acoustic and optical phonons in modifying the optical absorption lineshape, polarization dynamics, and population dynamics of a two-level atom (quantum dot) in the "colored" electromagnetic vacuum of a photonic band gap (PBG) material. This is based on a microscopic Hamiltonian describing both radiative and vibrational processes quantum mechanically. Phonon sidebands in an ordinary electromagnetic reservoir are recaptured in a simple model of optical phonons using a mean-field factorization of the atomic and lattice displacement operators. Our formalism is then used to treat the non-Markovian dynamics of the same system within the structured electromagnetic density of states of a photonic crystal. We elucidate the extent to which phonon-assisted decay limits the lifetime of a single photon-atom bound state and derive the modified spontaneous emission dynamics due to coupling to various phonon baths. We demonstrate that coherent interaction with undamped phonons can lead to enhanced lifetime of a photon-atom bound state in a PBG by (i) dephasing and reducing the transition electric dipole moment of the atom and (ii) reducing the quantum mechanical overlap of the state vectors of the excited and ground state (polaronic shift). This results in reduction of the steady-state atomic polarization but an increase in the fractionalized upper state population in the photon-atom bound state. We demonstrate, on the other hand, that the lifetime of the photon-atom bound state in a PBG is limited by the lifetime of phonons due to lattice anharmonicities (break-up of phonons into lower energy phonons) and purely nonradiative decay. We demonstrate how these additional damping effects limit the extent of the polaronic (Franck-Condon) shift of

  16. Reasoning about emotional agents

    OpenAIRE

    Meyer, J.-J.

    2004-01-01

    In this paper we discuss the role of emotions in artificial agent design, and the use of logic in reasoning about the emotional or affective states an agent can reside in. We do so by extending the KARO framework for reasoning about rational agents appropriately. In particular we formalize in this framework how emotions are related to the action monitoring capabilities of an agent.

  17. Mobile Marketing

    OpenAIRE

    Luengo Cascudo, Alberto

    2010-01-01

    El principal objetivo de este proyecto es explicar y entender la importancia del Mobile Marketing como nueva herramienta de negocio en el Marketing empresarial. Para ello, el primer objetivo es entender los dos factores que para mí son la clave de su importancia: la evolución del entorno tecnológico y el cambio en los hábitos del consumidor. Debido a la novedad de esta nueva forma de Marketing y al hecho de que está en constante definición, es básico exponer de la forma más cla...

  18. Device Data Protection in Mobile Healthcare Applications

    Science.gov (United States)

    Weerasinghe, Dasun; Rajarajan, Muttukrishnan; Rakocevic, Veselin

    The rapid growth in mobile technology makes the delivery of healthcare data and services on mobile phones a reality. However, the healthcare data is very sensitive and has to be protected against unauthorized access. While most of the development work on security of mobile healthcare today focuses on the data encryption and secure authentication in remote servers, protection of data on the mobile device itself has gained very little attention. This paper analyses the requirements and the architecture for a secure mobile capsule, specially designed to protect the data that is already on the device. The capsule is a downloadable software agent with additional functionalities to enable secure external communication with healthcare service providers, network operators and other relevant communication parties.

  19. Networked Mobilities and Performative Urban Environments

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    , an increasing number of such mobile practices are mediated by technologies of tangible and less tangible sorts. Thus by focusing on the complex relationship between material and virtual technologies within the sphere of mobility it is shown that we need to move beyond dichotomies of; global or local, nomad...... or sedentary, digital or material. The paper investigates the meaning of mobility and the potential in mediation and technologies to enhance the experiences and interaction in relation to urban transit spaces. In understanding the importance of mediation, global-local interactions, networks....... By studying embedded technologies and ‘ambient environments' we increase our knowledge about the over layering of the material environment with digital technologies. The presences of GPS, mediated surfaces, mobile agents (robots), RFID and other technologies that all relate to contemporary mobility practices...

  20. Wapice News Mobile Application

    OpenAIRE

    Söylemez, Ilke

    2017-01-01

    Since the mobile phones started to have an increasingly significant role in daily life, the mobile application development also started to be an important area in the software industry. The problem for mobile application developers is to develop a mobile application which supports all the devices and platforms on the market. This issue created a need for cross platform mobile applications. The cross platform mobile development refers to the development of mobile applications that could be use...

  1. New Aspects of Field Entropy Squeezing as an Indicator for Mixed State Entanglement in an Effective Two-Level System with Stark Shift

    Institute of Scientific and Technical Information of China (English)

    S.Abdel-Khalek; M.M.A.Ahmed; A-S F.Obada

    2011-01-01

    We present an effective two-level system in interaction through two-photon processes with a single mode quantized electromagnetic field,initially prepared in a coherent state.Field entropy squeezing as an indicator of the entanglement in a mixed state system is suggested.The temporal evolution of the negativity,Wehrl entropy,Wehrl phase distribution and field entropy squeezing are investigated.The results highlight the important roles played by both the Stark shift parameters and the mixed state setting in the dynamics of the Wehrl entropy,Wehrl phase distribution and field entropy squeezing.%We present an effective two-level system in interaction through two-photon processes with a single mode quantized electromagnetic Reid, initially prepared in a coherent state. Field entropy squeezing as an indicator of the entanglement in a mixed state system is suggested. The temporal evolution of the negativity, Wehrl entropy, Wehrl phase distribution and field entropy squeezing are investigated. The results highlight the important roles played by both the Stark shift parameters and the mixed state setting in the dynamics of the Wehrl entropy, Wehrl phase distribution and field entropy squeezing.

  2. 10th KES Conference on Agent and Multi-Agent Systems : Technologies and Applications

    CERN Document Server

    Chen-Burger, Yun-Heh; Howlett, Robert; Jain, Lakhmi

    2016-01-01

    The modern economy is driven by technologies and knowledge. Digital technologies can free, shift and multiply choices, often intruding on the space of other industries, by providing new ways of conducting business operations and creating values for customers and companies. The topics covered in this volume include software agents, multi-agent systems, agent modelling, mobile and cloud computing, big data analysis, business intelligence, artificial intelligence, social systems, computer embedded systems and nature inspired manufacturing, etc. that contribute to the modern Digital Economy. This volume highlights new trends and challenges in agent, new digital and knowledge economy research and includes 28 papers classified in the following specific topics: business process management, agent-based modeling and simulation, anthropic-oriented computing, learning paradigms, business informatics and gaming, digital economy, and advances in networked virtual enterprises. Published papers were selected for presentatio...

  3. Advertising on mobile applications

    OpenAIRE

    Sobolevsky, Alexandr

    2015-01-01

    The article analyzes the new method of mobile advertising. Advertising in mobile applications - a subspecies of mobile marketing, where advertising is distributed using mobile phones and smartphones. Ad placement is going on inside of applications and games for smartphones. It has a high potential due to the large number of mobile phone users (over 6.5 billion in 2013).

  4. Mobility Balance Sheet 2009

    International Nuclear Information System (INIS)

    Jorritsma, P.; Derriks, H.; Francke, J.; Gordijn, H.; Groot, W.; Harms, L.; Van der Loop, H.; Peer, S.; Savelberg, F.; Wouters, P.

    2009-06-01

    The Mobility Balance Sheet provides an overview of the state of the art of mobility in the Netherlands. In addition to describing the development of mobility this report also provides explanations for the growth of passenger and freight transport. Moreover, the Mobility Balance Sheet also focuses on a topical theme: the effects of economic crises on mobility. [nl

  5. Chemical warfare agents.

    Science.gov (United States)

    Kuca, Kamil; Pohanka, Miroslav

    2010-01-01

    Chemical warfare agents are compounds of different chemical structures. Simple molecules such as chlorine as well as complex structures such as ricin belong to this group. Nerve agents, vesicants, incapacitating agents, blood agents, lung-damaging agents, riot-control agents and several toxins are among chemical warfare agents. Although the use of these compounds is strictly prohibited, the possible misuse by terrorist groups is a reality nowadays. Owing to this fact, knowledge of the basic properties of these substances is of a high importance. This chapter briefly introduces the separate groups of chemical warfare agents together with their members and the potential therapy that should be applied in case someone is intoxicated by these agents.

  6. Mobile video with mobile IPv6

    CERN Document Server

    Minoli, Daniel

    2012-01-01

    Increased reliance on mobile devices and streaming of video content are two of the most recent changes that have led those in the video distribution industry to be concerned about the shifting or erosion of traditional advertising revenues. Infrastructure providers also need to position themselves to take advantage of these trends. Mobile Video with Mobile IPv6provides an overview of the current mobile landscape, then delves specifically into the capabilities and operational details of IPv6. The book also addresses 3G and 4G services, the application of Mobile IPv6 to streaming and other mobil

  7. Ion mobility spectrometer for online monitoring of trace compounds

    International Nuclear Information System (INIS)

    Li, F.; Xie, Z.; Schmidt, H.; Sielemann, S.; Baumbach, J.I.

    2002-01-01

    The principle, character and developments of the instrumentation of ion mobility spectrometry are reviewed. The application of ion mobility spectrometers in monitoring chemical warfare agents, explosives, drugs, environmental hazardous compounds and industrial process control are discussed. Process applications with respect to miniaturization of the instrument are presented

  8. Enabling ecosystem for mobile advertising in an emerging market

    OpenAIRE

    Wong, Chin Chin

    2017-01-01

    The global landscape for advertising has undergone major revolution attributed to the rapid advancement in information and communication technologies (ICT). ICT has opened up more opportunities for economic agents to advertise in the new economy. Among ICT, mobile phones provide the greatest opportunity to catch up with more developed countries in terms of socioeconomic development. Rapid growth in mobile phones in developing countries provides an excellent platform for mobile advertising (m-...

  9. Continuum deformation of multi-agent systems

    CERN Document Server

    Rastgoftar, Hossein

    2016-01-01

    This monograph presents new algorithms for formation control of multi-agent systems (MAS) based on principles of continuum mechanics. Beginning with an overview of traditional methods, the author then introduces an innovative new approach whereby agents of an MAS are considered as particles in a continuum evolving in ℝn whose desired configuration is required to satisfy an admissible deformation function. The necessary theory and its validation on a mobile-agent-based swarm test bed are considered for two primary tasks: homogeneous transformation of the MAS and deployment of a random distribution of agents on a desired configuration. The framework for this model is based on homogeneous transformations for the evolution of an MAS under no inter-agent communication, local inter-agent communication, and intelligent perception by agents. Different communication protocols for MAS evolution, the robustness of tracking of a desired motion by an MAS evolving in ℝn, and the effect of communication delays in an MAS...

  10. Multi-Agent Rendezvousing with a Finite Set of Candidate Rendezvous Points

    NARCIS (Netherlands)

    Fang, J.; Morse, A. S.; Cao, M.

    2008-01-01

    The discrete multi-agent rendezvous problem we consider in this paper is concerned with a specified set of points in the plane, called “dwell-points,” and a set of mobile autonomous agents with limited sensing range. Each agent is initially positioned at some dwell-point, and is able to determine

  11. Mobile OS Comparative Study

    OpenAIRE

    Joseph, Jyothy; K, Shinto Kurian

    2013-01-01

    In the fast growing mobile revolutionary era, many operating systems are playing vital role in present market. This study is intending to identify the apt and secure mobile based on mobile operating systems capability and user requirements.

  12. 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.

  13. MOBILITY: A SYSTEMS APPROACH

    Directory of Open Access Journals (Sweden)

    Mykola I. Striuk

    2015-10-01

    Full Text Available A comprehensive study on the problem of mobility in the socio-educational and technical systems was carried out: the evolution of the concept of mobility in scientific sources of XIX–XXI centuries was analyzed and the new sources on the issue of mobility introduced into scientific circulation, the interrelation of the types of mobility in the socio-pedagogical and technical systems are theoretically grounded, an integrative model of mobility in the information society is proposed. The major trends in academic mobility are identified (the transition from student mobility to mobility programs and educational services providers, the new mobility programs (franchising, double/joint degrees, combinations, nostrification etc. are characterized. The new types of mobility providers are reviewed and attention is focused on virtual universities that are now the basis of virtual mobility of students and activities which are based on the use of new ICT in higher education, especially – the Internet and mobile learning environments.

  14. Micro Mobility Marketing

    DEFF Research Database (Denmark)

    Hosbond, Jens Henrik; Skov, Mikael B.

    2008-01-01

    , in our case a medium-sized retail supermarket. Two prototypes based on push and pull marketing strategies are implemented and evaluated. Taking outset in a synthesis of central issues in contemporary research on mobile marketing, we discuss their role in micro mobility marketing to point to similarities......Mobile marketing refers to marketing of services or goods using mobile technology and mobile marketing holds potentially great economical opportunities. Traditionally, mobile marketing has been viewed as mobility in the large taking place virtually anywhere, anytime. Further, research shows...... considerable number of studies on push-based SMS mobile marketing campaigns. This paper explores a related yet different form of mobile marketing namely micro mobility marketing. Micro mobility marketing denotes mobility in the small, meaning that promotion of goods takes place within a circumscribed location...

  15. Mobile Search and Advertising

    OpenAIRE

    Lovitskii, Vladimir; McCaffery, Colin; Thrasher, Michael; Traynor, David; Wright, Peter

    2009-01-01

    Mobile advertising is a rapidly growing sector providing brands and marketing agencies the opportunity to connect with consumers beyond traditional and digital media and instead communicate directly on their mobile phones. Mobile advertising will be intrinsically linked with mobile search, which has transported from the internet to the mobile and is identified as an area of potential growth. The result of mobile searching show that as a general rule such search result exceed 1...

  16. Trends in Mobile Marketing

    OpenAIRE

    Chocholová, Petra

    2010-01-01

    The principal aim of this thesis is to assess the state of the mobile marketing as of the first quarter of 2011 and to discuss various scenarios of the future development. This thesis defines the terms "mobile marketing" and "mobile advertising" and identifies the main players in the industry. It explores the main categories of mobile advertising such as mobile messaging, in-content and mobile internet advertising. Later, it analyzes the latest trends in the industry and describes in detail t...

  17. Radiopharmaceutical scanning agents

    International Nuclear Information System (INIS)

    1976-01-01

    This invention is directed to dispersions useful in preparing radiopharmaceutical scanning agents, to technetium labelled dispersions, to methods for preparing such dispersions and to their use as scanning agents

  18. Taskable Reactive Agent Communities

    National Research Council Canada - National Science Library

    Myers, Karen

    2002-01-01

    The focus of Taskable Reactive Agent Communities (TRAC) project was to develop mixed-initiative technology to enable humans to supervise and manage teams of agents as they perform tasks in dynamic environments...

  19. inventory management, VMI, software agents, MDV model

    Directory of Open Access Journals (Sweden)

    Waldemar Wieczerzycki

    2012-03-01

    Full Text Available Background: As it is well know, the implementation of instruments of logistics management is only possible with the use of the latest information technology. So-called agent technology is one of the most promising solutions in this area. Its essence consists in an entirely new way of software distribution on the computer network platform, in which computer exchange among themselves not only data, but also software modules, called just agents. The first aim is to propose the alternative method of the implementation of the concept of the inventory management by the supplier with the use of intelligent software agents, which are able not only to transfer the information but also to make the autonomous decisions based on the privileges given to them. The second aim of this research was to propose a new model of a software agent, which will be both of a high mobility and a high intelligence. Methods: After a brief discussion of the nature of agent technology, the most important benefits of using it to build platforms to support business are given. Then the original model of polymorphic software agent, called Multi-Dimensionally Versioned Software Agent (MDV is presented, which is oriented on the specificity of IT applications in business. MDV agent is polymorphic, which allows the transmission through the network only the most relevant parts of its code, and only when necessary. Consequently, the network nodes exchange small amounts of software code, which ensures high mobility of software agents, and thus highly efficient operation of IT platforms built on the proposed model. Next, the adaptation of MDV software agents to implementation of well-known logistics management instrument - VMI (Vendor Managed Inventory is illustrated. Results: The key benefits of this approach are identified, among which one can distinguish: reduced costs, higher flexibility and efficiency, new functionality - especially addressed to business negotiation, full automation

  20. Users, Bystanders and Agents

    DEFF Research Database (Denmark)

    Krummheuer, Antonia Lina

    2015-01-01

    Human-agent interaction (HAI), especially in the field of embodied conversational agents (ECA), is mainly construed as dyadic communication between a human user and a virtual agent. This is despite the fact that many application scenarios for future ECAs involve the presence of others. This paper...

  1. Asymptotically Optimal Agents

    OpenAIRE

    Lattimore, Tor; Hutter, Marcus

    2011-01-01

    Artificial general intelligence aims to create agents capable of learning to solve arbitrary interesting problems. We define two versions of asymptotic optimality and prove that no agent can satisfy the strong version while in some cases, depending on discounting, there does exist a non-computable weak asymptotically optimal agent.

  2. Reasoning about emotional agents

    NARCIS (Netherlands)

    Meyer, J.-J.

    In this paper we discuss the role of emotions in artificial agent design, and the use of logic in reasoning about the emotional or affective states an agent can reside in. We do so by extending the KARO framework for reasoning about rational agents appropriately. In particular we formalize in

  3. Radiographic scanning agent

    International Nuclear Information System (INIS)

    Bevan, J.A.

    1983-01-01

    This invention relates to radiodiagnostic agents and more particularly to a composition and method for preparing a highly effective technetium-99m-based bone scanning agent. One deficiency of x-ray examination is the inability of that technique to detect skeletal metastases in their incipient stages. It has been discovered that the methanehydroxydiphosphonate bone mineral-seeking agent is unique in that it provides the dual benefits of sharp radiographic imaging and excellent lesion detection when used with technetium-99m. This agent can also be used with technetium-99m for detecting soft tissue calcification in the manner of the inorganic phosphate radiodiagnostic agents

  4. Agente adaptable y aprendizaje

    Directory of Open Access Journals (Sweden)

    Arturo Angel Lara Rivero

    2013-05-01

    Full Text Available En este trabajo se contrasta el concepto de agente programado con el de agente complejo adaptable, se presenta una nueva visión ligada al aprendizaje y la estructura del agente. La imagen del agente se analiza considerando los modelos internos, la práctica, el concepto de rutina y la influencia en su comportamiento, y la importancia del aprendizaje ex ante y ex post. Por último se muestra que la resolución de problemas está sujeta a restricciones del agente y se describen las formas de explorar el espacio de soluciones mediante tres tipos de exploración: exhaustiva, aleatoria y selectiva.

  5. Performance Analysis of the Mobile IP Protocol (RFC 3344 and Related RFCS)

    Science.gov (United States)

    2006-12-01

    field of 9 identifies the ICMP message as an adverstisement . Code Mobile IP home agents and foreign agents use the value of 16 to prevent any nodes...ANALYSIS OF THE MOBILE IP PROTOCOL (RFC 3344 AND RELATED RFCS) by Chin Chin Ng December 2006 Thesis Co-Advisors: George W. Dinolt J. D...December 2006 3. REPORT TYPE AND DATES COVERED Master’s Thesis 4. TITLE AND SUBTITLE Performance Analysis of the Mobile IP Protocol (RFC 3344 and

  6. Synergy between Software Product Line and Intelligent Mobile Middleware

    DEFF Research Database (Denmark)

    Zhang, Weishan; Hansen, Klaus Marius

    2007-01-01

    with OWL ontology reasoning enhanced BDI (belief-desire-intention) agents in an ongoing research project called PLIMM (product line enabled intelligent mobile middleware), in which Frame based software product line techniques are applied. Besides the advantages of a software product line, our approach can...... handle ontology evolution and keep all related assets in a consistent state. Ontology evolution is a problem that has not been addressed by current mobile middleware. Another advantage is the ability to configure Jadex BDI agents for different purpose and enhance agent intelligence by adding logic...

  7. Trends in practical applications of heterogeneous multi-agent systems : the PAAMS collection

    CERN Document Server

    Rodríguez, Juan; Mathieu, Philippe; Campbell, Andrew; Ortega, Alfonso; Adam, Emmanuel; Navarro, Elena; Ahrndt, Sebastian; Moreno, María; Julián, Vicente

    2014-01-01

    PAAMS, the International Conference on Practical Applications of Agents and Multi-Agent Systems is an evolution of the International Workshop on Practical Applications of Agents and Multi-Agent Systems. PAAMS is an international yearly tribune to present, to discuss, and to disseminate the latest developments and the most important outcomes related to real-world applications. It provides a unique opportunity to bring multi-disciplinary experts, academics and practitioners together to exchange their experience in the development of Agents and Multi-Agent Systems. This volume presents the papers that have been accepted for the 2014 special sessions: Agents Behaviours and Artificial Markets (ABAM), Agents and Mobile Devices (AM), Bio-Inspired and Multi-Agents Systems: Applications to Languages (BioMAS), Multi-Agent Systems and Ambient Intelligence (MASMAI), Self-Explaining Agents (SEA), Web Mining and Recommender systems (WebMiRes) and Intelligent Educational Systems (SSIES).

  8. The balance of kinetic and total energy simulated by the OSU two-level atmospheric general circulation model for January and July

    Science.gov (United States)

    Wang, J.-T.; Gates, W. L.; Kim, J.-W.

    1984-01-01

    A three-year simulation which prescribes seasonally varying solar radiation and sea surface temperature is the basis of the present study of the horizontal structure of the balances of kinetic and total energy simulated by Oregon State University's two-level atmospheric general circulation model. Mechanisms responsible for the local energy changes are identified, and the energy balance requirement's fulfilment is examined. In January, the vertical integral of the total energy shows large amounts of external heating over the North Pacific and Atlantic, together with cooling over most of the land area of the Northern Hemisphere. In July, an overall seasonal reversal is found. Both seasons are also characterized by strong energy flux divergence in the tropics, in association with the poleward transport of heat and momentum.

  9. A Global Optimizing Policy for Decaying Items with Ramp-Type Demand Rate under Two-Level Trade Credit Financing Taking Account of Preservation Technology

    Directory of Open Access Journals (Sweden)

    S. R. Singh

    2013-01-01

    Full Text Available An inventory system for deteriorating items, with ramp-type demand rate, under two-level trade credit policy taking account of preservation technology is considered. The objective of this study is to develop a deteriorating inventory policy when the supplier provides to the retailer a permissible delay in payments, and during this credit period, the retailer accumulates the revenue and earns interest on that revenue; also the retailer invests on the preservation technology to reduce the rate of product deterioration. Shortages are allowed and partially backlogged. Sufficient conditions of the existence and uniqueness of the optimal replenishment policy are provided, and an algorithm, for its determination, is proposed. Numerical examples draw attention to the obtained results, and the sensitivity analysis of the optimal solution with respect to leading parameters of the system is carried out.

  10. A two-level model of rise time in quantum cascade laser materials applied to 5 micron, 9 micron and terahertz-range wavelengths

    International Nuclear Information System (INIS)

    Webb, J F; Yong, K S C; Haldar, M K

    2014-01-01

    An equivalent circuit simulation of a two-level rate equation model for quantum cascade laser (QCL) materials is used to study the turn on delay and rise time for three QCLs with 5 micron, 9 micron and terahertz-range wavelengths. In order to do this it is necessary that the model can deal with large signal responses and not be restricted to small signal responses; the model used here is capable of this. The effect of varying some of the characteristic times in the model is also investigated. The comparison of the terahertz wave QCL with the others is particularly important given the increased interest in terahertz sources which have a large range of important applications, such as in medical imaging

  11. Problem of two-level hierarchical minimax program control the final state of regional social and economic system in the presence of risks

    International Nuclear Information System (INIS)

    Shorikov, A. F.

    2015-01-01

    This article discusses a discrete-time dynamical system consisting of a set a controllable objects (region and forming it municipalities). The dynamics each of these is described by the corresponding vector nonlinear discrete-time recurrent vector equations and its control system consist from two levels: basic (control level I) that is dominating and subordinate level (control level II). Both levels have different criterions of functioning and united a priori by determined informational and control connections defined in advance. In this paper we study the problem of optimization of guaranteed result for program control by the final state of regional social and economic system in the presence of risks. For this problem we proposed in this work an economical and mathematical model of two-level hierarchical minimax program control the final state of regional social and economic system in the presence of risks and the general scheme for its solving

  12. Problem of two-level hierarchical minimax program control the final state of regional social and economic system in the presence of risks

    Energy Technology Data Exchange (ETDEWEB)

    Shorikov, A. F., E-mail: afshorikov@mail.ru [Ural Federal University, 19 S. Mira, Ekaterinburg, 620002, Russia Institute of Mathematics and Mechanics, Ural Branch of Russian Academy of Sciences, 16 S. Kovalevskaya, Ekaterinburg, 620990 (Russian Federation)

    2015-11-30

    This article discusses a discrete-time dynamical system consisting of a set a controllable objects (region and forming it municipalities). The dynamics each of these is described by the corresponding vector nonlinear discrete-time recurrent vector equations and its control system consist from two levels: basic (control level I) that is dominating and subordinate level (control level II). Both levels have different criterions of functioning and united a priori by determined informational and control connections defined in advance. In this paper we study the problem of optimization of guaranteed result for program control by the final state of regional social and economic system in the presence of risks. For this problem we proposed in this work an economical and mathematical model of two-level hierarchical minimax program control the final state of regional social and economic system in the presence of risks and the general scheme for its solving.

  13. Analysis, control and design of a non-inverting buck-boost converter: A bump-less two-level T-S fuzzy PI control.

    Science.gov (United States)

    Almasi, Omid Naghash; Fereshtehpoor, Vahid; Khooban, Mohammad Hassan; Blaabjerg, Frede

    2017-03-01

    In this paper, a new modified fuzzy Two-Level Control Scheme (TLCS) is proposed to control a non-inverting buck-boost converter. Each level of fuzzy TLCS consists of a tuned fuzzy PI controller. In addition, a Takagi-Sugeno-Kang (TSK) fuzzy switch proposed to transfer the fuzzy PI controllers to each other in the control system. The major difficulty in designing fuzzy TLCS which degrades its performance is emerging unwanted drastic oscillations in the converter output voltage during replacing the controllers. Thereby, the fuzzy PI controllers in each level of TLCS structure are modified to eliminate these oscillations and improve the system performance. Some simulations and digital signal processor based experiments are conducted on a non-inverting buck-boost converter to support the effectiveness of the proposed TLCS in controlling the converter output voltage. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  14. Decay-out from low-lying superdeformed bands in Pb isotopes: Tunneling widths in a two-level mixing model

    International Nuclear Information System (INIS)

    Wilson, A.N.; Davidson, P.M.

    2004-01-01

    A recently developed two-level mixing model of superdeformed decay is applied to evaluate the tunneling width between the superdeformed and normally deformed potential wells in 192 Pb and 194 Pb. Estimates are made of level densities and γ decay widths for levels in the normally deformed well, which are required for evaluation of the model. Experimental quasicontinuum results are used to suggest a spin-dependent reduction of the energy gap in the level spectrum, resulting in approximately constant level densities and decay widths in the normal well over the decay-out region for each isotope. However, it transpires that the model's prediction of the tunneling width is nearly independent of the normally deformed state widths for both isotopes. This observation is used to extract potential barrier heights for the two nuclei that depend mainly on experimentally determined values

  15. EMI performance comparison of two-level and three-level inverters in small dc-link capacitors based motor drives

    DEFF Research Database (Denmark)

    Maheshwari, Ram Krishan; Munk-Nielsen, Stig; Busquets-Monge, S.

    2012-01-01

    The size of passive components in an adjustable speed drive can be reduced by using small dc-link capacitors. The EMI filter in the drive also consists of passive components. The size of the filter can be reduced by using a three-level inverter, which can have low output voltage distortion. However......, the three-level inverter based on small dc-link capacitors requires a PWM strategy to maintain neutral-point voltage balance. In this paper, the common mode voltage, which is the determining factor for the EMI filter size, is analyzed for a virtual-vector-based PWM strategy. The common mode voltage......, the shaft voltage, and the conducted emission for the small dc-link capacitor based three-level inverter are compared with that of the two-level inverter operated with space vector PWM strategy. Experimental results for the common mode voltage, the shaft voltage, and the conducted emission are presented...

  16. Stability of various entanglements in the interaction between two two-level atoms with a quantized field under the influences of several decay sources

    Science.gov (United States)

    Valizadeh, Sh.; Tavassoly, M. K.; Yazdanpanah, N.

    2018-02-01

    In this paper the interaction between two two-level atoms with a single-mode quantized field is studied. To achieve exact information about the physical properties of the system, one should take into account various sources of dissipation such as photon leakage of cavity, spontaneous emission rate of atoms, internal thermal radiation of cavity and dipole-dipole interaction between the two atoms. In order to achieve the desired goals, we obtain the time evolution of the associated density operator by solving the time-dependent Lindblad equation corresponding to the system. Then, we evaluate the temporal behavior of total population inversion and quantum entanglement between the evolved subsystems, numerically. We clearly show that how the damping parameters affect on the dynamics of considered properties. By analyzing the numerical results, we observe that increasing each of the damping sources leads to faster decay of total population inversion. Also, it is observed that, after starting the interaction, the entanglement between one atom with other parts of the system as well as the entanglement between "atom-atom" subsystem and the "field", tend to some constant values very soon. Moreover, the stable values of entanglement are reduced via increasing the damping factor Γ A (ΓA^{(1)} = ΓA^{(2)} = ΓA ) where ΓA is the spontaneous emission rate of each atom. In addition, we find that by increasing the thermal photons, the entropies (entanglements) tend sooner to some increased stable values. Accordingly, we study the atom-atom entanglement by evaluating the concurrence under the influence of dissipation sources, too. At last, the effects of dissipation sources on the genuine tripartite entanglement between the three subsystems include of two two-level atoms and a quantized field are numerically studied. Due to the important role of stationary entanglement in quantum information processing, our results may provide useful hints for practical protocols which require

  17. Comparison of the therapeutic effect between a transforminal along with a caudal epidural injection, as well as two-level transforaminal epidural injections ina radiculopathy patient

    International Nuclear Information System (INIS)

    Hwang, Jung Han; Hwang, Cheol Mog; Cho, Young Jun; Kim, Keun Won; Kim, Young Joong; Seo, Jae Young; Lim, Seong Joo; Kang, Byeong Seong

    2017-01-01

    The aim of this study was to evaluate the therapeutic effect of a transforaminal epidural steroid injection (TFESI) along with a caudal epidural steroid injection (ESI), compared to two-level TFESIs in a multi-level radiculopathy patient. A total of 895 lumbar ESIs were performed in 492 patients with multi-level radiculopathy from January 2012 to January 2015. Before injections were performed, the initial Numeric Rating Scale (NRS) score was assessed in all patients, categorized into no pain (excellent), mild (good, NRS: 1-3), moderate (fair, NRS: 4-6), and severe pain (poor, NRS: 7-10). Therapeutic effects were examined for two groups: one-level TFESI along with caudal and ESI two-level TFESIs. Patient outcomes were assessed by NRS in a serial follow-up at one, three, and six months. One TFESI along with caudal ESI was performed in 274 patients and two TFESIs for 218. For the former group with one TFESI along with caudal ESI, excellent results were shown: 219 (79.9%) patients after one month, 200 (72.9%) after three, and 193 (70.4%) after six months. In the patient group with two TFESIs (n = 218) the outcomes were also very good: 152 (69.7%) after one month, 131 (60.0%) after three months, and 123 (56.4%) patients after six months. The therapeutic effect of one TFESI along with caudal ESI was better than two TFESIs in for one, threes, and six months (p < 0.01). Transforaminal epidural steroid with caudal epidural injection is a more effective tool for lumbosacral radiculopathy than two level transforaminal injections in multi-level radiculopathy patients

  18. Comparison of the therapeutic effect between a transforminal along with a caudal epidural injection, as well as two-level transforaminal epidural injections ina radiculopathy patient

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Jung Han; Hwang, Cheol Mog; Cho, Young Jun; Kim, Keun Won; Kim, Young Joong; Seo, Jae Young; Lim, Seong Joo [Dept. of Diagnostic Radiology, Konyang University Hospital, Deajeon (Korea, Republic of); Kang, Byeong Seong [Dept. of Radiology, University of Ulsan College of Medicine, Ulsan University Hospital, Ulsan (Korea, Republic of)

    2017-01-15

    The aim of this study was to evaluate the therapeutic effect of a transforaminal epidural steroid injection (TFESI) along with a caudal epidural steroid injection (ESI), compared to two-level TFESIs in a multi-level radiculopathy patient. A total of 895 lumbar ESIs were performed in 492 patients with multi-level radiculopathy from January 2012 to January 2015. Before injections were performed, the initial Numeric Rating Scale (NRS) score was assessed in all patients, categorized into no pain (excellent), mild (good, NRS: 1-3), moderate (fair, NRS: 4-6), and severe pain (poor, NRS: 7-10). Therapeutic effects were examined for two groups: one-level TFESI along with caudal and ESI two-level TFESIs. Patient outcomes were assessed by NRS in a serial follow-up at one, three, and six months. One TFESI along with caudal ESI was performed in 274 patients and two TFESIs for 218. For the former group with one TFESI along with caudal ESI, excellent results were shown: 219 (79.9%) patients after one month, 200 (72.9%) after three, and 193 (70.4%) after six months. In the patient group with two TFESIs (n = 218) the outcomes were also very good: 152 (69.7%) after one month, 131 (60.0%) after three months, and 123 (56.4%) patients after six months. The therapeutic effect of one TFESI along with caudal ESI was better than two TFESIs in for one, threes, and six months (p < 0.01). Transforaminal epidural steroid with caudal epidural injection is a more effective tool for lumbosacral radiculopathy than two level transforaminal injections in multi-level radiculopathy patients.

  19. Mobile Operating Systems

    OpenAIRE

    Vipin Kamboj; Hitesh Gupta

    2012-01-01

    Mobile phones are used by every people in today’s life. We use mobile phones without knowing the different factors that a mobile used including its technology, operating system, CPU ,RAM etc. Many types of operating system are used by different mobile. Every operating system has their advantage

  20. Mobile Africa : an introduction

    NARCIS (Netherlands)

    Bruijn, de M.E.; Dijk, van R.A.; Foeken, D.W.J.

    2001-01-01

    The case studies in this book on mobility in sub-Saharan Africa critically discuss dichotomous interpretations of mobility and reject the idea that migration indicates a breakdown in society. They adopt the approach that sedentary and mobile worlds converge and that mobility is part of the

  1. Evolution of Mobile Applications

    Directory of Open Access Journals (Sweden)

    Phongtraychack Anachack

    2018-01-01

    Full Text Available Currently, we can see the rapid evolution of mobile technology, which involves mobile communication, mobile hardware, and mobile software. Features of mobile phones largely depend on software. In contemporary information and communication age [1–4], mobile application is one of the most concerned and rapidly developing areas. At the same time, the development of mobile application undergoes great changes with the introduction of new software, service platforms and software development kits (SDK. These changes lead to appearance of many new service platforms such as Google with Android and Apple with iOS. This article presents the information about the evolution of mobile application, gives some statistical data on the past and present situation, demonstrates how individual users of mobile devices can benefit, and shows how mobile applications affect society from the ethical perspective.

  2. Moral actor, selfish agent.

    Science.gov (United States)

    Frimer, Jeremy A; Schaefer, Nicola K; Oakes, Harrison

    2014-05-01

    People are motivated to behave selfishly while appearing moral. This tension gives rise to 2 divergently motivated selves. The actor-the watched self-tends to be moral; the agent-the self as executor-tends to be selfish. Three studies present direct evidence of the actor's and agent's distinct motives. To recruit the self-as-actor, we asked people to rate the importance of various goals. To recruit the self-as-agent, we asked people to describe their goals verbally. In Study 1, actors claimed their goals were equally about helping the self and others (viz., moral); agents claimed their goals were primarily about helping the self (viz., selfish). This disparity was evident in both individualist and collectivist cultures, attesting to the universality of the selfish agent. Study 2 compared actors' and agents' motives to those of people role-playing highly prosocial or selfish exemplars. In content (Study 2a) and in the impressions they made on an outside observer (Study 2b), actors' motives were similar to those of the prosocial role-players, whereas agents' motives were similar to those of the selfish role-players. Study 3 accounted for the difference between the actor and agent: Participants claimed that their agent's motives were the more realistic and that their actor's motives were the more idealistic. The selfish agent/moral actor duality may account for why implicit and explicit measures of the same construct diverge, and why feeling watched brings out the better angels of human nature.

  3. MOBILITY: A SYSTEMS APPROACH

    OpenAIRE

    Mykola I. Striuk; Serhiy O. Semerikov; Andrii M. Striuk

    2015-01-01

    A comprehensive study on the problem of mobility in the socio-educational and technical systems was carried out: the evolution of the concept of mobility in scientific sources of XIX–XXI centuries was analyzed and the new sources on the issue of mobility introduced into scientific circulation, the interrelation of the types of mobility in the socio-pedagogical and technical systems are theoretically grounded, an integrative model of mobility in the information society is proposed. The major t...

  4. Mobile platform security

    CERN Document Server

    Asokan, N; Dmitrienko, Alexandra

    2013-01-01

    Recently, mobile security has garnered considerable interest in both the research community and industry due to the popularity of smartphones. The current smartphone platforms are open systems that allow application development, also for malicious parties. To protect the mobile device, its user, and other mobile ecosystem stakeholders such as network operators, application execution is controlled by a platform security architecture. This book explores how such mobile platform security architectures work. We present a generic model for mobile platform security architectures: the model illustrat

  5. Towards flexible and scalable distributed monitoring with mobile agents

    NARCIS (Netherlands)

    Liotta, A.

    2001-01-01

    The tremendous success of the Internet has made possible and even encouraged the realisation of systems characterised by very large scale and high level of distribution. Managing such systems requires systematic communication between a centralised station and distributed components. In many cases, a

  6. Decentralized Services Orchestration Using Intelligent Mobile Agents with Deadline Restrictions

    OpenAIRE

    Magalhães , Alex; Lung , Lau Cheuk; Rech , Luciana

    2010-01-01

    International audience; The necessity for better performance drives service orchestration towards decentralization. There is a recent approach where the integrator - that traditionally centralizes all corporative services and business logics - remains as a repository of interface services, but now lacks to know all business logics and business workflows. There are several techniques using this recent approach, including hybrid solutions, peer-to-peer solutions and trigger-based mechanisms. A ...

  7. The Uniframe Mobile Agent Based Resource Discovery Service

    National Research Council Canada - National Science Library

    Gandhamaneni, Jayasree

    2004-01-01

    .... The UniFrame paradigm provides an approach for automatic or semi-automatic creation of a DCS by seamless integration of software components taking into account both functional and non-functional (such as QoS) requirements...

  8. Using of colleague learning mobile agents for protecting the ...

    African Journals Online (AJOL)

    With the growing use of the internet network, using tools that can help user to transact ... detecting obtrusive in the networks, games and entertainment, etc. one of the ... the existing methods, advantages and disadvantages will be investigated.

  9. Agent Architectures for Compliance

    Science.gov (United States)

    Burgemeestre, Brigitte; Hulstijn, Joris; Tan, Yao-Hua

    A Normative Multi-Agent System consists of autonomous agents who must comply with social norms. Different kinds of norms make different assumptions about the cognitive architecture of the agents. For example, a principle-based norm assumes that agents can reflect upon the consequences of their actions; a rule-based formulation only assumes that agents can avoid violations. In this paper we present several cognitive agent architectures for self-monitoring and compliance. We show how different assumptions about the cognitive architecture lead to different information needs when assessing compliance. The approach is validated with a case study of horizontal monitoring, an approach to corporate tax auditing recently introduced by the Dutch Customs and Tax Authority.

  10. A review of the types of mobile activities in mobile inquiry-based learning

    NARCIS (Netherlands)

    Suarez, Angel; Specht, Marcus; Prinsen, Fleur; Kalz, Marco; Ternier, Stefaan

    2017-01-01

    Inquiry-based Learning is increasingly suggested as an efficient approach for fostering learners’ curiosity and motivation. It helps learners to develop their ability to work in complex and unpredictable environments making them more critical thinkers and agentic learners. Although mobile technology

  11. Mobile operators as banks or vice-versa? and: the challenges of Mobile channels for banks

    NARCIS (Netherlands)

    L-F. Pau (Louis-François)

    2004-01-01

    textabstractThis short paper addresses the strategic challenges of deposit banks, and payment clearinghouses, posed by the growing role of mobile operators as collectors and payment agents of flow of cash for themselves and third parties. Through analysis and data analysis from selected operators ,

  12. Stabilized radiographic scanning agents

    International Nuclear Information System (INIS)

    Fawzi, M.B.

    1982-01-01

    Stable compositions useful as technetium 99m-based scintigraphic agents comprise gentisic acid or a pharmaceutically-acceptable salt or ester thereof in combination with a pertechnetate reducing agent or dissolved in pertechnetate-99m (sup(99m)TcOsub(4)sup(-)) solution. The compositions are especially useful in combination with a phosphate or phosphonate material that carries the radionuclide to bone, thus providing a skeletal imaging agent

  13. Abrechnung mobiler Dienste im Mobile-Payment-Referenzmodell

    OpenAIRE

    Pousttchi, Key; Wiedemann, Dietmar Georg

    2005-01-01

    The purpose of the paper is to analyze mobile payments in the mobile commerce scenario. Therefore, we first classify the mobile payment in the mobile commerce scenario by explaining general offer models, charging concepts, and intermediaries. Second, we describe the mobile payment reference model, especially, the mobile payment reference organization model and different mobile payment standard types. Finally, we conclude our findings.

  14. Charging of mobile services by mobile payment reference model

    OpenAIRE

    Pousttchi, Key; Wiedemann, Dietmar Georg

    2005-01-01

    The purpose of the paper is to analyze mobile payments in the mobile commerce scenario. Therefore, we first classify the mobile payment in the mobile commerce scenario by explaining general offer models, charging concepts, and intermediaries. Second, we describe the mobile payment reference model, especially, the mobile payment reference organization model and different mobile payment standard types. Finally, we conclude our findings.

  15. Language competition in a population of migrating agents

    Science.gov (United States)

    Lipowska, Dorota; Lipowski, Adam

    2017-05-01

    Influencing various aspects of human activity, migration is associated also with language formation. To examine the mutual interaction of these processes, we study a Naming Game with migrating agents. The dynamics of the model leads to formation of low-mobility clusters, which turns out to break the symmetry of the model: although the Naming Game remains symmetric, low-mobility languages are favored. High-mobility languages are gradually eliminated from the system, and the dynamics of language formation considerably slows down. Our model is too simple to explain in detail language competition of migrating human communities, but it certainly shows that languages of settlers are favored over nomadic ones.

  16. Contrast agents for MRI

    International Nuclear Information System (INIS)

    Bonnemain, B.

    1994-01-01

    Contrast agents MRI (Magnetic Resonance Imaging) have been developed to improve the diagnostic information obtained by this technic. They mainly interact on T1 and T2 parameters and increase consequently normal to abnormal tissues contrast. The paramagnetic agents which mainly act on longitudinal relaxation rate (T1) are gadolinium complexes for which stability is the main parameter to avoid any release of free gadolinium. The superparamagnetic agents that decrease signal intensity by an effect on transversal relaxation rate (T2) are developed for liver, digestive and lymph node imaging. Many area of research are now opened for optimal use of present and future contrast agents in MRI. (author). 28 refs., 4 tabs

  17. Decontamination Data - Blister Agents

    Data.gov (United States)

    U.S. Environmental Protection Agency — Decontamination efficacy data for blister agents on various building materials using various decontamination solutions. This dataset is associated with the following...

  18. The Design and Development of an Omni-Directional Mobile Robot Oriented to an Intelligent Manufacturing System.

    Science.gov (United States)

    Qian, Jun; Zi, Bin; Wang, Daoming; Ma, Yangang; Zhang, Dan

    2017-09-10

    In order to transport materials flexibly and smoothly in a tight plant environment, an omni-directional mobile robot based on four Mecanum wheels was designed. The mechanical system of the mobile robot is made up of three separable layers so as to simplify its combination and reorganization. Each modularized wheel was installed on a vertical suspension mechanism, which ensures the moving stability and keeps the distances of four wheels invariable. The control system consists of two-level controllers that implement motion control and multi-sensor data processing, respectively. In order to make the mobile robot navigate in an unknown semi-structured indoor environment, the data from a Kinect visual sensor and four wheel encoders were fused to localize the mobile robot using an extended Kalman filter with specific processing. Finally, the mobile robot was integrated in an intelligent manufacturing system for material conveying. Experimental results show that the omni-directional mobile robot can move stably and autonomously in an indoor environment and in industrial fields.

  19. Head First Mobile Web

    CERN Document Server

    Gardner, Lyza; Grigsby, Jason

    2011-01-01

    Despite the huge number of mobile devices and apps in use today, your business still needs a website. You just need it to be mobile. Head First Mobile Web walks you through the process of making a conventional website work on a variety smartphones and tablets. Put your JavaScript, CSS media query, and HTML5 skills to work-then optimize your site to perform its best in the demanding mobile market. Along the way, you'll discover how to adapt your business strategy to target specific devices. Navigate the increasingly complex mobile landscapeTake both technical and strategic approaches to mobile

  20. Mobile Portal Implementation Strategy

    DEFF Research Database (Denmark)

    Gao, Ping; Damsgaard, Jan

    2005-01-01

    Mobile portal plays an important role in mobile commerce market. Current literature focuses on static analysis on the value chain of mobile portals. This article provides a dynamic perspective on mobile portal strategy. Drawing upon network economics, we describe mobile portal implementation...... as a fourphase process. In different phase, a portal provider has various challenges to overcome and adopt diverse strategies, and correspondingly the regulator has different foci. The conceptual framework proposed in this article offers a basis for further analyses on the market dynamics of mobile commerce......, and can be generalized to studying other networked technologies...