WorldWideScience

Sample records for monolithic mobile agent

  1. Mobile Agents

    Science.gov (United States)

    Satoh, Ichiro

    Mobile agents are autonomous programs that can travel from computer to computer in a network, at times and to places of their own choosing. The state of the running program is saved, by being transmitted to the destination. The program is resumed at the destination continuing its processing with the saved state. They can provide a convenient, efficient, and robust framework for implementing distributed applications and smart environments for several reasons, including improvements to the latency and bandwidth of client-server applications and reducing vulnerability to network disconnection. In fact, mobile agents have several advantages in the development of various services in smart environments in addition to distributed applications.

  2. MOBILE AGENT: EMERGING TECHNOLOGY

    OpenAIRE

    RAJGURU P. V. DR. DESHMUKH S. D

    2011-01-01

    Mobile agent technology has been promoted as an emerging technology that makes it much easier to design, implement, and maintain distributed systems, introduction to basic concepts of mobile agents like agent mobility, agent types and places and agent communication. Then benefits of the usage of mobile agents are summarized and illustrated by selected applications. The next section lists requirements and desirable properties for mobile agent languages and systems. We study the main features, ...

  3. Secure Mobile Trade Agent

    Directory of Open Access Journals (Sweden)

    Musbah M. Aqe

    2007-01-01

    Full Text Available E-commerce on the internet has the ability to produce millions of transactions and a great number of merchants whose supply merchandise over the internet. As a result, it is difficult for entities to roam over every site on the internet and choose the best merchandise to trade. So, in this paper we introduced a mobile trade agent that visit the sites to gather and evaluate the information from merchant servers and decide to trade goods on behalf of the user. We observed that the combination of public key cryptosystem with distributed object technology make this proposed scheme more secure and efficient than the already existed schemes.

  4. Mobile Agents - Smart Messages

    OpenAIRE

    Hurst, Leon; Cunningham, Padraig

    1997-01-01

    Wireless communication with Mobile Computing devices is known to be problematic. It is very different in character from conventional communication over wired networks. Since many distributed applications make assumptions about network characteristics, they may not be used in a hostile mobile environment. We are proposing a new kind of messaging system which incorporates adaptive behaviour into the messages themselves. We call these `Smart Messages?, and implement them using ...

  5. Mobile agent driven by aspect

    Directory of Open Access Journals (Sweden)

    Youssef Hannad

    2010-11-01

    Full Text Available Domain application of mobile agents is quite large. They are used for network management and the monitoring of complex architecture. Mobile agent is also essential into specific software architecture such that adaptable grid architecture. Even if the concept of mobile agent seems to be obvious, the development is always complex because it needs to understand network features but also security features and negotiation algorithms. We present a work about an application of aspects dedicated to mobile agent development over a local network. At this level, the underlying protocol is called jini and allows managing several essential concepts such that short transaction and permission management. Three subsets of aspects are defined in this work. A part is for the description of agent host and its security level, accessible resource, etc. A second part is about mobile agent and their collaboration. This means how they can operate on an agent host with the respect of the execution context. All the results are illustrated through a distributed monitoring application called DMA. Its main objective is the observation of component servers.

  6. New agents in HSC mobilization.

    Science.gov (United States)

    Domingues, Mélanie J; Nilsson, Susan K; Cao, Benjamin

    2017-02-01

    Mobilized peripheral blood (PB) is the most common source of hematopoietic stem cells (HSC) for autologous transplantation. Granulocyte colony stimulating factor (G-CSF) is the most commonly used mobilization agent, yet despite its widespread use, a considerable number of patients still fail to mobilize. Recently, a greater understanding of the interactions that regulate HSC homeostasis in the bone marrow (BM) microenvironment has enabled the development of new molecules that mobilize HSC through specific inhibition, modulation or perturbation of these interactions. AMD3100 (plerixafor), a small molecule that selectively inhibits the chemokine receptor CXCR4 is approved for mobilization in combination with G-CSF in patients with Non-Hodgkin's lymphoma and multiple myeloma. Nevertheless, identifying mobilization strategies that not only enhance HSC number, but are rapid and generate an optimal "mobilized product" for improved transplant outcomes remains an area of clinical importance. In recent times, new agents based on recombinant proteins, peptides and small molecules have been identified as potential candidates for therapeutic HSC mobilization. In this review, we describe the most recent developments in HSC mobilization agents and their potential impact in HSC transplantation.

  7. Mobile agent security using proxy-agents and trusted domains

    OpenAIRE

    Mitrovic, Nikola; Arronategui Arribalzaga, Unai

    2009-01-01

    Commercial or wide-network deployment of Mobile Agent Systems is not possible without satisfying security architecture. In this paper we propose architecture for secure Mobile Agent Systems, using Trusted Domains and Proxy agents. Existing approaches are based on security services at the level of an agent system, library or specific objects. Our concept uses proxy agents to enable transparent security services both to security-aware mobile agents and legacy agents. Per-agent and domain-level...

  8. 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...

  9. Analysis and Optimization for Mobile Agent Communication

    Institute of Scientific and Technical Information of China (English)

    YANGBo; LIUDayou

    2005-01-01

    Communication performance is one of the most important factors affecting the efficiency of mobile agent system. Only traditional optimization techniques for communication performance are not enough, especially in large-scale intelligent mobile agent system, so more intelligent optimization techniques are needed. In the background, the paper studies communication of mobile agent system from the viewpoint of performance. The paper makes qualitative and quantitative analysis of four important factors that will affect the communication performance of mobile agent system and presents the communication performance optimization model. The model hasthree primary functions. First, the model provides a formalism method to describe the communication task and process of mobile agent. Second, the model provides a means to make quantitative analysis of the performance of mobile agent system. Third, the model can plan out an optimal communication scheme for mobile agent to minimize the cost of whole communication. The model could thus be a building block for the optimization of the communication behavior of mobile agent.

  10. 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.

  11. 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.

  12. Decentralized network management based on mobile agent

    Institute of Scientific and Technical Information of China (English)

    李锋; 冯珊

    2004-01-01

    The mobile agent technology can be employed effectively for the decentralized management of complex networks. We show how the integration of mobile agent with legacy management protocol, such as simple network management protocol (SNMP), leads to decentralized management architecture. HostWatcher is a framework that allows mobile agents to roam network, collect and process data, and perform certain adaptive actions. A prototype system is built and a quantitative analysis underlines the benefits in respect to reducing network load.

  13. Security of Mobile Agents on the Internet.

    Science.gov (United States)

    Corradi, Antonio; Montanari, Rebecca; Stefanelli, Cesare

    2001-01-01

    Discussion of the Internet focuses on new programming paradigms based on mobile agents. Considers the security issues associated with mobile agents and proposes a security architecture composed of a wide set of services and components capable of adapting to a variety of applications, particularly electronic commerce. (Author/LRW)

  14. The Research on Mobile-agent Security

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Mobile agent technology offers a new computing paradigm in which a program, in the form of a software agent, can suspend its execution in a host computer, transfer itself to another agent-enabled host in the network, and resume execution of the new host. As the sophistication of mobile software has increased with the time, so have the associated threats to security. This paper provides an overview of the range of threats facing the designers of mobile agent. The paper also identifies generic security objectives, and a range of measures for countering the identified threats.

  15. Information Service Model with Mobile Agent Supported

    Institute of Scientific and Technical Information of China (English)

    邹涛; 王继成; 张福炎

    2000-01-01

    Mobile Agent is a kind of novel agent technology characterized by mobile, intelligent, parallel and asynchronous computing. In this paper, a new information service model that adopts mobile agent technology is introduced first,and then an experimental system DOLTRIA system that is implemented based on the model is described. The DOLTRIA system implemented by WWW framework and Java can search for relevant HTML documents on a set of Web servers. The result of experiments shows that performance improvement can be achieved by this model, and both the elapsed time and network traffic are reduced significantly.

  16. NETWORK MANAGEMENT WITH SECURED MOBILE AGENT

    Institute of Scientific and Technical Information of China (English)

    迈克尔; 徐良贤

    2002-01-01

    Network management scheme must consider security challenges for the Mobile Agent paradigm to be accepted in the Internet computing world. Techniques to provide security solutions have been proposed and some have achieved good results. For example, it is possible to launch a code with a guarantee that it cannot attack the hosting sites. The main problem remaining, however, is protecting the mobile code against malicious service providers, the host problem. This paper proposed a Mobile Agent management scheme in a hierarchical level that provides to user a reliable and flexible global access to internet/network information services. We further described a protection mechanism to Mobile Agents against malicious hosts. As an effort to address host problems we first identify the kinds of attack that may be performed by malicious hosts, and propose a mechanism to prevent these attacks. At each agent host we introduce a trusted third party entity on each server called Secure Service Station (SSS) to carry out security actions.

  17. A Highly Secure Mobile Agent System Architecture

    Science.gov (United States)

    Okataku, Yasukuni; Okutomi, Hidetoshi; Yoshioka, Nobukazu; Ohgishi, Nobuyuki; Honiden, Shinichi

    We propose a system architecture for mobile agents to improve their security in the environments of insecure networks and non-sophisticated terminals such as PDAs. As mobile agents freely migrate onto their favorite terminals through insecure networks or terminals, it is not appropriate for them to store some secret information for authentication and encryption/decryption. We introduce one and more secure nodes(OASIS NODE) for securely generating and verifying authentication codes. The each agent’s data are encrypted by a pseudo-chaos cipher mechanism which doesn’t need any floating processing co-processor. We’ve constructed a prototype system on a Java mobile agent framework, “Bee-gent" which implements the proposed authentication and cipher mechanisms, and evaluated their performances and their applicability to business fields such as an auction system by mobile agents.

  18. An Application of Mobile Agent System in Network Management

    Institute of Scientific and Technical Information of China (English)

    YANGChen-xiang; DUJun-ping; YINYi-xin

    2004-01-01

    This paper describes an application of a reusable mobile agent system in network management. A mobile agent reusable system is constructed to realize a new method in forming mobile agent systems. By using this method, an agent can change its route dynamically without making any change to its specific behavior. By classifying mobile agents into two categories, the task agent can be reusable in different networks. In this way, a mobile agent system can easily carry out network management tasks.

  19. Safe motion planning for mobile agents: A model of reactive planning for multiple mobile agents

    Energy Technology Data Exchange (ETDEWEB)

    Fujimura, Kikuo.

    1990-01-01

    The problem of motion planning for multiple mobile agents is studied. Each planning agent independently plans its own action based on its map which contains a limited information about the environment. In an environment where more than one mobile agent interacts, the motions of the robots are uncertain and dynamic. A model for reactive agents is described and simulation results are presented to show their behavior patterns. 18 refs., 2 figs.

  20. 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.

  1. Brahms Mobile Agents: Architecture and Field Tests

    Science.gov (United States)

    Clancey, William J.; Sierhuis, Maarten; Kaskiris, Charis; vanHoof, Ron

    2002-01-01

    We have developed a model-based, distributed architecture that integrates diverse components in a system designed for lunar and planetary surface operations: an astronaut's space suit, cameras, rover/All-Terrain Vehicle (ATV), robotic assistant, other personnel in a local habitat, and a remote mission support team (with time delay). Software processes, called agents, implemented in the Brahms language, run on multiple, mobile platforms. These mobile agents interpret and transform available data to help people and robotic systems coordinate their actions to make operations more safe and efficient. The Brahms-based mobile agent architecture (MAA) uses a novel combination of agent types so the software agents may understand and facilitate communications between people and between system components. A state-of-the-art spoken dialogue interface is integrated with Brahms models, supporting a speech-driven field observation record and rover command system (e.g., return here later and bring this back to the habitat ). This combination of agents, rover, and model-based spoken dialogue interface constitutes a personal assistant. An important aspect of the methodology involves first simulating the entire system in Brahms, then configuring the agents into a run-time system.

  2. 移动Agent的应用%Application of Mobile Agent

    Institute of Scientific and Technical Information of China (English)

    王继宏; 胡建平

    2000-01-01

    Based on the active ,individuality of the mobile Agent and low-consumption of the network bandwidth,mobile Agent is the newly born network communication and complete distributed computing mode. It has largely developing potential.. This paper presents the role of mobile Agent in present application and discusses the typical mobile Agent area based on the characters of mobile Agent. We provide a new way to classify the applications.

  3. Mobile Agent PLM Architecture for extended enterprise

    Directory of Open Access Journals (Sweden)

    Abdelhak Boulaalam

    2011-01-01

    Full Text Available Nowadays manufacturers are under increased pressure to have an add value for their products to struggle the low-cost production in emerging countries. Distributed control and Intelligent Product are a new and exciting opportunity to build more effective process networks for a wide range of applications in logistics and product development, Radio Frequency Identification is applied increasingly; this technology applied in conjunction with the Mobile Agent system can bring more values in managing and control the lifecycle of products by optimizing the three essential factors: cost, quality and deadline for the survival of a company in the competitive manufacturing world. In this paper we propose Mobile Agent PLM Architecture for extended enterprise, based on Mobile Agent and RFID or, more generally, Product Embedded Information Devices (PEID, for tracking and managing the information of the whole product lifecycle in the extended enterprise, and to satisfy new requirements for increased integrability, traceability, adaptability, extendibility, and closed-loop PLM. Mobile Agents are suitable for tracking information in distributing environment and the mobility aspect, at any time and any place. This paper proposes a first architecture based on these technologies.

  4. Dispatching mobile Agents for DDM applicationss

    Institute of Scientific and Technical Information of China (English)

    LI Xi-ning; Guillaume Autran

    2008-01-01

    Techniques for mining information from distributed data sources accessible over the Internet are a growing area of research. The mobile Agent paradigm opens a new door for distributed data mining and knowledge discovery applications. In this paper we present the design of a mobile agent system which couples service discovery, using a logical language based application programming interface, and database access. Combining mobility with database access provides a means to create more efficient data mining applications. The processing of data is moved to network wide data locations instead of the traditional approach of bringing huge amount of data to the processing location. Our proposal aims at implementing system tools that will enable intelligent mobile Agents to roam the Internet searching for distributed data services. Agents access the data, discover patterns, extract useful information from facts recorded in the databases, then communicate local results back to the user. The user then generates a global data model through the aggregation of results provided by all Agents. This overcomes barriers posed by network congestion, poor security, and unreliability.

  5. 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)

  6. A Forward Integrity and Itinerary Secrecy Protocol for Mobile Agents

    Institute of Scientific and Technical Information of China (English)

    GUAN Huanmei; MENG Xuejun; ZHANG Huanguo

    2006-01-01

    The security problem of mobile agents is widely being discussed. The problem which protects mobile agents from malicious hosts is difficult to solve, because a host has access to the complete internal state of an agent. Forward integrity in mobile agents guarantees that offers contained in a mobile agent from previously visited host can not be modified by a malicious host. Itinerary secrecy can prevent mobile agent from being passively attack. This paper proposes a new forward integrity and itinerary secrecy protocol for mobile agent. The protocol can also resist collusion truncation attack.

  7. Mobile Agents Systems in Wireless Applications

    Directory of Open Access Journals (Sweden)

    Mihaela Muntean

    2009-06-01

    Full Text Available The paper presents an introduction in the Mobile Agents Systems and describes how this technology can be used in wireless applications. Also it is shown the possibility of securing wireless applications that use mobile agents and distributed computing. Wireless networks are a relatively new technology in the LAN market. With the weak encryption and security defined in the IEEE standards, wireless LANs, when improperly deployed or administered, can provide a significant risk to those economic sectors. These sectors include health-care, government, and banking in particular. Increasingly diverse heterogeneous wireless infrastructures in combination with more narrowly defined roles of parties participating in the delivery of applications to mobile users pose new challenges for support for delivering these applications.

  8. Application of mobile scanning agent in the network security

    Institute of Scientific and Technical Information of China (English)

    闵君; 冯珊; 唐超; 梅纲

    2004-01-01

    To enhance the security of network systems, puts forward a kind of software agent is put forward, which has the induction ability of network frameworks and the ability of behavior independence. It is mobile scanning agent. More attentions is paid to expound how to design and realize mobile scanning agent. Besides, it is also explained the programs of mobile scanning agent system. In the end, it expects mobile scanning agent.

  9. Consensus in networks of mobile communicating agents

    Science.gov (United States)

    Baronchelli, Andrea; Díaz-Guilera, Albert

    2012-01-01

    Populations of mobile and communicating agents describe a vast array of technological and natural systems, ranging from sensor networks to animal groups. Here, we investigate how a group-level agreement may emerge in the continuously evolving network defined by the local interactions of the moving individuals. We adopt a general scheme of motion in two dimensions and we let the individuals interact through the minimal naming game, a prototypical scheme to investigate social consensus. We distinguish different regimes of convergence determined by the emission range of the agents and by their mobility, and we identify the corresponding scaling behaviors of the consensus time. In the same way, we rationalize also the behavior of the maximum memory used during the convergence process, which determines the minimum cognitive/storage capacity needed by the individuals. Overall, we believe that the simple and general model presented in this paper can represent a helpful reference for a better understanding of the behavior of populations of mobile agents.

  10. Consensus in evolving networks of mobile agents

    Science.gov (United States)

    Baronchelli, Andrea; Díaz-Guilera, Albert

    2012-02-01

    Populations of mobile and communicating agents describe a vast array of technological and natural systems, ranging from sensor networks to animal groups. Here, we investigate how a group-level agreement may emerge in the continuously evolving networks defined by the local interactions of the moving individuals. We adopt a general scheme of motion in two dimensions and we let the individuals interact through the minimal naming game, a prototypical scheme to investigate social consensus. We distinguish different regimes of convergence determined by the emission range of the agents and by their mobility, and we identify the corresponding scaling behaviors of the consensus time. In the same way, we rationalize also the behavior of the maximum memory used during the convergence process, which determines the minimum cognitive/storage capacity needed by the individuals. Overall, we believe that the simple and general model presented in this talk can represent a helpful reference for a better understanding of the behavior of populations of mobile agents.

  11. Transportation dynamics on networks of mobile agents

    CERN Document Server

    Yang, Han-Xin; Xie, Yan-Bo; Lai, Ying-Cheng; Wang, Bing-Hong

    2011-01-01

    Most existing works on transportation dynamics focus on networks of a fixed structure, but networks whose nodes are mobile have become widespread, such as cell-phone networks. We introduce a model to explore the basic physics of transportation on mobile networks. Of particular interest are the dependence of the throughput on the speed of agent movement and communication range. Our computations reveal a hierarchical dependence for the former while, for the latter, we find an algebraic power law between the throughput and the communication range with an exponent determined by the speed. We develop a physical theory based on the Fokker-Planck equation to explain these phenomena. Our findings provide insights into complex transportation dynamics arising commonly in natural and engineering systems.

  12. Evolution of Cooperation among Mobile Agents

    CERN Document Server

    Chen, Zhuo; Cai, Yun-Ze; Xu, Xiao-Ming

    2010-01-01

    We study the effects of mobility on the evolution of cooperation among self-driven agents, which move at a constant speed v in a two-dimensional plane without boundary restrictions and average directions of neighbors within a radius R for collective motion. Adopting the the prisoner's dilemma game and the snowdrift game as metaphors, we find that cooperation can be maintained and even enhanced for small v and modest values of R, when compared with the case that all agents do not move. Depending on the payoff parameter and the game model, the cooperator frequency may show resonant behavior, or reach an absorbing state of all cooperators as the increase of R and the initial population density. These findings may help understanding the role of individual motion in social systems.

  13. Wireless network topology for monitoring mobile agents

    Science.gov (United States)

    Fraser, Matthew J.; James, Daniel A.; Thiel, David V.

    2005-02-01

    A wireless network of multiple sensor nodes for monitoring large numbers of mobile agents is described and investigated. Wireless monitoring provides time critical information from a number of data sources allowing near real-time analysis of the collected data. The developed wireless network provides a moderate data rate, is able to support many wireless nodes and is a low power solution. Novel network structures have been developed to satisfy all of these requirements. This paper evaluates a number of currently available wireless communication protocols, concluding that a Bluetooth wireless network satisfies the above criteria. To support a large number of devices, topologies using inter-piconet and piconet sharing methods have been developed. These network structures are outlined in detail and have been developed with the current Bluetooth hardware limitations in mind. The proposed wireless networks have been developed to be implemented with current Bluetooth hardware. A summary of network performance is included for each developed network structure, and from these figures an appropriate network structure has been chosen that satisfies the requirements of a wireless sensor network for monitoring mobile agents.

  14. A Novel Security Approach in Mobile Agent Using Encryption

    Directory of Open Access Journals (Sweden)

    Nidhi Gupta

    2012-06-01

    Full Text Available 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 replacement of the client-server model. The proposed system is Mobile Agent System. It reduces network load and latency in which there is usually no transmission ofintermediate result. This conserves the network bandwidth .Since the agents are autonomous; the mobile device that dispatches the agent need not be connected all the time.

  15. Application and Development of Mobile Agent in AN

    Institute of Scientific and Technical Information of China (English)

    XU Li; ZHENG Bao-yu

    2004-01-01

    Active Networks represent a significant step in the evolution of packet-switched networks. It aims to move dynamic computation within the network. Mobile agent technology is a novel paradigm for distributed computation. This paper discusses the applicability of mobile agent technology for the development of active networks, both security policy and resource management, and other expected application as well. Based on the discussion, it describes a general mobile agent based Active Network (AN) architecture at last.

  16. Intelligent Detection System framework using Mobile agents

    CERN Document Server

    Jaisankar, N; Swamy, K Durai

    2010-01-01

    An intrusion detection system framework using mobile agents is a layered framework mechanism designed to support heterogeneous network environments to identify intruders at its best. Traditional computer misuse detection techniques can identify known attacks efficiently, but perform very poorly in other cases. Anomaly detection has the potential to detect unknown attacks; however, it is a very challenging task since its aim is to detect unknown attacks without any priori knowledge about specific intrusions. This technology is still at its early stage. The objective of this paper is that the system can detect anomalous user activity. Existing research in this area focuses either on user activity or on program operation but not on both simultaneously. In this paper, an attempt to look at both concurrently is presented. Based on an intrusion detection framework [1], a novel user anomaly detection system has been implemented and conducted several intrusion detection experiments in a simulated environment by analy...

  17. Secure Web Transaction with Anonymous Mobile Agent over Internet

    Institute of Scientific and Technical Information of China (English)

    WANG ChangJie(王常杰); ZHANG FangGuo(张方国); WANG YuMin(王育民)

    2003-01-01

    A major problem of mobile agents is their apparent inability to authenticate transactions in hostile environments. In this paper, a new secure anonymous mobile agent scheme is proposed for the prevention of agent tempering without compromising the mobility or autonomy of the agent. In the scheme, a mobile agent can produce valid signature on website's bid (it means to transact a contact with the web site) on behalf of its customer, without revealing the customer's real private key. In addition, the anonymity of the customer is also achieved when its agent transacts with the websites. Furthermore, the customer who issues a malicious agent or denies the transaction can be identified and detected by Agent Management Center (AMC). Therefore, the scheme is practical in the future electronic commerce over Internet.

  18. Monolithic Integration of GaAs-Based Resonant Tunneling Diode and High Electron Mobility Transistor

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The resonant tunneling diode (RTD) is a kind of novel ultra-high speed and ultra-high frequency negative differential resistance nanoelectronic device. Integration of RTD and other three-terminal compound semiconductor devices is one important direction of high speed integrated circuit development. In this paper, monolithic integration technology of RTD and high electron mobility transistor (HEMT) based on GaAs substrate was discussed. A top-RTD and bottom-HEMT material structure was proposed and epitaxyed. Based on wet chemical etching, electron beam lithography,metal lift-off and air bridge technology, RTD and HEMT were fabricated on the same wafer. The peak-to-valley current ratio of RTD is 4 and the peak voltage is 0.5 V. The maximal transconductance is 120 mS/mm for a 0.25 μm gate length depletion mode HEMT. Current levels of two devices are basically suited. The results validate the feasibility of the designed integration process.

  19. The Study and Perspective of Mobile Agent Security

    Institute of Scientific and Technical Information of China (English)

    MU Hong; WANG Ru-chuan; WANG Hai-yan

    2004-01-01

    Security is an important issue for the widespread deployment of applications based on software agent technology. It is generally agreed that without the proper countermeasures in place, use of agent-based applications will be severely impeded. So many projects have focused on the security issues of mobile agent and many mechanisms have been proposed to solve the security problem. This paper discusses the security issues and the countermeasures. Then it points out some directions for the research of the mobile agent security.

  20. MODEL-BASED PERFORMANCE EVALUATION APPROACH FOR MOBILE AGENT SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Li Xin; Mi Zhengkun; Meng Xudong

    2004-01-01

    Claimed as the next generation programming paradigm, mobile agent technology has attracted extensive interests in recent years. However, up to now, limited research efforts have been devoted to the performance study of mobile agent system and most of these researches focus on agent behavior analysis resulting in that models are hard to apply to mobile agent systems. To bridge the gap, a new performance evaluation model derived from operation mechanisms of mobile agent platforms is proposed. Details are discussed for the design of companion simulation software, which can provide the system performance such as response time of platform to mobile agent. Further investigation is followed on the determination of model parameters. Finally comparison is made between the model-based simulation results and measurement-based real performance of mobile agent systems. The results show that the proposed model and designed software are effective in evaluating performance characteristics of mobile agent systems. The proposed approach can also be considered as the basis of performance analysis for large systems composed of multiple mobile agent platforms.

  1. Impact of mobile phase composition on the performance of porous polymeric monoliths in the elution of small molecules.

    Science.gov (United States)

    Causon, Tim J; Hilder, Emily F; Nischang, Ivo

    2012-11-09

    The influence of mobile phase solvent composition and consequently retention factor on the chromatographic performance for a set of small molecules was studied using a commercially available poly(styrene-co-divinyl benzene) analytical scale porous polymeric monolithic column as an example. Chromatographic elution performance was studied across retention factors from close to 0 up to 100 realized for a set of structurally similar small molecules in a binary reversed-phase solvent environment of acetonitrile and water. By altering the mobile phase composition from volume fractions of acetonitrile of just 10% (v/v) to only acetonitrile it was systematically shown that gel porosity of the monolithic column plays a dominant role in modulating mass transport and the associated chromatographic efficiency in a consistent manner. Up to a sixfold difference in plate height was recorded for the most strongly retained hydrophobic solute (ethylbenzene) at a constant, low flow velocity simply by varying the amount of acetonitrile in the mobile phase. Plate height curves recorded for the set of solutes that comprise benzene, toluene, ethylbenzene as well as phenol and benzyl alcohol further demonstrate the importance of functional group content of the solute and the modulated porous gel structure on mass transport. These results highlight some important practical considerations for characterizing the chromatographic properties of any polymeric monolithic column. First, it is imperative that any chromatographic performance characterization using plate height data explicitly considers the influence of mobile phase composition, retention factor, molecular size and functional groups of the probe solute. Second, as the physicochemical conditions of the material are directly reflected in the gel porosity, a range of different mobile phase compositions, retention factors and probe-specific effects must be investigated to yield a fair appraisal of the chromatographic performance.

  2. Mobile Agents for Web-Based Systems Management.

    Science.gov (United States)

    Bellavista, Paolo; Corradi, Antonio; Tarantino, Fabio; Stefanelli, Cesare

    1999-01-01

    Discussion of mobile agent technology that overcomes the limits of traditional approaches to the management of global Web systems focuses on the MAMAS (mobile agents for the management of applications and systems) management environment that uses JAVA as its implementation language. Stresses security and interoperability. (Author/LRW)

  3. Agent-based Multimodal Interface for Dynamically Autonomous Mobile Robots

    Science.gov (United States)

    2003-01-01

    Agent-based Multimodal Interface for Dynamically Autonomous Mobile Robots Donald Sofge, Magdalena Bugajska, William Adams, Dennis...computing paradigm for integrated distributed artificial intelligence systems on autonomous mobile robots (Figure 1). Figure 1 – CoABS Grid...Architecture for Dynamically Autonomous Mobile Robots The remainder of the paper is organized as follows. Section 2 describes our integrated AI

  4. Mobile Agent Based on Internet%基于Internet的移动Agent

    Institute of Scientific and Technical Information of China (English)

    徐练; 周龙骧; 王翰虎

    2001-01-01

    Mobile Agent is a hybrid of Internet technology and Artificial Intelligence. Today there are tremendous amount of information resources distributing among Internet ,but it's very difficult to find the wanted-thing. Internet has increasingly become a vital compute platform for electron commercial which has highly popular through the world. Developing new Internet-based application programs such as shopping online,e-business,search engine etc pose new task. Mobile Agent proffers new clue and technology. Considering Internet,this thesis conducts a research on architecture,mobile mechanism in mobile Agent system. Based on the Agent theory research and engineering ,the thesis focuses point at researching Mobile Agents,which have the ability to rove through the network. Using OMG's "Mobile Agent Facility Specification" for reference,we design a model architecture of Mobile Agent System. Based on the architecture ,the article analyzes the key technology and gives methods to resolving them ,emphases on mobility mechanism of Agent and implementing it. At last a model of java-based Mobile Agent System is given.

  5. Pivotal Technology Research of Grid Based on Mobile Agent

    Institute of Scientific and Technical Information of China (English)

    CHEN Hong-wei; WANG Ru-chuan

    2004-01-01

    Grid Based on Mobile Agent is a new grid scheme. The purpose of the paper is to solve the pivotal technology of Grid Based on Mobile Agent ( GBMA) combined with thought of Virtual Organization ( VO). In GBMA, virtual organization is viewed as the basic management unit of the grid, and mobile agent is regarded as an important interactive means. Grid architecture, grid resource management and grid task management are the core technology problem of GBMA. The simulation results show that Inter- VO pattern has the obvious advantage because it can make full use of resources from other virtual organizations in GBMA environment.

  6. 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

  7. Web Crawler Based on Mobile Agent and Java Aglets

    Directory of Open Access Journals (Sweden)

    Md. Abu Kausar

    2013-09-01

    Full Text Available With the huge growth of the Internet, many web pages are available online. Search engines use web crawlers to collect these web pages from World Wide Web for the purpose of storage and indexing. Basically Web Crawler is a program, which finds information from the World Wide Web in a systematic and automated manner. This network load farther will be reduced by using mobile agents.The proposed approach uses mobile agents to crawl the pages. A mobile agent is not bound to the system in which it starts execution. It has the unique ability to transfer itself from one system in a network to another system. The main advantages of web crawler based on Mobile Agents are that the analysis part of the crawling process is done locally rather than remote side. This drastically reduces network load and traffic which can improve the performance and efficiency of the whole crawling process.

  8. Retrieving Information from the Invisible Web Using Mobile Agents

    Directory of Open Access Journals (Sweden)

    Fabien-Kenzo Sato

    2005-01-01

    Full Text Available This study proposes a model of information retrieval on the invisible Web by using the mobile agent paradigm. The developed architecture uses the power of a search engine to provide a list of sites of the invisible Web which are likely to be relevant and launches a dynamic search on these sites, thanks to mobile agents. To compare and experiment in real conditions, two versions were implemented: a version using the traditional client/server paradigm and a version using mobile agents. Client/server tests on actual Websites generated satisfactory qualitative results. A series of comparative experiments of the two versions implemented were carried out using a test site. Results show that the mobile agent version generates much less traffic and is thus faster than the client/server version, especially with low bandwidth. Moreover, as the mobile agents carry out calculations on the server rather than on the client’s site, this approach relieves the resources of the client terminal. Thus, the mobile agent approach seems particularly advantageous in the case of weak resource terminals such as PDAs.

  9. Adaptive Hybrid Mobile Agent Protocol for Wireless Multihop Internet Access

    Directory of Open Access Journals (Sweden)

    A. Velmurugan

    2006-01-01

    Full Text Available Internet-based Mobile Ad Hoc Networking (MANET is an emerging technology that supports self-organizing mobile networking infrastructures. This is expected to be of great use in commercial applications for the next generation Internet users. A number of technical challenges are faced today due to the heterogeneous, dynamic nature of this hybrid MANET. A new hybrid routing scheme AODV_ALMA is proposed, which act simultaneously combining mobile agents to find path to the gateway to establish connection with Internet host and on-demand distance vector approach to find path in local MANET is one of the unique solution. An adaptive gateway discovery mechanism based on mobile agents making use of pheromone value, pheromone decay time and balance index is used to estimate the path and next hop to the gateway. The mobile nodes automatically configure the address using mobile agents first selecting the gateway and then using the gateway prefix address. The mobile agents are also used to track changes in topology enabling high network connectivity with reduced delay in packet transmission to Internet. The performance tradeoffs and limitations with existing solutions for various mobility conditions are evaluated using simulation."

  10. Fault Tolerance Mobile Agent System Using Witness Agent in 2-Dimensional Mesh Network

    Directory of Open Access Journals (Sweden)

    Ahmad Rostami

    2010-09-01

    Full Text Available Mobile agents are computer programs that act autonomously on behalf of a user or its owner and travel through a network of heterogeneous machines. Fault tolerance is important in their itinerary. In this paper, existent methods of fault tolerance in mobile agents are described which they are considered in linear network topology. In the methods three agents are used to fault tolerance by cooperating to each others for detecting and recovering server and agent failure. Three types of agents are: actual agent which performs programs for its owner, witness agent which monitors the actual agent and the witness agent after itself, probe which is sent for recovery the actual agent or the witness agent on the side of the witness agent. Communication mechanism in the methods is message passing between these agents. The methods are considered in linear network. We introduce our witness agent approach for fault tolerance mobile agent systems in Two Dimensional Mesh (2D-Mesh Network. Indeed Our approach minimizes Witness-Dependency in this network and then represents its algorithm.

  11. A Flexible and Reliable Architecture for Mobile Agent Security

    Directory of Open Access Journals (Sweden)

    Ghossoon M.W. Al-Saadoon

    2009-01-01

    Full Text Available Problem statement: Wireless application protocol is a protocol that makes it possible to surf the Internet from a cellular phone or other handheld wireless. Many of us that surf the Internet from home with a 56 kbps modem think that it is slow and a cell phone only uses 9.6 kbps so WAP has to take the lesser bandwidth into consideration. For this reason, this study proposed a flexible and reliable system to be implemented by using the characteristic of agents “mobile agent” through wireless application protocol for identification of distributed Intruder. The problem appears when the limitation of data transfer when the distributed systems are used (which includes the heterogeneous database through internet. For this reason the suggested approach will be the solution to the problem of WAP for mobile agent. Approach: The purpose of this study was to present the ability for dispatch mobile agent from a host to carry out operations directly to the remote point of interest, thus agent’s scans provide an appropriate response which is faster than a hierarchical IDS that communicates with a central coordinator based elsewhere on the network. Results: The methodology was used in order to understand the mobile agent mechanism and will introduce the distributed computing mechanisms that are intended for large scale distributed systems. Since the distributed security agent models system was built using mobile agent and net, this will develop small applications for data stores, like sequential query language server. The method used the algorithms built refer to each part of the structure and the rules that implemented (users and the security agent system roles. The result was simulating the intended for business roles for both commercial and government modules, which included the solution to the problem and to architecture to be more flexible and reliable. Conclusion/Recommendations: One of main conclusion for the mobile agent used WAP protocol: To make

  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

    CERN Document Server

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

    2012-01-01

    In this paper, we study into 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. DEVELOPING A NEW MECHANISM FOR LOCATING AND MANAGING MOBILE AGENTS

    Directory of Open Access Journals (Sweden)

    AHMED Y. YOUSUF

    2012-10-01

    Full Text Available There is a trade- off between the agent tracking process and the message delivery process in locating mobile agent systems. In the proposed system we try to strike a balance between these two processes. Communication in Multiagent system requires an efficient mechanism to manage these communications. Reliability and transparency are the design goal for any modern mechanism. In this paper we develop a new mechanism to manage the communication among autonomous mobile agents. This mechanism has the ability to manage agent mobility in an efficient, scalable and transparent way. So no message is lost and all transitions are transparent to the user. The architecture of the proposed mechanism is described and the naming, communication, localization and re-localization ways are given.

  16. Multi-agent cooperative intrusion response in mobile adhoc networks

    Institute of Scientific and Technical Information of China (English)

    Yi Ping; Zou Futai; Jiang Xinghao; Li Jianhua

    2007-01-01

    The nature of adhoc networks makes them vulnerable to security attacks. Many security technologies such as intrusion prevention and intrusion detection are passive in response to intrusions in that their countermeasures are only to protect the networks, and there is no automated network-wide counteraction against detected intrusions. the architecture of cooperation intrusion response based multi-agent is propose. The architecture is composed of mobile agents. Monitor agent resides on every node and monitors its neighbor nodes. Decision agent collects information from monitor nodes and detects an intrusion by security policies. When an intruder is found in the architecture, the block agents will get to the neighbor nodes of the intruder and form the mobile firewall to isolate the intruder. In the end, we evaluate it by simulation.

  17. 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.

  18. A Secure Mobile Agent System against Tailgating Attacks

    Directory of Open Access Journals (Sweden)

    P. Marikkannu

    2011-01-01

    Full Text Available Problem statement: A lot of real time applications have extended their hands towards Mobile Agents to accomplish various tasks, due to its flexibility in its functionalities. Since Mobile Agent Systems are used in a distributed environment, it is obvious that they may be vulnerable to various security threats. Most of the security threats faced by the mobile agent systems are overcome by existing security algorithms and architectures. One of the major threats which are not of much focus in a mobile agent system is the Tailgating attack. Approach: In this study, mobile agent system architecture has been proposed to overcome Tailgating. The proposed architecture uses the mechanism of Dual Check-point to preclude Tailgating attacks. Also, to support the mechanism, we use fragmentation and defragmentation techniques. This assures a free flow of data within the system. Results: The results obtained prove that the system is much efficient in its operations as well is immune to Tailgating attacks. Conclusion: The security of the system is improved with the implementation of the Dual Check-point method.

  19. A Method for Interaction of Mobile Agent and SNMP

    Institute of Scientific and Technical Information of China (English)

    ZHANGPuhan; SUNYufang

    2003-01-01

    Typically, most of existing network man-agement applications are based on protocol SNMP(Simple network management protocol). The protocol is based on static, centralized and non-scalable client/server architec-tures, where some central entity processes large amounts of raw data gathered from each network element. By this reason, the management applications are not flexible, have problems of scalability and produce too much traffic in the network. Mobile agents have been proposed as a so-lution to the problems. However, most of proposed solu-tions often ignore the existing of legacy network manage-ment frameworks and have to change them. This paper presents a method to extend an existing legacy network management framework targeted at network management with an interface for integration with mobile agents and implemented it by using java technology and aglet which is a mobile agent system from IBM.

  20. A mobile agent approach for secure integrated medical information systems.

    Science.gov (United States)

    Liu, Chia-Hui; Chung, Yu-Fang; Chiang, Te-Wei; Chen, Tzer-Shyong; Wang, Sheng-De

    2012-10-01

    Different patient-related information in medical organizations is the primary reference for medical personnel diagnosing, treating, and caring patients. With the rapid development of information technology, paper-based medical records have gradually been changed to electronic forms. However, different medical organizations present individual system specifications and data-saving formats so that the medical information of the same patient cannot be exchanged, shared, and securely accessed. In order not to largely change the present medical information systems as well as not to increase abundant costs, Virtual Integrated Medical-information Systems (VIMS) is proposed to assist various hospitals in information exchange. Furthermore, with Mobile Agent, the dispersed medical information can be securely integrated. It presents confidentiality, non-repudiation, source authentication, and integrity in network transmission. Virtual Integrated Medical-information Systems (VIMS) is a virtual electronic integration system combined with Mobile Agent technology. With the features of independence, adaptability, mobility, objectives, and autonomy, Mobile Agent is applied to overcome the problems from heterogeneous systems. With the features, the over-dispersed medical records can be integrated. Moreover, Mobile Agent can ensure the instantaneity and usability of medical records from which doctors can make the most appropriate evaluation and diagnoses. It will avoid the waste of medical resources, such as repetition medication, as well as become the reference of further consultation or health check. Not only can it improve the medical care quality, but it can be provided for medical research.

  1. 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.

  2. Mobile Agents需求及体系结构%MOBILE AGENTS' REQUIREMENT AND ARCHITECTURE

    Institute of Scientific and Technical Information of China (English)

    何炎祥; 宋志凯; 李锋

    2000-01-01

    Mobile Agents 是分布系统的一种新体系结构和实现方法.Mobile Agents适用的应用有:网络管理、信息获取、远程设备控制、电子商务、移动计算等.本文主要从底层讨论了Mobile Agents的运行需求和体系结构.

  3. Emergence of metapopulations and echo chambers in mobile agents

    CERN Document Server

    Starnini, Michele; Baronchelli, Andrea

    2016-01-01

    Multi-agent models often describe populations segregated either in the physical space, i.e. subdivided in metapopulations, or in the ecology of opinions, i.e. partitioned in echo chambers. Here we show how the interplay between homophily and social influence controls the emergence of both kinds of segregation in a simple model of mobile agents, endowed with a continuous opinion variable. In the model, physical proximity determines a progressive convergence of opinions but differing opinions result in agents moving away from each others. This feedback between mobility and social dynamics determines to the onset of a stable dynamical metapopulation scenario where physically separated groups of like-minded individuals interact with each other through the exchange of agents. The further introduction of confirmation bias in social interactions, defined as the tendency of an individual to favor opinions that match his own, leads to the emergence of echo chambers where different opinions can coexist also within the ...

  4. Distributed formation stabilization for mobile agents using virtual tensegrity structures

    NARCIS (Netherlands)

    Yang, Qingkai; Cao, Ming; Fang, Hao; Chen, Jie

    2015-01-01

    This paper investigates the distributed formation control problem for a group of mobile Euler-Lagrange agents to achieve global stabilization by using virtual tensegrity structures. Firstly, a systematic approach to design tensegrity frameworks is elaborately explained to confine the interaction rel

  5. Interaction with autonomous, mobile agents in a hazard monitoring context

    NARCIS (Netherlands)

    Cramer, H.; Evers, V.; Winterboer, A.; Pavlin, G.; Maris, M.; Groen, F.; Olsen Jr., D.R.; Arthur, R.B.; Hinckley, K.; Ringel Morris, M.; Hudson, S.E.; Greenberg, S.

    2009-01-01

    This paper discusses our ongoing research on user interaction with autonomous mobile agents. The overarching project, DIADEM, involves the development of a (semi-)autonomous system that detects potential environmental hazards in heavily populated urban-industrial areas by using input from both a

  6. Mobile Agent-Based Directed Diffusion in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Victor C. M. Leung

    2007-01-01

    Full Text Available In the environments where the source nodes are close to one another and generate a lot of sensory data traffic with redundancy, transmitting all sensory data by individual nodes not only wastes the scarce wireless bandwidth, but also consumes a lot of battery energy. Instead of each source node sending sensory data to its sink for aggregation (the so-called client/server computing, Qi et al. in 2003 proposed a mobile agent (MA-based distributed sensor network (MADSN for collaborative signal and information processing, which considerably reduces the sensory data traffic and query latency as well. However, MADSN is based on the assumption that the operation of mobile agent is only carried out within one hop in a clustering-based architecture. This paper considers MA in multihop environments and adopts directed diffusion (DD to dispatch MA. The gradient in DD gives a hint to efficiently forward the MA among target sensors. The mobile agent paradigm in combination with the DD framework is dubbed mobile agent-based directed diffusion (MADD. With appropriate parameters set, extensive simulation shows that MADD exhibits better performance than original DD (in the client/server paradigm in terms of packet delivery ratio, energy consumption, and end-to-end delivery latency.

  7. 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.

  8. High Efficiency and Light Mobile Electronic Business System Based on Mobile Agent Middleware

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yunyong; LIU Jinde

    2004-01-01

    Mobile Network technology has been being the research focus during the 1990's.The middleware technology is imported for the sake of running distributed transaction smoothly.In this paper,a mobile agent based middleware high efficiency mobile electronic business oriented middleware (HEMEBOM) is designed and implemented based on the requirement and background of collaborative electronic business.Its architecture,elements and excellent properties are mainly focused.Then high efficiency mobile electronic business systemμMcommerce is built using HEMEBOM.

  9. A Transport Model of Mobile Agent Based on Secure Hybrid Encryption

    Institute of Scientific and Technical Information of China (English)

    SUNZhixin; CHENZhixian; WANGRuchuan

    2005-01-01

    The solution of security problems of mobile agents is a key issue, which will decide whether mobile agents can be widely used. The paper analyzes main security problems, which currently are confronted with mobile agent systems and existing protection solutions. And then the paper presents a Security Transport model of mobile agents based on a hybrid encryption algorithm (TMSHE).Meanwhile, it expatiates on implementation of the algorithm. The algorithm of TMSHE model mainly consists of two parts, i.e., employing a hybrid encryption algorithm to encrypt mobile agents and using Transport layer security (TLS) to encrypt communication channel. Mobile agents by hybrid encryption move through communication channels, which are encrypted by TLS. The simulation results indicate that the model can protect mobile agents' security effectively, and consequently the security and steadiness of the whole mobile agent system are also improved. The model has succeeded in getting application in a prototypesystem- Intrusion detection system based on mobile agents.

  10. Mobile Agents for Service Personalization in Smart Environments

    Directory of Open Access Journals (Sweden)

    Iván Marsá-Maestre

    2008-05-01

    Full Text Available Service personalization is an important goal for any smart environment. Comfort systems may be adjusted in an automatic way when a given user is present, and multimedia devices may offer a music or movie catalog with favorite contents or may even pick one of them for the user. To achieve this goal, we propose a Service Oriented Architecture implementation based on multiagent systems. We specially take advantage of the mobility features of software agents. In particular, we have developed a hierarchical, agent-based solution intended to be applicable to different smart space scenarios, ranging from small environments, like smart homes or smart offices, to large smart spaces like cities. In this paper we describe the global architecture and focus on our approach to service personalization using mobile agents that follow the users as they move through different smart spaces.

  11. A Mobile Agent-Based Prototype of Heterogeneous Distributed Virtual Environment Systems

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Mobile agents provide a new method for the distributed computation. This paper presents the advantages of using mobile agents in a distributed virtual environment (DVE) sys tem, and describes the architecture of heterogeneous computer's distributed virtual environment system (HCNVES) designed to populate some mobile agents as well as stationary agents. Finally, the paper introduces how heterogeneous computer network communication is to be realized.

  12. Mobile Agents and Their Security Problems%Mobile Agent及其安全性问题

    Institute of Scientific and Technical Information of China (English)

    刘建勋; 李仁发; 张申生

    2000-01-01

    该文首先简单介绍了mobile agent的概念与mobile agent 所具有的一些优点,并介绍了mobile agent系统的应用领域及研究现状,然后详细分析了mobile agent系统的安全性问题,即(1)保护运行mobile agent的主机或实体不受恶意Agent的攻击;(2)保护mobile agent不受恶意的运行环境以及不协作的或者有敌意的其它Agent的攻击.并对已有的一些解决方案的思想作了分析介绍.

  13. Control of Synchronization Regimes in Networks of Mobile Interacting Agents

    Science.gov (United States)

    Perez-Diaz, Fernando; Zillmer, Ruediger; Groß, Roderich

    2017-05-01

    We investigate synchronization in a population of mobile pulse-coupled agents with a view towards implementations in swarm-robotics systems and mobile sensor networks. Previous theoretical approaches dealt with range and nearest-neighbor interactions. In the latter case, a synchronization-hindering regime for intermediate agent mobility is found. We investigate the robustness of this intermediate regime under practical scenarios. We show that synchronization in the intermediate regime can be predicted by means of a suitable metric of the phase response curve. Furthermore, we study more-realistic K -nearest-neighbor and cone-of-vision interactions, showing that it is possible to control the extent of the synchronization-hindering region by appropriately tuning the size of the neighborhood. To assess the effect of noise, we analyze the propagation of perturbations over the network and draw an analogy between the response in the hindering regime and stable chaos. Our findings reveal the conditions for the control of clock or activity synchronization of agents with intermediate mobility. In addition, the emergence of the intermediate regime is validated experimentally using a swarm of physical robots interacting with cone-of-vision interactions.

  14. Using Mobile Agents and Overlay Networks to Secure Electrical Networks

    Energy Technology Data Exchange (ETDEWEB)

    Dawes, Neal A.; Prosser, Bryan J.; Fulp, Errin W.; McKinnon, Archibald D.

    2013-02-11

    ABSTRACT The use of wandering, mobile agents can provide a robust approach for managing, monitoring, and securing electrical distribution networks. However, the topological structure of electrical networks can affect system performance. For example, if the multi-agent system relies on a regular inspection rate (on average, points of interest are inspected with equal frequency), then locations that are not well connected will on average be inspected less frequently. This paper discusses creation and use of overlay networks that create a virtual grid graph can provide faster coverage and a more uniform average agent sampling rate. Using overlays agents wander a virtual neighborhood consisting of only points of interest that are interconnected in a regular fashion (each point has the same number of neighbors). Experimental results will show that an overlay can often provide better network coverage and a more uniform inspection rate, which can improve cyber security by providing a faster detection of threats.

  15. Using Mobile Agents and Overlay Networks to Secure Electrical Netoworks

    Energy Technology Data Exchange (ETDEWEB)

    Dawes, Neal A.; Prosser, Bryan J.; Fulp, Errin W.; McKinnon, Archibald D.

    2013-04-01

    ABSTRACT The use of wandering, mobile agents can provide a robust approach for managing, monitoring, and securing electrical distribution networks. However, the topological structure of electrical networks can affect system performance. For example, if the multi-agent system relies on a regular inspection rate (on average, points of interest are inspected with equal frequency), then locations that are not well connected will on average be inspected less frequently. This paper discusses creation and use of overlay networks that create a virtual grid graph can provide faster coverage and a more uniform average agent sampling rate. Using overlays agents wander a virtual neighborhood consisting of only points of interest that are interconnected in a regular fashion (each point has the same number of neighbors). Experimental results will show that an overlay can often provide better network coverage and a more uniform inspection rate, which can improve cyber security by providing a faster detection of threats

  16. Swarm Dynamics of a Group of Mobile Autonomous Agents

    Institute of Scientific and Technical Information of China (English)

    LIU Bo; CHU Tian-Guang; WANG Long; WANG Zhan-Feng

    2005-01-01

    @@ We propose a simple swarm model to study collective behaviour ofa group of mobile autonomous agents interact ing through a long range attraction and short range repulsion function. It is shown that the individuals (agents) will aggregate and eventually form a cohesive cluster of finite size around the swarm centre in a finite time, and the size depends only on the parameters of the swarm model. Furthermore, it is also shown that all the individuals will converge to equilibrium positions of the swarm model, and thus the configuration of the swarm converges to a constant constellation. Numerical simulations are also worked out to illustrate the analytical results.

  17. Building Distributed Web GIS: A Mobile-Agent Based Approach

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The diversity of GISs and the wide-spread availability of WWWhave l e d to an increasing amount of research on integrating a variety of heterogeneous and autonomous GISs in a cooperative environment to construct a new generation o f GIS characterizing in open architecture, distributed computation, interoperabi lity, and extensibility. Our on-going research project MADGI S (Mobile Agent based Distributed Geographic Information System) is reported, in which we pro pose the architecture of MADGIS to meet the requirements of integrating distribu ted GIS applications under Internet environment. We first describe the architect ure of MADGIS, and detailed discussions focusing on the structure of client site , server site and mobile agent in MADGIS. Then we explore key techniques for MAD GIS implementation.

  18. Mobile Agent Based Framework for Integrating Digital Library System

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Few of the current approaches to achieve the integration of digital library system have considered the influence of network factors on quality of service for the integration system of digital libraries. For this reason, a mobile agent based framework for integrating digital library system is proposed. Based on this framework, a prototype system is implemented and the key technique for it are described. Compared with the current approaches, using mobile agent technique to achieve the integration of digital library system can not only avoid transmitting a lot of data on the network, lower the dependence on network bandwidth for the system, but also improve the quality of service for the integration system of digital libraries in intermitted or unreliable network connection settings.

  19. Applying Web Services with Mobile Agents for Computer Network Management

    Directory of Open Access Journals (Sweden)

    Mydhili K.Nair

    2011-03-01

    Full Text Available The exponential rise in complexity of the underlying network elements of a computer network makes itsManagement an intricate, multifaceted and complex problem to solve. With every passing decade, newtechnologies are developed to ease this problem of Network Management. The last decade of the premillenniumera saw the peak of CORBA and Mobile Agent Based implementations, while the first decadeof post millennium saw the emergence of Web Services. All of these technologies evolved as independent,self-contained implementation streams. There is a genuine dearth in finding authentic research outcomeswhere quantifiable, measureable benefits of convergence of these technologies applied to NetworkManagement are put forth. This paper aims to fill this research gap. Here we put forth the experimentalresults obtained of a framework we developed in-house for Network Management that combined twoseemingly divergent distributed computing technologies, namely, Web Services and Mobile Agents.

  20. The Study of Mobile Agent Technology%移动Agent技术研究

    Institute of Scientific and Technical Information of China (English)

    董红斌; 石纯一

    2000-01-01

    Mobile Agent is a new distributed computing model. This articte introduces the concepts,origin,behavior,development language,general structure of mobile agent,and attempts to present an account of current research efforts.

  1. Load Balancing on Open Networks: A Mobile Agent Approach

    Directory of Open Access Journals (Sweden)

    R. B. Patel

    2006-01-01

    Full Text Available In order to disperse the load on a Web server, generally the server cluster is configured to distribute access requests, or mirror servers are distributed geographically on different networks. Use of the Internet and the World-Wide-Web (WWW has become widespread in recent years and mobile agent technology has proliferated at an equally rapid rate to evenly distribute the requests to web servers through load balancing. There are various loads balancing policies came into picture. Primitive one is Message Passing Interface (MPI. Its wide availability and portability make it an attractive choice, however the communication requirements are sometimes inconventior and inefficient when implementing the primitives provided by MPI. Mobile agent (MA based approach have the merits of high flexibility, efficiency, low network traffic, less communication latency as well as highly asynchronous. In this study we present dynamic load balancing using mobile agent technology in which when a node is overloaded, task migrates to less utilized nodes so as to share the workload. However, the decision of which nodes receive migrating task is made in real-time by design and implementation of a framework called Platform for Load balancing (PLB. It is implemented on PMADE (A Platform for Mobile Agent Distribution and Execution. PLB integrated web servers can dispatch MAs to retrieve load information and accomplish load redistribution on all servers. The performance evaluation demonstrates that the PLB framework provides a foundation to develop efficient load balancing schemes on wide range of web server systems from cluster to open network and the results of a comparison of PLB, with some existing ones, is also reported.

  2. Design of monoliths through their mechanical properties.

    Science.gov (United States)

    Podgornik, Aleš; Savnik, Aleš; Jančar, Janez; Krajnc, Nika Lendero

    2014-03-14

    Chromatographic monoliths have several interesting properties making them attractive supports for analytics but also for purification, especially of large biomolecules and bioassemblies. Although many of monolith features were thoroughly investigated, there is no data available to predict how monolith mechanical properties affect its chromatographic performance. In this work, we investigated the effect of porosity, pore size and chemical modification on methacrylate monolith compression modulus. While a linear correlation between pore size and compression modulus was found, the effect of porosity was highly exponential. Through these correlations it was concluded that chemical modification affects monolith porosity without changing the monolith skeleton integrity. Mathematical model to describe the change of monolith permeability as a function of monolith compression modulus was derived and successfully validated for monoliths of different geometries and pore sizes. It enables the prediction of pressure drop increase due to monolith compressibility for any monolith structural characteristics, such as geometry, porosity, pore size or mobile phase properties like viscosity or flow rate, based solely on the data of compression modulus and structural data of non-compressed monolith. Furthermore, it enables simple determination of monolith pore size at which monolith compressibility is the smallest and the most robust performance is expected. Data of monolith compression modulus in combination with developed mathematical model can therefore be used for the prediction of monolith permeability during its implementation but also to accelerate the design of novel chromatographic monoliths with desired hydrodynamic properties for particular application.

  3. Emergence of metapopulations and echo chambers in mobile agents

    Science.gov (United States)

    Starnini, Michele; Frasca, Mattia; Baronchelli, Andrea

    2016-08-01

    Multi-agent models often describe populations segregated either in the physical space, i.e. subdivided in metapopulations, or in the ecology of opinions, i.e. partitioned in echo chambers. Here we show how both kinds of segregation can emerge from the interplay between homophily and social influence in a simple model of mobile agents endowed with a continuous opinion variable. In the model, physical proximity determines a progressive convergence of opinions but differing opinions result in agents moving away from each others. This feedback between mobility and social dynamics determines the onset of a stable dynamical metapopulation scenario where physically separated groups of like-minded individuals interact with each other through the exchange of agents. The further introduction of confirmation bias in social interactions, defined as the tendency of an individual to favor opinions that match his own, leads to the emergence of echo chambers where different opinions coexist also within the same group. We believe that the model may be of interest to researchers investigating the origin of segregation in the offline and online world.

  4. 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.

  5. Percolation and cooperation with mobile agents: Geometric and strategy clusters

    CERN Document Server

    Vainstein, Mendeli H; Arenzon, Jeferson J

    2014-01-01

    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 rP, which accounts for the population viscosity, and an interaction radius rint, which defines the instantaneous contact network for the game dynamics. We show that, differently from the rP=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 extin...

  6. A MOBILE AGENT BASED INTRUSION DETECTION SYSTEM ARCHITECTURE FOR MOBILE AD HOC NETWORKS

    Directory of Open Access Journals (Sweden)

    Binod Kumar Pattanayak

    2014-01-01

    Full Text Available Applications of Mobile Ad Hoc Networks (MANETs have become extensively popular over the years among the researchers. However, the dynamic nature of MANETs imposes a set of challenges to its efficient implementation in practice. One of such challenges represents intrusion detection and prevention procedures that are intended to provide secured performance of ad hoc applications. In this study, we introduce a mobile agent based intrusion detection and prevention architecture for a clustered MANET. Here, a mobile agent resides in each cluster of the ad hoc network and each cluster runs a specific application at any point of time. This application specific approach makes the network more robust to external intrusions directed at the nodes in an ad hoc network.

  7. New Framework for Improving Big Data Analysis Using Mobile Agent

    Directory of Open Access Journals (Sweden)

    Youssef M. ESSA

    2014-01-01

    Full Text Available the rising number of applications serving millions of users and dealing with terabytes of data need to a faster processing paradigms. Recently, there is growing enthusiasm for the notion of big data analysis. Big data analysis becomes a very important aspect for growth productivity, reliability and quality of services (QoS. Processing of big data using a powerful machine is not efficient solution. So, companies focused on using Hadoop software for big data analysis. This is because Hadoop designed to support parallel and distributed data processing. Hadoop provides a distributed file processing system that stores and processes a large scale of data. It enables a fault tolerant by replicating data on three or more machines to avoid data loss.Hadoop is based on client server model and used single master machine called NameNode. However, Hadoop has several drawbacks affecting on its performance and reliability against big data analysis. In this paper, a new framework is proposed to improve big data analysis and overcome specified drawbacks of Hadoop. These drawbacks are replication tasks, Centralized node and nodes failure. The proposed framework is called MapReduce Agent Mobility (MRAM. MRAM is developed by using mobile agent and MapReduce paradigm under Java Agent Development Framework (JADE.

  8. Research on Mobile Agent System Construction%移动Agent系统构建研究

    Institute of Scientific and Technical Information of China (English)

    贾志勇; 谢立

    2003-01-01

    Mobile agent technology has strong adaptability to the status of network and executing environment, and provides a flexible and uniform framework for Web and distributed applications.Mobile agent system, as the foundation of agent computing, should provide the basic supports like executing support, agent migration, andcommunication, as well the extensive supports like naming service, security, fault tolerance, interoperation,application development and management tools. Based on the analysis of current mobile agent system, this article discusses these supports deeply, and also points out the main challenges to the development of mobile agent system.

  9. Decentralized formation control of mobile agents: A unified framework

    Science.gov (United States)

    Chen, Fei; Chen, Zengqiang; Liu, Zhongxin; Xiang, Linying; Yuan, Zhuzhi

    2008-08-01

    This paper studies the formation control problem for systems consisting of multiple mobile agents that are described by first-order differential equations and second-order differential equations respectively. The following issues are investigated: bounded input, disturbance, and time delay. In derivation of the main results, a blend of graph-theoretic and system-theoretic tools is employed, where local potential functions and LaSalle’s Invariant Principle play central roles. Finally, numerical examples which support the analytical results very well are also included.

  10. Mobile intelligent agent entity model towards QoS guarantee

    Institute of Scientific and Technical Information of China (English)

    LI Jie; WANG Ru-chuan; BIAN Zhen-gai

    2006-01-01

    Implementing a flexible configuration of the QoS parameter in a distributed computing network has become a problem due to the weak scalability of current approaches.In an effort to solve this problem,an inner basic model of an intelligent agent (IA) is presented.The IA functionality was extended by introducing a primarily mobile agent.A QoS guarantee scheme was subsequently designed and implemented based on the model as well.By utilizing the proposed scheme,the IA can sense,predict and configure the data flow traffic.Since the communicating ability was considered and provided,the competition among different devices could be eliminated effectively and the global traffic can be optimized.The results of the simulations have shown that the proposed model can provide a QoS guarantee.

  11. An Experimental Approach for Optimising Mobile Agent Migrations

    CERN Document Server

    Gavalas, Damianos

    2010-01-01

    The field of mobile agent (MA) technology has been intensively researched during the past few years, resulting in the phenomenal proliferation of available MA platforms, all sharing several common design characteristics. Research projects have mainly focused on identifying applications where the employment of MAs is preferable compared to centralised or alternative distributed computing models. Very little work has been made on examining how MA platforms design can be optimised so as the network traffic and latency associated with MA transfers are minimised. The work presented in this paper addresses these issues by investigating the effect of several optimisation ideas applied on our MA platform prototype. Furthermore, we discuss the results of a set of timing experiments that offers a better understanding of the agent migration process and recommend new techniques for reducing MA transfers delay.

  12. Impact of mobility structure on the optimization of small-world networks of mobile agents

    CERN Document Server

    Lee, Eun

    2015-01-01

    In ad hoc wireless networking, units are connected to each other rather than to a central, fixed, infrastructure. Constructing and maintaining such networks create several trade-off problems between robustness, communication speed, power consumption, etc., that bridges engineering, computer science and the physics of complex systems. In this work, we address the role of mobility patterns of the agents on the optimal tuning of a small-world type network construction method. By this method, the network is updated periodically and held static between the updates. We investigate the optimal updating times for different scenarios of the movement of agents (modeling, for example, the fat-tailed trip distances, and periodicities, of human travel). We find that these mobility patterns affect the power consumption in non-trivial ways and discuss how these effects can best be handled.

  13. Impact of mobility structure on optimization of small-world networks of mobile agents

    Science.gov (United States)

    Lee, Eun; Holme, Petter

    2016-06-01

    In ad hoc wireless networking, units are connected to each other rather than to a central, fixed, infrastructure. Constructing and maintaining such networks create several trade-off problems between robustness, communication speed, power consumption, etc., that bridges engineering, computer science and the physics of complex systems. In this work, we address the role of mobility patterns of the agents on the optimal tuning of a small-world type network construction method. By this method, the network is updated periodically and held static between the updates. We investigate the optimal updating times for different scenarios of the movement of agents (modeling, for example, the fat-tailed trip distances, and periodicities, of human travel). We find that these mobility patterns affect the power consumption in non-trivial ways and discuss how these effects can best be handled.

  14. A Handoff Mechanism in VANET Using Mobile Agent

    Directory of Open Access Journals (Sweden)

    Anshu Garg

    2012-06-01

    Full Text Available Nowadays, everything is moving towards theinfrastructure less wireless environment to bring thesmartness of the society. In this situation, it isnecessary to bring the smart technologies in the adhocnetwork environment. As vehicular traffic is aforemost problem in modern cities and on highway.Huge amount of time and resources are wasted whiletraveling due to traffic congestion. VANET isproviding comfort and safety for passengers.Moreover, various transactions like information onaccident, roadcondition, petrol bank details, menu inthe restaurant, and discount sales can be provided tothe drivers and passengers. The speed and time inwhich the message is sent and received plays anessential part in the Intelligent Transport System(ITS. For this the VANET requires efficient andreliable methods for data communication, gatheringand retrieving information for seamless handoff inVANET. In this paper we discusses the architecture ofVANET consists clusters that’s designed by mobileagents having instantaneous conditions of MobileNodes available in VANET. For efficient datacommunication, an attempt has been made to create anew clustering concept with the help of mobile agentsamong the VANET nodes. Subsequently for smoothand seamless handoff we have considered the calladmission control mechanism with the help of Geneticalgorithms applied over information retrieval systemmanaged by mobile agent with the effect of shadowingfor reducing the data overhead over VANET.

  15. 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.

  16. 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.

  17. SECURING MOBILE ANT AGENT USING CHINESE REMAINDER THEOREM

    Directory of Open Access Journals (Sweden)

    Srinath Doss

    2013-01-01

    Full Text Available Recent days, research in wireless network becomes major area for the past few decades. In wireless routing many routing methods such as table driven, source driven; many characteristics such as reactive routing, proactive routing; many routing algorithms such as dijikstra’s shortest path, distributed bell-man ford algorithm are proposed in the literature. For effective wireless routing, the recent ant colony optimization proves better result than the existing methodologies. The ant colony optimization is a swarm intelligence technique which widely used for combinatorial optimization problems such as travelling salesman, network routing, clustering. The ant colony optimization is a real time routing protocol which offers highly reliable and optimal routing for both single path and multi path routing. As the ant is a small tiny mobile agent, providing security is critical issue. In this study, a secured ant colony optimization using Chinese remainder theorem is proposed.

  18. Simulation of Service Supply Chain Formation Based on Mobile Agent

    Institute of Scientific and Technical Information of China (English)

    YANG Zhe; ZHANG Da-lu; XU Jian

    2005-01-01

    In E-Commerce, consumers and service suppliers can find the services through the searching of Mobile Agents (MA).The suppliers disassemble the service requests of consumers into the sub-requests. Then suppliers respond the subrequests cooperatively. Thus the Service Supply Chain(SSC) can be formed. But the existing bottom-up and upbottom supply chain formation fashions cannot be adapted to the SSC in distributed environment of E-Commerce. Task Dependency Network is exploited to illustrate the service relationship among consumers and suppliers. The formation of SSC with some simulations is elaborated. Then the influence on the formation of SSC caused by the type of service suppliers, the quantities of MA and its variety in number is elucidated.

  19. An Overview of Workflow Management on Mobile Agent Technology

    Directory of Open Access Journals (Sweden)

    Anup Patnaik

    2014-07-01

    Full Text Available Mobile agent workflow management/plugins is quite appropriate to handle control flows in open distributed system; basically it is the emerging technology which can bring the process oriented tasks to run as a single unit from diverse frameworks. This workflow technology offers organizations the opportunity to reshape business processes beyond the boundaries of their own organizations so that instead of static models, modern era incurring dynamic workflows which can respond the changes during its execution, provide necessary security measures, great degree of adaptivity, troubleshoot the running processes and recovery of lost states through fault tolerance. The prototype that we are planning to design makes sure to hold reliability, security, robustness, scalability without being forced to make tradeoffs the performance. This paper is concerned with design, implementation and evaluation of performance on the improved methods of proposed prototype models based on current research in this domain.

  20. 移动代理系统综述%A SURVEY OF MOBILE AGENT SYSTEM

    Institute of Scientific and Technical Information of China (English)

    朱淼良; 邱瑜

    2001-01-01

    Mobile agent technology is a new distributed computation paradigm. With its potential power, the technology aroused a great interest and experienced a rapid development in the last ten years. Various mobile agent systems were made for different targets and were implemented in different means. It is necessary to explore the current mobile agent systems and to summarize the implementation technologies for further research. In this paper a comprehensive explanation of mobile agent systems is given. First the definition and peculiarities of mobile agents and mobile agent systems are stated. Its advantages are enumerated. Then eight representative mobile agent systems are surveyed and the design issues about mobile agent programming language, mobility, communication, fault tolerance and security are discussed. Finally, the deficiencies and the trends of mobile agent technology are pointed out.%移动代理技术是新型的分布计算技术,具有很好的应用前景.移动代理系统是实现移动代理应用的基础框架.简述了移动代理(mobile agent)的定义和特点、移动代理系统(mobile agent system)的定义和基本内容、移动代理技术的优点和应用范围.着重讨论了8个有代表性的移动代理系统,就各自的体系结构和特色作出说明,并且综合分析了实现移动代理系统所需的技术和当前研究中存在的问题及可能的发展趋势.

  1. CACM: A New Coordination Model in Mobile Agent-Based Information Retrieval Applications

    Institute of Scientific and Technical Information of China (English)

    TANGXinhuai; ZHANGYaying; YAOYinxiong; YOUJinyuan

    2005-01-01

    In mobile agent systems, an application may be composed of several mobile agents that cooperatively perform a task. Multiple mobile agents need to communicate and interact with each other to accomplish their cooperative goal. Coordination model aims to provide solutions to interactions between concurrent activities, hiding the computing details and focusing on interaction between activities. A Context-aware coordination model (CACM), which combines mobility and coordination, is proposed for mobile agent applications, i.e. in mobile agent based information retrieval applications. The context-aware coordination model transfers interactions between agents from globally coupling interactions to locally uncoupling tuple space interactions. In addition, programmable tuple space is adopted to solve the problems of context-aware coordination introduced by mobility and data heterogeneity in mobile agent systems. Furthermore, environment specific and application specific coordination policy can be integrated into the programmable tuple space for customized requirements. Finally an application sample system-information retrieval in mobile agent applications is carried out to test the performance of the proposed model.

  2. Design on PKI-Based Anonymous Mobile Agent Security in E-Commerce

    Institute of Scientific and Technical Information of China (English)

    MENG Xiangsong; HAN Fengwu

    2006-01-01

    The security of mobile agent directly decides its usage width in e-commerce. Especially, to protect users' private information is becoming more important now and future. So an anonymous mobile agent security mechanism with the secure authentication infrastructure based on PKI(public key infrastructure) is proposed in the paper. The multi-agent system is programmed by java language and every agent must register itself in CA(certificate authority) before working in the net and express his legit identity which is temptly produced and used only once. The CA ensures the legal of all agents' identity which take part in communicaiton or trade. And every user agent identity only is used once which makes other agents cannot decipher users' private information. The security mechanism of the multi-agent system implements anonymity, integrity, data confidentiality of mobile agent based on the MH(multiple hop) integrity protection regard to PKI limit.

  3. Mobile agent application and integration in electronic anamnesis system.

    Science.gov (United States)

    Liu, Chia-Hui; Chung, Yu-Fang; Chen, Tzer-Shyong; Wang, Sheng-De

    2012-06-01

    Electronic anamnesis is to transform ordinary paper trails to digitally formatted health records, which include the patient's general information, health status, and follow-ups on chronic diseases. Its main purpose is to let the records could be stored for a longer period of time and could be shared easily across departments and hospitals. Which means hospital management could use less resource on maintaining ever-growing database and reduce redundancy, so less money would be spent for managing the health records. In the foreseeable future, building up a comprehensive and integrated medical information system is a must, because it is critical to hospital resource integration and quality improvement. If mobile agent technology is adopted in the electronic anamnesis system, it would help the hospitals to make the medical practices more efficiently and conveniently. Nonetheless, most of the hospitals today are still using paper-based health records to manage the medical information. The reason why the institutions continue using traditional practices to manage the records is because there is no well-trusted and reliable electronic anamnesis system existing and accepted by both institutions and patients. The threat of privacy invasion is one of the biggest concerns when the topic of electronic anamnesis is brought up, because the security threats drag us back from using such a system. So, the medical service quality is difficult to be improved substantially. In this case, we have come up a theory to remove such security threats and make electronic anamnesis more appealing for use. Our theory is to integrate the mobile agent technology with the backbone of electronic anamnesis to construct a hierarchical access control system to retrieve the corresponding information based upon the permission classes. The system would create a classification for permission among the users inside the medical institution. Under this framework, permission control center would distribute an

  4. 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

  5. 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.

  6. Reliability of Mobile Agents for Reliable Service Discovery Protocol in MANET

    CERN Document Server

    Neogy, Roshni; Neogy, Sarmistha; 10.5121/ijwmn.2011.3518

    2011-01-01

    Recently mobile agents are used to discover services in mobile ad-hoc network (MANET) where agents travel through the network, collecting and sometimes spreading the dynamically changing service information. But it is important to investigate how reliable the agents are for this application as the dependability issues(reliability and availability) of MANET are highly affected by its dynamic nature.The complexity of underlying MANET makes it hard to obtain the route reliability of the mobile agent systems (MAS); instead we estimate it using Monte Carlo simulation. Thus an algorithm for estimating the task route reliability of MAS (deployed for discovering services) is proposed, that takes into account the effect of node mobility in MANET. That mobility pattern of the nodes affects the MAS performance is also shown by considering different mobility models. Multipath propagation effect of radio signal is considered to decide link existence. Transient link errors are also considered. Finally we propose a metric t...

  7. Research on Applications of Cryptography for Multi-Mobile Agent System

    Institute of Scientific and Technical Information of China (English)

    HUANG Hai-ping; WANG Ru-chuan; XU Xiao-long

    2004-01-01

    With the development of information network and agent technology, Multi-Mobile Agents' Cooperation can not only improve the computing efficiency, but also have a comprehensive applicative value in solving the security issues of mobile agent system. Aiming at the security and flexibility, this paper proposes a kind of basic architecture and the design pattern of Multi-Mobile Agent System (MMAS). Combined with cryptography, it builds the security mechanism on keys' distribution and management and Coalition Signature of MMAS. Through the analysis of security and validity, the introduction and application of cryptography can improve the performance of MMAS.

  8. Access Path Planning of Mobile Agent in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Chaoyu Yang

    2014-02-01

    Full Text Available Adopting the two-stage optimization model and hybrid optimized algorithm based on evolutionary computation, a new two-stage optimization model that more conforms to the actual demand is proposed on the basis of formal description of Mobile Agent access path planning. This new model divides the access path planning problem into two sub problems of integer linear programming --data integration sub paths and return sub paths, which can reduce search space and improve the efficiency of algorithm. Then a hybrid optimized method named GAPSO, combined with GA (Genetic Algorithm and PSO (Particle Swarm Optimization, is advanced to solve this model, which integrates discrete PSO into the interlace operation of GA to avoid infeasible solution and improve search quality. Meanwhile convergence can be accelerated by optimizing the GA population with PSO in search of return sub paths. By means of virtual connected topology graph, the high-quality to-be-accessed candidate node set is acquired, the number of to-be-selected nodes is reduced,and the complexity of solution space is decreased, making planning algorithm performance not rely on network scale directly any more. Simulation results show that the advantages of the optimization model is obvious as the node number increases, and GASPO has a better performance than GA and BPSO in the same model

  9. 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.

  10. 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.

  11. Mobile Agent Platform and Naming Scheme of Agents%移动代理平台及其代理命名方法

    Institute of Scientific and Technical Information of China (English)

    Sudin SHRESTHA; 徐拾义; Jagath RATNAYEKE

    2004-01-01

    Mobile agent technology has drawn a tremendous amount of attention from researchers in distributed computing recently as it promises to provide an elegant and efficient way of solving complex distributed problems, as well as offering a new approach to human-computer-interaction. In mobile agent systems, the mobile agent travels autonomously from one computer to another within the agent enabled networks, executes itself in the agent execution environment, collects useful information and makes its own decision on behalf of its owner. This mobility nature of mobile agent demands its unique name in the whole network otherwise it gets lost or conflicts with other mobile agent having same name. This paper proposes a naming scheme which promises a unique name for a mobile agent within that network.

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

    NARCIS (Netherlands)

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

    2010-01-01

    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 l

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

    NARCIS (Netherlands)

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

    2009-01-01

    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 l

  14. Key Management and Authentication in Ad Hoc Network based on Mobile Agent

    Directory of Open Access Journals (Sweden)

    Yi Zhang

    2009-08-01

    Full Text Available Key management and authentication is important to security of Mobile Ad Hoc network (MANET. Based on the (t, n threshold cryptography, this paper introduced mobile agents to exchange private key and network topological information with nodes in the network. This method avoids a centralized certification authority to distribute the public keys and the certificates, thus enhances security. Carrying private key and some state variables, mobile agents navigate in the network according to visitsbalance policy, namely, node with the least visits would be first visited by mobile agent. Any t nodes in the network can cooperate to perform an authentication upon a new node wanting to join the network. Experimental results show that the mobile agent performs very well for improving the success ratio of authentication and enhance security while reducing the communication overhead and resource consumption.

  15. Monolithic spectrometer

    Science.gov (United States)

    Rajic, Slobodan; Egert, Charles M.; Kahl, William K.; Snyder, Jr., William B.; Evans, III, Boyd M.; Marlar, Troy A.; Cunningham, Joseph P.

    1998-01-01

    A monolithic spectrometer is disclosed for use in spectroscopy. The spectrometer is a single body of translucent material with positioned surfaces for the transmission, reflection and spectral analysis of light rays.

  16. 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

  17. Computational Analysis of .NET Remoting and Mobile agent in Distributed Environment

    CERN Document Server

    Tiwari, Vivek; Tiwari, Renu; Kirar, Malam

    2010-01-01

    A mobile agent is a program that is not bound to the system on which it began execution, but rather travels amongst the hosts in the network with its code and current execution state (i.e. Distributed Environment).The implementation of distributed applications can be based on a multiplicity of technologies, e.g. plain sockets, Remote Procedure Call (RPC), Remote Method Invocation (RMI), Java Message Service (JMS), .NET Remoting, or Web Services. These technologies differ widely in complexity, interoperability, standardization, and ease of use. The Mobile Agent technology is emerging as an alternative to build a smart generation of highly distributed systems. In this work, we investigate the performance aspect of agent-based technologies for information retrieval. We present a comparative performance evaluation model of Mobile Agents versus .Net remoting by means of an analytical approach. A quantitative measurements are performed to compare .Net remoting and mobile agents using communication time, code size (...

  18. Automated pre-column derivatization of thiolic fruit-antibrowning agents by sequential injection coupled to high-performance liquid chromatography using a monolithic stationary phase and an in-loop stopped-flow approach.

    Science.gov (United States)

    Karakosta, Theano D; Tzanavaras, Paraskevas D; Themelis, Demetrius G

    2011-08-01

    The present study reports the very first application of ethyl propiolate (EP) as an advantageous pre-column derivatization reagent for the determination of thiols by liquid chromatography (LC). Cysteine (CYS), glutathione (GSH) and N-acetylcysteine (NAC) were derivatized online under stopped-flow conditions in a sequential injection (SI) system coupled to HPLC. The formed derivatives were separated isocratically with a monolithic stationary phase (100×4.6 mm id) and UV detected at 285 nm. Critical parameters that affected the online pre-column derivatization reaction (e.g. the reaction time and the amount concentration of EP) and the separation (e.g. pH and the composition of the mobile phase) were investigated. The developed analytical scheme offers a total analysis time of less than 10 min, limits of detection in the range of 0.24-0.35 μmol/L and satisfactory linearity up to 200 μmol/L for all analytes. The proposed method was applied to the analysis of the selected thiols--that are often employed as antibrowning agents--in fresh fruit samples.

  19. Integration of a mobile autonomous robot in a surveillance multi-agent system

    OpenAIRE

    Dias, Bruno Miguel Morais

    2014-01-01

    This dissertation aims to guarantee the integration of a mobile autonomous robot equipped with many sensors in a multi-agent distributed and georeferenced surveillance system. The integration of a mobile autonomous robot in this system leads to new features that will be available to clients of surveillance system may use. These features may be of two types: using the robot as an agent that will act in the environment or by using the robot as a mobile set of sensors. As an agent in the syst...

  20. Study of the Security in Network Management Based on Mobile Agents

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhi; WANG Ru-chuan

    2004-01-01

    Security of mobile-agent based network management must be considered due to the widespread adoption of mobile agents in network management, which involves the protections of mobile agents, management station and managed devices. The integrated security model proposed in our paper incorporates the effective security countermeasures of these entities into a trusted execution environment and two security protection layers. Sandbox based on Java virtual machine and Java card independent on the network devices also with the cryptography technology in this model together protect the network management process.

  1. On the Migration Mechanism of Mobile Agent System%移动Agent系统的迁移机制研究

    Institute of Scientific and Technical Information of China (English)

    张冠群; 陶先平; 李新; 冯新宇; 吕建

    2001-01-01

    Mobility is inherent in Internet,traditional message passing,RPC,or Remote Evaluation,can not meet more and more various mobility requirements. Mobile Agent implements computation migration,including data,code and control,is a good way to suit Internet. Migration mechanism is the key technology of mobile Agent. We discuss it from the perspective of both system programmer and application programmer and introduce migration mechanisms of some famous Java based mobile Agent system.At last,present the structured migration mechanism of self-designed mobile Agent system Mogent.

  2. An Intelligent Mobile-Agent Based Scalable Network Management Architecture for Large-Scale Enterprise System

    CERN Document Server

    Sharma, A K; Singh, Vijay

    2012-01-01

    Several Mobile Agent based distributed network management models have been proposed in recent times to address the scalability and flexibility problems of centralized (SNMP or CMIP management models) models. Though the use of Mobile Agents to distribute and delegate management tasks comes handy in dealing with the previously stated issues, many of the agent-based management frameworks like initial flat bed models and static mid-level managers employing mobile agents models cannot efficiently meet the demands of current networks which are growing in size and complexity. Moreover, varied technologies, such as SONET, ATM, Ethernet, DWDM etc., present at different layers of the Access, Metro and Core (long haul) sections of the network, have contributed to the complexity in terms of their own framing and protocol structures. Thus, controlling and managing the traffic in these networks is a challenging task. This paper presents an intelligent scalable hierarchical agent based model for the management of large-scal...

  3. 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.

  4. Ion mobility spectrometry and its applications in detection of chemical warfare agents.

    Science.gov (United States)

    Mäkinen, Marko A; Anttalainen, Osmo A; Sillanpää, Mika E T

    2010-12-01

    When fast detection of chemical warfare agents in the field is required, the ion mobility spectrometer may be the only suitable option. This article provides an essential survey of the different ion mobility spectrometry detection technologies. (To listen to a podcast about this feature, please go to the Analytical Chemistry multimedia page at pubs.acs.org/page/ancham/audio/index.html.).

  5. Changes of lymphocyte kinetics in the normal rat, induced by the lymphocyte mobilizing agent polymethacrylic acid

    NARCIS (Netherlands)

    Ormai, S.; Hagenbeek, A.; Palkovits, M.; Bekkum, D.W. van

    1973-01-01

    The changes in lymphocyte kinetics induced by the lymphocyte mobilizing agent polymethacrylic acid (PMAA) were studied in the normal rat. Quantitative data are presented concerning the degree of lymphocyte mobilization in the spleen and in various lymph nodes at different times after PMAA administra

  6. An Agent Driven Human-centric Interface for Autonomous Mobile Robots

    Science.gov (United States)

    2003-01-01

    An Agent Driven Human-centric Interface for Autonomous Mobile Robots Donald Sofge, Dennis Perzanowski, Magdalena Bugajska, William Adams...Human-centric, Multimodal, Dynamic Autonomy, CoABS Grid, Mobile Robots 1. INTRODUCTION One of the challenges in implementing dynamically...autonomous behaviors in mobile robots is achieving a truly human-centric interface so that human operators can interact with the robots as naturally as they

  7. Domain-Partitioned Element Management Systems Employing Mobile Agents for Distributed Network Management

    Directory of Open Access Journals (Sweden)

    Anish Saini

    2014-06-01

    Full Text Available Network management systems based on mobile agents are efficiently a better alternative than typicalclient / server based architectures. Centralized management models like SNMP or CMIP based management models suffer from scalability and flexibility issues which are addressed to great extent by flat bed or static mid-level manager models based on mobile agents, yet the use of mobile agents to distribute and delegate management tasks for above stated agent-based management frameworks like initial flat bed models and static mid-level managers cannot efficiently meet the demands of current networks which are growing in size and complexity. In view of the above mentioned limitations, we proposed a domain partitioned network management model based-on mobile agent & Element Management Systems in order to minimize management data flow to a centralized server. Intelligent agent allocated to specific EMS performs local network management and reports the results to the superior manager and finally the global manager performs global network management using those submitted management results. Experimental results of various scenarios of the proposed model have been presented to support the arguments given in favor of the prototype system based on mobile agents..

  8. Stable Flocking Motion of Mobile Agents Following a Leader in Fixed and Switching Networks

    Institute of Scientific and Technical Information of China (English)

    Hui Yu; Yong-Ji Wang

    2006-01-01

    Multiple mobile agents with double integrator dynamics, following a leader to achieve a flocking motion formation, are studied in this paper. A class of local control laws for a group of mobile agents is proposed. From a theoretical proof, the following conclusions are reached: (i) agents globally align their velocity vectors with a leader, (ii) they converge their velocities to the leaders velocity, (iii) collisions among interconnected agents are avoided, and (iv) agent's artificial potential functions are minimized. We model the interaction and/or communication relationship between agents by algebraic graph theory. Stability analysis is achieved by using classical Lyapunov theory in a fixed network topology, and differential inclusions and nonsmooth analysis in a switching network topology respectively. Simulation examples are provided.

  9. Architecture for Intrusion Detection System with Fault Tolerance Using Mobile Agent

    Directory of Open Access Journals (Sweden)

    Chintan Bhatt

    2011-10-01

    Full Text Available This paper is a survey of the work, done for making an IDS fault tolerant.Architecture of IDS that usesmobile Agent provides higher scalability. Mobile Agent uses Platform for detecting Intrusions using filterAgent, co-relater agent, Interpreter agent and rule database. When server (IDS Monitor goes down,other hosts based on priority takes Ownership. This architecture uses decentralized collection andanalysis for identifying Intrusion. Rule sets are fed based on user-behaviour or applicationbehaviour.This paper suggests that intrusion detection system (IDS must be fault tolerant; otherwise, theintruder may first subvert the IDS then attack the target system at will.

  10. A Mobile Agent-based Web Page Constructing Framework MiPage

    Science.gov (United States)

    Fukuta, Naoki; Ozono, Tadachika; Shintani, Toramatsu

    In this paper, we present a programming framework, `MiPage', for realizing intelligent WWW applications based on the mobile agent technology. On the framework, an agent is programmed by using hyper text markup language and logic programming language. To realize the framework, we designed a new logic programming environment `MiLog', and an agent program compiler `MiPage Compiler'. The framework enables us to enhance both richness of the services and manageability of the application.

  11. Research on Mobile Agent Security%移动Agent安全性研究

    Institute of Scientific and Technical Information of China (English)

    董春冻; 王聪; 周星; 李戈

    2013-01-01

    Mobile Agent technology is a distributed network-computing mode,it combines the characteristic of Agent with the idea of mobile and solves the problem of task assigning and cooperation between network. It makes the use of network technology more and more extensive. But at the same time,the security problems of mobile Agent become more and more important. On the basis of simply introdu-cing mobile Agent technology,analyze its security requirements,and emphasize on security problems of mobile Agent and security policy of mobile Agent,give the solution for mobile Agent security.%移动Agent技术是一种分布式的网络计算模式,它将Agent的特点和移动的思想相结合,很好地解决了网络间任务分配与合作问题,使得一些网络技术的应用越来越广泛。但与此同时,移动Agent安全性问题的重要性也显得更为突出。文中在简要介绍移动Agent技术的基础上,分析了移动Agent的安全需求,重点讨论了移动Agent在安全性方面的问题,并给出了针对移动Agent安全问题的解决方法。

  12. Multi-agent Optimal Control of Ball Balancing on a Mobile

    Directory of Open Access Journals (Sweden)

    Adel Akbarimajd

    2015-12-01

    Full Text Available Multi-agent systems have origin in computer engineering however, they have found applications in different field. One of the newly emerged problems in multi-agent systems is multi-agent control. In multi-agent control it is desired that the control is done in distributed manner. That is the controller of each agent should be implemented based on local feedback. In this a mechanism is introuded as a test bed for multi-agent control systems. The introduced mechanism is balancing of a ball on link located on a planar mobile robot. Dynamic equations of the mechanism is derived and the control task is distributed among two agents. For each agent a two loop controller designed wherein external loop is a LQR controller and inner loop is a simple proportional controller. Regulation and fault tolerance performance of controller scheme is evaluated by simulations.

  13. 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.

  14. Mobile Agents: A Distributed Voice-Commanded Sensory and Robotic System for Surface EVA Assistance

    Science.gov (United States)

    Clancey, William J.; Sierhuis, Maarten; Alena, Rick; Crawford, Sekou; Dowding, John; Graham, Jeff; Kaskiris, Charis; Tyree, Kim S.; vanHoof, Ronnie

    2003-01-01

    A model-based, distributed architecture integrates diverse components in a system designed for lunar and planetary surface operations: spacesuit biosensors, cameras, GPS, and a robotic assistant. The system transmits data and assists communication between the extra-vehicular activity (EVA) astronauts, the crew in a local habitat, and a remote mission support team. Software processes ("agents"), implemented in a system called Brahms, run on multiple, mobile platforms, including the spacesuit backpacks, all-terrain vehicles, and robot. These "mobile agents" interpret and transform available data to help people and robotic systems coordinate their actions to make operations more safe and efficient. Different types of agents relate platforms to each other ("proxy agents"), devices to software ("comm agents"), and people to the system ("personal agents"). A state-of-the-art spoken dialogue interface enables people to communicate with their personal agents, supporting a speech-driven navigation and scheduling tool, field observation record, and rover command system. An important aspect of the engineering methodology involves first simulating the entire hardware and software system in Brahms, and then configuring the agents into a runtime system. Design of mobile agent functionality has been based on ethnographic observation of scientists working in Mars analog settings in the High Canadian Arctic on Devon Island and the southeast Utah desert. The Mobile Agents system is developed iteratively in the context of use, with people doing authentic work. This paper provides a brief introduction to the architecture and emphasizes the method of empirical requirements analysis, through which observation, modeling, design, and testing are integrated in simulated EVA operations.

  15. Embeded Mobile Database Based on Mobile Agent%基于Mobile Agent的嵌入式移动数据库

    Institute of Scientific and Technical Information of China (English)

    王乐; 杨永福

    2009-01-01

    With the development of mobile computing technology, Mobile Database is moving towards the application gradually,and disphying its superiority in Embedded Operating System.There are so many characteristics in Mobile Environment, such as mobility,frequent breaking receiver,low bandwidth,limited battery power and so on,which determined there must be some differences between Computing Environment of Mobile Database and Distributed Database and put forward a number of new requirements to the Mobile Database. This article introduces the Development Status of embedded Mobile Database,analyses characteristics of Mobile Database and its architecture and introduces the technology of Agent and the application of Mobile Agent in Mobile Database.%随着移动计算技术的发展,移动数据库逐步走向应用,在嵌入式操作系统中移动数据库更显示出其优越性.移动环境中所具有移动性、频繁断接收、低带宽、电池电量有限性等特性,决定了移动数据库中计算环境不同于分布式数据库,给移动数据库研究提出了许多新的要求.该文从分析移动数据库特点、体系结构;介绍移动数据库系统中一些关键性技术;Agent技术及移动Agent在移动数据库中的应用.

  16. Control of the mobile robot based on the Mobile-C mobile agent%基于Mobile-C移动代理的移动机器人的控制

    Institute of Scientific and Technical Information of China (English)

    张楠; 葛为民

    2011-01-01

    本文提出一种使用Mobile-C移动代理控制移动机器人的方法,详细介绍了Mobile-C的结构和报文格式,以及与Ch结合的优势.机器人通过Mobile-C移动代理的控制,可以在运行中动态地切换成新的算法,来处理意料之外的情况.文章最后用一个分布式应用的实验说明了Mobile-C移动代理控制机器人的方法.%This article presents a method of controlling mobile robot using the Mobile-C mobile agent, details of the Mobile-Cs structure and message format, and the advantages of combined with Ch. By the control of Mobile-C mobile agent, the ro-bot can dynamically switch to the new algorithm at runtime to deal with unexpected situations. At last, the distributed appli-cation experiment illustrates the Mobile-C mobile agent approach to control the robot.

  17. Investigation of oil recovery improvement by coupling an interfacial tension agent and a mobility control agent in light oil reservoirs. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Pitts, M.

    1995-12-01

    This research studied the oil recovery potential of flooding light oil reservoirs by combining interfacial tension reducing agent(s) with a mobility control agent. The specific objectives were: To define the mechanisms and limitations of co-injecting interfacial tension reduction agent(s) and a mobility control agent to recover incremental oil. Specifically, the study focused on the fluid-fluid and fluid-rock interactions. To evaluate the economics of the combination technology and investigate methods to make the process more profitable. Specific areas of study were to evaluate different chemical concentration tapers and the volume of chemical injection required to give optimal oil recovery.

  18. Disinfection of biological agents in the field using a mobile ...

    Science.gov (United States)

    Report The Army’s Net Zero Initiative is an energy-conservation program that focuses on energy as well as water and waste usage procedures. All Net Zero projects are geared toward helping the military installation or community become more sustainable and resilient, with an emphasis on taking a systems approach. Net Zero projects must advance the state of the science and are focused on three general topic areas: water, energy, and waste, and the nexuses among them. This project examined the inactivation and/or removal of biological contaminants in dirty wash water using a portable ozone-UV AOP process. The strain of E. coli used in these experiments is not a biological warfare agent, but acts as a surrogate for certain of the vegetative biological agents such as the enterohemorrhagic strain designated E. coli 0157:H7.

  19. 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.

  20. Searching dynamic agents with a team of mobile robots.

    Science.gov (United States)

    Juliá, Miguel; Gil, Arturo; Reinoso, Oscar

    2012-01-01

    This paper presents a new algorithm that allows a team of robots to cooperatively search for a set of moving targets. An estimation of the areas of the environment that are more likely to hold a target agent is obtained using a grid-based Bayesian filter. The robot sensor readings and the maximum speed of the moving targets are used in order to update the grid. This representation is used in a search algorithm that commands the robots to those areas that are more likely to present target agents. This algorithm splits the environment in a tree of connected regions using dynamic programming. This tree is used in order to decide the destination for each robot in a coordinated manner. The algorithm has been successfully tested in known and unknown environments showing the validity of the approach.

  1. Searching Dynamic Agents with a Team of Mobile Robots

    Directory of Open Access Journals (Sweden)

    Miguel Juliá

    2012-06-01

    Full Text Available This paper presents a new algorithm that allows a team of robots to cooperatively search for a set of moving targets. An estimation of the areas of the environment that are more likely to hold a target agent is obtained using a grid-based Bayesian filter. The robot sensor readings and the maximum speed of the moving targets are used in order to update the grid. This representation is used in a search algorithm that commands the robots to those areas that are more likely to present target agents. This algorithm splits the environment in a tree of connected regions using dynamic programming. This tree is used in order to decide the destination for each robot in a coordinated manner. The algorithm has been successfully tested in known and unknown environments showing the validity of the approach.

  2. An Anonymous Payment Protocol with Mobile Agents in Hostile Environments

    Institute of Scientific and Technical Information of China (English)

    LIU Yi; XIANG Ming-sen; WANG Yu-min

    2005-01-01

    By using Pedersen' s verifiable secret sharing scheme and the theory of cross validation, we propose an anonymous payment protocol which have following features:protecting the confidentiality of sensitive payment information from spying by malicious hosts; using a trusted third party in a minimal way; verifying the validity of the share by the merchant; allowing agent to verify that the product which it is about to receive is the one it is paying for; keeping the customer anonymous.

  3. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Stuart G [Los Alamos National Laboratory; Farinholt, Kevin M [Los Alamos National Laboratory; Figueiredo, Eloi [Los Alamos National Laboratory; Park, Gyuhae [Los Alamos National Laboratory; Farrar, Charles R [Los Alamos National Laboratory; Flynn, Eric B [UCSD; Mascarenas, David L [UCSD; Todd, Michael D [UCSD

    2008-01-01

    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.

  5. Research and Application of Mobile Agents Based CORBA%基于CORBA的移动Agent研究及其应用

    Institute of Scientific and Technical Information of China (English)

    王建国; 李增智

    2000-01-01

    Current CORBA and Mobile Agents are two new technologies. They have own characteristics and shortcoming or the difference of implementation. This article analyzes their compensatory relation each other,and tries integrating them to construct tile architecture for network management with mobile agents based CORBA. At the same time,this paper expatiates how mobile agents work in the architecture,and summarizes the new characteristics brought with by this combinative technology.

  6. 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.

  7. Mobile Agent as an Approach to Improve QoS in Vehicular Ad Hoc Network

    CERN Document Server

    Kumar, Rakesh

    2011-01-01

    Vehicular traffic is a foremost problem in modern cities. Huge amount of time and resources are wasted while traveling due to traffic congestion. With the introduction of sophisticated traffic management systems, such as those incorporating dynamic traffic assignments, more stringent demands are being placed upon the available real time traffic data. In this paper we have proposed mobile agent as a mechanism to handle the traffic problem on road. Mobile software agents can be used to provide the better QoS (Quality of Service) in vehicular ad hoc network to improve the safety application and driver comfort.

  8. An Autonomous Attestation Token to Secure Mobile Agents in Disaster Response

    Science.gov (United States)

    Hein, Daniel M.; Toegl, Ronald

    Modern communication and computing devices have the potential to increase the efficiency of disaster response. Mobile agents are a decentralized and flexible technology to leverage this potential. While mobile agent platforms suffer from a greater variety of security risks than the classic client-server approach, Trusted Computing is capable of alleviating these problems. Unfortunately, Remote Attestation, a core concept of Trusted Computing, requires a powerful networked entity to perform trust decisions. The existence and availability of such a service in a disaster response scenario cannot be relied upon.

  9. Instance-oriented delegation: A solution for providing security to Grid-based mobile agent middleware

    Institute of Scientific and Technical Information of China (English)

    MA Tian-chi; LI Shan-ping

    2005-01-01

    New challenges are introduced when people try to build a general-purpose mobile agent middleware in Grid environment. In this paper, an instance-oriented security mechanism is proposed to deal with possible security threats in such mobile agent systems. The current security support in Grid Security Infrastructure (GSI) requires the users to delegate their privileges to certain hosts. This host-oriented solution is insecure and inflexible towards mobile agent applications because it cannot prevent delegation abuse and control well the diffusion of damage. Our proposed solution introduces security instance, which is an encapsulation of one set of authorizations and their validity specifications with respect to the agent's specific code segments, or even the states and requests. Applications can establish and configure their security framework flexibly on the same platform, through defining instances and operations according to their own logic. Mechanisms are provided to allow users delegating their identity to these instances instead of certain hosts. By adopting this instance-oriented security mechanism, a Grid-based general-purpose MA middleware, Everest, is developed to enhance Globus Toolkit's security support for mobile agent applications.

  10. A Multi-Agent Emotion Generating System for Mobile Robots System

    Science.gov (United States)

    Nair, Shivashankar B.; Kim, Dong Hwa

    Emotions are a complex phenomenon and are in constant research for so long. Emotions can be presupposed as a dynamic association of cells on elicitation. The use of agents for emotions generation and emotion modeling are on the rise in the recent years. In this work, we propose a dynamic emotion generation system based on multiple agents. A Multi-Agent System (MAS) to generate emotions targeted towards a mobile robot has been implemented. The agent-robot communication is still being investigated. An illustration of the use of this emotion generation module is explained in the context of the emotion system. Some ancillary investigations performed in using mobile robots for localization and terrain mapping have also been described.

  11. Secure Mobile Agent for Telemedicine Based on P2P Networks

    OpenAIRE

    Hsu, Wen-Shin; Pan, Jiann-I

    2013-01-01

    Exploring intelligent mobile agent (MA) technology for assisting medical services or transmitting personal patient-health information in telemedicine applications has been widely investigated. Conversely, peer-to-peer (P2P) networking has become one of the most popular applications used in the Internet because of its benefits for easy-to-manage resources and because it balances workloads. Therefore, constructing an agent-based telemedicine platform based on P2P networking architecture is nece...

  12. Research and Design of Network Management Construction Based on Mobile AGENT

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The technical characters of mobile agent (MA) originated in the distributional artificial intelligence domain is introduced. A network management construc- tion based on agent (NMCA) is then proposed. The NMCA structure features are elaborated in detail. A prototype design of NMCA is given by using the jKQML programming. The establishment of NMCA platform will be helpful to reduce the correspondence load of network management and improves the efficiency and the expansion ability of network management systems.

  13. Auto-agent: a behavior-based architecture for mobile navigation

    Science.gov (United States)

    Hwang, Kaoshing; Ju, Ming-Yi

    1998-10-01

    The design and construction of mobile robots is as much art as a science. In hardware architecture, researchers tend to construct a low-cost and reliable platform which equips with various sensory system for sensing the change of the environment to offer useful information to the navigation system. An autonomous navigation system plays a role in an mobile robot as the brain in human being. It generates action command according to those sensory data from the perception system to direct the mobile robot to go to desired positions or accomplish useful tasks without human intervention in real-world. An important problem in autonomous navigation is the need to cope with the large amount of uncertainty that is inherent of natural environment. Therefore the development of techniques for autonomous navigation in real-world environments constitutes one of the major trends in the current research on robotics. Inspired with the concept of software agents, reactive control and behavior-based control, a modular architecture, called Auto-agent, for mobile navigation is proposed. The main characteristic of Auto-agent is as following: Behavioral agents cooperate by means of communicating with other behavioral agents intermittently to achieve their local goal and the goals of the community as a whole because no one individually has sufficient competence, resources and information to solve the entire problem. Auto-agent gains advantages from the characteristics of distributed system, it offers the possibility to find an acceptable solution with a reasonable time and complexity range. Besides, the modular structure is convenient for an engineer to construct a new behavioral agent and to add it into Auto-agent.

  14. 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.

  15. Formation Control of Mobile Agents with Second-order Nonlinear Dynamics in Unknown Environments Containing Obstacles

    NARCIS (Netherlands)

    Huang, Jie; Cao, Ming; Zhou, Ning

    2016-01-01

    This paper investigates the formation control problem of multiple mobile agents with second-order nonlinear dynamics in complex environments containing multiple obstacles. By employing the null-space-based behavioral (NSB) control architecture, a novel fast terminal sliding mode based adaptive contr

  16. A Context-Aware Self-Adaptive Fractal Based Generalized Pedagogical Agent Framework for Mobile Learning

    Science.gov (United States)

    Boulehouache, Soufiane; Maamri, Ramdane; Sahnoun, Zaidi

    2015-01-01

    The Pedagogical Agents (PAs) for Mobile Learning (m-learning) must be able not only to adapt the teaching to the learner knowledge level and profile but also to ensure the pedagogical efficiency within unpredictable changing runtime contexts. Therefore, to deal with this issue, this paper proposes a Context-aware Self-Adaptive Fractal Component…

  17. Quantization effects on synchronized motion of teams of mobile agents with second-order dynamics

    NARCIS (Netherlands)

    Liu, Hui; Cao, Ming; De Persis, Claudio

    2012-01-01

    For a team of mobile agents governed by second-order dynamics, this paper studies how different quantizers affect the performances of consensus-type schemes to achieve synchronized collective motion. It is shown that when different types of quantizers are used for the exchange of relative position a

  18. Cryptanalysis of the One- Time Proxy Signature Scheme Used in Mobile Agents

    Institute of Scientific and Technical Information of China (English)

    FU Xiao-tong; XIAO Hong; XIAO Guo-zhen

    2005-01-01

    We cryptanalyze Kim et al ' s one-time proxy signature scheme used in mobile agents, and then a successful forgery is introduced. It is showed that a dishonest customer can successfully forge a valid one-time proxy signature by impersonating the server. Furthermore, he can request the server with responsibility for the forged bidding information.

  19. An Agent Based Intrusion Detection Model for Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    B. M. Reshmi

    2006-01-01

    Full Text Available Intrusion detection has over the last few years, assumed paramount importance within the broad realm of network security, more so in case of wireless mobile ad hoc networks. The inherently vulnerable characteristics of wireless mobile ad hoc networks make them susceptible to attacks in-spite of some security measures, and it may be too late before any counter action can take effect. As such, there is a need to complement traditional security mechanisms with efficient intrusion detection and response systems. This paper proposes an agent-based model to address the aspect of intrusion detection in cluster based mobile wireless ad hoc network environment. The model comprises of a set of static and mobile agents, which are used to detect intrusions, respond to intrusions, and distribute selected and aggregated intrusion information to all other nodes in the network in an intelligent manner. The model is simulated to test its operation effectiveness by considering the performance parameters such as, detection rate, false positives, agent overheads, and intrusion information distribution time. Agent based approach facilitates flexible and adaptable security services. Also, it supports component based software engineering components such as maintainability, reachability, reusability, adaptability, flexibility, and customization.

  20. 'Do you smell rotten eggs?' Evaluating interactions with mobile agents in crisis response situations

    NARCIS (Netherlands)

    A. Winterboer; H.S.M. Cramer; G. Pavlin; F.C.A. Groen; V. Evers

    2009-01-01

    In this paper, we present ongoing research concerning the interaction between users and autonomous mobile agents in the environmental monitoring domain. The overarching project, DIADEM, deals with developing a system that detects potentially hazardous situations in populated industrial areas using i

  1. MAPPS: A Framework of Peer-to-Peer Systems Based on JXTA and Mobile Agents

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Due to the success of Napster, Gnutella and Freenet, peer to peer (P2P) computing has suddenly emerged at the forefront of Internet computing. And a lot of problems including security, reliability and rooting are urgent to be solved.Unfortunately, traditional techniques are not directly applicable to P2P systems. This paper presents a new framework called MAPPS for designing P2P applications based on JXTA and mobile agents. The MAPPS framework is structured as three layers:the MAPPS infiastmcture based on mobile agents, MAPPS services and MAPPS applications. In this way, MAPPS not only follows the ootstanding architecture of JXTA, but also enhances the mobility and flexibility of P2P systems. Using MAPPS,developers of new P2P systems can design and implement P2P systems more efficiently.

  2. Sub-head Transmission of Heterogeneous Data by Cloned Agent to Android Mobile

    Directory of Open Access Journals (Sweden)

    S. Karthikeyan

    2014-07-01

    Full Text Available The occurrence of an event can be detected using sensor nodes. The eminent constraint of these sensor nodes is the non-replenishing battery. Conservation of energy is an important aspect due to its limited battery power. Energy utilization using cloned mobile agents is the ultimate aim in this proposed work. The network is divided into clusters and 2 subheads are elected from each cluster. The event occurred is sensed by a sensor and is transmitted to the subhead. The cloned mobile agent collects data from the subhead and transmits it to the sink. The gathered data from sink is then transferred to android mobile. The advantages of this mechanism are less delay and reduced energy consumption. When the energy of existing subhead is reduced to half of its initial energy, new subhead is selected. Thus energy utilization is minimized and overall lifetime of network is increased.

  3. Multiple Servers - Queue Model for Agent Based Technology in Cache Consistence Maintenance of Mobile Environment

    Directory of Open Access Journals (Sweden)

    G.Shanmugarathinam

    2013-01-01

    Full Text Available Caching is one of the important techniques in mobile computing. In caching, frequently accessed data is stored in mobile clients to avoid network traffic and improve the performance in mobile computing. In a mobile computing environment, the number of mobile users increases and requests the server for any updation, but most of the time the server is busy and the client has to wait for a long time. The cache consistency maintenance is difficult for both client and the server. This paper is proposes a technique using a queuing system consisting of one or more servers that provide services of some sort to arrive mobile hosts using agent based technology. This services mechanism of a queuing system is specified by the number of servers each server having its own queue, Agent based technology will maintain the cache consistency between the client and the server .This model saves wireless bandwidth, reduces network traffic and reduces the workload on the server. The simulation result was analyzed with previous technique and the proposed model shows significantly better performance than the earlier approach.

  4. AN INTELLIGENT MOBILE-AGENT BASED SCALABLE NETWORK MANAGEMENT ARCHITECTURE FOR LARGE-SCALE ENTERPRISE SYSTEM

    Directory of Open Access Journals (Sweden)

    A.K. Sharma

    2012-02-01

    Full Text Available Several Mobile Agent based distributed network management models have been proposed in recent times toaddress the scalability and flexibility problems of centralized (SNMP or CMIP management modelsmodels. Though the use of Mobile Agents to distribute and delegate management tasks comes handy indealing with the previously stated issues, many of the agent-based management frameworks like initial flatbed models and static mid-level managers employing mobile agents models cannot efficiently meet thedemands of current networks which are growing in size and complexity. Moreover, varied technologies,such as SONET, ATM, Ethernet, DWDM etc., present at different layers of the Access, Metro and Core(long haul sections of the network, have contributed to the complexity in terms of their own framing andprotocol structures. Thus, controlling and managing the traffic in these networks is a challenging task. Thispaper presents an intelligent scalable hierarchical agent based model for the management of large-scalecomplex networks to address aforesaid issues. The cost estimation, carried out with a view to compute theoverall management cost in terms of management data overhead, is being presented. The results obtainedthereafter establish the usefulness of the presented architecture as compare to centralized and flat bedagent based models.

  5. Performance Analysis of a Highly Available Home Agent in Mobile Networks

    Directory of Open Access Journals (Sweden)

    Abdelgadir T. Abdelgadir

    2011-01-01

    Full Text Available Problem statement: Network Mobility as a service is provided by the NEMO protocol in IPv6 environments. NEMO is an extension to MIPv6 and thus inherits the same reliability problems of MIPv6. MIPv6 is not reliable because the Home Agent (HA is a single point of failure. In order to provide real-time services for MIPv6 networks, reliability should be considered as part of any high availability solution used to deploy Mobile IPv6 networks. Approach: Many approaches have been taken to solve the problem of HA as a single point of failure. In our proposed solution, failure detection and recovery is handled by the home agent. Therefore, recovery is transparent to the mobile network. Results: In this study we opted for using HA redundancy to provide a highly available home agent solution which achieves recovery times suitable for real-time applications. Conclusion: The results show that achieving high availability in IPv6 based mobile networks which support NEMO is possible.

  6. RESEARCH ON SECURITY PROTOCOL FOR COLLABORATING MOBILE AGENTS IN NETWORK INTRUSION DETECTION SYSTEMS

    Directory of Open Access Journals (Sweden)

    Olumide Simeon Ogunnusi

    2013-01-01

    Full Text Available Despite the popularity of mobile agents in academic and commercial arena, the security issues associated with them have hindered their adoption on large scale distributed applications. However, researchers are making relentless effort to overcome the security impediments so that the interesting properties inherent in mobile agent application, especially in the field of intrusion detection, can be harnessed. Such properties include: adaptability, autonomous nature, low bandwidth utilization, latency eradication, mobility and intelligence. A number of protocols have been developed by researchers for different key distribution techniques to enhance their performance and to protect communicating entities against malicious attacks that can hinder their activities. However, they do not take into account the availability and fault tolerance of the protocols in case of any possible attack despite the authentication methods offered by encryption. This study therefore, proposes a fault-tolerant key distribution protocol for distributed mobile agents (communicating entities in network intrusion detection system to facilitate hitch-free collaboration geared towards intrusive packets detection in Wireless Local Area Network (WLAN.

  7. Agent based User Interface Design for Mobile Cloud Computing Environment (AUID

    Directory of Open Access Journals (Sweden)

    A. Viswanatha Reddy

    2012-06-01

    Full Text Available Mobility is the need of the hour and the Mobile Clouds are becoming popular and are able to meet the needs of the current day customers. Cloud computing being the state of art technology enables the individuals, entrepreneurs, small and medium companies to carry on their personal and business activities at all levels, without any interruption. Provisioning and offering an exactly matching service to the highly demanding customer has been a night mare and will continue to be the same in the mobile environment. In this paper, we propose an Interactive Multi Agent based User Interface that interacts with the end user on one side and with the mobile network cloud on the other side and offers an optimal solution so as to balance the interests of both the parties. Here the Mobile Agent Manager with its simple architecture and interactive capability, understands, analyzes and organizes the services being offered by the cloud to achieve customer satisfaction always and every time and on demand to meet explicit needs

  8. 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

  9. A Solution Model to Protect Mobile Agents Against Malicious Host Attack

    Institute of Scientific and Technical Information of China (English)

    迈克尔; 徐良贤

    2003-01-01

    Within an agent server, the model introduces a trusted third party entity called Secure Service Station(SSS). The SSS is a non-hardware component and is intended to prevent most attacks performed by malicioushosts, by providing mechanisms that ensure attack detection and provide integrity to mobile agents. This nobletechnique involves encapsulating partial results obtained on each intermediate host and binding these results togeth-er using a hash function, thus forming a strong bonded chain that cannot be compromised. An analytical model toexplore the system performance was also developed.

  10. Establishing Efficient C2C E-alliance Based on Mobile Agent

    Institute of Scientific and Technical Information of China (English)

    YU Xiao-bing; GUO Shun-sheng; GUO Jun

    2010-01-01

    In order to alleviate difficulties of conducting consumer-to-consumer(C2C)e-commerce transaction,establishing efficient e-alliance was proposed.E-alliance is the union of e-commerce sites.It is constructed by mobile agents.The mobile agent architecture was discussed.The process of selecting suitable e-commerce site to e-alliance was presented based on support vector machine(SVM)and fuzzy method.A prototype of the proposed system is implemented on a web platform.To enable data exchange between e-alliance and e-commerce,the system employs XML as data format.The prototype has demonstrated that the efficient C2C e-alliance is reasonable.

  11. Study of the Improvement on Network Management Performance with Mobile Agent

    Institute of Scientific and Technical Information of China (English)

    LI Jie; WANG Ru-chuan

    2003-01-01

    Owing to the increasing great complexity, computer network systems require more sophisticated management strategies to be adopted so as to guarantee adequate levels of performance. The classic centralized paradigm, adopted by SNMP, which was once appropriate in the prevenient phrase, has posed problems with the explosive expansion of networks, as well as other centralized models. Mobile Agent (MA), owing to its capability of implementing a distributed system, represents a challenging approach to provide network management with high performance. In this paper we analyze the network management structure model based on MA at first, and then we put forward a reference scenario based on MA and compare it with the traditional model. We also describe a prototype implementation based on our mobile agent system named MAS. Finally, we do some experiments to verify the performance of our framework prototype.

  12. Enhancement of QoS in Mobile Network through Channel Allocation using Software Agents

    Directory of Open Access Journals (Sweden)

    Nitin Muchhal

    2011-05-01

    Full Text Available In the last two decades the demand for mobile hosts is increasing rapidly. One of the biggest challenges in cellular systems is to fulfill the mobile user demand under the constraint of the limited spectrum. Some of the most common methods to increase the channel allocation and utilization are resource allocation schemes. Various channel allocation schemes have been proposed to provide Quality of Service (QoS and efficient channel utilization in cellular networks. This paper proposes architecture of Multi-agent system consisting of software agents to implement distributed dynamic channel allocation strategy. The strategy is based on the channel reassignment within the cell boundary and chained channel borrowing in neighboring cell areas. The QoS parameters analyzed are Call dropping probability and Call blocking probability.

  13. Secure mobile agent for telemedicine based on P2P networks.

    Science.gov (United States)

    Hsu, Wen-Shin; Pan, Jiann-I

    2013-06-01

    Exploring intelligent mobile agent (MA) technology for assisting medical services or transmitting personal patient-health information in telemedicine applications has been widely investigated. Conversely, peer-to-peer (P2P) networking has become one of the most popular applications used in the Internet because of its benefits for easy-to-manage resources and because it balances workloads. Therefore, constructing an agent-based telemedicine platform based on P2P networking architecture is necessary. The main purpose of this paper is to construct a safe agent-based telemedicine that based on P2P networking architecture. Two themes are addressed in this paper: (a) the P2P network architecture for an agent-based telemedicine service, and (b) the security mechanisms for the proposed telemedicine networking architecture. When an MA contains patient information and migrates from one host to another through the Internet, it can be attacked by other software agents or agent platforms that can illegally access patient information. The proposed P2P network architecture is based on the JXTA protocol and provides two types of telemedicine service models: the predictable service model and unpredictable service model. This architecture employs a two-layer safety mechanism for MAs (i.e., time-limited black boxes and RSA undetachable signature technologies), to provide a secure solution for agent-based telemedicine services.

  14. 移动Agent互操作性研究%The Research of the Interoperability of Mobile Agent

    Institute of Scientific and Technical Information of China (English)

    张云勇; 刘锦德

    2001-01-01

    Mobile Agent has taken a very momentous influence on some fields such as collaborative system and workflow management system because of its unique technical advantages. Until today,a large number of mobile Agent platforms have been developed but it is very difficult to collaborate those different Agent systems since the difference among their design structure and the technology which they take. Solving the interoperability of mobile Agent becomes the primary task. In this paper, the specification of MASIF is studied in detail,a clue of solving the interoperability is put forward and an addon for the interoperability of mobile Agent system called MASIF addon is developed by ourselves based on the specification.

  15. 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.

  16. Mobile-Agent的空洞避免路由算法%Hole Avoiding Routing Algorithm with Mobile-Agent

    Institute of Scientific and Technical Information of China (English)

    杨云; 顾沈君; 徐文春; 田浩澄; 韩龙生

    2012-01-01

    为了解决空洞恢复路由算法在能耗、路由开销及可扩展性等方面的问题,提出了使用移动代理(mobileagent,MA)进行网间处理来避免“路由空洞”的算法(hole avoiding routing algorithm with mobile-agent,HAMA).HAMA将网络中的节点分为“空洞相关节点”或“空洞无关节点”,通过采用MA方式,对“空洞相关节点”进行路由处理,为其找到一个最优下一跳节点,最终成功建立到Sink节点的路由,从而达到避免“路由空洞”的目的.HAMA使节点提前意识到“路由空洞”的存在,尽可能绕开路由空洞,从而降低网络能耗,均衡网络负载.与经典空洞路由算法GPSR(greedy perimeter stateless routing)相比,HAMA能够成功避免“路由空洞”,即使遇到“空洞相关节点”,也能较为成功地启用各种恢复机制绕过空洞,具有低成本、高性能的特点.%To solve problems such as energy consumption, routing efficiency and scalability in routing recovery algorithms, this paper proposes a hole avoiding routing algorithm with mobile-agent (HAMA). For the purpose of avoiding routing hole, HAMA divides the routing nodes into "hole relevant nodes" or "hole irrelevant nodes", deals with hole relevant nodes by routing algorithm with mobile-agent to find their optimal next node, and finally sets up a routing path to the Sink. The HAMA nodes are aware of the existence of "routing hole" in advance as much as possible to bypass the routing hole. The proposed algorithm is superior to other hole avoiding algorithms in reducing energy consumption and balancing network load. Compared with classic hole routing algorithm GPSR (greedy perimeter stateless routing), HAMA with low cost and high performance characteristics, can avoid hole successfully, and even has recovery mechanism when encountering hole relevant node.

  17. A mobile-agent-based approach to software coordination inthe HOOPE system

    Institute of Scientific and Technical Information of China (English)

    马晓星; 吕建; 陶先平; 李英军; 胡昊

    2002-01-01

    Software coordination is central to the construction of large-scale high-performance distributed applications with software services scattered over the decentralized Internet. In this paper, a new mobile-agent-based architecture is proposed for the utilization and coordination of geographically distributed computing resources. Under this architecture, a user application is built with a set of software agents that can travel across the network autonomously. These agents utilize the distributed resources and coordinate with each other to complete their task. This approach's advantages include the natural expression and flexible deployment of the coordination logic, the dynamic adaptation to the network environment and the potential of better application performance. This coordination architecture, together with an object-oriented hierarchical parallel application framework and a graphical application construction tool, is implemented in the HOOPE environment, which provides a systematic support for the development and execution of Internet-based distributed and parallel applications in the petroleum exploration industry.

  18. Behaviour Study of a Multi-Agent Mobile Robot System during Potential Field Building

    Directory of Open Access Journals (Sweden)

    István Nagy

    2009-12-01

    Full Text Available In this paper a multi-agent based mobile robot simulation system will bepresented where the behaviour of the system is studied with different number of agents (1,3,6 and also with different number of ultrasonic range sensors on agents (8 or 16 USsensors on individual agents. The task of the autonomous agents is to create the potentialfield (PF of an unknown environment. The classic problems of PF building, like oscillationand trapping, are not the focus of the article, but instead, the article is concerned with theagents’ self-organizing ability where self-organizing is controlled by a genetic algorithm(GA. The GA is equipped with two fitness functions where one “maintains” the distancesbetween certain agents (spat distr, while another “watches” the area coverage (areacover. In fact, the paper can be divided into three main parts. The first part describes theultrasonic sensing and range measuring with systematic errors, the potential field (PFbuilding and the moving strategies. The second part contains description of the GA, theoperation of the GA, the structure of the system, the fitness functions and a general systemerrordetermination. In the final third part, the obtained results are analyzed and presentedin the appendices.

  19. Designing a meta-level architecture in Java for adaptive parallelism by mobile software agents

    Science.gov (United States)

    Dominic, Stephen Victor

    Adaptive parallelism refers to a parallel computation that runs on a pool of processors that may join or withdraw from a running computation. In this dissertation, a functional system of agents and agent behaviors for adaptive parallelism is developed. Software agents have the properties of robustness and have capacity for fault-tolerance. Adaptation and fault-tolerance emerge from the interaction of self-directed autonomous software agents for a parallel computation application. The multi-agent system can be considered an object-oriented system with a higher-level architectural component, i.e., a meta level for agent behavior. The meta-level object architecture is based on patterns of behavior and communication for mobile agents, which are developed to support cooperative problem solving in a distributed-heterogeneous computing environment. Although parallel processing is a suggested application domain for mobile agents implemented in the Java language, the development of robust agent behaviors implemented in an efficient manner is an active research area. Performance characteristics for three versions of a pattern recognition problem are used to demonstrate a linear speed-up with efficiency that is compared to research using a traditional client-server protocol in the C language. The best ideas from existing approaches to adaptive parallelism are used to create a single general-purpose paradigm that overcomes problems associated with nodefailure, the use of a single-centralized or shared resource, requirements for clients to actively join a computation, and a variety of other limitations that are associated with existing systems. The multi-agent system, and experiments, show how adaptation and parallelism can be exploited by a meta-architecture for a distributed-scientific application that is of particular interest to design of signal-processing ground stations. To a large extent the framework separates concern for algorithmic design from concern for where and

  20. Monoliths in Bioprocess Technology

    Directory of Open Access Journals (Sweden)

    Vignesh Rajamanickam

    2015-04-01

    Full Text Available Monolithic columns are a special type of chromatography column, which can be used for the purification of different biomolecules. They have become popular due to their high mass transfer properties and short purification times. Several articles have already discussed monolith manufacturing, as well as monolith characteristics. In contrast, this review focuses on the applied aspect of monoliths and discusses the most relevant biomolecules that can be successfully purified by them. We describe success stories for viruses, nucleic acids and proteins and compare them to conventional purification methods. Furthermore, the advantages of monolithic columns over particle-based resins, as well as the limitations of monoliths are discussed. With a compilation of commercially available monolithic columns, this review aims at serving as a ‘yellow pages’ for bioprocess engineers who face the challenge of purifying a certain biomolecule using monoliths.

  1. Emergence of a snake-like structure in mobile distributed agents: an exploratory agent-based modeling approach.

    Science.gov (United States)

    Niazi, Muaz A

    2014-01-01

    The body structure of snakes is composed of numerous natural components thereby making it resilient, flexible, adaptive, and dynamic. In contrast, current computer animations as well as physical implementations of snake-like autonomous structures are typically designed to use either a single or a relatively smaller number of components. As a result, not only these artificial structures are constrained by the dimensions of the constituent components but often also require relatively more computationally intensive algorithms to model and animate. Still, these animations often lack life-like resilience and adaptation. This paper presents a solution to the problem of modeling snake-like structures by proposing an agent-based, self-organizing algorithm resulting in an emergent and surprisingly resilient dynamic structure involving a minimal of interagent communication. Extensive simulation experiments demonstrate the effectiveness as well as resilience of the proposed approach. The ideas originating from the proposed algorithm can not only be used for developing self-organizing animations but can also have practical applications such as in the form of complex, autonomous, evolvable robots with self-organizing, mobile components with minimal individual computational capabilities. The work also demonstrates the utility of exploratory agent-based modeling (EABM) in the engineering of artificial life-like complex adaptive systems.

  2. 基于Mobile-C移动代理的函数库封装与应用%Encapsulation and apply of the function library based on the Mobile-C mobile agent

    Institute of Scientific and Technical Information of China (English)

    李闯; 葛为民; 王肖峰

    2012-01-01

    本文基于Mobile-C移动代理控制移动机器人,简述了Mobile-C与Ch的优势,详细介绍了Mobile-C移动代理函数库的原理机制与封装调用.移动机器人通过Mobile-C移动代理来实现控制,可以在运行中动态地切换成新的算法,函数库的使用使得代理传送的代码量大大减少,减少网络延时,同时使程序的结构简单明了,为复杂控制的实现做好基础.文章最后用一个简单的实验验证了Mobile-C移动代理函数库封装的正确性.%This paper, based on the control of mobile robot by the Mobile-C mobile agent, introduces the advantages of mobile agent combined with Cb, details the mechanism and encapsulation of the Mobile-C function library. By the control of Mobile-C mobile agent, robots can dynamically switch to the new algorithm at runtime. The function library makes the agent transfer code decrease greatly, reduce the network time delay, at the same time makes program structure simple and clear, it does a good job in basic for the realization of complex control. At last, a simple experiment verifies the correctness of the Mobile-C mobile agent function library encapsulation.

  3. Migration Mechanism for the Mobile Agent Based on .Net%.NET环境下的移动代理迁移机制

    Institute of Scientific and Technical Information of China (English)

    王丹; 于戈; 王国仁

    2003-01-01

    The migration mechanism is one of the most important techniques for the mobile agent techniques. In this paper, migration mechanism for the mobile agent based on Microsoft .NET developing environment is researched. First, the two serialized techniques provided by .NET platform are analyzed and compared,and Binary serialization techniques are adopted to implement the data state migration of the mobile agent. Then, the Web serviceapproach is introduced to realize the code state migration of the mobile agent and the corresponding Web service is constructed. At last, the whole migration process of the mobile agent is described.

  4. An Agent Location Transparent Communication Method in Mobile Agent System%可移动agent系统位置透明通信的一种实现

    Institute of Scientific and Technical Information of China (English)

    王红; 林守勋; 曾广周

    2001-01-01

    在可移动的软件Agent(Mobile Software Agent,MSA)的应用中, Agent并不是孤立地完成计算任务,它们需要不断地与其它agent进行信息交换,而agent的位置又是经常变动的.文中提出了一种实现agent位置透明通信的方法,主要解决agent位置追踪问题和agent迁移时的消息处理问题.%Mobile Software Agent (MSA) is a new computing model that is more suitable for current distributed computing environment. In a MSA system, an agent is not isolate in accomplishing computing tasks. It needs to exchange some information with other agents continuously. But the location of an agent is often changed, so two problems have to be solved. First is the Agent Location Tracking, that is how to inform the current location of an agent to other agents when it migrates. Second is the message storage and transfer, that is how to handle the information that is sent to an agent when it is in the procedure of migration. This paper presents a Location Transparent Agent Communication method by using the AgentTracer and the AgentShadow. The AgentTracer is a mapping of each agent ID and its current location. When an agent is created, it gets an AgentShadow which mainly records the agent ID and the address of the AgentTracer to which it belongs. By using the AgentTracer and the AgentShadow, an agent can be traced all through its lifetime. In this paper we first describe the structure of the AgentTracer and the AgentShadow, then we present the procedure of message storage and transfer by using the AgentProxy. It has been realized in a MSA system based on Java.

  5. Preparation of imprinted monolithic column under molecular crowding conditions

    Institute of Scientific and Technical Information of China (English)

    Xiao Xia Li; Xin Liu; Li Hong Bai; Hong Quan Duan; Yan Ping Huang; Zhao Sheng Liu

    2011-01-01

    Molecular crowding is a new concept to obtain molecularly imprinted polymers (MIPs) with greater capacity and selectivity. In this work, molecular crowding agent was firstly applied to the preparation of MIPs monolithic column. A new polymerization system based on molecular crowding surrounding was developed to prepare enrofloxacin-imprinted monolith, which was composed of polystyrene and tetrahydrofuran. The result showed that the monolithic MIPs under molecular crowding conditions presented good molecular recognition for enrofloxacin with an imprinting factor of 3.03.

  6. A mobile multi-agent information system for ubiquitous fetal monitoring.

    Science.gov (United States)

    Su, Chuan-Jun; Chu, Ta-Wei

    2014-01-02

    Electronic fetal monitoring (EFM) systems integrate many previously separate clinical activities related to fetal monitoring. Promoting the use of ubiquitous fetal monitoring services with real time status assessments requires a robust information platform equipped with an automatic diagnosis engine. This paper presents the design and development of a mobile multi-agent platform-based open information systems (IMAIS) with an automated diagnosis engine to support intensive and distributed ubiquitous fetal monitoring. The automatic diagnosis engine that we developed is capable of analyzing data in both traditional paper-based and digital formats. Issues related to interoperability, scalability, and openness in heterogeneous e-health environments are addressed through the adoption of a FIPA2000 standard compliant agent development platform-the Java Agent Development Environment (JADE). Integrating the IMAIS with light-weight, portable fetal monitor devices allows for continuous long-term monitoring without interfering with a patient's everyday activities and without restricting her mobility. The system architecture can be also applied to vast monitoring scenarios such as elder care and vital sign monitoring.

  7. 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.

  8. Improve information retrieval and e-learning using mobile agent based on semantic web technology

    Directory of Open Access Journals (Sweden)

    Maged Elazony

    2015-07-01

    Full Text Available The Web-based education and E-Learning has become a very important branch of new educational technology. E-learning and Web-based courses offer advantages for learners by making access to resources and learning objects very fast, just-in-time and relevance, at any time or place. Web based Learning Management Systems should focus on how to satisfy the e-learners needs and it may advise a learner with most suitable resources and learning objects. But Because of many limitations using web 2.0 for creating E-learning management system, now-a-days we use Web 3.0 which is known as Semantic web. It is a platform to represent E-learning management system that recovers the limitations of Web 2.0.In this paper we present “improve information retrieval and e-learning using mobile agent based on semantic web technology”. This paper focuses on design and implementation of knowledge-based industrial reusable, interactive, web-based training activities at the sea ports and logistics sector and use e-learning system and semantic web to deliver the learning objects to learners in an interactive, adaptive and flexible manner. We use semantic web and mobile agent to improve Library and courses Search. The architecture presented in this paper is considered an adaptation model that converts from syntactic search to semantic search. We apply the training at Damietta port in Egypt as a real-world case study. we present one of possible applications of mobile agent technology based on semantic web to management of Web Services, this model improve the information retrieval and E-learning system.

  9. Research of Network Security Situational Assessment Quantization Based on Mobile Agent

    Science.gov (United States)

    Xiaorong, Cheng; Su, Lang; Mingxuan, Li

    As the security situational assessment widely applying to the computer network field, scholars have designed and implemented a large number of network security situational assessment methods. However, most works are based on local area network and single host, which is hardly to meet the demand of large-scale network security assessment. In this paper, we based on quantitative hierarchical network security situational assessment model, introduced the mobile agent technology, designed the distributed computing for large-scale network and evaluated the whole network security situation for future prediction.

  10. A Schelling model with switching agents: decreasing segregation via random allocation and social mobility

    Science.gov (United States)

    Hazan, Aurélien; Randon-Furling, Julien

    2013-10-01

    We study the behaviour of a Schelling-class system in which a fraction f of spatially-fixed switching agents is introduced. This new model allows for multiple interpretations, including: (i) random, non-preferential allocation (e.g. by housing associations) of given, fixed sites in an open residential system, and (ii) superimposition of social and spatial mobility in a closed residential system. We find that the presence of switching agents in a segregative Schelling-type dynamics can lead to the emergence of intermediate patterns (e.g. mixture of patches, fuzzy interfaces) as the ones described in [E. Hatna, I. Benenson, J. Artif. Soc. Social. Simul. 15, 6 (2012)]. We also investigate different transitions between segregated and mixed phases both at f = 0 and along lines of increasing f, where the nature of the transition changes.

  11. AN AGENT BASED APPROACH TO AVOID SELFISH NODE DYNAMICALLY IN MOBILE NETWORKS

    Directory of Open Access Journals (Sweden)

    Radhika Garg

    2012-09-01

    Full Text Available Mobile Networks is one of the busy networks on which lotof data is transferred at very high speed. Security andefficiency are the main challenges for such open network.One of the common attacks on such network is themisbehavior of a node as a Selfish Node. A selfish nodeitself utilizes the communication medium and will not helpin forwarding the packet. The proposed work is the agentbased analysis of network. For this work, an Agent is setupwhich will perform the analysis while communicating overthe network. The agent will observe the averagecommunication of each node and based on analysis, adynamic fuzzy rule will be decided. Now each nodetransmission will be checked on this fuzzy rule. A specificrule will be decided to identify the selfish node. The workis about to decide the compromising node that will replacethe selfish node to improve the throughput over thenetwork.

  12. An Active Networks Architecture Based on Mobile Agent%一种基于移动Agent的主动网络体系结构

    Institute of Scientific and Technical Information of China (English)

    张君雁; 闵帆; 杨国纬

    2003-01-01

    This paper proposes an active networks architecture which supports both integrated and discrete operationmodel based on mobile Agent technology. Mobile Agent is the component for customized function transferring, activenode provides software application layer, and Agent server processes mobile Agent specific customization. For devel-opment and deployment of specific application protocol, this paper also proposes an abstract protocol framework and aprotocol loading mechanism to enhance network performance.

  13. 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.

  14. Agent based Bandwidth Reservation Routing Technique in Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Vishnu Kumar Sharma,

    2011-12-01

    Full Text Available In mobile ad hoc networks (MANETs, inefficient resource allocation causes heavy losses to the service providers and results in inadequate user proficiency. For improving and automating the quality of service of MANETs, efficient resource allocation techniques are required. In this paper, we propose an agent based bandwidth reservation technique for MANET. The mobile agent from the source starts forwarding the data packets through the path which has minimum cost, congestion and bandwidth. The status of every node is collected which includes the bottleneck bandwidth field and the intermediate node computes the available bandwidth on the link. At the destination, after updating the new bottleneck bandwidth field, the data packet is feedback to the source. In resource reservation technique, if the available bandwidth is greater than bottleneck bandwidth, then bandwidth reservation for the flow is done. Using rate monitoring and adjustment methodologies, rate control is performed for the congested flows. By simulation results, we show that the resource allocation technique reduces the losses and improves the network performance.

  15. Application of sustainable foaming agents to control the mobility of carbon dioxide in enhanced oil recovery

    Directory of Open Access Journals (Sweden)

    Roozbeh Rafati

    2012-12-01

    Full Text Available Carbon dioxide (CO2 flooding is a conventional process in which the CO2 is injected into the oil reservoir to increase the quantity of extracting oil. This process also controls the amount of released CO2 as a greenhouse gas in the atmosphere which is known as CO2 sequestration process. However, the mobility of the CO2 inside the hydrocarbon reservoir is higher than the crude oil and always viscous fingering and gravity override problems occur during a CO2 injection. The most common method to overcome these problems is to trap the gas bubbles in the liquid phase in the form of aqueous foam prior to CO2 injection. Although, the aqueous foams are not thermodynamically stable, special care should be considered to ensure bulk foam preparation and stability. Selection of a proper foaming agent from a large number of available surfactants is the main step in the bulk foam preparation. To meet this purpose, many chemical and crude oil based surfactants have been reported but most of them are not sustainable and have disposal problems. The objective of this experimental study is to employ Lignosulfonate and Alkyl Polyglucosides (APGs as two sustainable foaming agents for the bulk foam stability investigations and foam flooding performance in porous media. In the initial part, the bulk foam stability results showed that APGs provided more stable foams in comparison with Lignosulfonate in all surfactant concentrations. In the second part, the results indicated that the bulk foam stability measurements provide a good indication of foam mobility in porous media. The foaming agent’s concentration which provided the maximum foam stability also gave the highest value of mobility reduction in porous media.

  16. Distributed Resource Exploitation for Autonomous Mobile Sensor Agents in Dynamic Environments

    Science.gov (United States)

    Doumit, Sarjoun; Minai, Ali

    This paper studies the distributed resource exploitation problem (DREP) where many resources are distributed across an unknown environment, and several agents move around in it with the goal to exploit/visit the resources. A resource may be anything that can be harvested/sensed/acted upon by an agent when the agent visits that resource's physical location. A sensory agent (SA) is a mobile and autonomous sensory entity that has the capability of sensing a resource's attribute and therefore determining the exploitatory gain factor or profitability when this resource is visited. This type of problem can be seen as a combination of two well-known problems: the Dynamic Traveling Salesman Problem (DTSP) [8] and the Vehicle Routing Problem (VRP) [1]. But the DREP differs significantly from these two. In the DTSP we have a single agent that needs to visit many fixed cities that have costs associated to their pairwise links, so it is an optimization of paths on a static graph with time-varying costs. In VRP on the other hand, we have a number of vehicles with uniform capacity, a common depot, and several stationary customers scattered around an environment, so the goal is to find the set of routes with overall minimum route cost to service all the customers. In our problem, we have multiple SAs deployed in an unknown environment with multiple dynamic resources each with a dynamically varying value. The goal of the SAs is to adapt their paths collaboratively to the dynamics of the resources in order to maximize the general profitability of the system.

  17. 基于Mobile Agent聚类挖掘算法研究%Study on Data Mining Clustering Algorithm Based on Mobile Agent

    Institute of Scientific and Technical Information of China (English)

    魏爽

    2014-01-01

    Mobile Agent技术是随着网络应用的日益深入而发展起来的一项新兴技术。Mobile Agent技术的智能性和移动性,不仅降低了网络负载,而且提高了通信效率;此外,其支持异步自主交互、支持断连操作,具有安全性、并行性,具有学习、容错、智能化路由能力等优点,使得Mobile Agent技术在复杂的分布式问题求解方面表现出非凡的优势,因此,将Mobile Agent技术应用于数据挖掘系统中,具有很好的研究及应用前景。%Mobile Agent technology is a entity which can autonomously move from one host to another in a heterogeneous net⁃work and communicate with other Agent and resources. The intelligence and mobility of Mobile Agent technology not only re⁃duce the network load, but improve communication efficiency. Supporting asynchronous autonomous interaction, breakpoint op⁃eration and concurrent calculation and being secure and capable of learning, fault-tolerance and intelligent routing, Mobile Agent, applied to distributed Web data mining system, technology has a great research and application prospect.

  18. Mobile Agent的迁移与定位机制%On Principles of Migration and Location of Mobile Agent

    Institute of Scientific and Technical Information of China (English)

    朱传宇; 周键; 袁兆山; 孔磊

    2001-01-01

    本文首先介绍了Agent的基本概念、模型,以及Mobile Agent的概念、技术特点与应用领域,主要论述了Mobile Agent的迁移方式,Mobile Agent的定位机制以及其存在的问题.

  19. Investigation of oil recovery improvement by coupling an interfacial tension agent and a mobility control agent in light oil reservoirs. Annual report, October 1992--September 1993

    Energy Technology Data Exchange (ETDEWEB)

    Pitts, M.J.

    1994-06-01

    Investigation of Oil Recovery Improvement by Coupling and Interfacial Tension Agent and a Mobility Control Agent in Light Oil Reservoirs will study 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 agent, surfactants, and polymers on a fluid-fluid and fluid-rock basis. The second area concerns the economic improvement of the combined technology. This report examines the interactions of different alkaline agents, surfactants, and polymer combinations on a fluid-fluid basis. Alkali and surfactant combine to reduce the interfacial tension between a low acid number, 42 API gravity crude oil and the aqueous solution to values lower than either agent alone. Surfactant structure can vary from linear chain sulfonates to alkyl aryl sulfonates to produce low interfacial tension values when combined with alkali. However as a class, the alkyl aryl sulfonates were the most effective surfactants. Surfactant olefinic character appears to be critical in developing low interfacial tensions. For the 42 API gravity crude oil, surfactants with molecular weights ranging from 370 to 450 amu are more effective in lowering interfacial tension. Ultra low interfacial tensions were achieved with all of the alkaline agents evaluated when combined with appropriate surfactants. Different interfacial tension reduction characteristics with the various alkali types indicates alkali interacts synergistically with the surfactants to develop interfacial tension reduction. The solution pH is not a determining factor in lowering interfacial tension. Surfactant is the dominant agent for interfacial tension reduction.

  20. A Method of Security Authentication for Mobile Agent%移动Agent的一种安全认证机制

    Institute of Scientific and Technical Information of China (English)

    丁建国; 白英彩; 柳惠琳; 陈涵生

    2001-01-01

    Mobile agent and its security are analyzed in this paper. Before the mobile agents are brought to actual application, enough security is meeded. A security authentication method is provided and a detail description is given in the paper. And further research about security for mobile agent is pointed out.%就移动Agent安全性进行了分析,移动Agent要真正走向实际应用的前提是能提供足够的安全性.提出并详细描述了移动Agent和代理服务器之间的一种安全认证机制,并指出进一步研究的方向和内容.

  1. 基于JavaCard的移动代理系统安全性研究%Research on Security of JavaCard based Mobile Agent System

    Institute of Scientific and Technical Information of China (English)

    陈志贤; 王绍棣; 王汝传; 孙知信

    2003-01-01

    With wide and increasing range applications of mobile agent technology, the security problem has gottenmore and more focus. This paper discusses the security problems that the mobile agent system faces with at presentand the existing protesting schemes for it. Then a solving method based on JavaCard is proposed to protect mobile a-gents. And a feasible solving method is also provided to solve the security problems of JavaCard itself.

  2. A secure model for mobile agent based on encrypted circuit construction

    Institute of Scientific and Technical Information of China (English)

    ZHENG Yan; WANG Ruchuan; MU Hong; WANG Haiyan

    2007-01-01

    As a new technology,mobile agent (MA) shows a wide application in the field of network technology.However,security has been one of the crucial problems in its application.A new protection model based on a trusted element is presented in this paper.The trusted element,which differs from the traditional trusted hardware such as a smart card or a co-processor,offers a third party service based on an encrypted circuit construction.The procedure of constructing an encrypted circuit is introduced and the method of using the trusted service to protect the MA is also described.An application example is given to show how to use the new model at the end of the paper.

  3. Research on cultural algorithm for solving routing problem of mobile agent

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The key idea behind cultural algorithm is to explicitly acquire problem-solving knowledge from the evolving population and in return apply that knowledge to guide the search. In this article, cultural algorithm-simulated annealing is proposed to solve the routing problem of mobile agent. The optimal individual is accepted to improve the belief space's evolution of cultural algorithms by simulated annealing. The step size in search is used as situational knowledge to guide the search of optimal solution in the population space. Because of this feature, the search time is reduced. Experimental results show that the algorithm proposed in this article can ensure the quality of optimal solutions, and also has better convergence speed. The operation efficiency of the system is considerably improved.

  4. INTELLIGENT PRODUCT BASED ON MOBILE AGENT TO ACCELERATE THE NEW PRODUCT DEVELOPMENT PROCESS

    Directory of Open Access Journals (Sweden)

    Abdelhak Boulaalam

    2013-01-01

    Full Text Available To improve the ever-increasing demands products that are customized, all business activities performed along the product life cycle must be coordinated and efficiently managed along the extended enterprise. For this, enterprise had wanted to retain control over the whole product lifecycle especially when the product is in use/repair/recycling (End of Life phase. Although there have been many previous research works about product lifecycle management in the Beginning of Life (BOL and Middle of Life (MOL phases, few addressed the End of Life (EOL phase, in particular. In this study, based on Auto-ID combined with mobile multi-agent system technologies, we will try to improve innovation: (a by minimize the lunch phase, (b and the involvement of the customer in product lifecycle (voice of customer."

  5. Research of Anti-spam System Basing on Immunity System and Mobile Agent

    Institute of Scientific and Technical Information of China (English)

    HUI Bei; WU Yue; JI Lin; CHEN Jia

    2007-01-01

    The human immune system has the function of self-discern.It can identify the non-self antigen and clear it through the immune response automatically.So,human body has the power of resisting disease.The anti-spam system basing on immune system is proposed by using immune system's theory,and it is introduced in the mail service of enterprise VPN.Regard VPN as the human body,the mobile agent is simulated the antibody because of its movable and intelligent,and the spam is simulated the antigen.It can clear the spam by using immune mechanism.This method is a new thinking of anti-spam mail.The advantage is overcoming the weakness on independence of traditional anti-spam system.

  6. FOREST GUARD: A complete safety for Wildlife using Mobile Agents and Sensor Clouds in WSN

    Directory of Open Access Journals (Sweden)

    Sumit Kumar Tetarave

    2012-11-01

    Full Text Available With growing human population and search for new habitus and unsustainable use of natural resources, over exploitation of forests and wildlife is taking place world over. This is resulting in drastic decline in the number of essential flora and fauna. We propose a complete safe guard model named Forest Guard, for saving wildlife from human as well as their own collisions. This model will not guard them directly; rather it will help in collecting vital information about their real-time condition and will alert the institutional mechanisms to take corrective initiatives. The paper mentions this indirect support in the form of wireless sensor networks (WSN. In WSN, our proposed model uses mobile agents (MAs for handling huge area communication and injecting them for different guarding issues of different species of wildlife. A novel concept of Virtual Sensor Cloud (VSC is being discussed to trace different group of endangered wild animals such as Tigers, Lions, Elephants, etc.

  7. Active defense scheme against DDoS based on mobile agent and network control in network confrontation

    Science.gov (United States)

    Luo, Rong; Li, Junshan; Ye, Xia; Wang, Rui

    2013-03-01

    In order to effective defend DDoS attacks in network confrontation, an active defense scheme against DDoS is built based on Mobile Agent and network control. A distributed collaborative active defense model is constructed by using mobile agent technology and encapsulating a variety of DDoS defense techniques. Meanwhile the network control theory is applied to establish a network confrontation's control model for DDoS to control the active defense process. It provides a new idea to solve the DDoS problem.

  8. An information potential approach for tracking and surveilling multiple moving targets using mobile sensor agents

    Science.gov (United States)

    Lu, W.; Zhang, G.; Ferrari, S.; Fierro, R.; Palunko, I.

    2011-05-01

    The problem of surveilling moving targets using mobile sensor agents (MSAs) is applicable to a variety of fields, including environmental monitoring, security, and manufacturing. Several authors have shown that the performance of a mobile sensor can be greatly improved by planning its motion and control strategies based on its sensing objectives. This paper presents an information potential approach for computing the MSAs' motion plans and control inputs based on the feedback from a modified particle filter used for tracking moving targets. The modified particle filter, as presented in this paper implements a new sampling method (based on supporting intervals of density functions), which accounts for the latest sensor measurements and adapts, accordingly, a mixture representation of the probability density functions (PDFs) for the target motion. It is assumed that the target motion can be modeled as a semi-Markov jump process, and that the PDFs of the Markov parameters can be updated based on real-time sensor measurements by a centralized processing unit or MSAs supervisor. Subsequently, the MSAs supervisor computes an information potential function that is communicated to the sensors, and used to determine their individual feedback control inputs, such that sensors with bounded field-of-view (FOV) can follow and surveil the target over time.

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

    Directory of Open Access Journals (Sweden)

    Jeng-Yueng Chen

    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.

  10. Preparation and Characterization of Temperature-responsive Porous Monoliths

    Institute of Scientific and Technical Information of China (English)

    ZHANG, Rongyue; QI, Li; XIN, Peiyong; YANG, Gengliang; CHEN, Yi

    2009-01-01

    A new temperature-responsive porous monolith has been prepared by surface-initiated activators generated by electron transfer atom transfer radical polymerization (AGET ATRP) grafting poly(N-isopropylacrylamide) (PNIPAAm) within the pores of the porous polymer monolith. The grafting copolymerization was carried out by a method based on a continuous flow-through technique without special deoxygenation procedure needed in the general ATRP. The addition of ascorbic acid could counteract the oxidation effect of oxygen diffusing into the reaction system. The resulting grafted monolith was characterized by a mercury intrusion method and the size of macropore was 3.65 μm, which was suitable for flow through the monolith for HPLC. The thermally responsive property of the grafted monolith was evaluated by HPLC using steroids with various hydrophobicities as probes. Through determination of retention factor of each steroid on the grafted monolith at different temperatures using water as mobile phase, it was found that the slope of the plot of retention factor of each steroid versus the temperature changed around the low critical solution temperature (LCST, 32 ℃) of PNIPAAm in water. It was relative to the grafted PNIPAAm temperature sensitivity that a hydrophobic and hydrophilic alternation would take place around its LCST.Based on this thermally responsive property, the grafted monolith was used as stationary phase for HPLC and to separate the steroids using water as mobile phase by changing the column temperature. As a mobile phase, water is much better than organic solvents concerning the environment.

  11. Clone-Based Mobile Agent Itinerary Planning Using Separate Trees For Data Fusion In WSNS

    Directory of Open Access Journals (Sweden)

    Soheil Javadi

    2012-09-01

    Full Text Available Recent studies demonstrate that Mobile Agent (MA approach could be more effective than conventional client-server model in Wireless Sensor Network (WSN. Particularly, itinerary planning for MAs is a significant aspect of these approaches. Tree-based methods have been widely used for this purpose where many agents are dispatched simultaneously. Most of tree-based methods try to construct an optimal/suboptimal tree in terms of an objective function. In contrast, in this paper we introduce a new approach that tries to separate the MA dispatching and data fusion operations by considering two itinerary trees which results in more flexibility to regulate the itinerary plan. Based on this idea, we propose an algorithm called Two Trees Clone-based Itinerary (TTCI which constructs two trees, one serves to distribute MA in the network and another to fuse back the sensed data. By experimental results, we demonstrate the performance improvement of TTCI algorithm in terms of overall energy consumption in comparison with the previous schemes. Meanwhile, the TTCI keeps the delay low.

  12. 基于移动Agent的移动云计算系统构建方法%Construction method of mobile cloud computing system based on mobile Agent

    Institute of Scientific and Technical Information of China (English)

    王素贞; 杜治娟

    2013-01-01

    This paper proposed a mobile cloud computing architecture based on mobile Agent paradigm concerning the problems faced by the mobile cloud computing, such as application migration on network, network latency and non-persistent connection issues caused by execution on the remote device, cross-cloud service problems, and security risks and privacy issues. In this architecture, break-point saving ideas and events replay mechanism were introduced in application migration issues, optimized contract net protocol was used in the synergy between the mobile Agents, and mobile Agent exchange keys for authentication. What's more, this paper described the workflow of this architecture using colored nested Petri nets, and designed a system of mobile e-book sales based on the architecture.%针对移动云计算面临的一系列问题,如应用程序在网络上迁移问题、远程设备上执行时的网络延迟和非持续连接问题、跨云服务问题以及安全风险和隐私问题,提出了一种基于移动Agent范型的移动云计算架构,其中,在应用程序迁移中引入断点保存思想和事件重播机制,在移动Agent协同过程中使用优化过的合同网协议,利用移动Agent交换密钥进行身份认证.用有色嵌套Petri网描述了此架构的执行流程,并在此基础上设计了移动电子图书销售系统.

  13. 在移动计算环境中基于移动代理的缓存失效方案%A Cache Invalidation Scheme Based on Mobile Agent in Mobile Computing Environments

    Institute of Scientific and Technical Information of China (English)

    吴劲; 卢显良; 任立勇

    2003-01-01

    Caching can reduce the bandwidth requirement in a mobile computing environment as well as minimize the energy consumption of mobile hosts. To affirm the validity of mobile host' cache content, servers periodically broadcast cache invalidation reports that contain information of data that has been updated. However, as mobile hosts may operate in sleeping mode (disconnected mode), it is possible that some reports may be missed and the clients are forced to discard the entire cache content. In this paper, we present a cache invalidation scheme base on mobile agent in mobile computing environments, which can manage consistency between mobile hosts and servers, to avoid losing cache invalidation reports.

  14. Synergy between Software Product Line and Intelligent Mobile Middleware

    DEFF Research Database (Denmark)

    Zhang, Weishan; Hansen, Klaus Marius

    2007-01-01

    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......Current mobile middleware is designed to have a monolithic structure according to a 'one-size-fits-all' paradigm, which lacks the flexibility for optimization, customization and adaptation to different situations. In this paper we investigate the usage of software product line techniques together...

  15. Mobile Agent Based Hierarchical Intrusion Detection System in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Surraya Khanum

    2012-01-01

    Full Text Available Security mechanism is a fundamental requirement of wireless networks in general and Wireless Sensor Networks (WSN in particular. Therefore, it is necessary that this security concern must be articulate right from the beginning of the network design and deployment. WSN needs strong security mechanism as it is usually deployed in a critical, hostile and sensitive environment where human labour is usually not involved. However, due to inbuilt resource and computing restriction, security in WSN needs a special consideration. Traditional security techniques such as encryption, VPN, authentication and firewalls cannot be directly applied to WSN as it provides defence only against external threats. The existing literature shows that there seems an inverse relationship between strong security mechanism and efficient network resource utilization. In this research article, we have proposed a Mobile Agent Based Hierarchical Intrusion Detection System (MABHIDS for WSN. The Proposed scheme performs two levels of intrusion detection by utilizing minimum possible network resources. Our proposed idea enhance network lifetime by reducing the work load on Cluster Head (CH and it also provide enhanced level of security in WSN.

  16. Optimization of a Common Buffer Platform for Monolithic Integration of InGaN/GaN Light-Emitting Diodes and AlGaN/GaN High-Electron-Mobility Transistors

    Science.gov (United States)

    Liu, Chao; Cai, Yuefei; Jiang, Huaxing; Lau, Kei May

    2016-04-01

    For the development of a metal-interconnection-free integration scheme for monolithic integration of InGaN/GaN light-emitting diodes (LEDs) and AlGaN/GaN high-electron-mobility transistors (HEMTs), a common buffer to achieve high brightness, low leakage current, and high breakdown in the integrated HEMT-LED device is essential. Different buffer structures have been investigated, and their impacts upon both the LED and HEMT parts of the HEMT-LED device have been analyzed. Results indicated that a GaN/AlN buffer structure is the most ideal to serve as a common buffer platform, offering both the excellent crystalline quality and superior buffer resistivity required by the HEMT-LED device. Growth of the AlN layer was particularly crucial for engineering the dislocation density, surface morphology, as well as resistivity of the buffer layer. Using the optimized GaN/AlN buffer structure, the LED part of the HEMT-LED device was improved, showing greatly enhanced light output power and suppressed reverse leakage current, while the breakdown characteristics of the HEMT part were also improved.

  17. 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.

  18. 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 s

  19. Information Retrieval Agent System Based on Mobile Agent Technology%基于Mobile Agent技术的搜索引擎IRAS

    Institute of Scientific and Technical Information of China (English)

    王命延; 孙春华; 孙恒

    2004-01-01

    介绍了基于Mobile Agent的软件技术,利用该技术设计了一个搜索引擎IRAS,描述了其设计思想、组成和工作流程.此外,通过与传统Robot搜索方式进行对比,分析了IRAS搜索引擎系统的性能优势.

  20. AN APPLICATION OF MOBILE AGENTS TO NETWORK MANAGEMENT%移动代理在网络管理中的应用

    Institute of Scientific and Technical Information of China (English)

    胥光辉; 李子全; 谢希仁; 徐永森

    2000-01-01

    Conventional network management, such as SNMP and CMIP, adopts a centralized, client-sercer modal. In this model agent has little intelligence, while manager does almost all the work. This may lead a lot of vital problems. Mobile agent is an autonomic program, which can hang up its execution, collect its runtime state messages, transfer itself and its state to another network node, and then resume its execution there. Apply mobile agent concept to network management is a novel idea, which can greatly improve the robustness and distribution of a network management system. In this paper, an actual network management architecture based on mobile agent is proposed. Nowadays there are few network devices which can support mobile agent directly, though some ones have already began to appear. In order to enable mobile agents manage a network, a workstation (maybe a PC) can be added into the network. This special machine can accept mobile agents from a remote manage station, then these mobile agents can do their work like SNMP or CMIP managers. This method is very useful when a manage station is connected with the managed network using a low, expensive, or unreliable link. Even the connection between the manage station and the managed network is lost, mobile agents can still manage the network. The structure of the added workstation can be divided into three layers. The lowest layer is operating system layer, which supply low communication services to higher layers. The middle layer includes mobile agent server and/or SNMP/CMIP server. The mobile agent server can supply three kinds of services to mobile agents: ① monitor and administer the state of mobile agents; ② migration support; ③ high communication between mobile agents. The highest layer is mobile agent layer. This layer includes some service agents. The immigrated agents can achieve their works through communicating with these service agents. Accordiag to the propossed model, a prototype system has been

  1. An Agent-based Model Simulation of Multiple Collaborating Mobile Ad Hoc Networks (MANET)

    Science.gov (United States)

    2011-06-01

    RESULTS: Agent Learning Profiles Discounted Positive Reinforcement Learning Learning and Forgetting Forgetting is triggered by task conditions that...disable rational and deliberate mental models –forcing the agent to ignore (or forget) routine processes. Positive reinforcement is earned by an...deliberate behavior of agents as rational entities (model-based functions). 6.Experiment with positive reinforcement learning (with incremental gain over

  2. Monolithic microwave integrated circuits

    Science.gov (United States)

    Pucel, R. A.

    Monolithic microwave integrated circuits (MMICs), a new microwave technology which is expected to exert a profound influence on microwave circuit designs for future military systems as well as for the commercial and consumer markets, is discussed. The book contains an historical discussion followed by a comprehensive review presenting the current status in the field. The general topics of the volume are: design considerations, materials and processing considerations, monolithic circuit applications, and CAD, measurement, and packaging techniques. All phases of MMIC technology are covered, from design to testing.

  3. A Self-Adaptive Multi-Agent System Approach for Collaborative Mobile Learning

    Science.gov (United States)

    de la Iglesia, Didac Gil; Calderon, Juan Felipe; Weyns, Danny; Milrad, Marcelo; Nussbaum, Miguel

    2015-01-01

    Mobile technologies have emerged as facilitators in the learning process, extending traditional classroom activities. However, engineering mobile learning applications for outdoor usage poses severe challenges. The requirements of these applications are challenging, as many different aspects need to be catered, such as resource access and sharing,…

  4. Chromatographic comparison of bupivacaine imprinted polymers prepared in crushed monolith, microsphere, silica-based composite and capillary monolith formats.

    Science.gov (United States)

    Oxelbark, Joakim; Legido-Quigley, Cristina; Aureliano, Carla S A; Titirici, Maria-Magdalena; Schillinger, Eric; Sellergren, Börje; Courtois, Julien; Irgum, Knut; Dambies, Laurent; Cormack, Peter A G; Sherrington, David C; De Lorenzi, Ersilia

    2007-08-10

    A comprehensive comparison of five chromatographic stationary phases based on molecularly imprinted polymers is presented. Efficiency, imprinting factors, water compatibility and batch-to-batch reproducibility are discussed for crushed monolith, microspheres, two silica-based composites and capillary monoliths, all imprinted with the local anaesthetic bupivacaine. Synthesis protocol and chromatographic test conditions have been kept fixed within certain limits, in order to provide further insight into the strengths and weaknesses of the different formats. Excluding microparticles, all formats give satisfactory performance, especially in aqueous mobile phases. An assessment of batch-to-batch reproducibility in different mobile phases adds further value to this comparison study.

  5. Influence of different carbon monolith preparation parameters on pesticide adsorption

    Directory of Open Access Journals (Sweden)

    Vukčević Marija

    2013-01-01

    Full Text Available The capacity of carbon monolith for pesticide removal from water, and the mechanism of pesticide interaction with carbon surface were examined. Different carbon monolith samples were obtained by varying the carbonization and activation parameters. In order to examine the role of surface oxygen groups in pesticide adsorption, carbon monolith surface was functionalized by chemical treatment in HNO3, H2O2 and KOH. The surface properties of the obtained samples were investigated by BET surface area, pore size distribution and temperature-programmed desorption. Adsorption of pesticides from aqueous solution onto activated carbon monolith samples was studied by using five pesticides belonging to different chemical groups (acetamiprid, dimethoate, nicosulfuron, carbofuran and atrazine. Presented results show that higher temperature of carbonization and the amount of activating agent allow obtaining microporous carbon monolith with higher amount of surface functional groups. Adsorption properties of the activated carbon monolith were more readily affected by the amount of the surface functional groups than by specific surface area. Results obtained by carbon monolith functionalisation showed that π-π interactions were the main force for adsorption of pesticides with aromatic structure, while acidic groups play an important role in adsorption of pesticides with no aromatic ring in the chemical structure.

  6. Embedded-monolith armor

    Science.gov (United States)

    McElfresh, Michael W.; Groves, Scott E; Moffet, Mitchell L.; Martin, Louis P.

    2016-07-19

    A lightweight armor system utilizing a face section having a multiplicity of monoliths embedded in a matrix supported on low density foam. The face section is supported with a strong stiff backing plate. The backing plate is mounted on a spall plate.

  7. Mobilities

    DEFF Research Database (Denmark)

    simple movements of people, goods, and information from A to B. The ‘mobilities turn’ has made it its hallmark to explore the ‘more than’ effects of a world increasingly on the move. This new title in the Routledge Series ‘Critical Concepts in Built Environment’ creates a state-of-the-art reference work......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...... 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...

  8. Monolithically integrated AlN/GaN electronics for harsh environments Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Recently, resonant-tunneling-diode (RTD) based circuits employing monolithically-integrated RTD on high electron mobility (HEMT) structures have been developed in a...

  9. Reducing interferences in wireless communication systems by mobile agents with recurrent neural networks-based adaptive channel equalization

    Science.gov (United States)

    Beritelli, Francesco; Capizzi, Giacomo; Lo Sciuto, Grazia; Napoli, Christian; Tramontana, Emiliano; Woźniak, Marcin

    2015-09-01

    Solving channel equalization problem in communication systems is based on adaptive filtering algorithms. Today, Mobile Agents (MAs) with Recurrent Neural Networks (RNNs) can be also adopted for effective interference reduction in modern wireless communication systems (WCSs). In this paper MAs with RNNs are proposed as novel computing algorithms for reducing interferences in WCSs performing an adaptive channel equalization. The method to provide it is so called MAs-RNNs. We perform the implementation of this new paradigm for interferences reduction. Simulations results and evaluations demonstrates the effectiveness of this approach and as better transmission performance in wireless communication network can be achieved by using the MAs-RNNs based adaptive filtering algorithm.

  10. Monolithic MACS micro resonators

    Science.gov (United States)

    Lehmann-Horn, J. A.; Jacquinot, J.-F.; Ginefri, J. C.; Bonhomme, C.; Sakellariou, D.

    2016-10-01

    Magic Angle Coil Spinning (MACS) aids improving the intrinsically low NMR sensitivity of heterogeneous microscopic samples. We report on the design and testing of a new type of monolithic 2D MACS resonators to overcome known limitations of conventional micro coils. The resonators' conductors were printed on dielectric substrate and tuned without utilizing lumped element capacitors. Self-resonance conditions have been computed by a hybrid FEM-MoM technique. Preliminary results reported here indicate robust mechanical stability, reduced eddy currents heating and negligible susceptibility effects. The gain in B1 /√{ P } is in agreement with the NMR sensitivity enhancement according to the principle of reciprocity. A sensitivity enhancement larger than 3 has been achieved in a monolithic micro resonator inside a standard 4 mm rotor at 500 MHz. These 2D resonators could offer higher performance micro-detection and ease of use of heterogeneous microscopic substances such as biomedical samples, microscopic specimens and thin film materials.

  11. The MONOLITH prototype

    CERN Document Server

    Ambrosio, M; Bencivenni, G; Candela, A M; Chiarini, A; Chignoli, F; De Deo, M; D'Incecco, M; Gerli, S; Giusti, P; Gómez, F; Gustavino, C; Lindozzi, M; Mannocchi, G; Menghetti, H; Morello, C; Murtas, F; Paoluzzi, G; Pilastrini, R; Redaelli, N G; Santoni, M; Sartorelli, G; Terranova, F; Trinchero, G C

    2000-01-01

    MONOLITH (Massive Observatory for Neutrino Oscillation or LImits on THeir existence) is the project of an experiment to study atmospheric neutrino oscillations with a massive magnetized iron detector. The baseline option is a 34 kt iron detector based on the use of about 50000 m/sup 2/ of the glass Resistive Plate Chambers (glass RPCs) developed at the Laboratori Nazionali del Gran Sasso (LNGS). An 8 ton prototype equipped with 23 m/sup 2/ of glass RPC has been realized and tested at the T7-PS beam at CERN. The energy resolution for pions follows a 68%/ square root (E(GeV))+2% law for orthogonally incident particles, in the energy range between 2 and 10 GeV. The time resolution and the tracking capability of the glass RPC are suitable for the MONOLITH experiment. (7 refs).

  12. 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

  13. Polymethacrylate monolithic and hybrid particle-monolithic columns for reversed-phase and hydrophilic interaction capillary liquid chromatography.

    Science.gov (United States)

    Jandera, Pavel; Urban, Jirí; Skeríková, Veronika; Langmaier, Pavel; Kubícková, Romana; Planeta, Josef

    2010-01-01

    We prepared hybrid particle-monolithic polymethacrylate columns for micro-HPLC by in situ polymerization in fused silica capillaries pre-packed with 3-5microm C(18) and aminopropyl silica bonded particles, using polymerization mixtures based on laurylmethacrylate-ethylene dimethacrylate (co)polymers for the reversed-phase (RP) mode and [2-(methacryloyloxy)ethyl]-dimethyl-(3-sulfopropyl) zwitterionic (co)polymers for the hydrophilic interaction (HILIC) mode. The hybrid particle-monolithic columns showed reduced porosity and hold-up volumes, approximately 2-2.5 times lower in comparison to the pure monolithic columns prepared in the whole volume of empty capillaries. The elution volumes of sample compounds are also generally lower in comparison to packed or pure monolithic columns. The efficiency and permeability of the hybrid columns are intermediate in between the properties of the reference pure monolithic and particle-packed columns. The chemistries of the embedded solid particles and of the interparticle monolithic moiety in the hybrid capillary columns contribute to the retention to various degrees, affecting the selectivity of separation. Some hybrid columns provided improved separations of proteins in comparison to the reference particle-packed columns in the reversed-phase mode. Zwitterionic hybrid particle-monolithic columns show dual mode retention HILIC/RP behaviour depending on the composition of the mobile phase and allow separations of polar compounds such as phenolic acids in the HILIC mode at lower concentrations of acetonitrile and, often in shorter analysis time in comparison to particle-packed and full-volume monolithic columns.

  14. Development of improved mobility control agents for surfactant/polymer flooding. Second annual report, October 1, 1979-September 30, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Martin, F.D.; Donaruma, L.G.; Hatch, M.J.

    1981-04-01

    The objective of this laboratory work is to develop improved mobility control agents that are more effective than the commercial polymers currently used in this process. During the second year of the project, the baseline testing of commercial products was completed. These baseline tests with polymers include studies on mobility control, retention, and shear degradation in Berea cores, the effect of common ions on rheological properties, thermal stability, microbial degradation, and surfactant-polymer interactions. These data are used for comparison of the commercial agents at standardized sets of conditions, and are also used to evaluate new, modified, or improved polymers. Work was also initiated on the synthesis, characterization, and preliminary screening of new and modified polymers. Testing of these analogs provides systematic correlations of polymer performance with polymer structure. This preliminary testing consists of measurements of shear degradation and viscosity loss in NaCl brines by the use of a simplified screening procedure. To date, a number of potential structure-utility relationships have been observed. Solution viscosities of all nonionic polymers tested are essentially insensitive to changes in NaCl concentration. Increasing the charge-to-mass ratio (degree of hydrolysis) of either polyacrylamides or N-alkyl analogs enhances the ability of these polymers to build viscosity in low salinity NaCl brines. However, such polymers are increasingly subject to viscosity loss as the salinity is increased. Above a certain critical molecular weight, polymers become more susceptible to shear degradation. Many of the polymers that possess stiffer backbones exhibit improved brine and shear stability. The results of these studies will be used to develop an improved mobility control polymer in the next phase of this project.

  15. A COMPARISON BETWEEN EXPERT SYSTEMS AND AUTONOMIC COMPUTING PLUS MOBILE AGENT APPROACHES FOR FAULT MANAGEMENT.

    Directory of Open Access Journals (Sweden)

    SERGIO ARMANDO GUTIÉRREZ

    2011-01-01

    Full Text Available En este trabajo se presenta una revisión de trabajos relacionados a la aplicación de sistemas expertos a la gestión de fallas. Se introduce también un enfoque novedoso, basado en el paradigma de la computación autónoma y la tecnología de agentes móviles, y sus principales características son comparadas con respecto a las equivalentes de los sistemas expertos. Los benefi cios del esquema basado en agentes móviles son presentados.

  16. A Connectionism Approach to the Emulation of Multi-Agent Mobile Robots

    OpenAIRE

    Massey, S; Zalzala, A.M.S.

    1994-01-01

    The work presented in this report deals with the modelling and subsequent neural network emulation of autonomous mobile robots, moving in pre-defined environments in response to given control signals. This work was undertaken with the intention of training neural network based controllers for the vehicles, in order to control them whilst they performed required navigational tasks, whilst avoiding collisions with each other and with environmental obstacles. The required modelling was carried o...

  17. Comparison of perfusion media and monoliths for protein and virus-like particle chromatography.

    Science.gov (United States)

    Wu, Yige; Abraham, Dicky; Carta, Giorgio

    2016-05-20

    Structural and performance characteristics of perfusion chromatography media (POROS HS 20 and 50) and those of a polymethacrylate monolith (CIM SO3-1 tube monolith column) are compared for protein and virus-like particle chromatography using 1mL columns. Axial flow columns are used for POROS while the monolith has a radial flow configuration, which provides comparable operating pressures. The POROS beads contain a bimodal distribution of pore sizes, some as large as 0.5μm, which allow a small fraction of the mobile phase to flow within the particles, while the monolith contains 1-2μm flow channels. For proteins (lysozyme and IgG), the dynamic binding capacity of the POROS columns is more than twice that of the monolith at longer residence times. While the DBC of the POROS HS 50 column decreases at shorter residence times, the DBC of the POROS HS 20 column for IgG remains nearly twice that of the monolith at residence times at least as low as 0.2min as a result of intraparticle convection. Protein recoveries are comparable for all three columns. For VLPs, however, the eluted peaks are broader and recovery is lower for the monolith than for the POROS columns and is dependent on the direction of flow in the monolith, which is attributed to denser layer observed by SEM at the inlet surface of the monolith that appears to trap VLPs when loading in the normal flow direction.

  18. Self-Organized Link State Aware Routing for Multiple Mobile Agents in Wireless Network

    Science.gov (United States)

    Oda, Akihiro; Nishi, Hiroaki

    Recently, the importance of data sharing structures in autonomous distributed networks has been increasing. A wireless sensor network is used for managing distributed data. This type of distributed network requires effective information exchanging methods for data sharing. To reduce the traffic of broadcasted messages, reduction of the amount of redundant information is indispensable. In order to reduce packet loss in mobile ad-hoc networks, QoS-sensitive routing algorithm have been frequently discussed. The topology of a wireless network is likely to change frequently according to the movement of mobile nodes, radio disturbance, or fading due to the continuous changes in the environment. Therefore, a packet routing algorithm should guarantee QoS by using some quality indicators of the wireless network. In this paper, a novel information exchanging algorithm developed using a hash function and a Boolean operation is proposed. This algorithm achieves efficient information exchanges by reducing the overhead of broadcasting messages, and it can guarantee QoS in a wireless network environment. It can be applied to a routing algorithm in a mobile ad-hoc network. In the proposed routing algorithm, a routing table is constructed by using the received signal strength indicator (RSSI), and the neighborhood information is periodically broadcasted depending on this table. The proposed hash-based routing entry management by using an extended MAC address can eliminate the overhead of message flooding. An analysis of the collision of hash values contributes to the determination of the length of the hash values, which is minimally required. Based on the verification of a mathematical theory, an optimum hash function for determining the length of hash values can be given. Simulations are carried out to evaluate the effectiveness of the proposed algorithm and to validate the theory in a general wireless network routing algorithm.

  19. Mobilization

    Science.gov (United States)

    1987-01-01

    istic and romantic emotionalism that typifies this genre. Longino, James C., et al. “A Study of World War Procurement and Industrial Mobilization...States. Harrisburg, PA: Military Service Publishing Co., 1941. CARL 355.22 J72b. Written in rough prose , this World War II era document explains the

  20. Bioaffinity chromatography on monolithic supports

    NARCIS (Netherlands)

    Tetala, K.K.R.; Beek, van T.A.

    2010-01-01

    Affinity chromatography on monolithic supports is a powerful analytical chemical platform because it allows for fast analyses, small sample volumes, strong enrichment of trace biomarkers and applications in microchips. In this review, the recent research using monolithic materials in the field of bi

  1. Bioaffinity chromatography on monolithic supports

    NARCIS (Netherlands)

    Tetala, K.K.R.; Beek, van T.A.

    2010-01-01

    Affinity chromatography on monolithic supports is a powerful analytical chemical platform because it allows for fast analyses, small sample volumes, strong enrichment of trace biomarkers and applications in microchips. In this review, the recent research using monolithic materials in the field of bi

  2. Dynamic Agent Classification and Tracking Using an Ad Hoc Mobile Acoustic Sensor Network

    Directory of Open Access Journals (Sweden)

    Friedlander David

    2003-01-01

    Full Text Available Autonomous networks of sensor platforms can be designed to interact in dynamic and noisy environments to determine the occurrence of specified transient events that define the dynamic process of interest. For example, a sensor network may be used for battlefield surveillance with the purpose of detecting, identifying, and tracking enemy activity. When the number of nodes is large, human oversight and control of low-level operations is not feasible. Coordination and self-organization of multiple autonomous nodes is necessary to maintain connectivity and sensor coverage and to combine information for better understanding the dynamics of the environment. Resource conservation requires adaptive clustering in the vicinity of the event. This paper presents methods for dynamic distributed signal processing using an ad hoc mobile network of microsensors to detect, identify, and track targets in noisy environments. They seamlessly integrate data from fixed and mobile platforms and dynamically organize platforms into clusters to process local data along the trajectory of the targets. Local analysis of sensor data is used to determine a set of target attribute values and classify the target. Sensor data from a field test in the Marine base at Twentynine Palms, Calif, was analyzed using the techniques described in this paper. The results were compared to "ground truth" data obtained from GPS receivers on the vehicles.

  3. Dynamic 3-D chemical agent cloud mapping using a sensor constellation deployed on mobile platforms

    Science.gov (United States)

    Cosofret, Bogdan R.; Konno, Daisei; Rossi, David; Marinelli, William J.; Seem, Pete

    2014-05-01

    The need for standoff detection technology to provide early Chem-Bio (CB) threat warning is well documented. Much of the information obtained by a single passive sensor is limited to bearing and angular extent of the threat cloud. In order to obtain absolute geo-location, range to threat, 3-D extent and detailed composition of the chemical threat, fusion of information from multiple passive sensors is needed. A capability that provides on-the-move chemical cloud characterization is key to the development of real-time Battlespace Awareness. We have developed, implemented and tested algorithms and hardware to perform the fusion of information obtained from two mobile LWIR passive hyperspectral sensors. The implementation of the capability is driven by current Nuclear, Biological and Chemical Reconnaissance Vehicle operational tactics and represents a mission focused alternative of the already demonstrated 5-sensor static Range Test Validation System (RTVS).1 The new capability consists of hardware for sensor pointing and attitude information which is made available for streaming and aggregation as part of the data fusion process for threat characterization. Cloud information is generated using 2-sensor data ingested into a suite of triangulation and tomographic reconstruction algorithms. The approaches are amenable to using a limited number of viewing projections and unfavorable sensor geometries resulting from mobile operation. In this paper we describe the system architecture and present an analysis of results obtained during the initial testing of the system at Dugway Proving Ground during BioWeek 2013.

  4. CO2 philic surfactant as possible mobility control agent in EOR applications

    Science.gov (United States)

    Sagir, Muhammad; Tan, Isa M.; Mushtaq, Muhammad

    2014-10-01

    The effect of an in house developed CO2 philic surfactant in foam assisted WAG (FAWAG) on CO2 mobility is reported. We reacted methallyl chloride with nonylphenol ethoxylated alcohol and then sulfonated the produced product. The effect of surfactant on IFT between CO2 and brine was investigated in order to measure the affinity of surfactant with CO2. The detailed effects of pressure and temperature on IFT between CO2 / brine / surfactant at the specified pressure and temperature conditions is studied and reported. In-house developed surfactant effectively lowered down the IFT between CO2/brine from 32 mN/m to less than 6.10 mN / m. In addition, the newly developed surfactant was evaluated for its foam stability. The synthesized novel surfactant was further investigated for its effect on CO2 mobility in porous media and the findings are presented here. The in house developed surfactant has a great potential for CO2- EOR applications.

  5. 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

  6. 基于主从样式的移动代理安全模型的研究与实现%Research and Implement of Master-Slave Pattern Based Security Model for Mobile Agent

    Institute of Scientific and Technical Information of China (English)

    穆鸿; 王汝传; 张登银

    2003-01-01

    In the ages of current network technology, as a new technology, the emergence of mobile agent shows us a wider and wider application prospect in the fields of network technology, such as Network Management,Intelligence Information Retrieval and Electronic Commence and so on. The security is the essence of mobile agent technology. In this paper we analyze the security issues and survey some representative approaches to solve the problem in mobile agent systems. We focus on the issues about the agent''s security and propose a master-slave designpattern based security model for mobile agent called SMAP(Secure Mobile Agent Platform). In the end we give anapplication example to show how to use these.

  7. The Pattern as a Reusable Component to Adaptive Framework for Load Balancing Mobile Agent in Internet Banking

    Directory of Open Access Journals (Sweden)

    A. Meiappane

    2012-03-01

    Full Text Available In recent years, the Software Architecture (SA of an Internet banking has become one of the most challengeable and risky fields of modern technology. The advent of the Internet has revolutionized the way banking is being done. In Internet banking, we analyzed some attributes such as usage, security, availability, load balancing and so on. Among those attributes Load Balancing is a serious problem in the Internet and it is necessary to build new systems incorporating load balancing as integral part of their design. The use of patterns, which is of a reusable component, is a good tool to help designers build load balancing systems. In this paper we are going to propose cluster load balancing technique by using mobile agent.

  8. 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.

  9. Bioavailable phosphorus (P) reduction is less than mobile P immobilization in lake sediment for eutrophication control by inactivating agents.

    Science.gov (United States)

    Wang, Changhui; He, Rui; Wu, Yu; Lürling, Miquel; Cai, Haiyuan; Jiang, He-Long; Liu, Xin

    2017-02-01

    Phosphorus (P) immobilization by inactivating agents in the sediment of eutrophic lakes to reduce immediately available P in lake water is often crucial for mitigating nuisance eutrophication symptoms, such as cyanobacterial blooms. Macrophytes and phytoplankton, however, can directly utilize P from the sediment for growth. Accordingly, a comprehensive analysis of the P bioavailability in lake sediment amended with two promising P-inactivation agents, namely Phoslock(®) and drinking water treatment residue (DWTR), was investigated in both short- and long-term studies (20 and 180 d). Phosphorus-availability was assessed using six chemical extraction methods and Hydrilla verticillata and Microcystis aeruginosa growth tests. The results showed that Phoslock(®) and DWTR significantly reduced mobile P (NH4Cl and Na2S2O4/NaHCO3 extractable P) in lake sediment, while P bioavailability that was assessed by different methods showed considerable deviations. Interestingly, appropriate bioavailable P chemical extraction methods were determined based on linear correlation analysis, and further comparison indicated that reduction of bioavailable P by DWTR (P) and Phoslock(®) (P) were clearly less than the mobile P immobilization (>75%) at recommended dosages, which was probably caused by the capability of macrophyte and cyanobacteria to utilize various fractions of P (except the residual P) in amended sediment under proper illumination. Therefore, DWTR and Phoslock(®) can effectively reduce P release from lake sediment, but the potential bioavailable P may pose uncertainties for eutrophication control in lakes that typically have regular sediment re-suspension. Overall, an evaluation of the bioavailable P pool in the lake ecosystem should be essential for successful lake geo-engineering.

  10. Porous polymer monolithic col

    Directory of Open Access Journals (Sweden)

    Lydia Terborg

    2015-05-01

    Full Text Available A new approach has been developed for the preparation of mixed-mode stationary phases to separate proteins. The pore surface of monolithic poly(glycidyl methacrylate-co-ethylene dimethacrylate capillary columns was functionalized with thiols and coated with gold nanoparticles. The final mixed mode surface chemistry was formed by attaching, in a single step, alkanethiols, mercaptoalkanoic acids, and their mixtures on the free surface of attached gold nanoparticles. Use of these mixtures allowed fine tuning of the hydrophobic/hydrophilic balance. The amount of attached gold nanoparticles according to thermal gravimetric analysis was 44.8 wt.%. This value together with results of frontal elution enabled calculation of surface coverage with the alkanethiol and mercaptoalkanoic acid ligands. Interestingly, alkanethiols coverage in a range of 4.46–4.51 molecules/nm2 significantly exceeded that of mercaptoalkanoic acids with 2.39–2.45 molecules/nm2. The mixed mode character of these monolithic stationary phases was for the first time demonstrated in the separations of proteins that could be achieved in the same column using gradient elution conditions typical of reverse phase (using gradient of acetonitrile in water and ion exchange chromatographic modes (applying gradient of salt in water, respectively.

  11. Application of mobile agent in IOT%物联网中移动代理的应用研究

    Institute of Scientific and Technical Information of China (English)

    魏葆春

    2013-01-01

    通过对物联网网络管理技术的研究,分析了物联网网络管理中存在的问题。针对物联网无线化、移动化的发展趋势,给出了基于分布式网络代理管理模型,该模型通过引入移动代理技术,能够使之更好地适应物联网的管理需求。%The problems existing in IOT network management are analyzed on the basis of research on the network management technology of IOT. A management model based on the distributed network proxy was established in allusion to the development trend of IOT wireless running and mobilization. The model can adapt to the management demands of IOT much better through introduction of the mobile agent technology.

  12. Cooperative Multi-Agent Mobile Sensor Platforms for Jet Engine Inspection: Concept and Implementation

    Science.gov (United States)

    Litt, Jonathan S.; Wong, Edmond; Krasowski, Michael J.; Greer, Lawrence C.

    2003-01-01

    Cooperative behavior algorithms utilizing swarm intelligence are being developed for mobile sensor platforms to inspect jet engines on-wing. Experiments are planned in which several relatively simple autonomous platforms will work together in a coordinated fashion to carry out complex maintenance-type tasks within the constrained working environment modeled on the interior of a turbofan engine. The algorithms will emphasize distribution of the tasks among multiple units; they will be scalable and flexible so that units may be added in the future; and will be designed to operate on an individual unit level to produce the desired global effect. This proof of concept demonstration will validate the algorithms and provide justification for further miniaturization and specialization of the hardware toward the true application of on-wing in situ turbine engine maintenance.

  13. Biobased monoliths for adenovirus purification.

    Science.gov (United States)

    Fernandes, Cláudia S M; Gonçalves, Bianca; Sousa, Margarida; Martins, Duarte L; Barroso, Telma; Pina, Ana Sofia; Peixoto, Cristina; Aguiar-Ricardo, Ana; Roque, A Cecília A

    2015-04-01

    Adenoviruses are important platforms for vaccine development and vectors for gene therapy, increasing the demand for high titers of purified viral preparations. Monoliths are macroporous supports regarded as ideal for the purification of macromolecular complexes, including viral particles. Although common monoliths are based on synthetic polymers as methacrylates, we explored the potential of biopolymers processed by clean technologies to produce monoliths for adenovirus purification. Such an approach enables the development of disposable and biodegradable matrices for bioprocessing. A total of 20 monoliths were produced from different biopolymers (chitosan, agarose, and dextran), employing two distinct temperatures during the freezing process (-20 °C and -80 °C). The morphological and physical properties of the structures were thoroughly characterized. The monoliths presenting higher robustness and permeability rates were further analyzed for the nonspecific binding of Adenovirus serotype 5 (Ad5) preparations. The matrices presenting lower nonspecific Ad5 binding were further functionalized with quaternary amine anion-exchange ligand glycidyltrimethylammonium chloride hydrochloride by two distinct methods, and their performance toward Ad5 purification was assessed. The monolith composed of chitosan and poly(vinyl) alcohol (50:50) prepared at -80 °C allowed 100% recovery of Ad5 particles bound to the support. This is the first report of the successful purification of adenovirus using monoliths obtained from biopolymers processed by clean technologies.

  14. Adaptive Control Parameters for Dispersal of Multi-Agent Mobile Ad Hoc Network (MANET) Swarms

    Energy Technology Data Exchange (ETDEWEB)

    Kurt Derr; Milos Manic

    2013-11-01

    A mobile ad hoc network is a collection of independent nodes that communicate wirelessly with one another. This paper investigates nodes that are swarm robots with communications and sensing capabilities. Each robot in the swarm may operate in a distributed and decentralized manner to achieve some goal. This paper presents a novel approach to dynamically adapting control parameters to achieve mesh configuration stability. The presented approach to robot interaction is based on spring force laws (attraction and repulsion laws) to create near-optimal mesh like configurations. In prior work, we presented the extended virtual spring mesh (EVSM) algorithm for the dispersion of robot swarms. This paper extends the EVSM framework by providing the first known study on the effects of adaptive versus static control parameters on robot swarm stability. The EVSM algorithm provides the following novelties: 1) improved performance with adaptive control parameters and 2) accelerated convergence with high formation effectiveness. Simulation results show that 120 robots reach convergence using adaptive control parameters more than twice as fast as with static control parameters in a multiple obstacle environment.

  15. Application of Mobile Agent in Network Flow Control%移动Agent在网络流量控制中的应用

    Institute of Scientific and Technical Information of China (English)

    张卫华; 徐海水

    2013-01-01

      提出采用移动代理(mobile agent)的网管框架,将代理支撑环境驻留在设备上,替代功能固定的代理,网管中心根据实际网络状态选择适当功能的代理程序发送到设备,在代理运行环境中生成程序实例(instance),完成预期功能,移动代理不仅收集而且能够自主处理数据,从而加快响应速度,减轻网管中心负载,优化网络流量控制。阐述移动代理的结构,控制问题,以及用于网络流量管理的系统框架和原型的实现。%Uses the mobile agent to build up a network management framework, and puts the support en-vironment of the agent on the equipment to replace the function fixed agent. Network manage-ment center selects an appropriate agent program which is based on the actual network status to send to the device, and the program will be generated as an instance to complete the expected functions. Mobile agent not only collect but also process data by itself, so it can speed up the response, and ease the load of network management center, all of this can optimize network flow control. Describes the structure of the mobile agent, and how to control it, as well as the frame-work and the prototype implementation of network flow management system.

  16. Monolithic microchannel heatsink

    Science.gov (United States)

    Benett, William J.; Beach, Raymond J.; Ciarlo, Dino R.

    1996-01-01

    A silicon wafer has slots sawn in it that allow diode laser bars to be mounted in contact with the silicon. Microchannels are etched into the back of the wafer to provide cooling of the diode bars. To facilitate getting the channels close to the diode bars, the channels are rotated from an angle perpendicular to the diode bars which allows increased penetration between the mounted diode bars. This invention enables the fabrication of monolithic silicon microchannel heatsinks for laser diodes. The heatsinks have low thermal resistance because of the close proximity of the microchannels to the laser diode being cooled. This allows high average power operation of two-dimensional laser diode arrays that have a high density of laser diode bars and therefore high optical power density.

  17. Internet移动代理技术中的安全性研究%Study on security of Internet mobile agents technology

    Institute of Scientific and Technical Information of China (English)

    王常杰; 张方国; 王育民

    2001-01-01

    主要针对Internet的移动代理技术中的安全问题进行研究,介绍了移动代理技术的概念及目前主要的应用范畴,对该技术中的安全问题作了系统的分析.另外,对现有的移动代理系统的安全性能作了全面的比较,提出了后续的研究方向.%A research of security of Internet mobile agents technology ispresent in the paper. The conception of mobile agents and its main applications are introduced first and then we analyze the secruity questions in the mobile agents systems comprehensively. In addition, a general comparison of the security performance of the exiting mobile agents systems is given. As a result, we suggest the future study about the technology.

  18. 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

  19. 一种基于绑定邮箱的可靠移动Agent通信算法%Reliable Mobile Agent Communication Algorithm Based on Binding Mailbox

    Institute of Scientific and Technical Information of China (English)

    闫七斐; 惠晓威; 卢永

    2011-01-01

    In recent years, mobile Agent communications algorithm has been the focus of the study.This paper analyzes several mobile Agent communication algorithms and puts forward a reliable, secure, flexible and optimal utilization of message binding mailbox Agent communication algorithms based on previous studies.%移动Agent通信算法一直是近些年研究的重点.通过分析几种移动Agent通信机制,并且在总结前人研究的基础上,提出了一种可靠、安全、灵活和消息利用率最优的邮箱绑定Agent通信算法.

  20. Remotely detected NMR for the characterization of flow and fast chromatographic separations using organic polymer monoliths.

    Science.gov (United States)

    Teisseyre, Thomas Z; Urban, Jiri; Halpern-Manners, Nicholas W; Chambers, Stuart D; Bajaj, Vikram S; Svec, Frantisek; Pines, Alexander

    2011-08-01

    An application of remotely detected magnetic resonance imaging is demonstrated for the characterization of flow and the detection of fast, small molecule separations within hypercrosslinked polymer monoliths. The hyper-cross-linked monoliths exhibited excellent ruggedness, with a transit time relative standard deviation of less than 2.1%, even after more than 300 column volumes were pumped through at high pressure and flow. Magnetic resonance imaging enabled high-resolution intensity and velocity-encoded images of mobile phase flow through the monolith. The images confirm that the presence of a polymer monolith within the capillary disrupts the parabolic laminar flow profile that is characteristic of mobile phase flow within an open tube. As a result, the mobile phase and analytes are equally distributed in the radial direction throughout the monolith. Also, in-line monitoring of chromatographic separations of small molecules at high flow rates is shown. The coupling of monolithic chromatography columns and NMR provides both real-time peak detection and chemical shift information for small aromatic molecules. These experiments demonstrate the unique power of magnetic resonance, both direct and remote, in studying chromatographic processes.

  1. 采用增量时间戳安全技术的Mobile Agent系统%Mobile Agent System by Incremental Timestamp Security Technique

    Institute of Scientific and Technical Information of China (English)

    万燕; 孙永强; 朱向华; 唐进

    2002-01-01

    安全技术决定了Mobile Agent的实用性,其主要解决的问题是防范恶意Mobile Agent的重复攻击和越权攻击.在介绍了Mobile Agent的概念、特点及安全的重要性的基础上,提出了增量时间戳的概念及优点,并给出了具体例证.采用增量时间戳的Mobile Agent系统能够较好地避免执行系统受到恶意Mobile Agent的损害.增量时间戳技术已经在基于Lucent公司的Inferno系统上开发的Mobile Agent系统中得到了验证和实现.

  2. Mobile agent技术在互联网信息检索应用的探讨%Application of Mobile Agent in the Information Retrieval of Internet

    Institute of Scientific and Technical Information of China (English)

    李虹

    2008-01-01

    本文在介绍了mobile agent技术概况的基础上,提出了基于mobile agent的并行互联网信息检索方式,并建立了一种基于mobile agent的并行信息检索的框架及流程.并对其未来发展提出了展望.

  3. 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.

  4. 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.

  5. Express analysis of explosives, chemical warfare agents and drugs with multicapillary column gas chromatography and ion mobility increment spectrometry.

    Science.gov (United States)

    Buryakov, Igor A

    2004-02-05

    Description of a gas chromatograph designed for express analysis of explosives (2,4-dinitrotoluene, 2,4,6-trinitrotoluene, pentaerythritol tetranitrate), chemical warfare agents (mustard gas, lewisite, sarin) and drugs (heroin, cocaine hydrochloride, crack) is given. The devices comprises a multicapillary chromatographic column and an ion mobility increment spectrometer (MCC-IMIS). The main analytical characteristics of an IMIS (estimated detection limit (DL), linear dynamic range (LDR), speed of response) and a chromatographic column (separation power, degree of separation, a number of possible peaks at a chromatogram section, divided by analysis time) are determined. The maximum value of DL equal to 5 pg/ml was registered for cis-alpha-LW, and the lowest one of 0.001 pg/ml was for cocaine. The maximum value of LDR equal to 1000 was registered for sarin and the lowest one of 150 was for the ions of lewisite. Speed of response of one compound detection with the IMIS was 0.7 s.

  6. Porous Monoliths: Stationary Phases of Choice for High Performance Liquid Chromatography in Various Formats%用于高效液相色谱的不同形式的多孔整体固定相

    Institute of Scientific and Technical Information of China (English)

    SVEC Frantisek

    2005-01-01

    Modern porous monoliths have been conceived as a new class of stationary phases for high performance liquid chromatography (HPLC) in classical columns in the early 1990s and later extended to the capillary format. These monolithic materials are prepared using simple processes carried out in an external mold (inorganic monoliths) or within the confines of the column (organic monoliths and all capillary columns). These methods afford macroporous materials with large through-pores that enable applications in a rapid flow-through mode. Since all the mobile phase must flow through the monolith, the convection considerably accelerates mass transport within the monolithic separation medium and improves the separations. As a result, the monolithic columns perform well even at very high flow rates. The applications of monolithic capillary columns are demonstrated on numerous separations in the HPLC mode.

  7. 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.

  8. 基于Java语言的Mobile Agent实施方案%An Implementation Scheme of Mobile Agent Based on Java

    Institute of Scientific and Technical Information of China (English)

    杨晟; 魏海平; 吴兴

    2002-01-01

    与传统的分布式计算相比较,Mobile Agent模型无疑具有更广泛的发展前景.它采用面向对象的思想使Agent具有了类的一切特性.其中,事件驱动是Mobile Agent完成用户给定任务的根本保障.通常情况下,为了完成某项任务Agent要在网络(可能是异构网络)中频繁移动,而在移动过程中Agent又必须考虑自身及Agnet平台的安全问题,这些都对Mobile Agent的实现提出了更高的要求.Java语言由于其对移动代码的支持和高度的安全性使它成为开发Moblie Agnet的首选工具.以Java语言为基础,提出了Mobile Agent模型的一种可行性实施方案,并制定了相应的Mobile Agent模块,从而为Mobile Agent的实现开辟了新的途径.

  9. Silica-based polypeptide-monolithic stationary phase for hydrophilic chromatography and chiral separation.

    Science.gov (United States)

    Zhao, Licong; Yang, Limin; Wang, Qiuquan

    2016-05-13

    Glutathione (GSH)-, somatostatin acetate (ST)- and ovomucoid (OV)-functionalized silica-monolithic stationary phases were designed and synthesized for HILIC and chiral separation using capillary electrochromatography (CEC). GSH, ST and OV were covalently incorporated into the silica skeleton via the epoxy ring-opening reaction between their amino groups and the glycidyl moiety in γ-glycidoxypropyltrimethoxysilane (GPTMS) together with polycondensation and copolymerization of tetramethyloxysilane and GPTMS. Not only could the direction and electroosmotic flow magnitude on the prepared GSH-, ST- and OV-silica hybrid monolithic stationary phases be controlled by the pH of the mobile phase, but also a typical HILIC behavior was observed so that the nucleotides and HPLC peptide standard mixture could be baseline separated using an aqueous mobile phase without any acetonitrile during CEC. Moreover, the prepared monolithic columns had a chiral separation ability to separate dl-amino acids. The OV-silica hybrid monolithic column was most effective in chiral separation and could separate dl-glutamic acid (Glu) (the resolution R=1.07), dl-tyrosine (Tyr) (1.57) and dl-histidine (His) (1.06). Importantly, the chiral separation ability of the GSH-silica hybrid monolithic column could be remarkably enhanced when using gold nanoparticles (AuNPs) to fabricate an AuNP-mediated GSH-AuNP-GSH-silica hybrid monolithic column. The R of dl-Glu, dl-Tyr and dl-His reached 1.19, 1.60 and 2.03. This monolithic column was thus applied to separate drug enantiomers, and quantitative separation of all four R/S drug enantiomers were achieved with R ranging from 4.36 to 5.64. These peptide- and protein-silica monolithic stationary phases with typical HILIC separation behavior and chiral separation ability implied their promise for the analysis of not only the future metabolic studies, but also drug enantiomers recognition.

  10. Application of Convective Interaction Media (CIM) disk monolithic columns for fast separation and monitoring of organic acids.

    Science.gov (United States)

    Vodopivec, M; Podgornik, A; Berovic, M; Strancar, A

    2000-11-01

    The separation of organic acids on the anion-exchange monolithic support, commercially available as Convective Interaction Media (CIM), is presented in this study. It is demonstrated that citric, isocitric, pyruvic, fumaric, malic, and alpha-ketoglutaric acid can be successfully separated using a CIM monolithic column of suitable user-adjustable length. The effect of the mobile phase composition on the separation is investigated. CIM monolithic columns of adjustable length from 3 to 18 mm are compared regarding the resolution and the back pressure. It is shown that the CIM monolithic column of 12 mm in length enables a good separation of all six organic acids within 3 min and exhibits a linear dependence of back pressure versus flow rate. The resolution and the dynamic binding capacity are found to be flow-unaffected. A filtrated sample of bioprocess supernatant is analyzed without previous pretreatment, which indicates the possibility of online monitoring of small molecules during the bioprocess using CIM monolithic columns.

  11. 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

  12. Research on dynamic routing problems of mobile agent in Web search engine%Web搜索引擎中Mobile Agent动态路由问题研究

    Institute of Scientific and Technical Information of China (English)

    胡庆华

    2003-01-01

    随着Internet的发展,Web上大量、分布、动态的信息导致了"信息过载",传统搜索引擎面临严峻的挑战.目前对Mobile Agent系统的理论与应用研究已成为一个热点前沿课题.本文对Web搜索引擎中Mobile Agent动态路由问题进行了研究.

  13. In situ Fabrication of Monolithic Copper Azide

    Science.gov (United States)

    Li, Bing; Li, Mingyu; Zeng, Qingxuan; Wu, Xingyu

    2016-04-01

    Fabrication and characterization of monolithic copper azide were performed. The monolithic nanoporous copper (NPC) with interconnected pores and nanoparticles was prepared by decomposition and sintering of the ultrafine copper oxalate. The preferable monolithic NPC can be obtained through decomposition and sintering at 400°C for 30 min. Then, the available monolithic NPC was in situ reacted with the gaseous HN3 for 24 h and the monolithic NPC was transformed into monolithic copper azide. Additionally, the copper particles prepared by electrodeposition were also reacted with the gaseous HN3 under uniform conditions as a comparison. The fabricated monolithic copper azide was characterized by Fourier transform infrared (FTIR), inductively coupled plasma-optical emission spectrometry (ICP-OES), and differential scanning calorimetry (DSC).

  14. 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, P.H.; Gómez Chova, L.; Martí Belenguer, D.; Candel Torres, I.

    2009-01-01

    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 boome

  15. Monolithic stationary phases with incorporated fumed silica nanoparticles. Part I. Polymethacrylate-based monolithic column with incorporated bare fumed silica nanoparticles for hydrophilic interaction liquid chromatography.

    Science.gov (United States)

    Aydoğan, Cemil; El Rassi, Ziad

    2016-05-01

    Fumed silica nanoparticles (FSNPs), were incorporated for the first time into a polymethacrylate monolithic column containing glyceryl monomethacrylate (GMM) and ethylene dimethacrylate (EDMA) in order to develop a new monolithic column for hydrophilic interaction high performance liquid chromatography (HILIC). When compared to poly(GMM-EDMA) monolithic column without FSNPs, the same monolithic column with incorporated FSNPs yielded important effects on HILIC separations. The effects of monomers and FSNPs content of the polymerization mixture on the performance of the monolithic column were examined in details, and the optimized stationary phase was investigated over a wide range of mobile phase composition with polar acidic, weakly basic and neutral analytes including hydroxy benzoic acids, nucleotides, nucleosides, dimethylformamide, formamide and thiourea. The retention of these analytes was mainly controlled by hydrophilic interactions with the FSNPs and electrostatic repulsion from the negatively charged silica surface in the case of hydroxy benzoic acids and nucleotides. The electrostatic repulsion was minimized by decreasing the pH of the aqueous component of the mobile phase, which in turn enhanced the retention of acidic solutes. Nucleotides were best separated using step gradient elution at decreasing pH as well as ACN concentration in the mobile phase. Improved peak shape and faster analysis of nucleosides were attained by a fast linear gradient elution with a shallow decrease in the ACN content of the ACN-rich mobile phase. The run-to-run and column-to-column reproducibility were satisfactory. The percent relative standard deviations (%RSDs) for the retention times of tested solutes were lower than 2.5% under isocratic conditions and lower than 3.5 under gradient conditions.

  16. Preparation and examination of monolithic in-needle extraction (MINE) device for the direct analysis of liquid samples

    Energy Technology Data Exchange (ETDEWEB)

    Pietrzyńska, Monika, E-mail: monikapietrzynska@gmail.com; Voelkel, Adam; Bielicka-Daszkiewicz, Katarzyna

    2013-05-07

    Graphical abstract: -- Highlights: •MINE device for isolation of analytes from water samples. •Nine polymer poly(styrene-divinylbenzene) monoliths prepared in stainless steel needles. •High efficiency of in-needle extraction systems based on monolithic materials. •New possibilities in sample preparation area. -- Abstract: Combination of extraction and chromatographic techniques opens NEW possibilities in sample preparation area. Macroporous poly(styrene-divinylbenzene) (PS-DVB) monoliths were prepared by in situ polymerization in stainless steel needles. The surface of stainless steel needle was modified earlier by the silane coupling agent. Monolithic materials located inside needles were used as the in-needle extraction device. Scanning electron microscope (SEM) images were obtained for nine monoliths. Spectra of prepared materials were also performed with the use of two techniques: Attenuated Total Reflectance (ATR) and Fourier Transform Infrared Spectroscopy (FTIR). The new monolithic in-needle extraction (MINE) devices were used in the preparation of a series of test water samples for chromatographic analysis. The extraction of phenolic compounds from water samples was carried out by pumping liquid samples through the MINE device. Obtained results indicate a high efficiency of in-needle extraction systems based on monolithic materials. Breakthrough volume and the sorption efficiency of prepared monolithic in-needle extraction devices were determined experimentally. The achieved recovery was close to 90%, and determined LOQ values varied between 0.4 and 6 μg.

  17. Monolithic Fuel Fabrication Process Development

    Energy Technology Data Exchange (ETDEWEB)

    C. R. Clark; N. P. Hallinan; J. F. Jue; D. D. Keiser; J. M. Wight

    2006-05-01

    The pursuit of a high uranium density research reactor fuel plate has led to monolithic fuel, which possesses the greatest possible uranium density in the fuel region. Process developments in fabrication development include friction stir welding tool geometry and cooling improvements and a reduction in the length of time required to complete the transient liquid phase bonding process. Annealing effects on the microstructures of the U-10Mo foil and friction stir welded aluminum 6061 cladding are also examined.

  18. Pressure drop in CIM disk monolithic columns.

    Science.gov (United States)

    Mihelic, Igor; Nemec, Damjan; Podgornik, Ales; Koloini, Tine

    2005-02-11

    Pressure drop analysis in commercial CIM disk monolithic columns is presented. Experimental measurements of pressure drop are compared to hydrodynamic models usually employed for prediction of pressure drop in packed beds, e.g. free surface model and capillary model applying hydraulic radius concept. However, the comparison between pressure drop in monolith and adequate packed bed give unexpected results. Pressure drop in a CIM disk monolithic column is approximately 50% lower than in an adequate packed bed of spheres having the same hydraulic radius as CIM disk monolith; meaning they both have the same porosity and the same specific surface area. This phenomenon seems to be a consequence of the monolithic porous structure which is quite different in terms of the pore size distribution and parallel pore nonuniformity compared to the one in conventional packed beds. The number of self-similar levels for the CIM monoliths was estimated to be between 1.03 and 2.75.

  19. Mobile Probes in Mobile Learning

    DEFF Research Database (Denmark)

    Ørngreen, Rikke; Blomhøj, Ulla; Duvaa, Uffe

    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......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...... 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...

  20. Graphene-supported metal oxide monolith

    Energy Technology Data Exchange (ETDEWEB)

    Worsley, Marcus A.; Baumann, Theodore F.; Biener, Juergen; Biener, Monika A.; Wang, Yinmin; Ye, Jianchao; Tylski, Elijah

    2017-01-10

    A composition comprising at least one graphene-supported metal oxide monolith, said monolith comprising a three-dimensional structure of graphene sheets crosslinked by covalent carbon bonds, wherein the graphene sheets are coated by at least one metal oxide such as iron oxide or titanium oxide. Also provided is an electrode comprising the aforementioned graphene-supported metal oxide monolith, wherein the electrode can be substantially free of any carbon-black and substantially free of any binder.

  1. Graphene-supported metal oxide monolith

    Science.gov (United States)

    Worsley, Marcus A.; Baumann, Theodore F.; Biener, Juergen; Biener, Monika A.; Wang, Yinmin; Ye, Jianchao; Tylski, Elijah

    2017-01-10

    A composition comprising at least one graphene-supported metal oxide monolith, said monolith comprising a three-dimensional structure of graphene sheets crosslinked by covalent carbon bonds, wherein the graphene sheets are coated by at least one metal oxide such as iron oxide or titanium oxide. Also provided is an electrode comprising the aforementioned graphene-supported metal oxide monolith, wherein the electrode can be substantially free of any carbon-black and substantially free of any binder.

  2. Os Atores da Mobilizacao por Creches e Pre-Escolas Comunitarias (Mobilizing Agents for Nurseries and Infant Schools).

    Science.gov (United States)

    Filgueiras, Cristina Almeida Cunha

    1995-01-01

    Discusses the role of community nurseries and preschools, within the context of Brazilian popular movements and social policy of the last 15 years. States that the experiences of these organizations reveal great complexity in terms of social, political, and pedagogic mobilization. Concludes that for all involved there are several levels of…

  3. 一种新的基于Mobile Agent的3G VHE架构设计%A Novel Architecture of 3G VHE Based on Mobile Agents

    Institute of Scientific and Technical Information of China (English)

    满成圆; 宋俊德

    2005-01-01

    从移动终端受限性出发,基于Mobile Agent以实现个人移动性,对移动代理平台进行提取,将其作为移动终端操作系统的一部分.提出了使用与WAP协议有良好接口,且扩展性很强的外部功能接口(EFI)实现的移动代理平台以及提供业务和接口的移动代理.并给出了一个使用EFI实现的流媒体下载的实例.

  4. Hot foam for weed control-Do alkyl polyglucoside surfactants used as foaming agents affect the mobility of organic contaminants in soil?

    Science.gov (United States)

    Cederlund, H; Börjesson, E

    2016-08-15

    Use of alkyl polyglucosides (APGs) as a foaming agent during hot water weed control may influence the environmental fate of organic contaminants in soil. We studied the effects of the APG-based foaming agent NCC Spuma (C8-C10) on leaching of diuron, glyphosate, and polycyclic aromatic hydrocarbons (PAHs) in sand columns. We also examined how APG concentration affected the apparent water solubility and adsorption of the herbicides and of the PAHs acenaphthene, acenaphthylene and fluorene. Application of APGs at the recommended concentration of 0.3% did not significantly affect leaching of any of the compounds studied. However, at a concentration of 1.5%, leaching of both diuron and glyphosate was significantly increased. The increased leaching corresponded to an increase in apparent water solubility of diuron and a decrease in glyphosate adsorption to the sand. However, APG addition did not significantly affect the mobility of PAHs even though their apparent water solubility was increased. These results suggest that application of APG-based foam during hot water weed control does not significantly affect the mobility of organic contaminants in soil if used according to recommendations. Moreover, they suggest that APGs could be useful for soil bioremediation purposes if higher concentrations are used.

  5. Monolithically Integrated Micro Flapping Vehicles

    Science.gov (United States)

    2012-08-01

    Mechanical Logic • Memory Mm-Scale Ground Mobility Actuation & Mechanisms Ultrasonic Motors Reversible Adhesion Platform Design...MEMS Mm-Scale Ground Mobility PiezoMEMS Haltere Actuation & Mechanisms Ultrasonic Motors Reversible Adhesion Platform Design Flapping

  6. 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.

  7. A weak cation-exchange monolith as stationary phase for the separation of peptide diastereomers by CEC.

    Science.gov (United States)

    Ludewig, Ronny; Nietzsche, Sandor; Scriba, Gerhard K E

    2011-01-01

    A CEC weak cation-exchange monolith has been prepared by in situ polymerization of acrylamide, methylenebisacrylamide and 4-acrylamidobutyric acid in a decanol-dimethylsulfoxide mixture as porogen. The columns were evaluated by SEM and characterized with regard to the separation of diastereomers and α/β-isomers of aspartyl peptides. Column preparation was reproducible as evidenced by comparison of the analyte retention times of several columns prepared simultaneously. Analyte separation was achieved using mobile phases consisting of acidic phosphate buffer and ACN. Under these conditions the peptides migrated due to their electrophoretic mobility but the EOF also contributed as driving force as a function of the pH of the mobile phase due to increasing dissociation of the carboxyl groups of the polymer. Raising the pH of the mobile phase also resulted in deprotonation of the peptides reducing analyte mobility. Due to these mechanisms each pair of diastereomeric peptides displayed the highest resolution at a different pH of the buffer component of the mobile phase. Comparing the weak-cation exchange monolith to an RP monolith and a strong cation-exchange monolith different elution order of some peptide diastereomers was observed, clearly illustrating that interactions with the stationary phase contribute to the CEC separations.

  8. Monolithically integrated absolute frequency comb laser system

    Energy Technology Data Exchange (ETDEWEB)

    Wanke, Michael C.

    2016-07-12

    Rather than down-convert optical frequencies, a QCL laser system directly generates a THz frequency comb in a compact monolithically integrated chip that can be locked to an absolute frequency without the need of a frequency-comb synthesizer. The monolithic, absolute frequency comb can provide a THz frequency reference and tool for high-resolution broad band spectroscopy.

  9. Nanosecond monolithic CMOS readout cell

    Science.gov (United States)

    Souchkov, Vitali V.

    2004-08-24

    A pulse shaper is implemented in monolithic CMOS with a delay unit formed of a unity gain buffer. The shaper is formed of a difference amplifier having one input connected directly to an input signal and a second input connected to a delayed input signal through the buffer. An elementary cell is based on the pulse shaper and a timing circuit which gates the output of an integrator connected to the pulse shaper output. A detector readout system is formed of a plurality of elementary cells, each connected to a pixel of a pixel array, or to a microstrip of a plurality of microstrips, or to a detector segment.

  10. Compact monolithic capacitive discharge unit

    Science.gov (United States)

    Roesler, Alexander W.; Vernon, George E.; Hoke, Darren A.; De Marquis, Virginia K.; Harris, Steven M.

    2007-06-26

    A compact monolithic capacitive discharge unit (CDU) is disclosed in which a thyristor switch and a flyback charging circuit are both sandwiched about a ceramic energy storage capacitor. The result is a compact rugged assembly which provides a low-inductance current discharge path. The flyback charging circuit preferably includes a low-temperature co-fired ceramic transformer. The CDU can further include one or more ceramic substrates for enclosing the thyristor switch and for holding various passive components used in the flyback charging circuit. A load such as a detonator can also be attached directly to the CDU.

  11. Supporting the Air Mobility Needs of Geographic Combatant Commanders: An Evaluation Using the Principal-Agent Construct

    Science.gov (United States)

    2014-06-01

    respondents the flexibility to explore topics of their choosing. Hypothesis According to John Creswell , author of numerous articles and 22 books on...form of a principal-agent 6 See Appendix A, Interview Questions 7 Creswell , 139. relationship...Chicago Press, 2008. Creswell , John W. Research Design: Qualitative, Quantitative, and Mixed Methods Approaches. 3rd ed. Thousand Oaks, CA: SAGE

  12. Separation of Immunoglobulin in Conjunction with High Performance Liquid Chromatography Using Poly(vinyl ester resin) Monolith

    Institute of Scientific and Technical Information of China (English)

    YANG,Guanqun; YANG,Gengliang; LIU,Haiyan; BAI,Ligai; FENG,Xiaojuan; YANG,Xinru

    2009-01-01

    Using vinyl ester resin both as the monomer and the crosslinker,2,2-azobis(2-methylpropionitrile) (AIBN) as initiator,poly(vinyl ester resin) monolithic column was prepared to separate the immunoglobulin G (lgG) and yolk of eggs (lgY) from human plasma and egg yolk by HPLC respectively.The influence of concentration and pH of mobile phase on the chromatographic performance was investigated.Scanning electron microcopy showed that the poly(vinyl ester resin) monolithic stationary phase had a through-pore structure.Dynamic capacity of IgG on the polymeric monolithic column was investigated.The monolithic column had good flow-through properties and high resolution.The maximum adsorptive amount of IgG was 144 μg·g-1.

  13. Thiol-yne Click Adamantane Monolithic Stationary Phase for Capillary Electrochromatography

    Institute of Scientific and Technical Information of China (English)

    Dao, Thi Thu Hien; Guerrouache, Mohamed; Carbonnier, Benjamin

    2012-01-01

    A porous crosslinked organic polymer based on N-acryloxysuccinimide (NAS) and ethylene dimethacrylate (EDMA) was prepared inside 75 μm i.d. fused silica capillary as functionalizable monolithic stationary phase for electrochromatographic applications. Succinimide groups on the monolith surface provide reactive sites able to re- act readily through standard electrophile-nucleophile chemistry. Propargylamine was used to prepare alkyne func- tionalized poly(NAS-co-EDMA). Onto this thiol-reactive polymer surface was grafted adamantane units via a photochemically-driven addition reaction. Chemical characterization was performed in situ after each synthetic step by means of Raman spectroscopy and grafting kinetics was investigated to ensure quantitative grafting of 1-adamantanethiol. The as-designed monolithic stationary phase exhibited typical reversed-phase separation mechanism as evidenced by the linear increase of the logarithm of retention factor of neutral aromatic solutes with the increase of the aqueous buffer content in the mobile phase.

  14. Purification of Astaxanthin from Laminariajaponica by Ionic Liquid-based Monolithic Cartridge

    Institute of Scientific and Technical Information of China (English)

    YOON Chang-hwan; ZHU Tao; ROW Kyung-ho

    2012-01-01

    An effective and accurate method was developed for the extraction of astaxanthin from Laminariajaponica with subsequent separation by ionic liquid-based monolithic cartridge.The optimized extraction conditions including extraction solvent(ethanol),extraction time(90 min) and ultrasonic power(75 W) were obtained by systematical investigation.Chromatographic analysis was performed on a C18 column with ultraviolet(UV) detection at 476nm,and a solution consisting of methanol/acetonitrile/H20/dichloromethane(83:6:6:5,volume ratio) was used as the mobile phase at a flow rate of 0.7 mL/min.After ionic liquid-based monolithic solid phase extraction,17.82 μg/g astaxanthin was obtained from Laminariajaponica.This ionic liquid-based monolithic cartridge exhibits high affinity and selectivity for astaxanthin,and it can be potentially used as the stationary phase of high performance liquid chromatography( HPLC).

  15. 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 [...

  16. Mobile data offloading: an agent-based modelling study on the effectiveness of Wi-Fi offloading

    OpenAIRE

    Breukers, Yorick; de Reuver, Mark; Oey, Michel; Bouwman, Harry

    2015-01-01

    To reduce the load on cellular networks, offloading to Wi-Fi has long been discussed as a technological solution. Despite advances in scheduling algorithms and incentive schemes, most mobile operators do not actively promote Wi-Fi offloading and most Wi-Fi usage is limited to stationary in-home contexts of use. This study assesses the proportion of users on the street that can be offloaded to Wi-Fi access points, taking into account different city topologies, speed of movement and technical c...

  17. The Security Analyse of the Mobile Agent%移动代理的安全性分析

    Institute of Scientific and Technical Information of China (English)

    翟慧; 李超林

    2007-01-01

    本文介绍了移动Agent(代理)的概念和工作原理,并介绍了它的特点和应用领域,然后详述了移动代理环境,即aglets工作台.最后分析了移动代理存在的安全问题,并提出了一些解决方案.

  18. GaN Monolithic Power Amplifiers for Microwave Backhaul Applications

    Directory of Open Access Journals (Sweden)

    Roberto Quaglia

    2016-06-01

    Full Text Available Gallium nitride integrated technology is very promising not only for wireless applications at mobile frequencies (below 6 GHz but also for network backhaul radiolink deployment, now under deep revision for the incoming 5G generation of mobile communications. This contribution presents three linear power amplifiers realized on 0.25 μ m Gallium Nitride on Silicon Carbide monolithic integrated circuits for microwave backhaul applications: two combined power amplifiers working in the backhaul band around 7 GHz, and a more challenging third one working in the higher 15 GHz band. Architectures and main design steps are described, highlighting the pros and cons of Gallium Nitride with respect to the reference technology which, for these applications, is represented by gallium arsenide.

  19. Incorporation of ionic liquid into porous polymer monoliths to enhance the separation of small molecules in reversed-phase high-performance liquid chromatography.

    Science.gov (United States)

    Wang, Jiafei; Bai, Ligai; Wei, Zhen; Qin, Junxiao; Ma, Yamin; Liu, Haiyan

    2015-06-01

    An ionic liquid was incorporated into the porous polymer monoliths to afford stationary phases with enhanced chromatographic performance for small molecules in reversed-phase high-performance liquid chromatography. The effect of the ionic liquid in the polymerization mixture on the performance of the monoliths was studied in detail. While monoliths without ionic liquid exhibited poor resolution and low efficiency, the addition of ionic liquid to the polymerization mixture provides highly increased resolution and high efficiency. The chromatographic performances of the monoliths were demonstrated by the separations of various small molecules including aromatic hydrocarbons, isomers, and homologues using a binary polar mobile phase. The present column efficiency reached 27 000 plates/m, which showed that the ionic liquid monoliths are alternative stationary phases in the separation of small molecules by high-performance liquid chromatography.

  20. Monolith ERP and current IT-trends : Creating a step by step development model (SSDM) for existing monolith ERP system to adapt to the current IT-trends

    OpenAIRE

    Vuorenmaa, Riku

    2015-01-01

    ERP systems have been around for 25 years and have gone through evolution phases. None of the previous phases have however imposed so big a challenge and opportunities for the ERP producers / vendors as current outsourcing and cloud computing trends. Current traditional on-premises (monolith) ERP systems are put under pressure to cope with the demands imposed by cloud computing and other IT-trends (such as mobility). Traditional ERP systems have to adapt or face a risk of becoming obsolete. ...

  1. Novel preparation of monolithic imprinted columns for electrochromatographic separation by photopolymerization

    Institute of Scientific and Technical Information of China (English)

    Yu Ping Zhang; Guo Qiang Zuo; Wen Jun Gong; Yue E. Deng; Quan Ming Li

    2007-01-01

    A monolithic molecularly imprinted polymer with specific recognition ability for 4-hydroxybenzoic acid (4-HBA) was prepared by in situ photopolymerization, using methacrylic acid (MAA) as a functional monomer, ethylene glycol dimethacrylate (EDMA) as a cross-linking agent, toluene and isooctane as porogenic solvents and Irgacure 1800 as an initiator.Baseline separation of isomers of hydroxybenzoic acid was achieved in less than 8 min on this monolithic column using 4-HBA as template, but not on the blank polymer.Furthermore, some neutral compounds could also be baseline-separated on the imprinted polymer column in the mode of pressure-driven capillary electrochromatography.

  2. Comparison of various silica-based monoliths for the analysis of large biomolecules.

    Science.gov (United States)

    Vuignier, Karine; Fekete, Szabolcs; Carrupt, Pierre-Alain; Veuthey, Jean-Luc; Guillarme, Davy

    2013-07-01

    In the present study, three types of silica-based monoliths, i.e. the first and second generations of commercial silica monolithic columns and a wide-pore prototype monolith were compared for the analysis of large biomolecules. These molecules possess molecular weights between 1 and 66 kDa. The gradient kinetic performance of the first-generation monolith was lower than that of the second generation, for large biomolecules (>14 kDa) but very close with smaller ones (1.3-5.8 kDa). In contrast, the wide-pore prototype column was particularly attractive with proteins larger than 19 kDa (higher peak capacity). Among these three columns, the selectivity and retention remained quite similar but a possible larger number of accessible and charged residual silanols was noticed on the wide-pore prototype material, which led to unpredicted small changes in selectivity and slightly broader peaks than expected. The peak shapes attained with the addition of 0.1% formic acid in the mobile phase remained acceptable for MS coupling, particularly for biomolecules of less than 6 kDa. It was found that one of the major issues with all of these silica-based monoliths is the possible poor recovery of large biomolecules (principally with monoclonal antibody fragments of more than 25 kDa).

  3. Microfluidic devices and methods including porous polymer monoliths

    Science.gov (United States)

    Hatch, Anson V; Sommer, Gregory J; Singh, Anup K; Wang, Ying-Chih; Abhyankar, Vinay V

    2014-04-22

    Microfluidic devices and methods including porous polymer monoliths are described. Polymerization techniques may be used to generate porous polymer monoliths having pores defined by a liquid component of a fluid mixture. The fluid mixture may contain iniferters and the resulting porous polymer monolith may include surfaces terminated with iniferter species. Capture molecules may then be grafted to the monolith pores.

  4. 基于移动Agent技术的Internet模糊信息服务模型%An Internet Fuzzy Information Service Model Base on Mobile Agent

    Institute of Scientific and Technical Information of China (English)

    周斌; 杨文春; 丁永生

    2001-01-01

    This paper proposes an Internet fuzzy information service modelbased on Mobile Agent technology. It describes the overall frame and architecture of the model, the fuzzy indexing algorithm used for intelligent search through Internet, and implementation of a software platform for the model with Java language, which proves effective in experiments.%提出一种基于移动Agent技术的Internet模糊信息服务模型,讨论了其总体工作框架和结构。将模糊检索算法用于Internet信息的智能搜索,给出了信息检索系统的设计方法。用Java语言实现该模型的软件平台,通过实验验证了其可行性。

  5. Spatial Correlation-Based Mobile Agent Routing Algorithm in Wireless Sensor Networks%无线传感器网络中基于空间相关性的移动代理路由算法

    Institute of Scientific and Technical Information of China (English)

    胡海峰; 杨震

    2011-01-01

    资源受限的传感器节点密集分布在无线传感器网络监控区域,sink节点通过收集节点间观测信息对监控区域内发生的事件进行感知.本文提出SCMAR(Spatial Correlation-based Mobile Agent Routing)路由算法,在移动代理架构内,利用节点观测数据的空间相关性以能量有效的方式对感知事件进行估计.仿真结果表明SCMAR在各种应用环境下能量有效性均优于MARDF(Mobile Agent Routes for Data Fusion)路由算法.%Wireless Sensor Networks (WSN) are mainly characterized by dense deployment of resource-constrained sensor nodes which collectively transmit information about sensed events to the sink. In this paper, a Spatial Correlation-based Mobile A gent Routing (SCMAR) algorithm is proposed to exploit the spatial correlation between the sensed data to estimate the event with energy efficient way using the mobile agent paradigm. Hie simulation results show that SCMAR achieves better performance than existing Mobile Agent Routes far Data Fusion (MARDF) routing algorithm from perspectives of energy consumption in a variety of correlated data gathering applications.

  6. Research on Building Data Warehouse by the Means of Mobile Agent Technology%采用移动代理技术建立数据仓库的研究

    Institute of Scientific and Technical Information of China (English)

    钟国祥; 张为群

    2003-01-01

    The thesis sets forth for the policy maker a way of achieving the aim of building model data warehouse based on relation model distributed database by using Mobile Agent technology. According to the design principal of data warehouse and the standard technology,author puts forward forming metadatas by tree pattern or forests strctur-e,giving the definition of metadata. Model and the general principal of combining metadatas to form data warehouse and showing a picture tool of data warehouse designing system. It creates a Mobile Agent orieinal form that can realize the constrction of data warehouse based on relation model distributed database.

  7. Hierarchically macroporous silver monoliths using Pluronic F127: Facile synthesis, characterization and its application as an efficient biomaterial for pathogens

    Directory of Open Access Journals (Sweden)

    Gowhar Ahmad Naikoo

    2016-03-01

    Full Text Available Herein we report the facile synthesis of three dimensional macroporous (MP silver monoliths serving as intelligent biomaterials against Gram negative (Escherichia coli, Salmonella typhimurium and Gram positive (Bacillus subtilis bacteria with more efficacy against Gram negative bacteria. The macroporous silver monoliths were examined by Fourier transform infra red (FTIR spectroscopy, thermogravimetric analysis (TGA, X-ray diffraction (XRD study, field emission scanning electron microscopy (FESEM, energy dispersion X-ray spectroscopy analysis (EDX and Brunauer–Emmet–Teller (BET adsorption technique. From the antibacterial activity results, it was concluded that macroporous silver monoliths can serve as efficient disinfection agents. The enhanced antibacterial properties of macroporous silver monoliths was possibly due to high surface free energy of the surface Ag+ atoms leading to cell membrane damage followed by cell death.

  8. Macroporous glass monoliths prepared from powdered niobium phosphate glass by fast sintering

    Energy Technology Data Exchange (ETDEWEB)

    Lacerda Mauricio, Vitor; Alves, Oswaldo Luiz; Odone Mazali, Italo, E-mail: mazali@iqm.unicamp.br

    2011-03-15

    Macroporous monoliths were prepared by very fast sintering (between 3 and 15 min) of niobophosphate glass powders at low temperature (1018 K) using cellulose as a foaming agent. The porous materials were analyzed by thermal analysis, Raman spectroscopy, scanning electron microscopy and powder X-ray diffraction, and further investigated using X-ray microtomography, a non-destructive technique capable of reconstructing three-dimensional models of samples and providing structural measurements. The progression of the porosity of the monoliths depends on the sintering time (3 to 15 min) and the amount (up to 50% in mass) of cellulose used. The macroporous glass monoliths may find application in integrated chemical systems and in filtering processes.

  9. Monolithic Continuous-Flow Bioreactors

    Science.gov (United States)

    Stephanopoulos, Gregory; Kornfield, Julia A.; Voecks, Gerald A.

    1993-01-01

    Monolithic ceramic matrices containing many small flow passages useful as continuous-flow bioreactors. Ceramic matrix containing passages made by extruding and firing suitable ceramic. Pores in matrix provide attachment medium for film of cells and allow free movement of solution. Material one not toxic to micro-organisms grown in reactor. In reactor, liquid nutrients flow over, and liquid reaction products flow from, cell culture immobilized in one set of channels while oxygen flows to, and gaseous reaction products flow from, culture in adjacent set of passages. Cells live on inner surfaces containing flowing nutrient and in pores of walls of passages. Ready access to nutrients and oxygen in channels. They generate continuous high yield characteristic of immobilized cells, without large expenditure of energy otherwise incurred if necessary to pump nutrient solution through dense biomass as in bioreactors of other types.

  10. High pressure-resistant SU-8 microchannels for monolithic porous structure integration

    Science.gov (United States)

    Carlier, Julien; Chuda, Katarzyna; Arscott, Steve; Thomy, Vincent; Verbeke, Bernard; Coqueret, Xavier; Camart, Jean Christophe; Druon, Christian; Tabourier, Pierre

    2006-10-01

    Integrated lab-on-chip (LOC) microsystems dedicated to proteomic analysis require specific pretreatment steps such as protein trypsic digestion, concentration, desalting or separation of biological samples. These steps can be achieved thanks to porous monolithic polymers. This paper deals with the integration of such a polymer into SU-8 microchannels by using a multi-material technology (SU-8, Pyrex and silicon). A solution for the fabrication of complete polymer microchannels which are high pressure- and solvents-resistant is proposed. This technique uses the negative photoresist SU-8 which is compatible with the protein analysis performed here. Our process requires a novel technological step using a silane coupling agent. This modification of the SU-8/Pyrex interface leads to the fabrication of a 100 µm × 160 µm section microchannel (length of 3 cm), closed with a Pyrex® lid by SU-8 bonding resistant to 80 bar. An improvement of the SU-8/monolithic structure is also demonstrated thanks to a specific treatment of the polymer enabling good anchoring of the monolith in the microchannels, and the pressure-resistance tests were also achieved with the monolithic structure integrated in the microchannels. A digestion step of a protein sample of benzoylarginine ethyl ester in a SU-8 microchannel was achieved after the functionalization of a monolith anchored in the microchannel. Analysis by UV/VIS spectroscopy of this in situ digestion has been reported.

  11. Anisotropically structured magnetic aerogel monoliths

    Science.gov (United States)

    Heiligtag, Florian J.; Airaghi Leccardi, Marta J. I.; Erdem, Derya; Süess, Martin J.; Niederberger, Markus

    2014-10-01

    Texturing of magnetic ceramics and composites by aligning and fixing of colloidal particles in a magnetic field is a powerful strategy to induce anisotropic chemical, physical and especially mechanical properties into bulk materials. If porosity could be introduced, anisotropically structured magnetic materials would be the perfect supports for magnetic separations in biotechnology or for magnetic field-assisted chemical reactions. Aerogels, combining high porosity with nanoscale structural features, offer an exceptionally large surface area, but they are difficult to magnetically texture. Here we present the preparation of anatase-magnetite aerogel monoliths via the assembly of preformed nanocrystallites. Different approaches are proposed to produce macroscopic bodies with gradient-like magnetic segmentation or with strongly anisotropic magnetic texture.Texturing of magnetic ceramics and composites by aligning and fixing of colloidal particles in a magnetic field is a powerful strategy to induce anisotropic chemical, physical and especially mechanical properties into bulk materials. If porosity could be introduced, anisotropically structured magnetic materials would be the perfect supports for magnetic separations in biotechnology or for magnetic field-assisted chemical reactions. Aerogels, combining high porosity with nanoscale structural features, offer an exceptionally large surface area, but they are difficult to magnetically texture. Here we present the preparation of anatase-magnetite aerogel monoliths via the assembly of preformed nanocrystallites. Different approaches are proposed to produce macroscopic bodies with gradient-like magnetic segmentation or with strongly anisotropic magnetic texture. Electronic supplementary information (ESI) available: Digital photographs of dispersions and gels with different water-to-ethanol ratios; magnetic measurements of an anatase aerogel containing 0.25 mol% Fe3O4 nanoparticles; XRD patterns of the iron oxide and

  12. Monolithic cells for solar fuels.

    Science.gov (United States)

    Rongé, Jan; Bosserez, Tom; Martel, David; Nervi, Carlo; Boarino, Luca; Taulelle, Francis; Decher, Gero; Bordiga, Silvia; Martens, Johan A

    2014-12-07

    Hybrid energy generation models based on a variety of alternative energy supply technologies are considered the best way to cope with the depletion of fossil energy resources and to limit global warming. One of the currently missing technologies is the mimic of natural photosynthesis to convert carbon dioxide and water into chemical fuel using sunlight. This idea has been around for decades, but artificial photosynthesis of organic molecules is still far away from providing real-world solutions. The scientific challenge is to perform in an efficient way the multi-electron transfer reactions of water oxidation and carbon dioxide reduction using holes and single electrons generated in an illuminated semiconductor. In this tutorial review the design of photoelectrochemical (PEC) cells that combine solar water oxidation and CO2 reduction is discussed. In such PEC cells simultaneous transport and efficient use of light, electrons, protons and molecules has to be managed. It is explained how efficiency can be gained by compartmentalisation of the water oxidation and CO2 reduction processes by proton exchange membranes, and monolithic concepts of artificial leaves and solar membranes are presented. Besides transferring protons from the anode to the cathode compartment the membrane serves as a molecular barrier material to prevent cross-over of oxygen and fuel molecules. Innovative nano-organized multimaterials will be needed to realise practical artificial photosynthesis devices. This review provides an overview of synthesis techniques which could be used to realise monolithic multifunctional membrane-electrode assemblies, such as Layer-by-Layer (LbL) deposition, Atomic Layer Deposition (ALD), and porous silicon (porSi) engineering. Advances in modelling approaches, electrochemical techniques and in situ spectroscopies to characterise overall PEC cell performance are discussed.

  13. 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.

  14. Monolithic Time Delay Integrated APD Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The overall goal of the proposed program by Epitaxial Technologies is to develop monolithic time delay integrated avalanche photodiode (APD) arrays with sensitivity...

  15. Monolithic multinozzle emitters for nanoelectrospray mass spectrometry

    Science.gov (United States)

    Wang, Daojing; Yang, Peidong; Kim, Woong; Fan, Rong

    2011-09-20

    Novel and significantly simplified procedures for fabrication of fully integrated nanoelectrospray emitters have been described. For nanofabricated monolithic multinozzle emitters (NM.sup.2 emitters), a bottom up approach using silicon nanowires on a silicon sliver is used. For microfabricated monolithic multinozzle emitters (M.sup.3 emitters), a top down approach using MEMS techniques on silicon wafers is used. The emitters have performance comparable to that of commercially-available silica capillary emitters for nanoelectrospray mass spectrometry.

  16. 移动代理人编程技术与移动用戶管理系统探讨(英文)%Maintaining Persistent Look-and-Feel for Roaming User with Mobile Agent in Distributed Environment

    Institute of Scientific and Technical Information of China (English)

    施国琛; 邓有光; 黄德胜; 马建华; 黄润和

    2002-01-01

    Mobile agents refer to self-contained and identifiable computer programs that can migrate along the network and can act on behalf of the user or other agents. Mobile agents often work on heterogeneous network and operating system environment. Therefore, an integrated logical interface to access physical structure via mobile agent application has become more and more urgent. In this paper, we proposed a tracking and persistent agent-based mobility management system in case of distance learning. The main purpose of our system is addressed to achieve the universal access objective. In order to let the whole mobility management system full play, firstly, we proposed a mobile agent communication network model and the mobile agent evolution states. The mobile agent communication network model facilitates the agent computation, and the mobile agent evolution states assist agent supervisor to monitor client agents. Secondly, we encapsulate the utility tools to be a role-setting object. The role-setting object is an application-driven component, which can provide customization benefits for user to match user's demands. These integrated technologies are sufficient in distance learning (virtual university) environment.%有自我控制与辨别身份能力的移动代理人编程技术,不但能够在网路上移动,也能够与其他代理人编程沟通及执行任务.由于移动代理人常常运作于异质的网路或作业系统(operating system)环境下,因此,一个具有整体逻辑性操作界面来存取实体结构的管理系统就显得越发重要.提出了一个能够追踪和维持移动代理人的管理系统,并且应用于远距教学(distance learning).此系统的主要目的在于提供移动代理人通用的存取环境.为了能使此系统完全运作,论述了移动代理人通信网路模组、移动代理人演化阶段来支援管理代理人与用户端代理人.另外,也将移动代理人所使用的工具编程整合成为角色扮演(role

  17. 无线传感网络中使用动态代理的节点收敛算法%Node Coverage Algorithms in Wireless Sensor Networks Using Mobile Agents

    Institute of Scientific and Technical Information of China (English)

    RAINA Manik; KUMAR Subhas; PATRO Ranjeet

    2006-01-01

    This paper proposes fault tolerant algorithms for routing mobile agents in a single channel wireless sensor network which cover every node in the network. These algorithms use local knowledge (assume no knowledge of global deployment or topology, etc). We propose the algorithms and show mathematical analysis to support our claims. The paper ends with simulation studies and discussion of results.

  18. Activated Carbon Fiber Monoliths as Supercapacitor Electrodes

    Directory of Open Access Journals (Sweden)

    Gelines Moreno-Fernandez

    2017-01-01

    Full Text Available Activated carbon fibers (ACF are interesting candidates for electrodes in electrochemical energy storage devices; however, one major drawback for practical application is their low density. In the present work, monoliths were synthesized from two different ACFs, reaching 3 times higher densities than the original ACFs’ apparent densities. The porosity of the monoliths was only slightly decreased with respect to the pristine ACFs, the employed PVDC binder developing additional porosity upon carbonization. The ACF monoliths are essentially microporous and reach BET surface areas of up to 1838 m2 g−1. SEM analysis reveals that the ACFs are well embedded into the monolith structure and that their length was significantly reduced due to the monolith preparation process. The carbonized monoliths were studied as supercapacitor electrodes in two- and three-electrode cells having 2 M H2SO4 as electrolyte. Maximum capacitances of around 200 F g−1 were reached. The results confirm that the capacitance of the bisulfate anions essentially originates from the double layer, while hydronium cations contribute with a mixture of both, double layer capacitance and pseudocapacitance.

  19. Synthesis of Mesoporous Titania-Silica Monolith Composites — A Comprehensive Study on their Photocatalytic Degradation of Acid Blue 113 Dye Under UV Light

    Science.gov (United States)

    Thejaswini, Thurlapathi Vl; Prabhakaran, Deivasigamani

    2016-10-01

    The present work deals with the synthesis of bi-continuous macro and mesoporous crack-free titania-silica monoliths, with well-defined structural dimensions and high surface area. The work also highlights their potential photocatalytic environmental applications. The highly ordered titania-silica monoliths are synthesized through direct surface template method using organic precursors of silica and titania in the presence of surface directing agents such as pluronic P123 and PEG, under acetic acid medium. The monoliths are synthesized with different Ti/Si ratios to obtain monolithic designs that exhibit better photocatalytic activity for dye degradation. The titania-silica monoliths are characterized using XRD, SEM, EDAX, FT-IR, TG-DTA and BET analysis. The photocatalytic activity of the synthesized monoliths is tested on the photodegradation of a textile dye (acid blue 113). It is observed that the monolith with 7:3 ratio of Ti/Si showed significant photocatalysis behavior in the presence of UV light. The influence of various physico-chemical properties such as, solution pH, photocatalyst dosage, light intensity, dye concentration, effect of oxidants, etc. are analyzed and optimized using a customized photoreactor set-up. Under optimized conditions, the monoliths exhibited superior degradation kinetics, with the dye dissipation complete within 10min of photolysis. The mesoporous catalysts are recoverable and reusable up to four cycles of repeated usage.

  20. A System Architecture of Data Mining in Network based on Mobile Agent and RDF%基于移动Agent及RDF的网络数据挖掘系统体系结构

    Institute of Scientific and Technical Information of China (English)

    吴跃; 王军; 周明天; 王湖南

    2002-01-01

    In this paper,a system architecture of data mining in network-based on the technology of Mobile Agent and RDF is presented.This system architecture provides a standrad and uniform structured data-platform for the concrete data-mining application.Mobile Agent implements the concrete data mining application.The relative technologies of this system architecture are introduced first,then two species of logic architecture of the network based application system are explained.And an accomplished protyping of network-based data mining system architecture is proposed.The comdination of the up-to-date XML/RDF and Mobile Agnet technolgies provides a new method for data mining in network.

  1. Distributed Mobility Management Scheme for Mobile IPv6

    Science.gov (United States)

    Wakikawa, Ryuji; Valadon, Guillaume; Shigechika, Noriyuki; Murai, Jun

    Mobile IPv6 and Network Mobility (NEMO) have been standardized as IP extensions. While these technologies are planned to be adopted by several communities, such as the vehicle, aviation, and cellular industries, Mobile IPv6 has serious deployment issues such as scalability, protocol resilience, and redundancy. In these technologies, a special router called a home agent is introduced to support the movement of mobile nodes. This home agent introduces overlapping, inefficient routes, and becomes a single point of failure and a performance bottleneck. In this paper, a new concept for scalable and dependable mobility management scheme is proposed. Multiple home agents serve the same set of mobile nodes. The Home Agent Reliability protocol and Home Agent migration are introduced to achieve this concept. We also propose an overlay network named a Global Mobile eXchange (GMX) that efficiently handles data traffic from and to mobile nodes, and operates home agents as would an Internet eXchange Point (IXP).

  2. Monolithic stationary phases with incorporated fumed silica nanoparticles. Part II. Polymethacrylate-based monolithic column with "covalently" incorporated modified octadecyl fumed silica nanoparticles for reversed-phase chromatography.

    Science.gov (United States)

    Aydoğan, Cemil; El Rassi, Ziad

    2016-05-01

    This study is concerned with the incorporation of surface modified fumed silica nanoparticles (FSNPs) into polymethacrylate based monolithic columns for use in reversed phase chromatography (RPC) of small solutes and proteins. First, FSNPs were modified with 3-(trimethoxysilyl)propylmethacrylate (TMSPM) to yield the "hybrid" methacryloyl fumed silica nanoparticle (MFSNP) monomer. The resulting MFSNP was then mixed with glyceryl monomethacrylate (GMM) and ethylene dimethacrylate (EDMA) in a binary porogenic solvent composed of cyclohexanol and dodecanol, and the in situ copolymerization of MFSNP, GMM and EDMA was performed in a stainless steel column of 4.6 mm i.d. The silanol groups of the hybrid monolith thus obtained were grafted with octadecyl ligands by perfusing the hybrid monolithic column with a solution of 4% w/v of dimethyloctadecylchlorosilane (DODCS) in toluene while the column was maintained at 110°C for 6h (in a heated HPLC oven). One of the originalities of this study was to demonstrate MFSNP as a novel derivatized "hybrid monomer" in making RPC monolithic columns with surface bound octadecyl ligands. In this respect, the RPC behavior of the monolithic column with "covalently" incorporated FNSPs having surface grafted octadecyl ligands was evaluated with alkylbenzenes, aniline derivatives and phenolic compounds. The results showed that the hybrid poly(GMA-EDMA-MFSNP) having surface bound octadecyl ligands exhibited hydrophobic interactions under reversed phase elution conditions. Furthermore, six standard proteins were baseline separated on the column using a 10min linear gradient elution at increasing ACN concentration in the mobile phase at a flow rate of 1.0mL/min using a 10 cm×4.6mm i.d. column. The relative standard deviations (RSDs) for the retention times of the tested solutes were lower than 2.1% and 2.4% under isocratic elution and gradient elution conditions, respectively.

  3. Monolithically integrated Ge CMOS laser

    Science.gov (United States)

    Camacho-Aguilera, Rodolfo

    2014-02-01

    Ge-on-Si devices are explored for photonic integration. Through the development of better growth techniques, monolithic integration, laser design and prototypes, it was possible to probe Ge light emitters with emphasis on lasers. Preliminary worked shows thermal photonic behavior capable of enhancing lamination at high temperatures. Increase luminescence is observed up to 120°C from L-band contribution. Higher temperatures show contribution from Δ -band. The increase carrier thermal contribution suggests high temperature applications for Ge light emitters. A Ge electrically pumped laser was probed under 0.2% biaxial strain and doping concentration ~4.5×1019cm-3 n-type. Ge pnn lasers exhibit a gain >1000cm-1 with 8mW power output, presenting a spectrum range of over 200nm, making Ge the ideal candidate for Si photonics. Large temperatures fluctuations and process limit the present device. Theoretically a gain of >4000cm- gain is possible with a threshold of as low as 1kA/cm2. Improvements in Ge work

  4. Detection of aqueous phase chemical warfare agent degradation products by negative mode ion mobility time-of-flight mass spectrometry [IM(tof)MS].

    Science.gov (United States)

    Steiner, Wes E; Harden, Charles S; Hong, Feng; Klopsch, Steve J; Hill, Herbert H; McHugh, Vincent M

    2006-02-01

    The use of negative ion monitoring mode with an atmospheric pressure ion mobility orthogonal reflector time-of-flight mass spectrometer [IM(tof)MS] to detect chemical warfare agent (CWA) degradation products from aqueous phase samples has been determined. Aqueous phase sampling used a traditional electrospray ionization (ESI) source for sample introduction and ionization. Certified reference materials (CRM) of CWA degradation products for the detection of Schedule 1, 2, or 3 toxic chemicals or their precursors as defined by the chemical warfare convention (CWC) treaty verification were used in this study. A mixture of six G-series nerve related CWA degradation products (EMPA, IMPA, EHEP, IHEP, CHMPA, and PMPA) and their related collision induced dissociation (CID) fragment ions (MPA and EPA) were found in each case to be clearly resolved and detected using the IM(tof)MS instrument in negative ion monitoring mode. Corresponding ions, masses, drift times, K(o) values, and signal intensities for each of the CWA degradation products are reported.

  5. Methacrylate-based monolithic layers for planar chromatography of polymers.

    Science.gov (United States)

    Maksimova, E F; Vlakh, E G; Tennikova, T B

    2011-04-29

    A series of macroporous monolithic methacrylate-based materials was synthesized by in situ free radical UV-initiated copolymerization of functional monomers, such as glycidyl methacrylate (GMA), butyl methacrylate (BuMA), 2-aminoethyl methacrylate (AEMA), 2-hydroxyethyl methacrylate (HEMA) and 2-cyanoethyl methacrylate (CEMA), with crosslinking agent, namely, ethylene glycol dimethacrylate (EDMA). The materials obtained were applied as the stationary phases in simple and robust technique - planar chromatography (PLC). The method of separation layer fabrication representing macroporous polymer monolith bound to the specially prepared glass surface was developed and optimized. The GMA-EDMA and BuMA-EDMA matrixes were successfully applied for the separation of low molecular weight compounds (the mixture of several dies), as well as poly(vinylpyrrolidone) and polystyrene homopolymers of different molecular weights using reversed-phase mechanism. The materials based on copolymers AEMA-HEMA-EDMA and CEMA-HEMA-EDMA were used for normal-phase PLC separation of 2,4-dinitrophenyl amino acids and polystyrene standards.

  6. Monolithic molecularly imprinted polymeric capillary columns for isolation of aflatoxins.

    Science.gov (United States)

    Szumski, Michał; Grzywiński, Damian; Prus, Wojciech; Buszewski, Bogusław

    2014-10-17

    Monolithic molecularly imprinted polymers extraction columns have been prepared in fused-silica capillaries by UV or thermal polymerization in a two-step process. First, a poly-(trimethylolpropane trimethacrylate) (polyTRIM) core monolith was synthesized either by UV or thermal polymerization. Then it was grafted with the mixture of methacrylic acid (MAA) as a functional monomer, ethylene dimethacrylate (EDMA) as a cross-linking agent, 5,7-dimethoxycoumarin (DMC) as an aflatoxin-mimicking template, toluene as a porogen solvent and 2,2-azobis-(2-methylpropionitrile) (AIBN) as an initiator of the polymerization reaction. Different thermal condition of the photografting and different concentrations of the grafting mixture were tested during polymerization. The extraction capillary columns were evaluated in the terms of their hydrodynamic and chromatographic properties. Retention coefficients for aflatoxin B1 and DMC were used for assessment of the selectivity and imprinting factor. The obtained results indicate that the temperature of photografting and concentration of the grafting mixture are key parameters that determine the quality of the prepared MIPs. From the MIP columns characterized by the highest permeability the column of the highest imprinting factor was applied for isolation of aflatoxins B1, B2, G1 and G2 from the model aqueous sample followed by on-line chromatographic separation. The process was performed using a micro-MISPE-microLC-LIF system of a novel design, which allowed for detection of the eluates from the sample preparation part as well as from the chromatographic separation.

  7. Ionic liquid-based zwitterionic organic polymer monolithic column for capillary hydrophilic interaction chromatography.

    Science.gov (United States)

    Wang, Tingting; Chen, Yihui; Ma, Junfeng; Zhang, Xiaodan; Zhang, Lihua; Zhang, Yukui

    2015-08-21

    In the current study, a novel ionic liquid-based zwitterionic organic polymer monolithic column was developed by copolymerizing 1-vinyl-3-(butyl-4-sulfonate) imidazolium, acrylamide and N,N'-methylenebisacrylamide in a quaternary porogenic solvent consisting of formamide, dimethyl sulphoxide, polyethylene glycol 8000 and polyethylene glycol 10,000 for capillary hydrophilic interaction chromatography. The monolithic stationary phase was optimized by adjusting the amount of monomer in the polymerization solution along with the composition of porogenic solvent. The optimized monolith exhibited excellent selectivity and favorable retention for nucleosides and benzoic acid derivatives. The primary factors affecting the separation efficiency of the monolithic column (including acetonitrile content, pH, and buffer salt concentration in the mobile phase) have been thoroughly evaluated. Excellent reproducibility of the retention times for five nucleosides was achieved, with relative standard deviations of run-to-run (n = 3), column-to-column (n = 3) and batch-to-batch (n = 3) in the range of 0.18-0.48%, 2.33-4.20% and 3.07-6.50%, respectively.

  8. Preparation of a thermoresponsive polymer grafted polystyrene monolithic capillary for the separation of bioactive compounds.

    Science.gov (United States)

    Koriyama, Takuya; Asoh, Taka-Aki; Kikuchi, Akihiko

    2016-11-01

    To develop aqueous microseparation columns for bioactive compounds, a thermoresponsive polymer grafted polymer monolith was prepared inside silica capillaries having an I.D. of 100μm by polymerization of styrene (St) with m/p-divinylbenzene (DVB) in the presence of polydimethylsiloxane as porogen, followed by surface-initiated atom transfer radical polymerization (SI-ATRP) of N-isopropylacrylamide (NIPAAm). SEM analysis indicated that the resulting poly(N-isopropylacrylamide) (PNIPAAm) grafted polystyrene monolith had a consecutive three-dimensionally interconnected structure and through-pores, similar to the base polystyrene (PSt) monolith. The elution behavior of steroids with different hydrophobicity was evaluated using micro-high-performance liquid chromatography in sole aqueous mobile phase. Temperature dependent interaction changes were observed between steroids and the PNIPAAm modified surfaces. Furthermore, the interaction between bioactive compounds and the PNIPAAm grafted PSt surfaces was controlled and eventually separate these molecules with different hydrophobicities by simple temperature modulation in aqueous environment. The PNIPAAm grafted PSt monolithic capillary showed improved separation properties of bioactive compounds, compared with a PNIPAAm grafted hollow capillary in aqueous environment.

  9. MADIDS:A Novel Distributed IDS Based on Mobile Agent%MADIDS:一种基于移动代理的新型分布式入侵检测系统

    Institute of Scientific and Technical Information of China (English)

    罗光春; 卢显良; 李炯; 张骏

    2003-01-01

    When traditional Intrusion Detection System(IDS) is used to detect and analyze the great flow data transfer in high-speed network,it usually causes the computation bottleneck. This paper presents a new Mobile Agent Distributed IDS(MADIDS) system based on the mobile agents. This system is specifically designed to process the great flow data transfer in high-speed network. In MADIDS,the agents that are set at each node process the data transfer by distributed computation architecture. Meanwhile by using the reconfiguration quality of the mobile agents ,the load balance of distributed computation can be dynamically implemented to gain the high-performance computing ability. This ability makes the detecting and analyzing of high-speed network possible. MADIDS can effectively solve the detection and analysis performance bottleneck caused by the great flow data transfer in high-speed network. It enhances the performance of IDS in high-speed network. In this paper,we construct the infrastructure and theoretical model of MADIDS,and the deficiencies of MADIDS and future research work are also indicated.

  10. 一个基于CORBA和移动智能体的分布式网管集成框架%A Distributed Network Management Architecture Based on CORBA and Mobile Agent

    Institute of Scientific and Technical Information of China (English)

    吴刚; 王怀民; 吴泉源

    2001-01-01

    文中分析了当前主流网管系统在体系结构上的缺陷,阐述了分布对象技术(CORBA)与移动智能体技术各自在网管领域的应用方法与优势.结合这些优势,给出了一个基于CORBA和移动智能体的分布式网管集成框架,并进一步通过实验模拟证实了其可行性.%The increasing scale and complexity of the network are makingnetwork management more and more important. The wide-used network management systems based on SNMP or CMIP adopt a Client/Server paradigm and are characterized by centralization. Due to the simplicity of the manager/agent model, these traditional systems are widely used. But there are also many drawbacks coming with the simplicity and centralization. Analyzing the limitations of the traditional network management systems, the paper describes the benefits of using CORBA and Mobile Agent technology in this field. Common Object Request Broker Architecture (CORBA) comes from OMG for distributed object process and integration. With the distributed object platform ORB, interface definition language IDL, and the abundant common services of CORBA, an open network management system can be constructed easily. The architecture based on CORBA presented in this paper mainly addresses the integratebility, extensibility, reusability, and scalability of distributed network management. It benefits from the large amount of SNMP/CMIP devices and the mature management platform. At the same time, it provides not only an extensible application framework to process all kinds of changes quickly through CORBA's distributed object model, but also the independence of programming language though IDL. And it also does well in information sharing and interoperation between high-level services. A mobile agent is an active computing entity characterized by the autonomous, interactive and mobile properties. Due to the autonomous migration on the heterogeneous network, the mobile agent can agilely decentralize the management

  11. Modified monolithic silica capillary for preconcentration of catecholamines

    Institute of Scientific and Technical Information of China (English)

    Wei Chang; Tusyo-shi Komazu

    2009-01-01

    Preconcentration of catecholamines by the modified monolithic silica in the capillary was investigated in this study. In order to achieve a microchip-based method for determining catecholamines in the saliva, the monolithic silica was fabricated in the capillary and the monolithic silica was chemically modified by on-column reaction with phenylboronate. Different modified methods were compared. The concentration conditions were optimized. This study indicates the applicability of the modified monolithic silica capillary when it was used to concentrate catecholamines.

  12. Modified monolithic silica capillary for preconcentration of catecholamines

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Preconcentration of catecholamines by the modified monolithic silica in the capillary was investigated in this study. In order to achieve a microchip-based method for determining catecholamines in the saliva,the monolithic silica was fabricated in the capillary and the monolithic silica was chemically modified by on-column reaction with phenylboronate. Different modified methods were compared. The concentration conditions were optimized. This study indicates the applicability of the modified monolithic sili...

  13. Fracture resistance of monolithic zirconia molar crowns with reduced thickness

    OpenAIRE

    Nakamura, Keisuke; Harada, A.; Inagaki, R.; Kanno, Taro; Niwano, Y; Milleding, Percy; Ørtengren, Ulf Thore

    2015-01-01

    This is the accepted manuscript version. Published version is available at Acta Odontologica Scandinavica Objectives. The purpose of the present study was to analyze the relationship between fracture load of monolithic zirconia crowns and axial/occlusal thickness, and to evaluate the fracture resistance of monolithic zirconia crowns with reduced thickness in comparison with that of monolithic lithium disilicate crowns with regular thickness. Materials and methods. Monolithic zi...

  14. Histidine-modified organic-silica hybrid monolithic column for mixed-mode per aqueous and ion-exchange capillary electrochromatography.

    Science.gov (United States)

    Tang, Sheng; Liu, Shujuan; Liang, Xiaojing; Tang, Xiaofen; Wu, Xingcai; Guo, Yong; Liu, Xia; Jiang, Shengxiang

    2015-06-01

    A novel organic-silica hybrid monolith was prepared through the binding of histidine onto the surface of monolithic matrix for mixed-mode per aqueous and ion-exchange capillary electrochromatography. The imidazolium and amino groups on the surface of the monolithic stationary phase were used to generate an anodic electro-osmotic flow as well as to provide electrostatic interaction sites for the charged compounds at low pH. Typical per aqueous chromatographic behavior was observed in water-rich mobile phases. Various polar and hydrophilic analytes were selected to evaluate the characteristics and chromatographic performance of the obtained monolith. Under per aqueous conditions, the mixed-mode mechanism of hydrophobic and ion-exchange interactions was observed and the resultant monolithic column proved to be very versatile for the efficient separations of these polar and hydrophilic compounds (including amides, nucleosides and nucleotide bases, benzoic acid derivatives, and amino acids) in highly aqueous mobile phases. The successful applications suggested that the histidine-modified organic-silica hybrid monolithic column could offer a wide range of retention behaviors and flexible selectivities toward polar and hydrophilic compounds.

  15. Development of a monolithic ferrite memory array

    Science.gov (United States)

    Heckler, C. H., Jr.; Bhiwandker, N. C.

    1972-01-01

    The results of the development and testing of ferrite monolithic memory arrays are presented. This development required the synthesis of ferrite materials having special magnetic and physical characteristics and the development of special processes; (1) for making flexible sheets (laminae) of the ferrite composition, (2) for embedding conductors in ferrite, and (3) bonding ferrite laminae together to form a monolithic structure. Major problems encountered in each of these areas and their solutions are discussed. Twenty-two full-size arrays were fabricated and fired during the development of these processes. The majority of these arrays were tested for their memory characteristics as well as for their physical characteristics and the results are presented. The arrays produced during this program meet the essential goals and demonstrate the feasibility of fabricating monolithic ferrite memory arrays by the processes developed.

  16. Carbon Fiber Composite Monoliths as Catalyst Supports

    Energy Technology Data Exchange (ETDEWEB)

    Contescu, Cristian I [ORNL; Gallego, Nidia C [ORNL; Pickel, Joseph M [ORNL; Blom, Douglas Allen [ORNL; Burchell, Timothy D [ORNL

    2006-01-01

    Carbon fiber composite monoliths are rigid bodies that can be activated to a large surface area, have tunable porosity, and proven performance in gas separation and storage. They are ideal as catalyst supports in applications where a rigid support, with open structure and easy fluid access is desired. We developed a procedure for depositing a dispersed nanoparticulate phase of molybdenum carbide (Mo2C) on carbon composite monoliths in the concentration range of 3 to 15 wt% Mo. The composition and morphology of this phase was characterized using X-ray diffraction and electron microscopy, and a mechanism was suggested for its formation. Molybdenum carbide is known for its catalytic properties that resemble those of platinum group metals, but at a lower cost. The materials obtained are expected to demonstrate catalytic activity in a series of hydrocarbon reactions involving hydrogen transfer. This project demonstrates the potential of carbon fiber composite monoliths as catalyst supports.

  17. Carbon Fiber Composite Monoliths for Catalyst Supports

    Energy Technology Data Exchange (ETDEWEB)

    Contescu, Cristian I [ORNL; Gallego, Nidia C [ORNL; Pickel, Joseph M [ORNL; Blom, Douglas Allen [ORNL; Burchell, Timothy D [ORNL

    2006-01-01

    Carbon fiber composite monoliths are rigid bodies that can be activated to a large surface area, have tunable porosity, and proven performance in gas separation and storage. They are ideal as catalyst supports in applications where a rigid support, with open structure and easy fluid access is desired. We developed a procedure for depositing a dispersed nanoparticulate phase of molybdenum carbide (Mo2C) on carbon composite monoliths in the concentration range of 3 to 15 wt% Mo. The composition and morphology of this phase was characterized using X-ray diffraction and electron microscopy, and a mechanism was suggested for its formation. Molybdenum carbide is known for its catalytic properties that resemble those of platinum group metals, but at a lower cost. The materials obtained are expected to demonstrate catalytic activity in a series of hydrocarbon reactions involving hydrogen transfer. This project demonstrates the potential of carbon fiber composite monoliths as catalyst supports.

  18. Eigenpolarization theory of monolithic nonplanar ring oscillators

    Science.gov (United States)

    Nilsson, Alan C.; Gustafson, Eric K.; Byer, Robert L.

    1989-01-01

    Diode-laser-pumped monolithic nonplanar ring oscillators (NPROs) in an applied magnetic field can operate as unidirectional traveling-wave lasers. The diode laser pumping, monolithic construction, and unidirectional oscillation lead to narrow linewidth radiation. Here, a comprehensive theory of the eigenpolarizations of a monolithic NPRO is presented. It is shown how the properties of the integral optical diode that forces unidirectional operation depend on the choice of the gain medium, the applied magnetic field, the output coupler, and the geometry of the nonplanar ring light path. Using optical equivalence theorems to gain insight into the polarization characteristics of the NPRO, a strategy for designing NPROs with low thresholds and large loss nonreciprocities is given. An analysis of the eigenpolarizations for one such NPRO is presented, alternative optimization approaches are considered, and the prospects for further reducing the linewidths of these lasers are briefly discussed.

  19. Physical and chemical sensing using monolithic semiconductor optical transducers

    Science.gov (United States)

    Zappe, Hans P.; Hofstetter, Daniel; Maisenhoelder, Bernd; Moser, Michael; Riel, Peter; Kunz, Rino E.

    1997-09-01

    We present two monolithically integrated optical sensor systems based on semiconductor photonic integrated circuits. These compact, robust and highly functional transducers perform all necessary optical and electro-optical functions on-chip; extension to multi-sensor arrays is easily envisaged. A monolithic Michelson interferometer for high-resolution displacement measurement and a monolithic Mach-Zehnder interferometer for refractometry are discussed.

  20. MANET网络中一种基于移动Agent的入侵检测系统%An Intrusion Detection System Based on Mobile Agent for MANET Networks

    Institute of Scientific and Technical Information of China (English)

    张毅; 张秀梅

    2011-01-01

    提出了一种在MANET网络中基于移动Agent的人侵检测系统.介绍了系统的基础算法、体系结构以及工作原理.根据系统的基础算法得到数据报文的最佳传输路径,通过各节点的观察并结合其他节点的观察,判断可疑行为超出了预警范围时,发出告警信号,并采用绕路的措施;之后综合考虑来自各个节点的告警信号,得出最终可靠的结论,并从网络中彻底删除该节点.利用NS-2网络仿真工具模拟了黑洞、虫洞等人侵行为,以及系统对这些行为的对抗,仿真结果表明,本系统具有很高的效率和鲁棒性.%This paper presents an intrusion detection system based on mobile Agent for mobile ad hoc Networks. We introduce the basic algorithm, the system structure and the working theory of the intrusion detection system. The best route can be gotten by the routing algorithm. Learning from the local observed behavior and the neighbor reported behavior, if the rating of malicious behavior exceeds a threshold, the local node send the alert message and use the spare routing. Collecting the alert message from the other nodes, the node concludes the decision and deletes the malicious node from the network. We have done the experiment in simulated environment of NS2 system. We simulate malicious behavior as the black hole and the worm hole. The simulated results show that, the intrusion detection system is very efficient and robust.

  1. Increased thermal conductivity monolithic zeolite structures

    Science.gov (United States)

    Klett, James; Klett, Lynn; Kaufman, Jonathan

    2008-11-25

    A monolith comprises a zeolite, a thermally conductive carbon, and a binder. The zeolite is included in the form of beads, pellets, powders and mixtures thereof. The thermally conductive carbon can be carbon nano-fibers, diamond or graphite which provide thermal conductivities in excess of about 100 W/mK to more than 1,000 W/mK. A method of preparing a zeolite monolith includes the steps of mixing a zeolite dispersion in an aqueous colloidal silica binder with a dispersion of carbon nano-fibers in water followed by dehydration and curing of the binder is given.

  2. Characterization of CIM monoliths as enzyme reactors.

    Science.gov (United States)

    Vodopivec, Martina; Podgornik, Ales; Berovic, Marin; Strancar, Ales

    2003-09-25

    The immobilization of the enzymes citrate lyase, malate dehydrogenase, isocitrate dehydrogenase and lactate dehydrogenase to CIM monolithic supports was performed. The long-term stability, reproducibility, and linear response range of the immobilized enzyme reactors were investigated along with the determination of the kinetic behavior of the enzymes immobilized on the CIM monoliths. The Michaelis-Menten constant K(m) and the turnover number k(3) of the immobilized enzymes were found to be flow-unaffected. Furthermore, the K(m) values of the soluble and immobilized enzyme were found to be comparable. Both facts indicate the absence of a diffusional limitation in immobilized CIM enzyme reactors.

  3. Monolithically integrated optoelectronic down-converter (MIOD)

    Science.gov (United States)

    Portnoi, Efrim L.; Venus, G. B.; Khazan, A. A.; Gorfinkel, Vera B.; Kompa, Guenter; Avrutin, Evgenii A.; Thayne, Iain G.; Barrow, David A.; Marsh, John H.

    1995-06-01

    Optoelectronic down-conversion of very high-frequency amplitude-modulated signals using a semiconductor laser simultaneously as a local oscillator and a mixer is proposed. Three possible constructions of a monolithically integrated down-converter are considered theoretically: a four-terminal semiconductor laser with dual pumping current/modal gain control, and both a passively mode-locked and a passively Q-switched semiconductor laser monolithically integrated with an electroabsorption or pumping current modulator. Experimental verification of the feasibility of the concept of down conversion in a laser diode is presented.

  4. Preparation and evaluation of a novel hybrid monolithic column based on pentafluorobenzyl imidazolium bromide ionic liquid.

    Science.gov (United States)

    Shan, Yuanhong; Qiao, Lizhen; Shi, Xianzhe; Xu, Guowang

    2015-01-02

    To develop a novel hybrid monolithic column based on pentafluorobenzyl imidazolium bromide ionic liquid, a new ionic liquid monomer was synthesized from 1-vinylimidazole and pentafluorobenzyl bromide. By employing a facile one-step copolymerization of polyhedral-oligomeric-silsesquioxane-type (POSS) cross-linking agent and the home-made ionic liquid monomer, the hybrid monolithic columns were in situ fabricated in fused-silica capillary. The morphology of monolithic column was characterized by scanning electron microscope (SEM) and the chemical composition was confirmed by Fourier-transform infrared spectroscopy (FT-IR) and elemental analysis. Excellent mechanical stability and slight swelling propensity were exhibited which was ascribed to the rigid hybrid monolithic skeleton. Reproducibility results of run-to-run, column-to-column, batch-to-batch and day-to-day were investigated and the RSDs were less than 0.46%, 1.84%, 3.96% and 3.17%, respectively. The mixed-mode retention mechanism with hydrophobic interaction, π-π stacking, ion-exchange, electrostatic interaction and dipole-dipole interaction was explored systematically using analytes with different structure types. Satisfied separation capability and column efficiency were achieved for the analysis of small molecular compounds such as alkylbenzenes, polycyclic aromatic hydrocarbons, nucleosides and halogenated compounds. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Secure Tactical Mobile Intelligent Agents

    Science.gov (United States)

    2004-09-30

    Exchange System for Ad Hoc Networks", Eleventh International Workshop on Security Protocols, Cambridge, UK, Apr. 2-4, 2003, Lecture Notes in Computer Science 1.2.8...in Ad hoc Networks ", 3rd International Conference on AD-HOC Networks & Wireless, July 20-22, 2004, Lecture Notes in Computer Science 3158, Springer

  6. J2ME accessing distributed database based on mobile agent%基于移动agent的J2ME分布式数据库访问

    Institute of Scientific and Technical Information of China (English)

    茹蓓; 肖云鹏

    2011-01-01

    J2ME mobile device, as its limited computational and mnemonic ability, does not support database system actually. At present, most systems use J2ME-J2EE-database solution, but the linear solution does not adapt to characteristic of wireless environment such as highly delay and disconnection frequently. By using and extending agent theory, proposed a new method of four layers C/S J2ME accessing distributed database scheme, and developed a prototype system by open source project named Aglets. The result of evaluation shows that the scheme is practical, speedy and robust.%由于移动手持设备有限的计算和存储能力,J2ME没有提供真正意义上的数据库系统,目前大多数系统采用J2ME-J2EE-数据库系统的解决方案,然而这种线性部署并不适合无线计算环境下频繁断接、高延时等特性.通过借鉴移动agent思想并对其功能进行扩充,提出基于移动agent的J2ME分布式数据库四层C/S访问机制,并在开源Aglets平台基础上开发了一个分布式通信录系统原型,实验评估显示该方案有效地提高了J2ME设备对分布式数据库的访问效率和健壮性.

  7. 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.

  8. Preparation and evaluation of poly(alkyl methacrylate-co-methacrylic acid-co-ethylene dimethacrylate) monolithic columns for separating polar small molecules by capillary liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Shu-Ling; Wu, Yu-Ru; Lin, Tzuen-Yeuan; Fuh, Ming-Ren, E-mail: msfuh@scu.edu.tw

    2015-04-29

    Highlights: • Methacrylic acid (MAA) was used to increase hydrophilicity of polymeric monoliths. • Fast separation of phenol derivatives was achieved in 5 min using MAA-incorporated column. • Separations of aflatoxins and phenicol antibiotics were achieved using MAA-incorporated column. - Abstract: In this study, methacrylic acid (MAA) was incorporated with alkyl methacrylates to increase the hydrophilicity of the synthesized ethylene dimethacrylate-based (EDMA-based) monoliths for separating polar small molecules by capillary LC analysis. Different alkyl methacrylate–MAA ratios were investigated to prepare a series of 30% alkyl methacrylate–MAA–EDMA monoliths in fused-silica capillaries (250-μm i.d.). The porosity, permeability, and column efficiency of the synthesized MAA-incorporated monolithic columns were characterized. A mixture of phenol derivatives is employed to evaluate the applicability of using the prepared monolithic columns for separating small molecules. Fast separation of six phenol derivatives was achieved in 5 min with gradient elution using the selected poly(lauryl methacrylate-co-MAA-co-EDMA) monolithic column. In addition, the effect of acetonitrile content in mobile phase on retention factor and plate height as well as the plate height-flow velocity curves were also investigated to further examine the performance of the selected poly(lauryl methacrylate-co-MAA-co-EDMA) monolithic column. Moreover, the applicability of prepared polymer-based monolithic column for potential food safety applications was also demonstrated by analyzing five aflatoxins and three phenicol antibiotics using the selected poly(lauryl methacrylate-co-MAA-co-EDMA) monolithic column.

  9. 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

  10. Monolithic Integration of GaN-based LEDs

    Energy Technology Data Exchange (ETDEWEB)

    Ao, Jin-Ping, E-mail: jpao@ee.tokushima-u.ac.jp [Institute of Technology and Science, University of Tokushima 2-1 Minami-Josanjima, Tokushima 770-8506 (Japan)

    2011-02-01

    The technology of monolithically integrated GaN-based light-emitting diodes (LEDs) is reported. First, the technology details to realize monolithic integration are described, including the circuit design for high-voltage and alternating current (AC) operation and the technologies for device isolation. The performances of the fabricated monolithic LED arrays are then demonstrated. A monolithic series array with totally 40 LEDs exhibited expected operation function under AC bias. The operation voltage of the array is 72 V when 20 LEDs were connected in series. Some modified circuit designs for high-voltage operation and other monolithic LED arrays are finally reviewed.

  11. Research on IPV6 Intrusion Detection Systems Based on Mobile Agent%IPV6下基于移动Agent的入侵检测系统研究

    Institute of Scientific and Technical Information of China (English)

    周琳

    2011-01-01

    在分析传统入侵检测系统的基础上,将移动Agent技术融入入侵检测系统.结合IPV6协议自身的特点,提出了IPV6下基于移动Agent的入侵检测系统模型,并对系统中关键模块进行了详细描述.该系统可以通过移动Agent在主机之间自主迁移分析数据,并及时发现入侵行为.实验证明,该系统具有良好的安全防御性能.%Based on the analysis of the traditional intrusion detection system, mobile Agent technology is integrated into intrusion detection system. IPV6 intrusion detection system based on mobile Agent is proposed combined with the IPV6 protocol's characteristic, and the key modules are described in detail. The system can make migration analysis automaticly between host and host through mobile agent and detect intrusion behavior. Experiments show that the system has good security performance.

  12. Routing strategy with mobile agent based on hierarchical DSR for vehicular communication network%车载通信网中基于DSR分层机制的移动代理路由策略研究

    Institute of Scientific and Technical Information of China (English)

    马志欣; 赵鼎新; 谢显中; 王昭然

    2011-01-01

    分析了现有动态源路由(dynamic source routing,DSR)协议机制以及在车载通信网路由发现中存在的问题,提出一种基于DSR分层机制的移动代理路由策略(cluster mobile agent-dynamic source routing,CM-DSR),并对设计的算法进行仿真实验.结果表明,所提出的CM-DSR协议与DSR路由协议相比较,较大幅度地降低了端到端的传输延迟,减少了路由请求次数,包的提交率也有一定程度的提高.%In this paper, we analyzed the existing mechanisms of DSR routing protocol and the routing discovery problem especially existed in Vehicle Communication Network. Moreover, we proposed a mobile agent routing strategy( Cluster Mobile agent-Dynamic Source Routing, CM-DSR)based on DSR stratification mechanism, we also conducted a simulation experiment on our algorithm. Extensive simulation results showed that the proposed CM-DSR protocol compared to DSR routing protocol can reduce significantly the end to end transmission delay and routing request times, while improve the packet delivery rate to some extent.

  13. Monolithic resonant optical reflector laser diodes

    Science.gov (United States)

    Hirata, T.; Suehiro, M.; Maeda, M.; Hihara, M.; Hosomatsu, H.

    1991-10-01

    The first monolithic resonant optical reflector laser diode that has a waveguide directional coupler and two DBR reflectors integrated by compositional disordering of quantum-well heterostructures is described. A linewidth of 440 kHz was obtained, and this value is expected to be greatly decreased by reducing the propagation loss in the integrated waveguide.

  14. Constant capacitance in nanopores of carbon monoliths.

    Science.gov (United States)

    García-Gómez, Alejandra; Moreno-Fernández, Gelines; Lobato, Belén; Centeno, Teresa A

    2015-06-28

    The results obtained for binder-free electrodes made of carbon monoliths with narrow micropore size distributions confirm that the specific capacitance in the electrolyte (C2H5)4NBF4/acetonitrile does not depend significantly on the micropore size and support the foregoing constant result of 0.094 ± 0.011 F m(-2).

  15. Smart Sensing Strip Using Monolithically Integrated Flexible Flow Sensor for Noninvasively Monitoring Respiratory Flow.

    Science.gov (United States)

    Jiang, Peng; Zhao, Shuai; Zhu, Rong

    2015-12-15

    This paper presents a smart sensing strip for noninvasively monitoring respiratory flow in real time. The monitoring system comprises a monolithically-integrated flexible hot-film flow sensor adhered on a molded flexible silicone case, where a miniaturized conditioning circuit with a Bluetooth4.0 LE module are packaged, and a personal mobile device that wirelessly acquires respiratory data transmitted from the flow sensor, executes extraction of vital signs, and performs medical diagnosis. The system serves as a wearable device to monitor comprehensive respiratory flow while avoiding use of uncomfortable nasal cannula. The respiratory sensor is a flexible flow sensor monolithically integrating four elements of a Wheatstone bridge on single chip, including a hot-film resistor, a temperature-compensating resistor, and two balancing resistors. The monitor takes merits of small size, light weight, easy operation, and low power consumption. Experiments were conducted to verify the feasibility and effectiveness of monitoring and diagnosing respiratory diseases using the proposed system.

  16. III-nitride monolithic LED covering full RGB color gamut

    Science.gov (United States)

    El-Ghoroury, Hussein S.; Chuang, Chih-Li; Kisin, Mikhail V.

    2016-03-01

    We present numerical simulation of III-nitride monolithic multi-color LED covering full red-green-blue (RGB) color gamut. The RGB LED structure was grown at Ostendo Technologies Inc. and has been used in Ostendo proprietary Quantum Photonic Imager (QPI) device. Active region of our RGB LED incorporates specially designed intermediate carrier blocking layers (ICBLs) controlling transport of each type of carriers and subsequent carrier injection redistribution among the optically active quantum wells (QWs) with different emission wavelengths. ICBLs are proved to be essential elements of multi-color LED active region design requiring optimization both in material composition and doping level. Strong interdependence between ICBL parameters and active QW characteristics presents additional challenge to multi-color LED design. Combination of several effects was crucial for adequate simulation of RGB LED color control features. Standard drift-diffusion transport model has been appended with rate equations for dynamic QW-confined carrier populations which appear severely off-balanced from corresponding mobile carrier subsystems. QW overshoot and Auger-assisted QW depopulation were also included into the carrier kinetic model thus enhancing the non-equilibrium character of QW confined populations and supporting the mobile carrier transport across the MQW active region. For device simulation we use COMSOL-based program suit developed at Ostendo Technologies Inc.

  17. Mobile-agent-based Distributed Intrusion Detection System%基于移动Agent的分布式入侵检测系统研究

    Institute of Scientific and Technical Information of China (English)

    李树文; 孙敏

    2012-01-01

    This paper builds a model of Distributed Intrusion Detection System Based on mobile Agent and discusses the realiza- tion of the model, and simulation tests are carried out about its properties. The model takes the working method of "Collective disposition within a domain and mutual cooperation among domains". The protected network is divided into a number of do- mains, and each of them is a complete analysis center of distributed intrusion detection system. These domains have relatively equal positions, mutually cooperate, and complete distributed intrusion detection together. In this way, single point failures can be overcome, management becomes easy, and it is easily analyzed and discriminated whether the attack is locally aggressive or distributed.%随着网络信息量及速度的急剧上升,入侵检测技术必然也随之改变,分布式入侵检测就是一个好的选择。本文构建出一个基于移动Agent分布式入侵检测模型;探讨了该模型的实现并对其性能进行了仿真实验验证。该模型采用“域内集中处理,域间互助协作”的工作方式,将整个受保护的网络划分成若干个域,每个域内是一个完整的中心分析型分布式入侵检测系统,域间地位平等,互相协作,共同完成分布式入侵检测。这样以来,既能克服单点故障问题,又便于管理,容易分析判别是本地攻击还是分布式攻击。

  18. FLUIDIZED BED STEAM REFORMER (FBSR) PRODUCT: MONOLITH FORMATION AND CHARACTERIZATION

    Energy Technology Data Exchange (ETDEWEB)

    Jantzen, C

    2006-09-13

    ; (3) compressive strength; and (4) durability must not be compromised--binding agent should not react with the NAS product and binding agent should not create an unfavorable pH environment that may cause accelerated leaching. It is the goal of the present study to survey cementitious waste forms based on Ordinary Portland Cement (OPC), Ceramicrete, and hydroceramic binders by correlating waste loading, density and compressive strength and then determine if these binders affect the product performance in terms of the PCT response. This will be done by making a one-to-one comparison of the PCT response measured on granular NAS mineral product (mixed bed and fines products) with the PCT response of the monolithed NAS product in the different binders. Future studies may include, refining the above binders, and examining other binders. It is likely that binders formed from kaolin would be most compatible with the chemistry of the THOR{reg_sign} mineral waste form which is made by steam reforming of kaolin and sodium rich wastes. The economics of production on a large scale have yet to be investigated for any of the binders tested.

  19. A monolithic integrated photonic microwave filter

    Science.gov (United States)

    Fandiño, Javier S.; Muñoz, Pascual; Doménech, David; Capmany, José

    2016-12-01

    Meeting the increasing demand for capacity in wireless networks requires the harnessing of higher regions in the radiofrequency spectrum, reducing cell size, as well as more compact, agile and power-efficient base stations that are capable of smoothly interfacing the radio and fibre segments. Fully functional microwave photonic chips are promising candidates in attempts to meet these goals. In recent years, many integrated microwave photonic chips have been reported in different technologies. To the best of our knowledge, none has monolithically integrated all the main active and passive optoelectronic components. Here, we report the first demonstration of a tunable microwave photonics filter that is monolithically integrated into an indium phosphide chip. The reconfigurable radiofrequency photonic filter includes all the necessary elements (for example, lasers, modulators and photodetectors), and its response can be tuned by means of control electric currents. This is an important step in demonstrating the feasibility of integrated and programmable microwave photonic processors.

  20. Macroporous Monolithic Polymers: Preparation and Applications

    Directory of Open Access Journals (Sweden)

    Cecilia Inés Alvarez Igarzabal

    2009-12-01

    Full Text Available In the last years, macroporous monolithic materials have been introduced as a new and useful generation of polymers used in different fields. These polymers may be prepared in a simple way from a homogenous mixture into a mold and contain large interconnected pores or channels allowing for high flow rates at moderate pressures. Due to their porous characteristics, they could be used in different processes, such as stationary phases for different types of chromatography, high-throughput bioreactors and in microfluidic chip applications. This review reports the contributions of several groups working in the preparation of different macroporous monoliths and their modification by immobilization of specific ligands on the products for specific purposes.

  1. Monolithic pixel detectors for high energy physics

    CERN Document Server

    Snoeys, W

    2013-01-01

    Monolithic pixel detectors integrating sensor matrix and readout in one piece of silicon have revolutionized imaging for consumer applications, but despite years of research they have not yet been widely adopted for high energy physics. Two major requirements for this application, radiation tolerance and low power consumption, require charge collection by drift for the most extreme radiation levels and an optimization of the collected signal charge over input capacitance ratio ( Q / C ). It is shown that monolithic detectors can achieve Q / C for low analog power consumption and even carryout the promise to practically eliminate analog power consumption, but combining suf fi cient Q / C , collection by drift, and integration of readout circuitry within the pixel remains a challenge. An overview is given of different approaches to address this challenge, with possible advantages and disadvantages.

  2. Update On Monolithic Fuel Fabrication Development

    Energy Technology Data Exchange (ETDEWEB)

    C. R Clark; J. M. Wight; G. C. Knighton; G. A. Moore; J. F. Jue

    2005-11-01

    Efforts to develop a viable monolithic research reactor fuel plate have continued at Idaho National Laboratory. These efforts have concentrated on both fabrication process refinement and scale-up to produce full sized fuel plates. Advancements have been made in the production of U-Mo foil including full sized foils. Progress has also been made in the friction stir welding and transient liquid phase bonding fabrication processes resulting in better bonding, more stable processes and the ability to fabricate larger fuel plates.

  3. FLUIDIZED BED STEAM REFORMER MONOLITH FORMATION

    Energy Technology Data Exchange (ETDEWEB)

    Jantzen, C

    2006-12-22

    Fluidized Bed Steam Reforming (FBSR) is being considered as an alternative technology for the immobilization of a wide variety of aqueous high sodium containing radioactive wastes at various DOE facilities in the United States. The addition of clay, charcoal, and a catalyst as co-reactants converts aqueous Low Activity Wastes (LAW) to a granular or ''mineralized'' waste form while converting organic components to CO{sub 2} and steam, and nitrate/nitrite components, if any, to N{sub 2}. The waste form produced is a multiphase mineral assemblage of Na-Al-Si (NAS) feldspathoid minerals with cage-like structures that atomically bond radionuclides like Tc-99 and anions such as SO{sub 4}, I, F, and Cl. The granular product has been shown to be as durable as LAW glass. Shallow land burial requires that the mineralized waste form be able to sustain the weight of soil overburden and potential intrusion by future generations. The strength requirement necessitates binding the granular product into a monolith. FBSR mineral products were formulated into a variety of monoliths including various cements, Ceramicrete, and hydroceramics. All but one of the nine monoliths tested met the <2g/m{sup 2} durability specification for Na and Re (simulant for Tc-99) when tested using the Product Consistency Test (PCT; ASTM C1285). Of the nine monoliths tested the cements produced with 80-87 wt% FBSR product, the Ceramicrete, and the hydroceramic produced with 83.3 wt% FBSR product, met the compressive strength and durability requirements for an LAW waste form.

  4. Monolithically integrated interferometer for optical displacement measurement

    Science.gov (United States)

    Hofstetter, Daniel; Zappe, Hans P.

    1996-01-01

    We discuss the fabrication of a monolithically integrated optical displacement sensors using III-V semiconductor technology. The device is configured as a Michelson interferometer and consists of a distributed Bragg reflector laser, a photodetector and waveguides forming a directional coupler. Using this interferometer, displacements in the 100 nm range could be measured at distances of up to 45 cm. We present fabrication, device results and characterization of the completed interferometer, problems, limitations and future applications will also be discussed.

  5. 基于S2C移动商务的Multi-Agent物流系统研究%Study on the Multi-Agent Logisitcs System for S2C Mobile Businesses

    Institute of Scientific and Technical Information of China (English)

    张健

    2011-01-01

    Having analyzed the characteristics of mobile business processes and the S2C practice, the paper draws on the multi-agent mechanism to establish a real-time smart logistics system and presents a four-tiered architecture consisting of application, business logic, agent, and physical entity. Then it designs the system communication function in connection with a case analysis on a S2C baby products online shop. At the end, a multi-agent based physical logistics system solution for mobile business environment is proposed.%在分析移动商务环境业务流程特点基础上,结合S2C模式"即时性"、"移动性"的特点,进行了Multi-Agent机制建立实时智能物流系统研究.给出了应用层、业务逻辑层、Agent层、物理实体层的四层系统体系结构,同时进行了系统通信设计,并结合S2C婴童用品网购实例进行分析.提出了在移动商务环境下,一种基于Multi-Agent技术的物理系统方案.

  6. Staging Mobilities / Designing Mobilities

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    2015-01-01

    In recent years, urban research has taken a ‘mobilities turn’. There has been a developing realisation that mobilities do not ‘just happen.’ Mobilities are carefully and meticulously designed, planned and staged (from above). However, they are equally importantly acted out, performed 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 that mobility...... asks: what are the physical, social, technical, and cultural conditions to the staging of contemporary urban mobilities? The theoretical framing in the Staging mobilities book is applied to four in-depth cases in the accompanying volume Designing mobilities.This book explore how places, sites...

  7. An overview of monolithic zirconia in dentistry

    Directory of Open Access Journals (Sweden)

    Özlem Malkondu

    2016-07-01

    Full Text Available Zirconia restorations have been used successfully for years in dentistry owing to their biocompatibility and good mechanical properties. Because of their lack of translucency, zirconia cores are generally veneered with porcelain, which makes restorations weaker due to failure of the adhesion between the two materials. In recent years, all-ceramic zirconia restorations have been introduced in the dental sector with the intent to solve this problem. Besides the elimination of chipping, the reduced occlusal space requirement seems to be a clear advantage of monolithic zirconia restorations. However, scientific evidence is needed to recommend this relatively new application for clinical use. This mini-review discusses the current scientific literature on monolithic zirconia restorations. The results of in vitro studies suggested that monolithic zirconia may be the best choice for posterior fixed partial dentures in the presence of high occlusal loads and minimal occlusal restoration space. The results should be supported with much more in vitro and particularly in vivo studies to obtain a final conclusion.

  8. Multi-layered hierarchical nanostructures for transparent monolithic dye-sensitized solar cell architectures

    Science.gov (United States)

    Passoni, Luca; Fumagalli, Francesco; Perego, Andrea; Bellani, Sebastiano; Mazzolini, Piero; Di Fonzo, Fabio

    2017-06-01

    Monolithic dye-sensitized solar cell (DSC) architectures hold great potential for building-integrated photovoltaics applications. They indeed benefit from lower weight and manufacturing costs as they avoid the use of a transparent conductive oxide (TCO)-coated glass counter electrode. In this work, a transparent monolithic DSC comprising a hierarchical 1D nanostructure stack is fabricated by physical vapor deposition techniques. The proof of concept device comprises hyperbranched TiO2 nanostructures, sensitized by the prototypical N719, as photoanode, a hierarchical nanoporous Al2O3 spacer, and a microporous indium tin oxide (ITO) top electrode. An overall 3.12% power conversion efficiency with 60% transmittance outside the dye absorption spectral window is demonstrated. The introduction of a porous TCO layer allows an efficient trade-off between transparency and power conversion. The porous ITO exhibits submicrometer voids and supports annealing temperatures above 400 °C without compromising its optoelectronical properties. After thermal annealing at 500 °C, the resistivity, mobility, and carrier concentration of the 800 nm-thick porous ITO layer are found to be respectively 2.3 × 10-3 Ω cm-1, 11 cm2 V-1 s-1, and 1.62 × 1020 cm-3, resulting in a series resistance in the complete device architecture of 45 Ω. Electrochemical impedance and intensity-modulated photocurrent/photovoltage spectroscopy give insight into the electronic charge dynamic within the hierarchical monolithic DSCs, paving the way for potential device architecture improvements.

  9. Monolithic Lumped Element Integrated Circuit (M2LEIC) Transistors.

    Science.gov (United States)

    INTEGRATED CIRCUITS, *MONOLITHIC STRUCTURES(ELECTRONICS), *TRANSISTORS, CHIPS(ELECTRONICS), FABRICATION, EPITAXIAL GROWTH, ULTRAHIGH FREQUENCY, POLYSILICONS, PHOTOLITHOGRAPHY, RADIOFREQUENCY POWER, IMPEDANCE MATCHING .

  10. 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.

  11. Selective oxidation of cyclohexene through gold functionalized silica monolith microreactors

    Science.gov (United States)

    Alotaibi, Mohammed T.; Taylor, Martin J.; Liu, Dan; Beaumont, Simon K.; Kyriakou, Georgios

    2016-04-01

    Two simple, reproducible methods of preparing evenly distributed Au nanoparticle containing mesoporous silica monoliths are investigated. These Au nanoparticle containing monoliths are subsequently investigated as flow reactors for the selective oxidation of cyclohexene. In the first strategy, the silica monolith was directly impregnated with Au nanoparticles during the formation of the monolith. The second approach was to pre-functionalize the monolith with thiol groups tethered within the silica mesostructure. These can act as evenly distributed anchors for the Au nanoparticles to be incorporated by flowing a Au nanoparticle solution through the thiol functionalized monolith. Both methods led to successfully achieving even distribution of Au nanoparticles along the length of the monolith as demonstrated by ICP-OES. However, the impregnation method led to strong agglomeration of the Au nanoparticles during subsequent heating steps while the thiol anchoring procedure maintained the nanoparticles in the range of 6.8 ± 1.4 nm. Both Au nanoparticle containing monoliths as well as samples with no Au incorporated were tested for the selective oxidation of cyclohexene under constant flow at 30 °C. The Au free materials were found to be catalytically inactive with Au being the minimum necessary requirement for the reaction to proceed. The impregnated Au-containing monolith was found to be less active than the thiol functionalized Au-containing material, attributable to the low metal surface area of the Au nanoparticles. The reaction on the thiol functionalized Au-containing monolith was found to depend strongly on the type of oxidant used: tert-butyl hydroperoxide (TBHP) was more active than H2O2, likely due to the thiol induced hydrophobicity in the monolith.

  12. 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...

  13. Multisyringe chromatography (MSC) using a monolithic column for the determination of sulphonated azo dyes.

    Science.gov (United States)

    Fernández, Cristina; Larrechi, M Soledad; Forteza, R; Cerdà, V; Callao, M Pilar

    2010-06-30

    A methodology based on multisyringe chromatography with a monolithic column was developed to determine three sulphonated azo textile dyes: Acid Yellow 23, Acid Yellow 9 and Acid Red 97. An ion pair reagent was needed because of the low affinity between the monolithic column and the anionic dyes. The proposed analytical system is simple, versatile and low-cost and has great flexibility in manifold configuration. The method was optimized through experimentation based on experimental design methodology. For this purpose two blocks of full factorial 2(3) were done sequentially. In the first experimental plan, the factors studied were: the % of acetonitrile in organic phase, the % of H(2)O in the mobile phase and the kind of ion pair reagent. In this stage, a simple configuration was used which has only one syringe for the mobile phase. After the first experimentation, we added a second syringe with a second mobile phase to the multisyringe module and performed a second full factorial 2(3). The factors studied in this case were: the % of acetonitrile in the second mobile phase, the pH and the concentration of ion pair reagent in both mobile phases. After this design, the optimal conditions were selected for obtaining a good resolution between the peaks of yellow dyes (1.47) and the elution of red dye in less than 8 min. The methodology was validated by spiking different amounts of each dye in real water samples, specifically, tap water, well water and water from a biological wastewater lagoon. Copyright 2010 Elsevier B.V. All rights reserved.

  14. Energy Absorption of Monolithic and Fibre Reinforced Aluminium Cylinders

    NARCIS (Netherlands)

    De Kanter, J.L.C.G.

    2006-01-01

    Summary accompanying the thesis: Energy Absorption of Monolithic and Fibre Reinforced Aluminium Cylinders by Jens de Kanter This thesis presents the investigation of the crush behaviour of both monolithic aluminium cylinders and externally fibre reinforced aluminium cylinders. The research is based

  15. Time-based position estimation in monolithic scintillator detectors

    NARCIS (Netherlands)

    Tabacchini, V.; Borghi, G.; Schaart, D.R.

    2015-01-01

    Gamma-ray detectors based on bright monolithic scintillation crystals coupled to pixelated photodetectors are currently being considered for several applications in the medical imaging field. In a typical monolithic detector, both the light intensity and the time of arrival of the earliest

  16. Time-based position estimation in monolithic scintillator detectors

    NARCIS (Netherlands)

    Tabacchini, V.; Borghi, G.; Schaart, D.R.

    2015-01-01

    Gamma-ray detectors based on bright monolithic scintillation crystals coupled to pixelated photodetectors are currently being considered for several applications in the medical imaging field. In a typical monolithic detector, both the light intensity and the time of arrival of the earliest scintilla

  17. Time-based position estimation in monolithic scintillator detectors

    NARCIS (Netherlands)

    Tabacchini, V.; Borghi, G.; Schaart, D.R.

    2015-01-01

    Gamma-ray detectors based on bright monolithic scintillation crystals coupled to pixelated photodetectors are currently being considered for several applications in the medical imaging field. In a typical monolithic detector, both the light intensity and the time of arrival of the earliest scintilla

  18. A Monolithic Perovskite Structure for Use as a Magnetic Regenerator

    DEFF Research Database (Denmark)

    Pryds, Nini; Clemens, Frank; Menon, Mohan

    2011-01-01

    A La0.67Ca0.26Sr0.07Mn1.05O3 (LCSM) perovskite was prepared for the first time as a ceramic monolithic regenerator used in a regenerative magnetic refrigeration device. The parameters influencing the extrusion process and the performance of the regenerator, such as the nature of the monolith paste...

  19. Energy Absorption of Monolithic and Fibre Reinforced Aluminium Cylinders

    NARCIS (Netherlands)

    De Kanter, J.L.C.G.

    2006-01-01

    Summary accompanying the thesis: Energy Absorption of Monolithic and Fibre Reinforced Aluminium Cylinders by Jens de Kanter This thesis presents the investigation of the crush behaviour of both monolithic aluminium cylinders and externally fibre reinforced aluminium cylinders. The research is based

  20. Hydrogel coated monoliths for enzymatic hydrolysis of penicillin G

    NARCIS (Netherlands)

    De Lathouder, K.M.; Smeltink, M.W.; Straathof, A.J.J.; Paasman, M.A.; Van de Sandt, E.J.A.X.; Kapteijn, F.; Moulijn, J.A.

    2008-01-01

    The objective of this work was to develop a hydrogel-coated monolith for the entrapment of penicillin G acylase (E. coli, PGA). After screening of different hydrogels, chitosan was chosen as the carrier material for the preparation of monolithic biocatalysts. This protocol leads to active immobilize

  1. 基于移动Agent的供应链订单跟踪系统研究%Research on Order Track System of Supply chain Based on Mobile Agent

    Institute of Scientific and Technical Information of China (English)

    郭钧; 郭顺生; 王天日

    2012-01-01

    Firstly, the relationship between the order fulfillment process (OFP) and other key business processes of supply chain management (SCM) was introduced and analyzed. Then the functional attributes of the order tracking were given. Subsequently, the technology foundations of mobile agent were investigated. Furthermore, an integrated framework model based on the mobile agent was constructed to realize the functional attributes of the order tracking. Finally, a prototype system was constructed to illustrate the superiority of the framework.%分析了订单履行流程与供应链管理其他关键业务流程的关系,给出了订单跟踪系统功能需求,并结合移动Agent技术,构建了基于移动Agent的供应链订单全生命周期跟踪系统框架结构.设计了原型系统,并在一个家电企业进行了验证.

  2. 抗攻击的基于移动代理的分布式入侵检测模型%Mobile Agent Based Distributed Intrusion Detection System Model Protecting from Attack

    Institute of Scientific and Technical Information of China (English)

    尚明磊; 许峰; 卢静; 黄皓

    2005-01-01

    为了增强IDS(Intrusion Detection System)在广域网中的健壮性,本文在对几种典型的入侵检测模型进行分析的基础上,提出了抗攻击的基于移动代理的分布式入侵检测模型(Mobile Agent Based Distributed Intrusion Detection System Model,MABDIDSM).MABDIDSM利用移动代理(mobile agent)在各局域网的控制台之间做环行移动,将各控制台上的入侵事件收集到管理中心进行综合分析处理.如果管理中心受到攻击,移动代理能够在剩余的控制台中选出新的管理中心,因此MABDIDSM在广域网范围内具有较强的抗攻击能力.

  3. Embodied Cultures of Mobilities

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    2010-01-01

    contemporary theorists understanding bodily movement, material sites of mobility, and social interactions must be consulted along the road (e.g. Latour’s work on objects and ANT, Thrift’s work on the body and ‘non-representational theory, and Massumi’s notions of affects and emotions related to bodily mobility......The paper explores the relationship between the body and mobility by looking into a number of modes of transportation and their ways of constructing particular engagements with mobility. The ‘mobile embodiments’ are significant to a material and symbolic set of relations between human agents...... 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...

  4. Activatable iRGD-based peptide monolith: Targeting, internalization, and fluorescence activation for precise tumor imaging.

    Science.gov (United States)

    Cho, Hong-Jun; Lee, Sung-Jin; Park, Sung-Jun; Paik, Chang H; Lee, Sang-Myung; Kim, Sehoon; Lee, Yoon-Sik

    2016-09-10

    A disulfide-bridged cyclic RGD peptide, named iRGD (internalizing RGD, c(CRGDK/RGPD/EC)), is known to facilitate tumor targeting as well as tissue penetration. After the RGD motif-induced targeting on αv integrins expressed near tumor tissue, iRGD encounters proteolytic cleavage to expose the CendR motif that promotes penetration into cancer cells via the interaction with neuropilin-1. Based on these proteolytic cleavage and internalization mechanism, we designed an iRGD-based monolithic imaging probe that integrates multiple functions (cancer-specific targeting, internalization and fluorescence activation) within a small peptide framework. To provide the capability of activatable fluorescence signaling, we conjugated a fluorescent dye to the N-terminal of iRGD, which was linked to the internalizing sequence (CendR motif), and a quencher to the opposite C-terminal. It turned out that fluorescence activation of the dye/quencher-conjugated monolithic peptide probe requires dual (reductive and proteolytic) cleavages on both disulfide and amide bond of iRGD peptide. Furthermore, the cleavage of the iRGD peptide leading to fluorescence recovery was indeed operative depending on the tumor-related angiogenic receptors (αvβ3 integrin and neuropilin-1) in vitro as well as in vivo. Compared to an 'always fluorescent' iRGD control probe without quencher conjugation, the dye/quencher-conjugated activatable monolithic peptide probe visualized tumor regions more precisely with lower background noise after intravenous injection, owing to the multifunctional responses specific to tumor microenvironment. All these results, along with minimal in vitro and in vivo toxicity profiles, suggest potential of the iRGD-based activatable monolithic peptide probe as a promising imaging agent for precise tumor diagnosis.

  5. A new large area monolithic silicon telescope

    CERN Document Server

    Tudisco, S; Cabibbo, M; Cardella, G; De Geronimo, G; Di Pietro, A; Fallica, G; Figuera, P; Musumarra, A; Papa, M; Pappalardo, G S; Rizzo, F; Valvo, G

    1999-01-01

    A new prototype of large area (20x20 mm sup 2) monolithic silicon telescope with an ultrathin DELTA E stage (1 mu m) has been built and tested. A particular mask for the ground electrode has been developed to improve the charge collection reducing the induction between the E and DELTA E stages. A special designed preamplifier has been used for the readout of the signal from the DELTA E stage to overcome the problem of the large input capacitance (40 nF). A rather low energy threshold charge discrimination has been obtained. Small side effects due to the electric field deformation near the ground electrode were observed and quantified.

  6. Monolithic aerogels with nanoporous crystalline phases

    Science.gov (United States)

    Daniel, Christophe; Guerra, Gaetano

    2015-05-01

    High porosity monolithic aerogels with nanoporous crystalline phases can be obtained from syndiotactic polystyrene and poly(2,6-dimethyl-1,4-phenylene)oxide thermoreversible gels by removing the solvent with supercritical CO2. The presence of crystalline nanopores in the aerogels based on these polymers allows a high uptake associated with a high selectivity of volatile organic compounds from vapor phase or aqueous solutions even at very low activities. The sorption and the fast kinetics make these materials particularly suitable as sorption medium to remove traces of pollutants from water and moist air.

  7. Robust naphthyl methacrylate monolithic column for high performance liquid chromatography of a wide range of solutes.

    Science.gov (United States)

    Jonnada, Murthy; El Rassi, Ziad

    2015-08-28

    An organic monolithic column based on the co-polymerization of 2-naphthyl methacrylate (NAPM) as the functional monomer and trimethylolpropane trimethacrylate (TRIM) as the crosslinker was introduced for high performance reversed-phase liquid chromatography (RPC). The co-polymerization was performed in situ in a stainless steel column of 4.6mm i.d. in the presence of a ternary porogen consisting of 1-dodecanol and cyclohexanol. This monolithic column (referred to as naphthyl methacrylate monolithic column or NMM column) showed high mechanical stability at relatively high mobile phase flow velocity indicating that the column has excellent hydrodynamic characteristics. To characterize the NMM column, different probe molecules including alkyl benzenes, and aniline, benzene, toluene and phenol derivatives were chromatographed on the column and the results in terms of k, selectivity and plate counts were compared to those obtained on an octadecyl silica (ODS) column in order to assess the presence of π-π and hydrophobic interactions on the NMM column under otherwise the same elution conditions. The NMM column offered additional π-π interactions with aromatic molecules in addition to hydrophobic interactions under RPC elution conditions. Run-to-run and column-to-column reproducibility of solute k values were evaluated, and percent relative standard deviation of column using shallow (30min at 1.0mL/min), steep (10min at 1.0mL/min) and ultra steep (1min at 3.0mL/min) linear gradient elution at increasing ACN concentration in the mobile phase using a 10cm×4.6mm i.d. column in case of shallow and steep linear gradients and a 3cm×4.6mm i.d. column for ultra steep linear gradient.

  8. 基于社会网络与声誉信任机制的移动多Agent系统信任模型%A MOBILE MULTI-AGENT SYSTEM TRUST MODEL BASED ON SOCIAL NETWORK AND REPUTATION TRUST MECHANISM

    Institute of Scientific and Technical Information of China (English)

    彭泽洲

    2012-01-01

    基于信任机制的移动多Agent系统中,代理Agent一般通过直接信誉值和推荐信誉值来判断对于另一个Agent的信任程度.由于系统相对巨大,直接信誉值通常难以获得,判断的正确性很大程度上依赖于推荐信誉值的准确性和可靠性.通过对整个多Agent系统进行社会网络的挖掘,用以得到与代理Agent存在潜在社会关系的一组Agent.对这组Agent提供的推荐信息充分信任,并优先使用这些Agent提供的信息进行推荐信誉值的计算.最后通过双方直接交易的多寡判断综合信任值中直接信誉值与推荐信誉值的权重.通过实验验证了该模型的有效性.%In trust mechanism-based mobile multi-Agent system, proxy Agent usually judges the trust degree of another Agent by the values of direct reputation and recommended reputation. Because of the relative large of the system, direct reputation is often difficult to obtain, so the correctness of the judgment depends on to a great extent the accuracy and reliability of the recommended reputation. In the paper, by mining the whole social network for entire multi-Agent system, a group of Agent which have potential community relationship with the proxy Agent is gotten. The recommendation information provided by this group is thoroughly trusted, and the information offered by these Agents is employed in prior to calculate the recommended reputation value. At last, the weight of the values of direct reputation and recommended reputation in composite trust value are calculated through the amount of direct transaction between both sides. The validity of the model has been verified by the experiment.

  9. Monolithic columns in plant proteomics and metabolomics.

    Science.gov (United States)

    Rigobello-Masini, Marilda; Penteado, José Carlos Pires; Masini, Jorge Cesar

    2013-03-01

    Since "omics" techniques emerged, plant studies, from biochemistry to ecology, have become more comprehensive. Plant proteomics and metabolomics enable the construction of databases that, with the help of genomics and informatics, show the data obtained as a system. Thus, all the constituents of the system can be seen with their interactions in both space and time. For instance, perturbations in a plant ecosystem as a consequence of application of herbicides or exposure to pollutants can be predicted by using information gathered from these databases. Analytical chemistry has been involved in this scientific evolution. Proteomics and metabolomics are emerging fields that require separation, identification, and quantification of proteins, peptides, and small molecules of metabolites in complex biological samples. The success of this work relies on efficient chromatographic and electrophoretic techniques, and on mass spectrometric detection. This paper reviews recent developments in the use of monolithic columns, focusing on their applications in "top-down" and "bottom-up" approaches, including their use as supports for immobilization of proteolytic enzymes and their use in two-dimensional and multidimensional chromatography. Whereas polymeric columns have been predominantly used for separation of proteins and polypeptides, silica-based monoliths have been more extensively used for separation of small molecules of metabolites. Representative applications in proteomics and in analysis of plant metabolites are given and summarized in tables.

  10. Growth techniques for monolithic YBCO solenoidal magnets

    Energy Technology Data Exchange (ETDEWEB)

    Scruggs, S.J. [Texas Center for Superconductivity at University of Houston, 4800 Calhoun, Houston, TX 77204 (United States)]. E-mail: Sscruggs2@uh.edu; Putman, P.T. [Texas Center for Superconductivity at University of Houston, 4800 Calhoun, Houston, TX 77204 (United States); Fang, H. [Texas Center for Superconductivity at University of Houston, 4800 Calhoun, Houston, TX 77204 (United States); Alessandrini, M. [Texas Center for Superconductivity at University of Houston, 4800 Calhoun, Houston, TX 77204 (United States); Salama, K. [Texas Center for Superconductivity at University of Houston, 4800 Calhoun, Houston, TX 77204 (United States)

    2006-10-01

    The possibility of growing large single domain YBCO solenoids by the use of a large seed has been investigated. There are two known methods for producing a similar solenoid. This first is a conventional top seeded melt growth process followed by a post processing machining step to create the bore. The second involves using multiple seeds spaced around the magnet bore. The appeal of the new technique lies in decreasing processing time compared to the single seed technique, while avoiding alignment problems found in the multiple seeding technique. By avoiding these problems, larger diameter monoliths can be produced. Large diameter monoliths are beneficial because the maximum magnetic field produced by a trapped field magnet is proportional to the radius of the sample. Furthermore, the availability of trapped field magnets with large diameter could enable their use in applications that traditionally have been considered to require wound electromagnets, such as beam bending magnets for particle accelerators or electric propulsion. A comparison of YBCO solenoids grown by the use of a large seed and grown by the use of two small seeds simulating multiple seeding is made. Trapped field measurements as well as microstructure evaluation were used in characterization of each solenoid. Results indicate that high quality growth occurs only in the vicinity of the seeds for the multiple seeded sample, while the sample with the large seeded exhibited high quality growth throughout the entire sample.

  11. High surface area, high permeability carbon monoliths

    Energy Technology Data Exchange (ETDEWEB)

    Lagasse, R.R.; Schroeder, J.L. [Sandia National Labs., Albuquerque, NM (United States). Organic Materials Processing Dept.

    1994-12-31

    The goal of this work is to prepare carbon monoliths having precisely tailored pore size distribution. Prior studies have demonstrated that poly(acrylonitrile) can be processed into a precursor having tailored macropore structure. Since the macropores were preserved during pyrolysis, this synthetic process provided a route to porous carbon having macropores with size =0.1 to 10{mu}m. No micropores of size <2 nm could be detected in the carbon, however, by nitrogen adsorption. In the present work, the authors have processed a different polymer, poly(vinylidene chloride) into a macroporous precursor, Pyrolysis produced carbon monoliths having macropores derived from the polymer precursor as well as extensive microporosity produced during the pyrolysis of the polymer. One of these carbons had BET surface area of 1,050 m{sup 2}/g and about 1.2 cc/g total pore volume, with about 1/3 of the total pore volume in micropores and the remainder in 1{mu}m macropores. No mesopores in the intermediate size range could be detected by nitrogen adsorption. Carbon materials having high surface area as well as micron size pores have potential applications as electrodes for double layer supercapacitors containing liquid electrolyte, or as efficient media for performing chemical separations.

  12. Hydrothermal method for preparing calcium phosphate monoliths

    Directory of Open Access Journals (Sweden)

    García Carrodeguas Raúl

    2003-01-01

    Full Text Available A new hydrothermal route for preparing biphasic calcium phosphate monoliths is proposed. Firstly, a slurry of beta-tricalcium phosphate/ortho-phosphoric acid (b-TCP/H3PO4 is cast into the desired final shape and size to obtain a block composed of dicalcium phosphate dihydrate (DCPD and b-TCP. This block is then treated in 1.0 M Na2HPO4 at 60 °C in order to hydrolyze the DCPD into Ca10-x(HPO4x(PO4 6-x(OH2-x (CDHA and Ca8H2(PO46 .5H2O (OCP. The result is a monolithic piece which preserves the initial shape and size, but which is composed instead of CDHA, OCP, and b-TCP. During the initial stage, when the pH is slightly alkaline, the product of DCPD hydrolysis is CDHA. However, when a neutral or slightly acidic pH is reached OCP is formed. Test samples processed by this method showed complete conversion of DCPD into CDHA and OCP after 112 h of hydrolysis, and with a compressive strength of 16.2 MPa, similar to cancellous bone.

  13. Catastrophic failure of a monolithic zirconia prosthesis.

    Science.gov (United States)

    Chang, Jae-Seung; Ji, Woon; Choi, Chang-Hoon; Kim, Sunjai

    2015-02-01

    Recently, monolithic zirconia restorations have received attention as an alternative to zirconia veneered with feldspathic porcelain to eliminate chipping failures of veneer ceramics. In this clinical report, a patient with mandibular edentulism received 4 dental implants in the interforaminal area, and a screw-retained monolithic zirconia prosthesis was fabricated. The patient also received a maxillary complete removable dental prosthesis over 4 anterior roots. At the 18-month follow-up, all of the zirconia cylinders were seen to be fractured, and the contacting abutment surfaces had lost structural integrity. The damaged abutments were replaced with new abutments, and a new prosthesis was delivered with a computer-assisted design and computer-assisted manufacturing fabricated titanium framework with denture teeth and denture base resins. At the 6-month recall, the patient did not have any problems. Dental zirconia has excellent physical properties; however, care should be taken to prevent excessive stresses on the zirconia cylinders when a screw-retained zirconia restoration is planned as a definitive prosthesis.

  14. Private Computing and Mobile Code Systems

    NARCIS (Netherlands)

    Cartrysse, K.

    2005-01-01

    This thesis' objective is to provide privacy to mobile code. A practical example of mobile code is a mobile software agent that performs a task on behalf of its user. The agent travels over the network and is executed at different locations of which beforehand it is not known whether or not these ca

  15. A Comparison of Performance between Macro-mobility Protocol and Micro-mobility Protocol

    Institute of Scientific and Technical Information of China (English)

    TANG Hong; NIE Neng; WU Zhong-fu; ZHAO Jun; LIAO Xiao-feng

    2003-01-01

    Mobile IP is the proposed standard for IP mobility support. When a Mobile Node (MN) is far away from home, registration at its home agent can cause a long handoff delay that leads to significant packet drop and throughput reduction. In order to improve standard mobile IP, the mobility of MN has been divided into micro-mobility and macro-mobility. Some micro-mobility management protocols have been developed. We compare the performance between standard mobile IP (RFC2002,RFC3220,RFC3344) and micro-mobility management protocols and give some equations along with the analysis of calculating results.

  16. Preliminary comparison of monolithic and aperture optics for XRMF

    Energy Technology Data Exchange (ETDEWEB)

    Havrilla, G.J.; Worley, C.G.

    1997-08-01

    Comparisons between standard aperture optics and a custom designed monolithic capillary x-ray optic for the Kevex Omicron are presented. The results demonstrate the feasibility of retrofitting an Omicron with a monolithic capillary. Increased flux is observed especially at lower energies which results in an increase in sensitivity and potentially an increase in spatial resolution. Alignment is a critical factor in achieving optimal performance of the monolithic capillary. Further improvements in flux output, spot size and overall sensitivity are expected with better alignment.

  17. On monolithic stability and reinforcement analysis of high arch dams

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Monolithic stability safety and reinforcement based on monolithic stability are very important for arch dam design.In this paper,the issue is addressed based on deformation reinforcement theory.In this approach,plastic complementary energy norm can be taken as safety Index for monolithic stability.According to deformation reinforcement theory,the areas where unbalanced force exists require reinforcement,and the required reinforcement forces are just the unbalanced forces with opposite direction.Results show that areas with unbalanced force mainly concentrate in dam-toes,dam-heels and faults.

  18. Hierarchically Structured Monolithic ZSM-5 through Macroporous Silica Gel Zeolitization

    Institute of Scientific and Technical Information of China (English)

    Lei Qian; Zhao Tianbo; Li Fengyan; Zong Baoning; Tong Yangchuan

    2006-01-01

    The hierarchically structured ZSM-5 monolith was prepared through transforming the skeletons of the macroporous silica gel into ZSM-5 by the steam-assisted conversion method. The morphology and monolithic shapes of macroporous silica gel were well preserved. The hierarchically structured ZSM-5 monolith exhibited the hierarchical porosity, with mesopores and macropores existing inside the macroporous silica gel, and micropores formed by the ZSM-5. The products have been characterized properly by using the XRD, SEM and N2 adsorption-desorption methods.

  19. Preparation of carbon monoliths from orange peel for NOx retention

    Directory of Open Access Journals (Sweden)

    Liliana Giraldo

    2014-12-01

    Full Text Available A series of monoliths are prepared from orange peels and chemically activated with H3PO4, KOH, ZnCl2, and water vapor without a binder. The monoliths were characterized by N2 adsorption-desorption isotherms at 77 K, Boehm titrations and XPS. Thereafter, monoliths were tested for their ability to establish NOx retention. The results show that the retention capacities of NOx were a function of the textural properties and chemistries. The carbons synthesized with ZnCl2 and KOH retained similar amounts of NOx.

  20. A decoupled monolithic projection method for natural convection problems

    Science.gov (United States)

    Pan, Xiaomin; Kim, Kyoungyoun; Lee, Changhoon; Choi, Jung-Il

    2016-06-01

    We propose an efficient monolithic numerical procedure based on a projection method for solving natural convection problems. In the present monolithic method, the buoyancy, linear diffusion, and nonlinear convection terms are implicitly advanced by applying the Crank-Nicolson scheme in time. To avoid an otherwise inevitable iterative procedure in solving the monolithic discretized system, we use a linearization of the nonlinear convection terms and approximate block lower-upper (LU) decompositions along with approximate factorization. Numerical simulations demonstrate that the proposed method is more stable and computationally efficient than other semi-implicit methods, preserving temporal second-order accuracy.

  1. 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.

  2. Monolithically Peltier-cooled laser diodes

    Energy Technology Data Exchange (ETDEWEB)

    Hava, S.; Hunsperger, R.G.; Sequeira, H.B.

    1984-04-01

    A new method of cooling a GaAs/GaAlAs laser in an optical integrated circuit or on a discrete chip, by adding an integral thermoelectric (Peltier) cooling and heat spreading device to the laser, is presented. This cooling both reduces and stabilizes the laser junction temperature to minimize such deleterious effects as wavelength drift due to heating. A unified description of the electrical and thermal properties of a monolithic semiconductor mesa structure is given. Here it is shown that an improvement in thermal characteristics is obtained by depositing a relatively thick metallic layer, and by using this layer as a part of an active Peltier structure. Experimental results reveal a 14-percent increase in emitted power (external quantum efficiency) due to passive heat spreading and a further 8-percent if its Peltier cooler is operated. Fabrication techniques used to obtain devices exhibiting the above performance characteristics are given. 21 references.

  3. LSST primary/tertiary monolithic mirror

    Science.gov (United States)

    Sebag, J.; Gressler, W.; Liang, M.; Neill, D.; Araujo-Hauck, C.; Andrew, J.; Angeli, G.; Cho, M.; Claver, C.; Daruich, F.; Gessner, C.; Hileman, E.; Krabbendam, V.; Muller, G.; Poczulp, G.; Repp, R.; Wiecha, O.; Xin, B.; Kenagy, K.; Martin, H. M.; Tuell, M. T.; West, S. C.

    2016-08-01

    At the core of the Large Synoptic Survey Telescope (LSST) three-mirror optical design is the primary/tertiary (M1M3) mirror that combines these two large mirrors onto one monolithic substrate. The M1M3 mirror was spin cast and polished at the Steward Observatory Mirror Lab at The University of Arizona (formerly SOML, now the Richard F. Caris Mirror Lab at the University of Arizona (RFCML)). Final acceptance of the mirror occurred during the year 2015 and the mirror is now in storage while the mirror cell assembly is being fabricated. The M1M3 mirror will be tested at RFCML after integration with its mirror cell before being shipped to Chile.

  4. A monolithic thin film electrochromic window

    Energy Technology Data Exchange (ETDEWEB)

    Goldner, R.B.; Arntz, F.O.; Berera, G.; Haas, T.E.; Wong, K.K. (Tufts Univ., Medford, MA (United States). Electro-Optics Technology Center); Wei, G. (Mobil Solar Energy Corp., Billerica, MA (United States)); Yu, P.C. (PPG Industries, Inc., Monroeville, PA (United States))

    1991-01-01

    Three closely related thin film solid state ionic devices that are potentially important for applications are: electrochromic smart windows, high energy density thin film rechargeable batteries, and thin film electrochemical sensors. Each usually has at least on mixed ion/electron conductor, an electron-blocking ion conductor, and an ion-blocking electron conductor, and many of the technical issues associated with thin film solid state ionics are common to all three devices. Since the electrochromic window has the added technical requirement of electrically-controlled optical modulation, (over the solar spectrum), and since research at the authors' institution has focused primarily on the window structure, this paper will address the electrochromic window, and particularly a monolithic variable reflectivity electrochromic window, as an illustrative example of some of the challenges and opportunities that are confronting the thin film solid state ionics community. 33 refs.

  5. A monolithic thin film electrochromic window

    Energy Technology Data Exchange (ETDEWEB)

    Goldner, R.B.; Arntz, F.O.; Berera, G.; Haas, T.E.; Wong, K.K. [Tufts Univ., Medford, MA (United States). Electro-Optics Technology Center; Wei, G. [Mobil Solar Energy Corp., Billerica, MA (United States); Yu, P.C. [PPG Industries, Inc., Monroeville, PA (United States)

    1991-12-31

    Three closely related thin film solid state ionic devices that are potentially important for applications are: electrochromic smart windows, high energy density thin film rechargeable batteries, and thin film electrochemical sensors. Each usually has at least on mixed ion/electron conductor, an electron-blocking ion conductor, and an ion-blocking electron conductor, and many of the technical issues associated with thin film solid state ionics are common to all three devices. Since the electrochromic window has the added technical requirement of electrically-controlled optical modulation, (over the solar spectrum), and since research at the authors` institution has focused primarily on the window structure, this paper will address the electrochromic window, and particularly a monolithic variable reflectivity electrochromic window, as an illustrative example of some of the challenges and opportunities that are confronting the thin film solid state ionics community. 33 refs.

  6. Machining distortion prediction of aerospace monolithic components

    Institute of Scientific and Technical Information of China (English)

    Yun-bo BI; Qun-lin CHENG; Hui-yue DONG; Ying-lin KE

    2009-01-01

    To predict the distortion of aerospace monolithic components.a model is established to simulate the numerical control (NC)milling process using 3D finite element method(FEM).In this model,the cutting layer is simplified firstly.Then,the models of cutting force and cutting temperature are established to gain the cutting loads,which are applied to the mesh model of the part.Finally,a prototype of machining simulation environment is developed to simulate the milling process of a spar.Key factors influencing the distortion,such as initial residual stress,cutting loads,fixture layout,cutting sequence,and tool path are considered all together.The total distortion of the spar is predicted and an experiment is conducted to validate the numerical results.It is found that the maximum discrepancy between the simulation results and experiment values is 19.0%

  7. Solid oxide fuel cell having monolithic core

    Science.gov (United States)

    Ackerman, J. P.; Young, J. E.

    1983-10-01

    A solid oxide fuel cell is described for electrochemically combining fuel and oxidant for generating galvanic output, wherein the cell core has an array of electrolyte and interconnect walls that are substantially devoid of any composite inert materials for support. The core is monolithic, where each electrolyte wall consists of thin layers of cathode and anode materials sandwiching a thin layer of electrolyte material. The electrolyte walls are arranged and backfolded between adjacent interconnect walls operable to define a plurality of core passageways alternately arranged where the inside faces have only the anode material or only the cathode material exposed. Each layer of the electrolyte and interconnect materials 0.002 to 0.01 cm thick; and each layer of the cathode and anode materials is 0.002 to 0.05 cm thick.

  8. Silver deposition on chemically treated carbon monolith

    Directory of Open Access Journals (Sweden)

    Jovanović Zoran M.

    2009-01-01

    Full Text Available Carbon monolith was treated with HNO3, KOH and H2O2. Effects of these treatments on the surface functional groups and on the amount of silver deposited on the CM surface were studied by temperature programmed desorption (TPD and atomic absorption spectrometry (AAS. As a result of chemical treatment there was an increase in the amount of surface oxygen complexes. The increase in the amount of silver deposit is proportional to the amount of surface groups that produce CO under decomposition. However, the high amount of CO groups, decomposing above 600°C, induces the smaller Ag crystallite size. Therefore, the high temperature CO evolving oxides are, most likely, the initial centers for Ag deposition.

  9. 基于JADE移动Agent的分布式网络取证系统%Distributed network forensics based on JADE mobile Agent

    Institute of Scientific and Technical Information of China (English)

    杜钦生; 赵剑; 李博

    2012-01-01

    为了解决数据量大仅在中央系统一个点做取证分析容易导致网络拥挤和失败的问题,提出了一种包含有独立Agent实体的分布式网络取证系统.这些独立的Agent实体出发遍历各个分散的系统,提供了收集证据和将网络中路由可视化的高效机制,可以帮助时网络活动进行分析和取证调查.通过使用Java的Agent开发平台来实现具体的设计方案.实验表明,Agent的使用可以将处理负担和存储需求分散给多个网络系统,减轻在单一系统上的网络拥挤,数据的备份也能减轻单个中心节点失败的问题.%For the sheer volume of data and network congestion at the central system performing the forensics analysis, the distributed architecture consisting of independent agent entities is presented. An efficient mechanism for evidence collection and visualization of network traffic is provided to investigate the network forensics. The specific design is implemented on the Java Agent Development Platform (JADE). The results show this application of software agents distributes both the processing load and storage requirements to multiple networked systems and relieves network congestion on a single system. The single center point failure problem is alleviated with replication.

  10. Computational Environment of Software Agents

    Directory of Open Access Journals (Sweden)

    Martin Tomášek

    2008-05-01

    Full Text Available Presented process calculus for software agent communication and mobility canbe used to express distributed computational environment and mobile code applications ingeneral. Agents are abstraction of the functional part of the system architecture and theyare modeled as process terms. Agent actions model interactions within the distributedenvironment: local/remote communication and mobility. Places are abstraction of thesingle computational environment where the agents are evaluated and where interactionstake place. Distributed environment is modeled as a parallel composition of places whereeach place is evolving asynchronously. Operational semantics defines rules to describebehavior within the distributed environment and provides a guideline for implementations.Via a series of examples we show that mobile code applications can be naturally modeled.

  11. Evaluation of surfactants as steam diverters/mobility control agents in light oil steamfloods: Effect of oil composition, rates and experimental conditions

    Energy Technology Data Exchange (ETDEWEB)

    Mahmood, S.M.; Olsen, D.K.; Ramzel, E.B.

    1991-12-01

    A series of experiments was performed to evaluate the effectiveness of commercially available surfactants for steam-foam EOR applications in light oil reservoirs. The experiments were performed in a 3-ft long, 1-1/2 in.-diameter cylindrical sandpack of about 1 darcy permeability. The sandpack and injected fluids were preheated to 430{degree}F at 155 psi. The main objective of these tests was to investigate the effectiveness of several surfactants in providing mobility control under a variety of conditions expected in light-oil steamfloods. Thus, maximum pressure-rise and foam-bank buildup/decay were noted as operating conditions were changed in a test or in various tests. Tests were performed with various oil types, sacrificial salts, injection rates, injection strategies, vapor-to-liquid fractions (VLF), and steam/N{sub 2} ratios (SNR).

  12. Monolithic Rare Earth Doped PTR Glass Laser Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The main goal of the project is to demonstrate the feasibility of a monolithic solid state laser on the basis of PTR glass co-doped with luminescent rare earth ions....

  13. Plant oil-based shape memory polymer using acrylic monolith

    Directory of Open Access Journals (Sweden)

    T. Tsujimoto

    2015-09-01

    Full Text Available This article deals with the synthesis of a plant oil-based material using acrylic monolith. An acrylic monolith bearing oxirane groups was prepared via simple technique that involved the dissolution of poly(glycidyl methacrylate-comethyl methacrylate (PGMA in ethanolic – aqueous solution by heating and subsequent cooling. The PGMA monolith had topologically porous structure, which was attributed to the phase separation of the polymer solution. The PGMA monolith was impregnated by epoxidized soybean oil (ESO containing thermally-latent catalyst, and the subsequent curing produced a crosslinked material with relatively good transparency. The Young’s modulus and the tensile strength of polyESO/PGMA increased compared with the ESO homopolymer. The strain at break of polyESO/PGMA was larger than that of the ESO homopolymer and crosslinked PGMA. Furthermore, polyESO/PGMA exhibited good shape memory-recovery behavior.

  14. Application of monolithic chromatographic supports in virus research.

    Science.gov (United States)

    Krajacic, Mladen; Ravnikar, Maja; Štrancar, Aleš; Gutiérrez-Aguirre, Ion

    2017-05-12

    Key properties of monolithic chromatographic supports, make them suitable for separation and/or concentration of large biomolecules, especially virus particles and viral genomes. One by one, the studies that have been completed so far, contributed to the knowledge that monolith chromatography has hardly any limitation to be applied in virus research. Viruses of different sizes, possessing icosahedral structure and symmetrical morphology, as well as rod-shaped or filamentous viruses with helical structure, even enveloped ones, all of them could be successfully managed by means of monolith chromatography. Same is true for viral genomes, primarily when being distinct from other nucleic acid forms present in a host cell. This review is exclusively focused on viruses. It describes the application of monolith chromatography to different problematics within the virus research field. The reviewed achievements offer new possibilities and trigger new aspects in virology. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Monolithic Perovskite Silicon Tandem Solar Cells with Advanced Optics

    Energy Technology Data Exchange (ETDEWEB)

    Goldschmidt, Jan C.; Bett, Alexander J.; Bivour, Martin; Blasi, Benedikt; Eisenlohr, Johannes; Kohlstadt, Markus; Lee, Seunghun; Mastroianni, Simone; Mundt, Laura; Mundus, Markus; Ndione, Paul; Reichel, Christian; Schubert, Martin; Schulze, Patricia S.; Tucher, Nico; Veit, Clemens; Veurman, Welmoed; Wienands, Karl; Winkler, Kristina; Wurfel, Uli; Glunz, Stefan W.; Hermle, Martin

    2016-11-14

    For high efficiency monolithic perovskite silicon tandem solar cells, we develop low-temperature processes for the perovskite top cell, rear-side light trapping, optimized perovskite growth, transparent contacts and adapted characterization methods.

  16. Effect of accelerated aging on translucency of monolithic zirconia

    Directory of Open Access Journals (Sweden)

    O. Abdelbary

    2016-12-01

    Conclusion: Thickness of zirconia has significant effect on translucency. Aging has significant effect on thinner sections of zirconia. More research is required on zirconia towards making the material more translucent for its potential use as esthetic monolithic restoration.

  17. Monolithic CMOS pixel detector for international linear collider vertex detection

    Indian Academy of Sciences (India)

    J E Brau; O Igonkina; N Sinew; D Strom; C Baltay; W Emmet; H Neal; D Rabinowitz

    2007-12-01

    A monolithic CMS pixel detector is under development for an ILC experiment. This chronopixel array provides a time stamp resolution of one bunch crossing, a critical feature for background suppression. The status of this effort is summarized.

  18. Performance characteristics between monolithic and microservice-based systems

    OpenAIRE

    Flygare, Robin; Holmqvist, Anthon

    2017-01-01

    A new promising technology to face the problem of scalability and availability is the microservice architecture. The problem with this architecture is that there is no significant study that clearly proves the performance differences compared to the monolithic architecture. Our thesis aims to provide a more conclusive answer of how the microservice architecture differs performance wise compared to the monolithic architecture. In this study, we conducted several experiments on a self-developed...

  19. Sol-Gel Synthesis of Non-Silica Monolithic Materials

    Directory of Open Access Journals (Sweden)

    Bartłomiej Gaweł

    2010-04-01

    Full Text Available Monolithic materials have become very popular because of various applications, especially within chromatography and catalysis. Large surface areas and multimodal porosities are great advantages for these applications. New sol-gel preparation methods utilizing phase separation or nanocasting have opened the possibility for preparing materials of other oxides than silica. In this review, we present different synthesis methods for inorganic, non-silica monolithic materials. Some examples of application of the materials are also included.

  20. Reliability Analysis and Optimal Design of Monolithic Vertical Wall Breakwaters

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Burcharth, Hans F.; Christiani, E.

    1994-01-01

    Reliability analysis and reliability-based design of monolithic vertical wall breakwaters are considered. Probabilistic models of the most important failure modes, sliding failure, failure of the foundation and overturning failure are described . Relevant design variables are identified and relia......Reliability analysis and reliability-based design of monolithic vertical wall breakwaters are considered. Probabilistic models of the most important failure modes, sliding failure, failure of the foundation and overturning failure are described . Relevant design variables are identified...

  1. Extended Leach Testing of Simulated LAW Cast Stone Monoliths

    Energy Technology Data Exchange (ETDEWEB)

    Serne, R. Jeffrey [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Westsik, Joseph H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Williams, Benjamin D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jung, H. B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wang, Guohui [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-07-09

    This report describes the results from long-term laboratory leach tests performed at Pacific Northwest National Laboratory (PNNL) for Washington River Protection Solutions (WRPS) to evaluate the release of key constituents from monoliths of Cast Stone prepared with four simulated low-activity waste (LAW) liquid waste streams. Specific objectives of the Cast Stone long-term leach tests described in this report focused on four activities: 1. Extending the leaching times for selected ongoing EPA-1315 tests on monoliths made with LAW simulants beyond the conventional 63-day time period up to 609 days reported herein (with some tests continuing that will be documented later) in an effort to evaluate long-term leaching properties of Cast Stone to support future performance assessment activities. 2. Starting new EPA-1315 leach tests on archived Cast Stone monoliths made with four LAW simulants using two leachants (deionized water [DIW] and simulated Hanford Integrated Disposal Facility (IDF) Site vadose zone pore water [VZP]). 3. Evaluating the impacts of varying the iodide loading (starting iodide concentrations) in one LAW simulant (7.8 M Na Hanford Tank Waste Operations Simulator (HTWOS) Average) by manufacturing new Cast Stone monoliths and repeating the EPA-1315 leach tests using DIW and the VZP leachants. 4. Evaluating the impacts of using a non-pertechnetate form of Tc that is present in some Hanford tanks. In this activity one LAW simulant (7.8 M Na HTWOS Average) was spiked with a Tc(I)-tricarbonyl gluconate species and then solidified into Cast Stone monoliths. Cured monoliths were leached using the EPA-1315 leach protocol with DIW and VZP. The leach results for the Tc-Gluconate Cast Stone monoliths were compared to Cast Stone monoliths pertechnetate.

  2. Mechanically stable, hierarchically porous Cu3(btc)2 (HKUST-1) monoliths via direct conversion of copper(II) hydroxide-based monoliths.

    Science.gov (United States)

    Moitra, Nirmalya; Fukumoto, Shotaro; Reboul, Julien; Sumida, Kenji; Zhu, Yang; Nakanishi, Kazuki; Furukawa, Shuhei; Kitagawa, Susumu; Kanamori, Kazuyoshi

    2015-02-28

    The synthesis of highly crystalline macro-meso-microporous monolithic Cu3(btc)2 (HKUST-1; btc(3-) = benzene-1,3,5-tricarboxylate) is demonstrated by direct conversion of Cu(OH)2-based monoliths while preserving the characteristic macroporous structure. The high mechanical strength of the monoliths is promising for possible applications to continuous flow reactors.

  3. Monoliths: A Review of the Basics, Preparation Methods and Their Relevance to Oxidation

    Directory of Open Access Journals (Sweden)

    Sandeeran Govender

    2017-02-01

    Full Text Available Considerable research has been conducted on monolithic catalysts for various applications. Strategies toward coating monoliths are of equal interest and importance. In this paper, the preparation of monoliths and monolithic catalysts have been summarized. More specifically, a brief explanation for the manufacturing of ceramic and metallic monoliths has been provided. Also, different methods for coating γ-alumina, as a secondary support, are included. Techniques used to deposit metal-based species, zeolites and carbon onto monoliths are discussed. Furthermore, monoliths extruded with metal oxides, zeolites and carbon are described. The main foci are on the reasoning and understanding behind the preparation of monolithic catalysts. Ideas and concerns are also contributed to encourage better approaches when designing these catalysts. More importantly, the relevance of monolithic structures to reactions, such as the selective oxidation of alkanes, catalytic combustion for power generation and the preferential oxidation of carbon monoxide, has been described.

  4. Research of Distributed IDS based on Mobile Agent and Genetic Algorithm%移动Agent和遗传算法在分布式IDS中的应用研究

    Institute of Scientific and Technical Information of China (English)

    高为民; 方小勇

    2014-01-01

    Wireless communication in the wireless space radiation, propagation channel special open wil lead to security of network management and communication is under the great threat. In recent years, the application of genetic algorithm and the mobile agent in IDS more and more research. Based on the traditional knowledge of IDS due to the need to experts in the field of artificial rules and pat erns, and with the change of time and space wil lead to the expert rules limitations highlight, correctness and ef ectiveness of the detection is not high, so the need to optimize the performance of IDS. Firstly introduce the mobile Internet network architecture and security problems, and then put forward a general IDS model and classification, a design based on mobile Agent and genetic algorithm in intrusion detection system, the system has flexibility, scalability and strong adaptability and low error rate, meet the needs of mobile IPv6 environment to use. Experimental results show that the proposed design model in the performance of the algorithm and the detection ef iciency advantages, suitable for mobile network.%无线通信在无线空间传播信道特殊的辐射、开放性会导致网络运营和通信的安全性受到极大的威胁。近年来,将遗传算法和移动代理应用于IDS中的研究越来越多。传统的基于知识的IDS由于需要领域专家人工进行规则和模式的建立,并随着时间和空间的变化会导致专家规则库局限性突显,检测的有效性和正确性不高,因而需要对IDS的性能进行优化。文中首先介绍了移动互联网网络结构和安全问题,然后提出通用的IDS模型结构及分类,设计出一种基于移动Agent和遗传算法的入侵检测系统。该系统具有灵活性强、可扩展性好及适应性强和误检率低等特点,满足移动IPv6环境的使用。实验结果表明提出的设计模型在算法性能和检测效率上具有优势,适合于移动互联网。

  5. Enantiomer separation of acidic chiral compounds on a quinine-silica/zirconia hybrid monolith by capillary electrochromatography.

    Science.gov (United States)

    Tran, Le Ngoc; Park, Jung Hag

    2015-05-29

    A weak anion-exchanger chiral selector, quinine-incorporated silica/zirconia hybrid monolithic (QUI-S/ZHM) capillary column was prepared by sol-gel technology. The performance of the QUI-S/ZHM column was investigated for enantioresolution of a set of acidic chiral drugs and dinitrobenzoyl (DNB)-amino acids by capillary electrochromatography in aqueous organic mobile phases composed of acetonitrile (ACN) and triethylammonium acetate (TEAA) buffer. Effects of several parameters including the ACN content, concentration and pH of the mobile phase on the chiral separation were examined. Baseline resolutions of all the compounds were obtained in the mobile phase consisting of 70:30 ACN/TEAA (10mM, pH 6) under applied voltage of -10kV at 25°C within 20min.

  6. Preparation of hybrid monolithic columns via "one-pot" photoinitiated thiol-acrylate polymerization for retention-independent performance in capillary liquid chromatography.

    Science.gov (United States)

    Zhang, Haiyang; Ou, Junjie; Liu, Zhongshan; Wang, Hongwei; Wei, Yinmao; Zou, Hanfa

    2015-09-01

    A novel "one-pot" approach was developed for ultrarapid preparation of various hybrid monolithic columns in UV-transparent fused-silica capillaries via photoinitiated thiol-acrylate polymerization of an acrylopropyl polyhedral oligomertic silsesquioxane (acryl-POSS) and a monothiol monomer (1-octadecanethiol or sodium 3-mercapto-1-propanesulfonate) within 5 min, in which the acrylate not only homopolymerizes, but also couples with the thiol. This unique combination of two types of free-radical reaction mechanisms offers a simple way to fabricate various acrylate-based hybrid monoliths. The physical characterization, including scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, and thermal gravimetric analysis was performed. The results indicated that the monothiol monomers were successfully incorporated into acryl-POSS-based hybrid monoliths. The column efficiencies for alkylbenzenes on the C18-functionalized hybrid monolithic column reached to 60 000-73 500 plates/m at the velocity of 0.33 mm/s in capillary liquid chromatography, which was far higher than that of previously reported POSS-based columns prepared via thermal-initiated free-radical polymerization without adding any thiol monomers. By plotting the plate height (H) of the alkylbenzenes versus the linear velocity (u) of the mobile phase, the results revealed a retention-independent efficient performance of small molecules in the isocratic elution. These results indicated that more homogeneous hybrid monoliths formed via photoinitiated thiol-acrylate polymerization; particularly, the use of the multifunctional cross-linker possibly prevented the generation of gel-like micropores, reducing mass transfer resistance (C-term). Another sulfonate-containing hybrid monolithic column also exhibited hydrophobicity and ion-exchange mechanism, and the dynamic binding capacity was calculated as 71.1 ng/cm (75 μm i.d.).

  7. Biasable, Balanced, Fundamental Submillimeter Monolithic Membrane Mixer

    Science.gov (United States)

    Siegel, Peter; Schlecht, Erich; Mehdi, Imran; Gill, John; Velebir, James; Tsang, Raymond; Dengler, Robert; Lin, Robert

    2010-01-01

    This device is a biasable, submillimeter-wave, balanced mixer fabricated using JPL s monolithic membrane process a simplified version of planar membrane technology. The primary target application is instrumentation used for analysis of atmospheric constituents, pressure, temperature, winds, and other physical and chemical properties of the atmospheres of planets and comets. Other applications include high-sensitivity gas detection and analysis. This innovation uses a balanced configuration of two diodes allowing the radio frequency (RF) signal and local oscillator (LO) inputs to be separated. This removes the need for external diplexers that are inherently narrowband, bulky, and require mechanical tuning to change frequency. Additionally, this mixer uses DC bias-ability to improve its performance and versatility. In order to solve problems relating to circuit size, the GaAs membrane process was created. As much of the circuitry as possible is fabricated on-chip, making the circuit monolithic. The remainder of the circuitry is precision-machined into a waveguide block that holds the GaAs circuit. The most critical alignments are performed using micron-scale semiconductor technology, enabling wide bandwidth and high operating frequencies. The balanced mixer gets superior performance with less than 2 mW of LO power. This can be provided by a simple two-stage multiplier chain following an amplifier at around 90 GHz. Further, the diodes are arranged so that they can be biased. Biasing pushes the diodes closer to their switching voltage, so that less LO power is required to switch the diodes on and off. In the photo, the diodes are at the right end of the circuit. The LO comes from the waveguide at the right into a reduced-height section containing the diodes. Because the diodes are in series to the LO signal, they are both turned on and off simultaneously once per LO cycle. Conversely, the RF signal is picked up from the RF waveguide by the probe at the left, and flows

  8. Comparison of monolithic capillary electrochromatography and micellar electrokinetic chromatography for the separation of polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Salwiński, Aleksander; Delépée, Raphaël

    2014-05-01

    Atmospheric pollution of anthropic origin is recognized as a major risk factor for health, in particular for respiratory and cardio-vascular systems. Among these pollutants, polycyclic aromatic hydrocarbons (PAHs) are placed on the list of US Environmental Protection Agency (EPA) as 'priority' pollutants and four of them are assigned as potential carcinogens by The International Agency for Research on Cancer (IARC). In the present work two capillary techniques-micellar electrokinetic chromatography (MEKC) and monolithic capillary electrochromatography (CEC)-were compared for the separation of eleven PAHs. Both techniques compared in the present work are fully compatible with every standard apparatus of capillary electrophoresis. For MEKC, enhancement of selectivity and decrease of the separation window of eleven PAHs were obtained with methanol:borate 25 mM (20/80, v/v) running buffer containing 10 mM of hydroxypropylated γ-cyclodextrins with low SDS content (25 mM). In case of CEC, two acrylate-based monolithic stationary phases (MSPs) were evaluated for their application in the separation of eleven PAHs. The best MSP based on butyl acrylate was compared with MEKC in terms of sample capacity, PAHs elution order, LOQ, efficiency and effect of pH. Influence of the hydrophobicity of mobile phase on the PAHs elution order was also studied.

  9. Green approach using monolithic column for simultaneous determination of coformulated drugs.

    Science.gov (United States)

    Yehia, Ali M; Mohamed, Heba M

    2016-06-01

    Green chemistry and sustainability is now entirely encompassed across the majority of pharmaceutical companies and research labs. Researchers' attention is careworn toward implementing the green analytical chemistry principles for more eco-friendly analytical methodologies. Solvents play a dominant role in determining the greenness of the analytical procedure. Using safer solvents, the greenness profile of the methodology could be increased remarkably. In this context, a green chromatographic method has been developed and validated for the simultaneous determination of phenylephrine, paracetamol, and guaifenesin in their ternary pharmaceutical mixture. The chromatographic separation was carried out using monolithic column and green solvents as mobile phase. The use of monolithic column allows efficient separation protocols at higher flow rates, which results in short time of analysis. Two-factor three-level experimental design was used to optimize the chromatographic conditions. The greenness profile of the proposed methodology was assessed using eco-scale as a green metrics and was found to be an excellent green method with regard to the usage and production of hazardous chemicals and solvents, energy consumption, and amount of produced waste. The proposed method improved the environmental impact without compromising the analytical performance criteria and could be used as a safer alternate for the routine analysis of the studied drugs.

  10. Fast determination of prominent carotenoids in tomato fruits by CEC using methacrylate ester-based monolithic columns.

    Science.gov (United States)

    Adalid, Ana Maria; Herrero-Martínez, José Manuel; Roselló, Salvador; Maquieira, Angel; Nuez, Fernando

    2007-11-01

    In this study, the major carotenoids (beta-carotene and lycopene) present in tomato fruits were analyzed by CEC with a methacrylate ester-based monolithic column. The effects of the porogenic solvent ratio, and the hydrophobicity of bulk monomer employed were examined on carotenoids separations. A fast separation of these analytes was achieved in less than 5.0 min in a mobile phase containing 35% THF, 30% ACN, 30% methanol, and 5% of a 5 mM Tris aqueous buffer, pH 8, with lauryl methacrylate-based monoliths. The CEC method was evaluated in terms of detection limit and reproducibility (retention time, area, and column preparation) with values below 1.6 microg/mL and 7.2%, respectively. The proposed procedure was successfully applied to the determination of both carotenoids in fruits of several tomato-related species and its usefulness to analyze large series of samples for nutritional quality screening trials in tomato breeding programs is demonstrated. To our knowledge, this is the first work that exploits the powerful and user-friendly monolithic technology for quality breeding and germplasm evaluation program purposes.

  11. 一个基于移动Agent防止双重消费的离线电子支付模型及协议%A Model and Protocols of Off-line Electronic Payment Preventing Double-spending Based on Mobile Agents

    Institute of Scientific and Technical Information of China (English)

    温涛; 王济勇; 刘积仁

    2002-01-01

    Because it is quite unsatisfactory that in anonymous off-line payment schemes the multiple spending of coins can only be detected but not prevented,a model and protocols of off-line electronic payment system preventing double-spending and based on Mobile Agents are presented in this paper,which improve the off-line payment scheme based on hardware observer[1].Because the hardware device called Observer in[2] is replaced by the software object of Mobile Agents which is called Mobile Observer,thus customers don''''''''t need to worry about the bottle-neck and vulnerability owing to all the interactions to a single device.This paper discusses the life recycle of the Mobile Observer and the security problems of the Mobile Agents system.In addition,this model presents a recovery mechanism for the failure of the customer end system.Hence,the sceurity,robustness,practicality of the model are higher than any one of the previous systems.

  12. The Study and Implementation of Large-Scale Network Management Methods (SMANM) Based on the Mobile Agent%基于移动智体的大规模网络管理方法(SMANM)的研究与实现

    Institute of Scientific and Technical Information of China (English)

    庄力可; 张长水

    2003-01-01

    Facing the limitation of activity and efficiency for centralized network management ,we propose the networkmanagement method (SMANM) based on mobile agent and build up the intelligent network management platformbased on SMANM (SMANMP). Example analysis and simulation experiment show that this method can greatly re-duce the bandwidth consumption of large-scale information network ,increase the network management efficiency andactivity service ability.

  13. Rapid and simultaneous determination of imidazolium and pyridinium ionic liquid cations by ion-pair chromatography using a monolithic column

    Institute of Scientific and Technical Information of China (English)

    Xu Huang; Hong Yu; Ying Jie Dong

    2012-01-01

    A method for rapid and simultaneous determination of imidazolium and pyridinium ionic liquid cations by ion-pair chromatography with ultraviolet detection was developed.Chromatographic separations were performed on a reversed-phase silica-based monolithic column using 1-heptanesulfonic acid sodium-acetonitrile as mobile phase.The effects of ion-pair reagent and acetonitrile concentration on retention of the cations were investigated.The retention times of the cations accord with carbon number rule.The method has been successfully applied to the determination of four ionic liquids synthesized by organic chemistry laboratory.

  14. Postpolymerization modification of a hydroxy monolith precursor. Part I. Epoxy alkane and octadecyl isocyanate modified poly (hydroxyethyl methacrylate-co-pentaerythritol triacrylate) monolithic capillary columns for reversed-phase capillary electrochromatography.

    Science.gov (United States)

    Khadka, Shantipriya; El Rassi, Ziad

    2016-12-01

    A novel precursor monolithic capillary column referred to as "hydroxy monolith" or OHM was prepared by the in situ copolymerization of hydroxyethylmethacrylate (HEMA) with pentaerythritol triacrylate (PETA) yielding the neutral poly(HEMA-co-PETA) monolith. The neutral precursor OHM capillary thus obtained was subjected to postpolymerization modifications of the hydroxyl functional groups present on its surface with 1,2-epoxyalkanes catalyzed by boron trifluoride (BF3 ) ultimately providing Epoxy OHM C-m capillary column at varying alkyl chain lengths where m = 8, 12, 14, and 16 for RP-CEC. Also, the same precursor OHM was grafted with octadecyl isocyanate yielding Isocyanato OHM C-18 column to provide an insight into the effect of the nature of the linkage to the surface hydroxyl groups of the OHM precursor. While the epoxide reaction leaves on the surface of the OHM precursor hydroxy-ether linkages, the isocyanato reaction leaves carbamate linkages on the same surface of the OHM precursor. This study revealed that changing the alkyl chain length resulted in changing the column phase ratio (ϕ) and also the solute distribution constant (K). While increasing the surface alkyl chain length increased steeply the solute hydrophobic selectivity, i.e. methylene group selectivity, the nature of the ligand linkage produced different retention for the same solutes and affected the selectivity of slightly polar solutes. The various monoliths proved very useful for RP-CEC of different small solutes at varying polarity over a wide range of mobile phase composition. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Dedicated monolithic infrared spectrometer for process monitoring

    Science.gov (United States)

    Chadha, Suneet; Kyle, William; Bolduc, Roy A.; Curtiss, Lawrence E.

    1999-12-01

    Foster-Miller has leveraged its innovations in IR fiber- optic probes and the recent development of a miniature spectrometer to build a novel IR sensor system for process applications. The developed sensor systems is a low-cost alternative to process FTIR and filter based systems. A monolithic wedge-grating optic provides the spectral dispersion with low cost thermopile point or array detectors picking off the diffracted wavelengths from the optic. The integrated optic provides spectral discrimination between 3- 12 micrometers with resolution at 8 cm-1 or better and high overall optical throughput. The device has a fixed cylindrical grating uniquely bonded to the edge of a ZnSe conditioning 'wedge'. The conditioning optic overcomes limitations of concave gratings as it accepts high angle light at the narrow end of the wedge and progressively conditions it to be near normal to the grating. On return, the diffracted wavelengths are concentrated on the discrete or array detector elements by the wedge, providing throughput comparable to that of an FTIR. The miniature spectrometer coupled to flow through liquid cells or multipass gas cells provides significant cost advantage over conventional sampling methodologies. Currently, we are investigating process applications for the petroleum and dairy markets. The sensor system eliminates the cost, complexity, reliability and bandwidth/resolution problems associated with either Fabry Perot or Michelson Interferometer based approaches for low-cost process applications.

  16. The Advanced Virgo monolithic fused silica suspension

    Energy Technology Data Exchange (ETDEWEB)

    Aisa, D.; Aisa, S.; Campeggi, C.; Colombini, M. [University of Perugia and INFN Perugia (Italy); Conte, A. [University of Roma Sapienza and INFN Roma (Italy); Farnesini, L. [University of Perugia and INFN Perugia (Italy); Majorana, E.; Mezzani, F. [University of Roma Sapienza and INFN Roma (Italy); Montani, M. [University of Urbino and INFN Firenze (Italy); Naticchioni, L.; Perciballi, M. [University of Roma Sapienza and INFN Roma (Italy); Piergiovanni, F. [University of Urbino and INFN Firenze (Italy); Piluso, A. [University of Perugia and INFN Perugia (Italy); Puppo, P., E-mail: paola.puppo@roma1.infn.it [University of Roma Sapienza and INFN Roma (Italy); Rapagnani, P. [University of Roma Sapienza and INFN Roma (Italy); Travasso, F. [University of Perugia and INFN Perugia (Italy); Vicerè, A. [University of Urbino and INFN Firenze (Italy); Vocca, H. [University of Perugia and INFN Perugia (Italy)

    2016-07-11

    The detection of gravitational waves is one of the most challenging prospects faced by experimental physicists. Suspension thermal noise is an important noise source at operating frequencies between approximately 10 and 30 Hz, and represents a limit to the sensitivity of the ground based interferometric gravitational wave detectors. Its effects can be reduced by minimizing the losses and by optimizing the geometry of the suspension fiber as well as its attachment system. In this proceeding we will describe the mirrors double stage monolithic suspension system to be used in the Advanced Virgo (AdV) detector. We also present the results of the thermal noise study, performed with the help of a finite elements model, taking into account the precise geometry of the fibers attachment systems on the suspension elements. We shall demonstrate the suitability of this suspension for installation in AdV. - Highlights: • Suspension system design for the test masses of the gravitational wave detectors. • Finite element model studies. • Suspension thermal noise studies.

  17. 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.

  18. Monolithic supports with unique geometries and enhanced mass transfer.

    Energy Technology Data Exchange (ETDEWEB)

    Stuecker, John Nicholas; Ferrizz, Robert Matthew; Cesarano, Joseph, III; Miller, James Edward

    2004-01-01

    The catalytic combustion of natural gas has been the topic of much research over the past decade. Interest in this technology results from a desire to decrease or eliminate the emissions of harmful nitrogen oxides (NOX) from gas turbine power plants. A low-pressure drop catalyst support, such as a ceramic monolith, is ideal for this high-temperature, high-flow application. A drawback to the traditional honeycomb monoliths under these operating conditions is poor mass transfer to the catalyst surface in the straight-through channels. 'Robocasting' is a unique process developed at Sandia National Laboratories that can be used to manufacture ceramic monoliths with alternative 3-dimensional geometries, providing tortuous pathways to increase mass transfer while maintaining low pressure drops. This report details the mass transfer effects for novel 3-dimensional robocast monoliths, traditional honeycomb-type monoliths, and ceramic foams. The mass transfer limit is experimentally determined using the probe reaction of CO oxidation over a Pt / {gamma}-Al{sub 2}O{sub 3} catalyst, and the pressure drop is measured for each monolith sample. Conversion versus temperature data is analyzed quantitatively using well-known dimensionless mass transfer parameters. The results show that, relative to the honeycomb monolith support, considerable improvement in mass transfer efficiency is observed for robocast samples synthesized using an FCC-like geometry of alternating rods. Also, there is clearly a trade-off between enhanced mass transfer and increased pressure drop, which can be optimized depending on the particular demands of a given application.

  19. 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…

  20. Improved breakdown characteristics of monolithically integrated III-nitride HEMT-LED devices using carbon doping

    Science.gov (United States)

    Liu, Chao; Liu, Zhaojun; Huang, Tongde; Ma, Jun; May Lau, Kei

    2015-03-01

    We report selective growth of AlGaN/GaN high electron mobility transistors (HEMTs) on InGaN/GaN light emitting diodes (LEDs) for monolithic integration of III-nitride HEMT and LED devices (HEMT-LED). To improve the breakdown characteristics of the integrated HEMT-LED devices, carbon doping was introduced in the HEMT buffer by controlling the growth pressure and V/III ratio. The breakdown voltage of the fabricated HEMTs grown on LEDs was enhanced, without degradation of the HEMT DC performance. The improved breakdown characteristics can be attributed to better isolation of the HEMT from the underlying conductive p-GaN layer of the LED structure.

  1. Seamless handoff in Mobile IP

    NARCIS (Netherlands)

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

    2008-01-01

    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,

  2. Mobile Agent-Based Secure Task Partitioning and Allocation Algorithm for Cloud & Client Computing%一种基于移动Agent的云端计算任务安全分割与分配算法

    Institute of Scientific and Technical Information of China (English)

    徐小龙; 程春玲; 熊婧夷; 王汝传

    2011-01-01

    In order to protect the privacy of the task in the cloud & client computing environment and prevent the malicious nodes or the competitors from prying into the internal logic and objectives of the task, a mobile Agent-based secure task partitioning and allocation algorithm for cloud & client computing is proposed. The new algorithm takes into account the cloud computing cluster server nodes and user terminals nodes together, divides task into a number of appropriate sub-tasks, and utilizes mobile Agent to carry the code and data of sub-tasks to the suitable nodes in accordance with the corresponding task allocation for implementation. The result of developed prototype system shows that, under the protection of the algorithm, the malicious terminal node looking into the code and data of the sub-task assigned to it or even co-attacking the system still can not understand the overall workflow and final objective of the task.%为了保障云端计算环境中任务的计算私密性,防止恶意节点或竞争对手窥探任务的内部逻辑及实现目标,提出一种新颖的基于移动Agent的云端计算安全任务分割与分配算法.算法同时考虑集群服务器节点和用户终端节点的计算能力与各自特点,将任务合理地切分为若干子任务,采用移动Agent来携带子任务的代码和数据部署到适当的任务执行节点上执行.结合实验原型系统对该算法进行性能分析,结果表明其可有效地保障执行子任务的终端节点,即使窥探到分配给它的代码和数据,甚至协同攻击系统,也无法了解该任务的整体执行逻辑和总体目标等.

  3. Advanced Gasification Mercury/Trace Metal Control with Monolith Traps

    Energy Technology Data Exchange (ETDEWEB)

    Musich, Mark; Swanson, Michael; Dunham, Grant; Stanislowski, Joshua

    2010-10-05

    Two Corning monoliths and a non-carbon-based material have been identified as potential additives for mercury capture in syngas at temperatures above 400°F and pressure of 600 psig. A new Corning monolith formulation, GR-F1-2189, described as an active sample appeared to be the best monolith tested to date. The Corning SR Liquid monolith concept continues to be a strong candidate for mercury capture. Both monolith types allowed mercury reduction to below 5-μg/m{sup 3} (~5 ppb), a current U.S. Department of Energy (DOE) goal for trace metal control. Preparation methods for formulating the SR Liquid monolith impacted the ability of the monolith to capture mercury. The Energy & Environmental Research Center (EERC)-prepared Noncarbon Sorbents 1 and 2 appeared to offer potential for sustained and significant reduction of mercury concentration in the simulated fuel gas. The Noncarbon Sorbent 1 allowed sustained mercury reduction to below 5-μg/m{sup 3} (~5 ppb). The non-carbon-based sorbent appeared to offer the potential for regeneration, that is, desorption of mercury by temperature swing (using nitrogen and steam at temperatures above where adsorption takes place). A Corning cordierite monolith treated with a Group IB metal offered limited potential as a mercury sorbent. However, a Corning carbon-based monolith containing prereduced metallic species similar to those found on the noncarbon sorbents did not exhibit significant or sustained mercury reduction. EERC sorbents prepared with Group IB and IIB selenide appeared to have some promise for mercury capture. Unfortunately, these sorbents also released Se, as was evidenced by the measurement of H2Se in the effluent gas. All sorbents tested with arsine or hydrogen selenide, including Corning monoliths and the Group IB and IIB metal-based materials, showed an ability to capture arsine or hydrogen selenide at 400°F and 600 psig. Based on current testing, the noncarbon metal-based sorbents appear to be the most

  4. ADVANCED GASIFICATION MERCURY/TRACE METAL CONTROL WITH MONOLITH TRAPS

    Energy Technology Data Exchange (ETDEWEB)

    Mark A. Musich; Michael L. Swanson; Grant E. Dunham; Joshua J. Stanislowski

    2010-07-31

    Two Corning monoliths and a non-carbon-based material have been identified as potential additives for mercury capture in syngas at temperatures above 400°F and pressure of 600 psig. A new Corning monolith formulation, GR-F1-2189, described as an active sample appeared to be the best monolith tested to date. The Corning SR Liquid monolith concept continues to be a strong candidate for mercury capture. Both monolith types allowed mercury reduction to below 5-μg/m3 (~5 ppb), a current U.S. Department of Energy (DOE) goal for trace metal control. Preparation methods for formulating the SR Liquid monolith impacted the ability of the monolith to capture mercury. The Energy & Environmental Research Center (EERC)-prepared Noncarbon Sorbents 1 and 2 appeared to offer potential for sustained and significant reduction of mercury concentration in the simulated fuel gas. The Noncarbon Sorbent 1 allowed sustained mercury reduction to below 5-μg/m3 (~5 ppb). The non-carbon-based sorbent appeared to offer the potential for regeneration, that is, desorption of mercury by temperature swing (using nitrogen and steam at temperatures above where adsorption takes place). A Corning cordierite monolith treated with a Group IB metal offered limited potential as a mercury sorbent. However, a Corning carbon-based monolith containing prereduced metallic species similar to those found on the noncarbon sorbents did not exhibit significant or sustained mercury reduction. EERC sorbents prepared with Group IB and IIB selenide appeared to have some promise for mercury capture. Unfortunately, these sorbents also released Se, as was evidenced by the measurement of H2Se in the effluent gas. All sorbents tested with arsine or hydrogen selenide, including Corning monoliths and the Group IB and IIB metal-based materials, showed an ability to capture arsine or hydrogen selenide at 400°F and 600 psig. Based on current testing, the noncarbon metal-based sorbents appear to be the most effective arsine

  5. New Graphene Form of Nanoporous Monolith for Excellent Energy Storage.

    Science.gov (United States)

    Bi, Hui; Lin, Tianquan; Xu, Feng; Tang, Yufeng; Liu, Zhanqiang; Huang, Fuqiang

    2016-01-13

    Extraordinary tubular graphene cellular material of a tetrahedrally connected covalent structure was very recently discovered as a new supermaterial with ultralight, ultrastiff, superelastic, and excellent conductive characteristics, but no high specific surface area will keep it from any next-generation energy storage applications. Herein, we prepare another new graphene monolith of mesoporous graphene-filled tubes instead of hollow tubes in the reported cellular structure. This graphene nanoporous monolith is also composed of covalently bonded carbon network possessing high specific surface area of ∼1590 m(2) g(-1) and electrical conductivity of ∼32 S cm(-1), superior to graphene aerogels and porous graphene forms self-assembled by graphene oxide. This 3D graphene monolith can support over 10 000 times its own weight, significantly superior to CNT and graphene cellular materials with a similar density. Furthermore, pseudocapacitance-active functional groups are introduced into the new nanoporous graphene monolith as an electrode material in electrochemical capacitors. Surprisingly, the electrode of 3D mesoporous graphene has a specific capacitance of 303 F g(-1) and maintains over 98% retention after 10 000 cycles, belonging to the list for the best carbon-based active materials. The macroscopic mesoporous graphene monolith suggests the great potential as an electrode for supercapacitors in energy storage areas.

  6. Recent advances in polymer monoliths for ion-exchange chromatography.

    Science.gov (United States)

    Nordborg, Anna; Hilder, Emily F

    2009-05-01

    The use of polymeric materials in ion-exchange chromatography applications is advantageous because of their typically high mechanical stability and tolerance of a wide range of pH conditions. The possibility of using polymeric monoliths in ion-exchange chromatography is therefore obvious and many of the same strategies developed for polymeric particles have been adapted for use with polymeric monoliths. In this review different strategies for the synthesis of polymeric monoliths with ion-exchange functionality are discussed. The incorporation of ion-exchange functionality by co-polymerization is included, as also are different post-polymerization alterations to the monolith surface such as grafting. The formulations and strategies presented include materials intended for use in analytical separations in ion-exchange chromatography, sample pre-treatment or enrichment applications, and materials for capillary electrochromatography. Finally, examples of the use of polymeric monoliths in ion-exchange chromatography applications are included with examples published in the years 2003 to 2008.

  7. HPLC analysis of synthetic polymers on short monolithic columns.

    Science.gov (United States)

    Maksimova, Elena; Vlakh, Evgenia; Sinitsyna, Ekaterina; Tennikova, Tatiana

    2013-12-01

    Ultrashort monolithic columns (disks) were thoroughly studied as efficient stationary phases for precipitation-dissolution chromatography of synthetic polymers. Gradient elution mode was applied in all chromatographic runs. The mixtures of different flexible chain homopolymers, such as polystyrenes, poly(methyl methacrylates), and poly(tert-butylmethacrylates) were separated according to their molecular weights on both commercial poly(styrene-co-divinylbenzene) disks (12 id × 3 mm and 5 × 5 mm) and lab-made monolithic columns (4.6 id × 50 mm) filled with supports of different hydrophobicity. The experimental conditions were optimized to reach fast and highly efficient separation. It was observed that, similar to the separation of monoliths of other classes of (macro)molecules (proteins, DNA, oligonucleotides), the length of column did not affect the peak resolution. A comparison of the retention properties of the poly(styrene-co-divinylbenzene) disk-shaped monoliths with those based on poly(lauryl methacrylate-co-ethylene dimethacrylate), poly(butyl methacrylate-co-ethylene dimethacrylate), and poly(glycidyl methacrylate-co-ethylene dimethacrylate) supports demonstrated the obvious effect of surface chemistry on the resolution factor. Additionally, the results of the discussed chromatographic mode on the fast determination of the molecular weights of homopolymers used in this study were compared to those established by SEC on columns packed with sorbent beads of a similar nature to the monoliths. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Edge chipping and flexural resistance of monolithic ceramics☆

    Science.gov (United States)

    Zhang, Yu; Lee, James J.-W.; Srikanth, Ramanathan; Lawn, Brian R.

    2014-01-01

    Objective Test the hypothesis that monolithic ceramics can be developed with combined esthetics and superior fracture resistance to circumvent processing and performance drawbacks of traditional all-ceramic crowns and fixed-dental-prostheses consisting of a hard and strong core with an esthetic porcelain veneer. Specifically, to demonstrate that monolithic prostheses can be produced with a much reduced susceptibility to fracture. Methods Protocols were applied for quantifying resistance to chipping as well as resistance to flexural failure in two classes of dental ceramic, microstructurally-modified zirconias and lithium disilicate glass–ceramics. A sharp indenter was used to induce chips near the edges of flat-layer specimens, and the results compared with predictions from a critical load equation. The critical loads required to produce cementation surface failure in monolithic specimens bonded to dentin were computed from established flexural strength relations and the predictions validated with experimental data. Results Monolithic zirconias have superior chipping and flexural fracture resistance relative to their veneered counterparts. While they have superior esthetics, glass–ceramics exhibit lower strength but higher chip fracture resistance relative to porcelain-veneered zirconias. Significance The study suggests a promising future for new and improved monolithic ceramic restorations, with combined durability and acceptable esthetics. PMID:24139756

  9. Monolithic View of Galaxy Formation and Evolution

    Directory of Open Access Journals (Sweden)

    Cesare Chiosi

    2014-07-01

    Full Text Available We review and critically discuss the current understanding of galaxy formation and evolution limited to Early Type Galaxies (ETGs as inferred from the observational data and briefly contrast the hierarchical and quasi-monolithic paradigms of formation and evolution. Since in Cold Dark Matter (CDM cosmogony small scale structures typically collapse early and form low-mass haloes that subsequently can merge to assembly larger haloes, galaxies formed in the gravitational potential well of a halo are also expected to merge thus assembling their mass hierarchically. Mergers should occur all over the Hubble time and large mass galaxies should be in place only recently. However, recent observations of high redshift galaxies tell a different story: massive ETGs are already in place at high redshift. To this aim, we propose here a revision of the quasi-monolithic scenario as an alternative to the hierarchical one, in which mass assembling should occur in early stages of a galaxy lifetime and present recent models of ETGs made of Dark and Baryonic Matter in a Λ-CDM Universe that obey the latter scheme. The galaxies are followed from the detachment from the linear regime and Hubble flow at z ≥ 20 down to the stage of nearly complete assembly of the stellar content (z ∼ 2 − 1 and beyond.  It is found that the total mass (Mh = MDM + MBM and/or initial over-density of the proto-galaxy drive the subsequent star formation histories (SFH. Massive galaxies (Mh ~ _1012M⊙ experience a single, intense burst of star formation (with rates ≥ 103M⊙/yr at early epochs, consistently with observations, with a weak dependence on the initial over-density; intermediate mass haloes (Mh~_ 1010 − 1011M⊙ have star formation histories that strongly depend on their initial over-density; finally, low mass haloes (Mh ~_ 109M⊙ always have erratic, burst-like star forming histories. The present-day properties (morphology, structure, chemistry and photometry of the

  10. Monolithic Solid Oxide Fuel Cell development

    Science.gov (United States)

    Myles, K. M.; McPheeters, C. C.

    1989-12-01

    The Monolithic Solid Oxide Fuel Cell (MSOFC) is an oxide-ceramic structure in which appropriate electronic and ionic conductors are fabricated in a honeycomb shape similar to a block of corrugated paperboard. These electronic and ionic conductors are arranged to provide short conduction paths to minimize resistive losses. The power density achievable with the MSOFC is expected to be about 8 kW/kg or 4 kW/L, at fuel efficienceis over 50 percent, because of small cell size and low resistive losses in the materials. The MSOFC operates in the range of 700 to 1000 C, at which temperatures rapid reform of hydrocarbon fuels is expected within the nickel-YSZ fuel channels. Tape casting and hot roll calendering are used to fabricate the MSOFC structure. The performance of the MSOFC has improved significantly during the course of development. The limitation of this system, based on materials resistance alone without interfacial resistances, is 0.093 ohm-sq cm area-specific resistance (ASR). The current typical performance of MSOFC single cells is characterized by ASRs of about 0.4 to 0.5 ohm-sq cm. With further development the ASR is expected to be reduced below 0.2 ohm-sq cm, which will result in power levels greater than 1.4 W/sq cm. The feasibility of the MSOFC concept was proven, and the performance was dramatically improved. The differences in thermal expansion coefficients and firing shrinkages among the fuel cell materials were minimized. As a result of good matching of these properties, the MSOFC structure was successfully fabricated with few defects, and the system shows excellent promise for development into a practical power source.

  11. Monolithic Microwave Integrated Circuit (MMIC) Phased Array Demonstrated With ACTS

    Science.gov (United States)

    1996-01-01

    Monolithic Microwave Integrated Circuit (MMIC) arrays developed by the NASA Lewis Research Center and the Air Force Rome Laboratory were demonstrated in aeronautical terminals and in mobile or fixed Earth terminals linked with NASA's Advanced Communications Technology Satellite (ACTS). Four K/Ka-band experimental arrays were demonstrated between May 1994 and May 1995. Each array had GaAs MMIC devices at each radiating element for electronic beam steering and distributed power amplification. The 30-GHz transmit array used in uplinks to ACTS was developed by Lewis and Texas Instruments. The three 20-GHz receive arrays used in downlinks from ACTS were developed in cooperation with the Air Force Rome Laboratory, taking advantage of existing Air Force integrated-circuit, active-phased-array development contracts with the Boeing Company and Lockheed Martin Corporation. Four demonstrations, each related to an application of high interest to both commercial and Department of Defense organizations, were conducted. The location, type of link, and the data rate achieved for each of the applications is shown. In one demonstration-- an aeronautical terminal experiment called AERO-X--a duplex voice link between an aeronautical terminal on the Lewis Learjet and ACTS was achieved. Two others demonstrated duplex voice links (and in one case, interactive video links as well) between ACTS and an Army high-mobility, multipurpose wheeled vehicle (HMMWV, or "humvee"). In the fourth demonstration, the array was on a fixed mount and was electronically steered toward ACTS. Lewis served as project manager for all demonstrations and as overall system integrator. Lewis engineers developed the array system including a controller for open-loop tracking of ACTS during flight and HMMWV motion, as well as a laptop data display and recording system used in all demonstrations. The Jet Propulsion Laboratory supported the AERO-X program, providing elements of the ACTS Mobile Terminal. The successful

  12. 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.

  13. Monolithic series-connected gallium arsenide converter development

    Energy Technology Data Exchange (ETDEWEB)

    Spitzer, M.B.; McClelland, R.W.; Dingle, B.D.; Dingle, J.E.; Hill, D.S. (Kopin Corp., Taunton, MA (United States)); Rose, B.H. (Sandia National Labs., Albuquerque, NM (United States))

    1991-01-01

    We report the development of monolithic GaAs photovoltaic devices intended to convert light generated by a laser or other bright source to electricity. The converters described here can provide higher operating voltage than is possible using a single-junction converter, owing to use of a monolithic circuit that forms a planar series-connected string of single-junction sub-cells. This planar monolithic circuit is arranged to deliver the desired voltage and current during operation at the maximum power point. The paper describes two-, six-, and twelve-junction converters intended for illumination by a laser diode with a wavelength of 0.8 {mu}m. Design and characterization data are presented for optical power in the range of 100 mW to 1 W. The best conversion efficiency exceeds 50%. 9 refs., 4 figs., 2 tabs.

  14. Design of Monolithic Integrator for Strain-to-Frequency Converter

    Directory of Open Access Journals (Sweden)

    Tuan Mohd. Khairi Tuan Mat

    2012-01-01

    Full Text Available Strain-to-Frequency converter (SFC is a one of the analog conditioner tools that converts any strain signal to the frequency signal. The basic concept of SFC is by detecting any changing of strains, then converting the strain to the voltage signal and converting the voltage signal to the frequency signal. This tool consists of 3 main  components which are strain gauge, differential integrator and comparator. This paper presents the designing and analysis of monolithic integrator that to be used in the Strain-toFrequency converter. The primary goal is to design and simulate the performance of monolithic integrator for SFC using GATEWAY Silvaco Electronic Design Automation (S EDA tools and EXPERT software. The performances of SFC using the designed monolithic integrator are also investigated.

  15. Molecularly imprinted macroporous monolithic materials for protein recognition

    Institute of Scientific and Technical Information of China (English)

    Qi Liang Deng; Yan Li Li; Li Hua Zhang; Yu Kui Zhang

    2011-01-01

    Synthetic materials that can specifically recognize proteins will find wide application in many fields. In this report, bovine serum albumin was chosen as the template protein. Acrylamide and N, N'-methylenebisacrylamide were employed as the functional and cross-linker monomers, respectively. Molecularly imprinted macroporous monolithic materials that can preferentially bind the template protein in an aqueous environment were prepared by combination of molecular imprinting technique and freezing/thawing preparation method. The resulted imprinted macroporous monolithic columns were evaluated by utilizing as stationary phase in high performance liquid chromatography and solid-phase extraction materials. The experimental results indicated that the imprinted macroporous monolithic column exhibited good recognition for template protein, as compared with the control protein (hemoglobin), whereas the non-imprinted polymer (prepared under the same conditions except without addition template protein) had no selective properties.

  16. A Possible Astronomically Aligned Monolith at Gardom's Edge

    Science.gov (United States)

    Brown, Daniel; Alder, Andy; Bemand, Elizabeth

    2015-05-01

    A unique triangular shaped monolith located within the Peak District National Park at Gardom's Edge could be intentionally astronomically aligned. It is set within a landscape rich in late Neolithic and Bronze Age remains. We show that the stone is most likely in its original orientation owing to its clear signs of erosion and associated to the time period of the late Neolithic. It is tilted towards south and its north side slopes at an angle equal to the maximum altitude of the Sun at mid-summer. This alignment emphasizes the changing declinations of the Sun during the seasons as well as giving an indication of mid-summers day. This functionality is achieved by an impressive display of light and shadow on the north facing side of the monolith. Together with other monuments in the close vicinity the monolith would have represented an ideal marker or social arena for seasonal gatherings for the otherwise dispersed small communities.

  17. Preliminary shielding analysis for the CSNS target station monolith

    Institute of Scientific and Technical Information of China (English)

    张斌; 陈义学; 杨寿海; 吴军; 殷雯; 梁天骄; 贾学军

    2010-01-01

    The construction of the China Spallation Neutron Source (CSNS) has been initiated at Dongguan,Guangdong,China.In spallation neutron sources the target station monolith is contaminated by a large number of fast neutrons whose energies can be as large as those of the protons of the proton beam directed towards the tungsten target.A detailed radiation transport analysis of the target station monolith is important for the construction of the CSNS.The analysis is performed using the coupled Monte Carlo and multi-dimensional discrete ordinates method.Successful elimination of the primary ray effects via the two-dimensional uncollided flux and first collision source methodology is also illustrated.The dose at the edge of the monolith is calculated.The results demonstrate that the doses received by the hall staff members are below the required standard limit.

  18. Monolithic fuel cell based power source for burst power generation

    Science.gov (United States)

    Fee, D. C.; Blackburn, P. E.; Busch, D. E.; Dees, D. W.; Dusek, J.; Easler, T. E.; Ellingson, W. A.; Flandermeyer, B. K.; Fousek, R. J.; Heiberger, J. J.

    A unique fuel cell coupled with a low power nuclear reactor presents an attractive approach for SDI burst power requirements. The monolithic fuel cell looks attractive for space applications and represents a quantum jump in fuel cell technology. Such a breakthrough in design is the enabling technology for lightweight, low volume power sources for space based pulse power systems. The monolith is unique among fuel cells in being an all solid state device. The capability for miniaturization, inherent in solid state devices, gives the low volume required for space missions. In addition, the solid oxide fuel cell technology employed in the monolith has high temperature reject heat and can be operated in either closed or open cycles. Both these features are attractive for integration into a burst power system.

  19. A Possible Astronomically Aligned Monolith at Gardom's Edge

    CERN Document Server

    Brown, D; Bemand, E

    2012-01-01

    A unique triangular shaped monolith located within the Peak District National Park at Gardom's Edge could be intentionally astronomically aligned. It is set within a landscape rich in late Neolithic and Bronze Age remains. We show that the stone is most likely in its original orientation owing to its clear signs of erosion and associated to the time period of the late Neolithic. It is tilted towards South and its North side slopes at an angle equal to the maximum altitude of the Sun at mid-summer. This alignment emphasizes the changing declinations of the Sun during the seasons as well as giving an indication of mid-summers day. This functionality is achieved by an impressive display of light and shadow on the North-facing side of the Monolith. Together with other monuments in the close vicinity the monolith would have represented an ideal marker or social arena for seasonal gatherings for the else dispersed small communities.

  20. MONOLITHIC FUEL FABRICATION PROCESS DEVELOPMENT AT THE IDAHO NATIONAL LABORATORY_

    Energy Technology Data Exchange (ETDEWEB)

    G. A. Moore; F. J. Rice; N. E. Woolstenhulme; J-F. Jue; B. H. Park; S. E. Steffler; N. P. Hallinan; M. D. Chapple; M. C. Marshall; B. L. Mackowiak; C. R. Clark; B. H. Rabin

    2009-11-01

    Full-size/prototypic U10Mo monolithic fuel-foils and aluminum clad fuel plates are being developed at the Idaho National Laboratory’s (INL) Materials and Fuels Complex (MFC). These efforts are focused on realizing Low Enriched Uranium (LEU) high density monolithic fuel plates for use in High Performance Research and Test Reactors. The U10Mo fuel foils under development afford a fuel meat density of ~16 gU/cc and thus have the potential to facilitate LEU conversions without any significant reactor-performance penalty. An overview is provided of the ongoing monolithic UMo fuel development effort, including application of a zirconium barrier layer on fuel foils, fabrication scale-up efforts, and development of complex/graded fuel foils. Fuel plate clad bonding processes to be discussed include: Hot Isostatic Pressing (HIP) and Friction Bonding (FB).

  1. The Development and Application of a Mobile Agent System--Jama Based on Java%一种基于Java的可移动Agent系统--Jama的开发和应用

    Institute of Scientific and Technical Information of China (English)

    赵瑞彬; 周浩; 秦世引; 徐宁寿; 肖云

    2000-01-01

    根据作者研究开发一种基于Java的可移动智能体(Mobile Agent,MA)系统-Jama的实际经验和体会,在对开发可移动Agent系统所涉及的几个关键问题进行了深入的讨论之后,给出了Jama系统的组织结构和功能实现模式,并对Jama系统的功能特点做了重点说明.最后结合在网络环境下使智能自动化的实际工程背景,给出了以Jama系统为基础的将MA技术与简单网络管理协议(Simple Network Management Protocol,SNMP)相结合,以实现网络资源优化管理的应用模型.

  2. 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.

  3. Preparation of poly(γ-glutamic acid)/hydroxyapatite monolith via biomineralization for bone tissue engineering.

    Science.gov (United States)

    Park, Sung-Bin; Hasegawa, Urara; van der Vlies, André J; Sung, Moon-Hee; Uyama, Hiroshi

    2014-01-01

    A hybrid monolith of poly(γ-glutamic acid) and hydroxyapatite (PGA/HAp monolith) was prepared via biomineralization and used as a macroporous cell scaffold in bone tissue engineering. The PGA monolith having a bimodal pore size distribution was used as a substrate to induce biomineralization. The PGA/HAp monolith was obtained by immersing the PGA monolith in simulated body fluid. Pretreatment with CaCl2 enhanced the apatite-forming ability of the PGA monolith. Murine osteoblastic MC3T3-E1 cells efficiently attached and proliferated on the PGA/HAp monolith. MTT assay showed that both the PGA and PGA/HAp monolith did not have apparent cytotoxicity. Moreover, the PGA and PGA/HAp monoliths adsorbed bone morphogenetic protein-2 (BMP-2) by electrostatic interaction which was slowly released in the medium during cell culture. The PGA/HAp monolith enhanced BMP-2 induced alkaline phosphatase activity compared to the PGA monolith and a polystyrene culture plate. Thus, these PGA/HAp monoliths may have potential in bone tissue engineering.

  4. Numerical Simulation of Fluid Dynamics in a Monolithic Column

    Directory of Open Access Journals (Sweden)

    Kazuhiro Yamamoto

    2017-01-01

    Full Text Available As for the measurement of polycyclic aromatic hydrocarbons (PAHs, ultra-performance liquid chromatography (UPLC is used for PAH identification and densitometry. However, when a solvent containing a substance to be identified passes through a column of UPLC, a dedicated high-pressure-proof device is required. Recently, a liquid chromatography instrument using a monolithic column technology has been proposed to reduce the pressure of UPLC. The present study tested five types of monolithic columns produced in experiments. To simulate the flow field, the lattice Boltzmann method (LBM was used. The velocity profile was discussed to decrease the pressure drop in the ultra-performance liquid chromatography (UPLC system.

  5. A Monolithic Oxide-Based Transversal Thermoelectric Energy Harvester

    Science.gov (United States)

    Teichert, S.; Bochmann, A.; Reimann, T.; Schulz, T.; Dreßler, C.; Udich, S.; Töpfer, J.

    2016-03-01

    We report the fabrication and properties of a monolithic transversal thermoelectric energy harvester based on the combination of a thermoelectric oxide and a metal. The fabrication of the device is done with a ceramic multilayer technology using printing and co-firing processes. Five transversal devices were combined to a meander-like thermoelectric generator. Electrical measurements and finite element calculations were performed to characterize the resulting thermoelectric generator. A maximum experimental electrical power output of 30.2 mW at a temperature difference of {Δ }T = 208 K was found. The prepared monolithic thermoelectric generator provides at {Δ }T = 35 K sufficient energy to drive a simple electronic sensor application.

  6. Monolithic Michelson Interferometer as ultra stable wavelength reference

    Science.gov (United States)

    Wan, Xiaoke; Ge, Jian

    2010-07-01

    Ultra-stable Monolithic Michelson interferometer can be an ideal reference for highprecision applications such as RV measurement in planet searching and orbit study. The advantages include wide wavelength range, simple sinusoidal spectral format, and high optical efficiency. In this paper, we report that a monolithic Michelson interferometers has been in-house developed with minimized thermal sensitivity with compensation tuning. With a scanning white light interferometer, the thermal sensitivity is measured ~ 6x10-7/°C at 550 nm and it decreases to zero near 1000 nm. We expect the wideband wavelength reference source to be stabilized better than 0.3 m/s for RV experiments

  7. Synthesis of ZSM-5 Monoliths with Hierarchical Porosity

    Institute of Scientific and Technical Information of China (English)

    Tong Yangchuan; Zhao Tianbo; Li Fengyan; Zong Baoning; Wang Yue

    2006-01-01

    A new route to synthesize ZSM-5 monoliths with hierarchical pore structure has been referred to in this stud y. The successful incorporation of the macropores and mesopores within the ZSM-5 structure was achieved through transforming the skeleton of the macroporous silica gel into zeolite ZSM-5 using carbon materials as the transitional template. The ZSM-5 crystal covered part of the macroporous material, and provided micropores to the macroporous silica gel. The structure of carbon monolith was studied after dissolving the silica contained in the carbon/silica composite.

  8. Lectin-carbohydrate interactions on nanoporous gold monoliths.

    Science.gov (United States)

    Tan, Yih Horng; Fujikawa, Kohki; Pornsuriyasak, Papapida; Alla, Allan J; Ganesh, N Vijaya; Demchenko, Alexei V; Stine, Keith J

    2013-07-01

    Monoliths of nanoporous gold (np-Au) were modified with self-assembled monolayers of octadecanethiol (C18-SH), 8-mercaptooctyl α-D-mannopyranoside (αMan-C8-SH), and 8-mercapto-3,6-dioxaoctanol (HO-PEG2-SH), and the loading was assessed using thermogravimetric analysis (TGA). Modification with mixed SAMs containing αMan-C8-SH (at a 0.20 mole fraction in the SAM forming solution) with either octanethiol or HO-PEG2-SH was also investigated. The np-Au monoliths modified with αMan-C8-SH bind the lectin Concanavalin A (Con A), and the additional mass due to bound protein was assessed using TGA analysis. A comparison of TGA traces measured before and after exposure of HO-PEG2-SH modified np-Au to Con A showed that the non-specific binding of Con A was minimal. In contrast, np-Au modified with octanethiol showed a significant mass loss due to non-specifically adsorbed Con A. A significant mass loss was also attributed to binding of Con A to bare np-Au monoliths. TGA revealed a mass loss due to the binding of Con A to np-Au monoliths modified with pure αMan-C8-SH. The use of mass losses determined by TGA to compare the binding of Con A to np-Au monoliths modified by mixed SAMs of αMan-C8-SH and either octanethiol or HO-PEG2-SH revealed that binding to mixed SAM modified surfaces is specific for the mixed SAMs with HO-PEG2-SH but shows a significant contribution from non-specific adsorption for the mixed SAMs with octanethiol. Minimal adsorption of immunoglobulin G (IgG) and peanut agglutinin (PNA) towards the mannoside modified np-Au monoliths was demonstrated. A greater mass loss was found for Con A bound onto the monolith than for either IgG or PNA, signifying that the mannose presenting SAMs in np-Au retain selectivity for Con A. TGA data also provide evidence that Con A bound to the αMan-C8-SH modified np-Au can be eluted by flowing a solution of methyl α-D-mannopyranoside through the structure. The presence of Con A proteins on the modified np-Au surface was

  9. Paladin Enterprises: Monolithic particle physics models global climate.

    CERN Multimedia

    2002-01-01

    Paladin Enterprises presents a monolithic particle model of the universe which will be used by them to build an economical fusion energy system. The model is an extension of the work done by James Clerk Maxwell. Essentially, gravity is unified with electro-magnetic forces and shown to be a product of a closed loop current system, i.e. a particle - monolithic or sub atomic. This discovery explains rapid global climate changes which are evident in the geological record and also provides an explanation for recent changes in the global climate.

  10. Agentes de información Information Agents

    Directory of Open Access Journals (Sweden)

    Alfonso López Yepes

    2005-12-01

    Full Text Available Este artículo realiza un repaso sobre las tipologías de agentes de información y describe aspectos como movilidad, racionalidad y adaptatividad, y el ajuste final de estos conceptos a entornos distribuidos como Internet, donde este tipo de agentes tienen un amplio grado de aplicación. Asimismo, se propone una arquitectura de agentes para un sistema multiagente de recuperación de información donde se aplica un paradigma documental basado en el concepto de ciclo documental.This article summarizes the main information agent types reflecting on issues such as mobility, rationality, adaptability and the final adjustment of this concepts to distributed environments such as the Internet, where this kind of agents has wide range application. Likewise, an information agent architecture is proposed to create a multi-agent information retrieval system in which a documentary paradigm based on the documentary cycle is developed.

  11. Polyurea-Based Aerogel Monoliths and Composites

    Science.gov (United States)

    Lee, Je Kyun

    2012-01-01

    aerogel insulation material was developed that will provide superior thermal insulation and inherent radiation protection for government and commercial applications. The rubbery polyureabased aerogel exhibits little dustiness, good flexibility and toughness, and durability typical of the parent polyurea polymer, yet with the low density and superior insulation properties associated with aerogels. The thermal conductivity values of polyurea-based aerogels at lower temperature under vacuum pressures are very low and better than that of silica aerogels. Flexible, rubbery polyurea-based aerogels are able to overcome the weak and brittle nature of conventional inorganic and organic aerogels, including polyisocyanurate aerogels, which are generally prepared with the one similar component to polyurethane rubber aerogels. Additionally, with higher content of hydrogen in their structures, the polyurea rubber-based aerogels will also provide inherently better radiation protection than those of inorganic and carbon aerogels. The aerogel materials also demonstrate good hydrophobicity due to their hydrocarbon molecular structure. There are several strategies to overcoming the drawbacks associated with the weakness and brittleness of silica aerogels. Development of the flexible fiber-reinforced silica aerogel composite blanket has proven to be one promising approach, providing a conveniently fielded form factor that is relatively robust in industrial environments compared to silica aerogel monoliths. However, the flexible, silica aerogel composites still have a brittle, dusty character that may be undesirable, or even intolerable, in certain application environments. Although the cross - linked organic aerogels, such as resorcinol- formaldehyde (RF), polyisocyanurate, and cellulose aerogels, show very high impact strength, they are also very brittle with little elongation (i.e., less rubbery). Also, silica and carbon aerogels are less efficient radiation shielding materials due

  12. Constitutive Theory Developed for Monolithic Ceramic Materials

    Science.gov (United States)

    Janosik, Lesley A.

    1998-01-01

    with these service conditions by developing a multiaxial viscoplastic constitutive model that accounts for time-dependent hereditary material deformation (such as creep and stress relaxation) in monolithic structural ceramics. Using continuum principles of engineering mechanics, we derived the complete viscoplastic theory from a scalar dissipative potential function.

  13. [Ion-pair chromatography-indirect ultraviolet detection for determination of tetraethyl ammonium using a monolithic column and a packed column].

    Science.gov (United States)

    Zou, Chunmiao; Zhang, Xiaodong; Yu, Hong; Guan, Chao; Wang, Miaoyu

    2015-07-01

    Two methods were developed for the determination of tetraethyl ammonium by ion-pair chromatography-indirect ultraviolet detection using a monolithic column and a packed column with ionic liquid as additive in mobile phase. Chromatographic separations were performed on a monolithic column and a packed column both on reversed phase using imidazolium ionic liquid aqueous solution-ion-pair reagent-organic solvent as mobile phase. The effects of the background ultraviolet absorption reagent, detection wavelength, ion-pair reagent, organic solvent, column temperature and flow rate on the determination of tetraethyl ammonium were investigated. The difference between the two chromatographic columns was compared and the retention rules were discussed. Under the optimized chromatographic conditions, for tetraethyl ammonium on monolithic column and packed column, the retention times were 2.40 and 3.02 min; the detection limits (S/N=3), 0.04 and 0.07 mg/L; the RSDs (n = 5) for peak areas, 0.16% and 0.11%; and the RSDs (n=5) for retention times, 0.02% and 0.01%, respectively. The two methods have been successfully applied to the determination of tetraethyl ammonium ionic liquids synthesized by laboratory. The recoveries of the tetraethyl ammonium after spiking were 98.2% and 99.1%, respectively. The two methods can meet the requirements for the quantitative analysis of tetraethyl ammonium.

  14. Mobilities Design

    DEFF Research Database (Denmark)

    Jensen, Ole B.; Lanng, Ditte Bendix

    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...... between mobilities and design research is twofold. To mobilities research this means getting closer to the ‘material’, and to engage in the creative, explorative and experimental approaches of the design world which offer new potentials for innovative research. Design research, on the other hand, might...... enter into a fruitful relationship with mobilities research, offering a relational and mobile design thinking and a valuable base for a reflective design practice around the ubiquitous structures, spaces and systems of mobilities....

  15. [Determination of five avermectins in bovine liver by on-line solid-phase extraction with hydrophobic monolithic column coupled with high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Li, Xin; Zhang, Yaoqin; Ai, Lianfeng; Wang, Xuesheng; Wang, Manman; Xu, Houjun; Hao, Yulan

    2015-06-01

    A method based on on-line solid-phase extraction (SPE) with hydrophobic monolithic column coupled with high performance liquid chromatography-tandem mass spectrometry was developed for the simultaneous determination of five avermectins in bovine liver. A poly(butyl methacrylate-co-ethylene dimethacrylate) monolithic column was used as the sorbent. The parameters influenced on on-line SPE and separation process such as the loading mobile phase, the eluting flow rate and the solvent for the separation were investigated in detail. Blank samples, spiked samples, matrix effect and recovery experiments were investigated to evaluate the extraction efficiency and potential interfering compounds originating from the matrix. Under the optimized conditions, the method showed a linear range of 1-100 µg/L and the quantification limit of 5 µg/kg for each analyte. The presented method gave recoveries of 77.4%-98.4%. The relative standard deviations of intra-day and inter-day were 4.46%-8.03% and 4.79%-8.68%, respectively. Moreover, no significant changes were found in the extraction performance after more than 400 usages on one monolithic column, and even on the monoliths with various batches. The feasibility of the developed poly (butyl methacrylate-coethylene dimethacrylate) monolithic column based on the on-line SPE method for the determination of avermectins was further demonstrated by the analysis of real samples.

  16. A radiation hard bipolar monolithic front-end readout

    CERN Document Server

    Baschirotto, A; Cappelluti, I; Castello, R; Cermesoni, M; Gola, A; Pessina, G; Pistolesi, E; Rancoita, P G; Seidman, A

    1999-01-01

    A fast bipolar monolithic charge sensitive preamplifier (CSP), implemented in the monolithic 2 mu m BiCMOS technology (called HF2CMOS) was designed and built in a quad monolithic chip. Studies of radiation effects in the CSP $9 performance, from non-irradiated and up to neutron irradiation of 5.3*10/sup 14/ n/cm/sup 2/, have confirmed that the use of bipolar npn transistors is suitable for the radiation level of the future LHC collider environment. The CSP $9 presents a new circuit solution for obtaining adequate slew rate performances which results in an integral linearity better than 0.8554330n 5 V at 20 ns of shaping time, regardless of the bias current selected for the CSP. This way $9 the bias current of the CSP can be set for optimizing the power dissipation with respect to series and parallel noise, especially useful when the CSP is put in a radiation environment. A prototype test with a novel monolithic 20 ns $9 time constant RC-CR shaper, capable to sum up four inputs has been also realized, featurin...

  17. Carbon monolith: preparation, characterization and application as microextraction fiber.

    Science.gov (United States)

    Shi, Zhi-Guo; Chen, Fei; Xing, Jun; Feng, Yu-Qi

    2009-07-10

    A carbon monolith was synthesized via a polymerization-carbonization method, styrene and divinylbenzene being adopted as precursors and dodecanol as a porogen during polymerization. The resultant monolith had bimodal porous substructure, narrowly distributed nano skeleton pores and uniform textural pores or throughpores. The carbon monolith was directly used as an extracting fiber, taking place of the coated silica fibers in commercially available solid-phase microextraction device, for the extraction of phenols followed by gas chromatography-mass spectrometry. Under the studied conditions, the calibration curves were linear from 0.5 to 50 ng mL(-1) for phenol, o-nitrophenol, 2,4-dichlorophenol and p-chlorophenol. The limits of detection were between 0.04 and 0.43 ng mL(-1). The recoveries of the phenols spiked in real water samples at 10 ng mL(-1) were between 85% and 98% with the relative standard deviations below 10%. Compared with the commercial coated ones (e.g. PDMS, CW/DVB and DVB/CAR/PDMS), the carbon monolith-based fiber had advantages of faster extraction equilibrium and higher extraction capacity due to the superior pore connectivity and pore openness resulting from its bimodal porous substructure.

  18. Shear bond strength of indirect composite material to monolithic zirconia

    Science.gov (United States)

    2016-01-01

    PURPOSE This study aimed to evaluate the effect of surface treatments on bond strength of indirect composite material (Tescera Indirect Composite System) to monolithic zirconia (inCoris TZI). MATERIALS AND METHODS Partially stabilized monolithic zirconia blocks were cut into with 2.0 mm thickness. Sintered zirconia specimens were divided into different surface treatment groups: no treatment (control), sandblasting, glaze layer & hydrofluoric acid application, and sandblasting + glaze layer & hydrofluoric acid application. The indirect composite material was applied to the surface of the monolithic zirconia specimens. Shear bond strength value of each specimen was evaluated after thermocycling. The fractured surface of each specimen was examined with a stereomicroscope and a scanning electron microscope to assess the failure types. The data were analyzed using one-way analysis of variance (ANOVA) and Tukey LSD tests (α=.05). RESULTS Bond strength was significantly lower in untreated specimens than in sandblasted specimens (P<.05). No difference between the glaze layer and hydrofluoric acid application treated groups were observed. However, bond strength for these groups were significantly higher as compared with the other two groups (P<.05). CONCLUSION Combined use of glaze layer & hydrofluoric acid application and silanization are reliable for strong and durable bonding between indirect composite material and monolithic zirconia. PMID:27555895

  19. Cyclodextrin-Functionalized Monolithic Capillary Columns: Preparation and Chiral Applications.

    Science.gov (United States)

    Adly, Frady G; Antwi, Nana Yaa; Ghanem, Ashraf

    2016-02-01

    In this review, the recently reported approaches for the preparation of cyclodextrin-functionalized capillary monolithic columns are highlighted, with few applications in chiral separations using capillary liquid chromatography (CLC) and capillary electrochromatography (CEC). Chirality 28:97-109, 2016. © 2015 Wiley Periodicals, Inc.

  20. Monolithic natural gas storage delivery system based on sorbents

    Energy Technology Data Exchange (ETDEWEB)

    Hornbostel, Marc; Krishnan, Gopala N.; Sanjurjo, Angel

    2016-09-27

    The invention provides methods for producing a strong, light, sorbent-based storage/dispenser system for gases and fuels. The system comprises a porous monolithic material with an adherent strong impervious skin that is capable of storing a gas under pressure in a safe and usable manner.

  1. Monolithic natural gas storage delivery system based on sorbents

    Energy Technology Data Exchange (ETDEWEB)

    Hornbostel, Marc; Krishnan, Gopala N.; Sanjurjo, Angel

    2016-09-27

    The invention provides methods for producing a strong, light, sorbent-based storage/dispenser system for gases and fuels. The system comprises a porous monolithic material with an adherent strong impervious skin that is capable of storing a gas under pressure in a safe and usable manner.

  2. Multiple Quantum Well (MQW) Devices For Monolithic Integrated Optoelectronics

    Science.gov (United States)

    Wood, Thomas H.

    1988-05-01

    Semiconductor MQWs represent a new technology for opto-electronics. These MQWs have an electroabsorption effect approximately 50 times larger than conventional semiconductors. They are compatible with existing source and detector material systems and produce devices that are compact and high speed, which makes them useful for monolithic integrated optoelectronic devices.

  3. Morphosynthesis of cubic silver cages on monolithic activated carbon.

    Science.gov (United States)

    Wang, Fei; Zhao, Hong; Lai, Yijian; Liu, Siyu; Zhao, Binyuan; Ning, Yuesheng; Hu, Xiaobin

    2013-11-14

    Cubic silver cages were prepared on monolithic activated carbon (MAC) pre-absorbed with Cl(-), SO4(2-), or PO4(3-) anions. Silver insoluble salts served as templates for the morphosynthesis of silver cages. The silver ions were reduced by reductive functional groups on MAC micropores through a galvanic cell reaction mechanism.

  4. 3D-Printed MOF Monoliths for Gas Adsorption Processes.

    Science.gov (United States)

    Thakkar, Harshul; Eastman, Stephen; Al-Naddaf, Qasim; Rownaghi, Ali Asghar; Rezaei, Fateme

    2017-09-27

    Metal-Organic Frameworks (MOFs) have shown promising performance in separation, adsorption, reaction and storage of various industrial gases, however, their large-scale applications have been hampered by the lack of a proper strategy to formulate them into scalable gas-solid contactors. Herein, we report fabrication of MOF monoliths using 3D printing technique and evaluation of their adsorptive performance in CO2 removal from air. The 3D-printed MOF-74(Ni) and UTSA-16(Co) monoliths with MOF loadings as high as 80 and 85 wt %, respectively were developed and their physical and structural properties were characterized and compared with those of MOF powders. Our adsorption experiments showed that upon exposure to 5,000 ppm (0.5%) CO2 at 25 ºC, the MOF-74(Ni) and UTSA-16(Co) monoliths can adsorb CO2 with the uptake capacity of 1.35 and 1.31 mmol/g, respectively, which are 79 and 87% of the capacity of their MOF analogues under the same conditions. Furthermore, a stable performance was obtained for self-standing 3D-printed monolithic structures with relatively good adsorption kinetics. The preliminary findings reported in this investigation highlight the advantage of robocasting (3D printing) technique for shaping MOF materials into practical configurations that are suitable for various gas separation applications.

  5. From 1D to 3D - macroscopic nanowire aerogel monoliths.

    Science.gov (United States)

    Cheng, Wei; Rechberger, Felix; Niederberger, Markus

    2016-08-01

    Here we present a strategy to assemble one-dimensional nanostructures into a three-dimensional architecture with macroscopic size. With the assistance of centrifugation, we successfully gel ultrathin W18O49 nanowires with diameters of 1 to 2 nm and aspect ratios larger than 100 into 3D networks, which are transformed into monolithic aerogels by supercritical drying.

  6. Mobile Agents for Battlespace Information Exchange

    Science.gov (United States)

    2013-05-01

    Architecture ( CORBA ) standards. MASIF defines two interfaces MAFAgentSystem for MA management tasks and MAFFinder for MA discovery [MAL98]. AN...used for communication depends on the chosen framework. It is preferred however that communication is based on an open standard like CORBA or...provides a means to specifically identify an MA. When the MA identifier is coupled with a directory service (e.g. CORBA Name Service) then a specific

  7. 一种基于移动Agent的云端计算任务安全分割与分配算法%Security segmentation and allocation algorithm based on mobile Agent for cloud computing task

    Institute of Scientific and Technical Information of China (English)

    倪斌; 李红兰

    2015-01-01

    To guarantee the confidentiality and privacy of computing tasks operated in cloud computing environment,and avoid the malicious nodes or the competitors peering the internal structure,system logic and task objects,a new security seg-mentation and allocation algorithm of cloud computing task based on mobile Agent needs to be constructed. This algorithm com-bines with the computing ability and characteristics of cluster server nodes,and the relevant aspects of the user terminal nodes are taken into account. The entire task is segmented into some sub-task effectively,then the mobile Agent is taken as the carrier of data structure and code structure of the sub-task. The data and codes are allocated to reasonable task execution nodes corre-sponding to them. The performance is analyzed and explored by combining with experimental prototype system and this algo-rithm. It proved that the algorithm has better validity to guarantee the terminal nodes security of executing sub-task. When the malicious nodes peered the data and codes allocated to the task execution nodes,even the malicious nodes are combined together to attack on the system,it can not threaten the overall execution thought of the task and the security of the entire object.%为了让在云端计算环境中运行的计算任务机密和隐私得到保障,避免恶意节点或竞争对手窥视任务的内部结构、系统逻辑和任务目标,必须构建一种全新的基于移动Agent的云端计算任务安全分割与分配算法.这种算法不仅要结合集群服务器节点的计算能力和特征,还要将用户终端节点的相关方面也考虑进去,把整个大的任务合理地分割成若干子任务,并将移动Agent作为这些子任务的数据结构和代码构成的载体;然后把这些数据和代码分配到与之对应的合理的任务执行节点上进行工作.通过将实验原型系统和该算法结合起来进行性能分析与探索,证明该算法对执

  8. 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...... are increasingly becoming ‘second nature’ but also expressions of power, exclusion, and difference. In this talk I will be applying a perspective of ‘mobile situationism’ illustrating how mobile everyday life practices are staged ‘from above’ in planning and policy frameworks, design codes and architectural...... designs, but also how the situated and embodied mobile everyday life practices are staged ‘from below’ in concrete acts of choice concerning modes of mobilities, ways of moving and interacting. The ‘staging mobilites’ framework opens up to an understanding of the meaning of ‘mobilities design...

  9. Mobile payment

    CERN Document Server

    Lerner, Thomas

    2013-01-01

    Paying with mobile devices such as mobile phones or smart phones will expand worldwide in the coming years. This development provides opportunities for various industries (banking, telecommunications, credit card business, manufacturers, suppliers, retail) and for consumers.

  10. 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...... 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......Mobile phones are ubiquitous and have completely transformed the way we live, work, learn and conduct our everyday activities. Mobile phones have also changed the way users access lexicographic data. In fact, it can be argued that mobile phones and lexicography are not yet compatible. Modern users...

  11. 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...... are increasingly becoming ‘second nature’ but also expressions of power, exclusion, and difference. In this talk I will be applying a perspective of ‘mobile situationism’ illustrating how mobile everyday life practices are staged ‘from above’ in planning and policy frameworks, design codes and architectural...... designs, but also how the situated and embodied mobile everyday life practices are staged ‘from below’ in concrete acts of choice concerning modes of mobilities, ways of moving and interacting. The ‘staging mobilites’ framework opens up to an understanding of the meaning of ‘mobilities design...

  12. Mobile Lexicography

    DEFF Research Database (Denmark)

    Køhler Simonsen, Henrik

    2015-01-01

    Mobile phones are ubiquitous and have completely transformed the way we live, work, learn and conduct our everyday activities. Mobile phones have also changed the way users access lexicographic data. In fact, it can be argued that mobile phones and lexicography are not yet compatible. Modern users...... 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...... 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...

  13. Mobile robots

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, W.J.; Marquina, N.

    1986-01-01

    This book presents papers given at a conference on mobile robots. Topics the conference included are the following: mobility systems for robotic vehicles; detection and control of mobile robot motion by real-time computer vision, obstacle avoidance algorithms for an autonomous land vehicle; hierarchical processor and matched filters for range image processing; asynchronous distributed control system for a mobile robot, and, planning in a hierarchical nested autonomous control system.

  14. 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...

  15. Mobilities Design

    DEFF Research Database (Denmark)

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

    2017-01-01

    utilitarian transport from A to B; they constitute a rich societal phenomenon with, for example, social, cultural, sensorial, emotional, and material dimensions. The article proposes two fruitful links between the mobilities turn and the designerly examination of mobilities spaces. First, the mobilities turn...

  16. 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...

  17. Predicting poor peripheral blood stem cell collection in patients with multiple myeloma receiving pre-transplant induction therapy with novel agents and mobilized with cyclophosphamide plus granulocyte-colony stimulating factor: results from a Gruppo Italiano Malattie EMatologiche dell'Adulto Multiple Myeloma Working Party study.

    Science.gov (United States)

    Musto, Pellegrino; Simeon, Vittorio; Grossi, Alberto; Gay, Francesca; Bringhen, Sara; Larocca, Alessandra; Guariglia, Roberto; Pietrantuono, Giuseppe; Villani, Oreste; D'Arena, Giovanni; Cuomo, Carmela; Musto, Clelia; Morabito, Fortunato; Petrucci, Maria Teresa; Offidani, Massimo; Zamagni, Elena; Tacchetti, Paola; Conticello, Concetta; Milone, Giuseppe; Palumbo, Antonio; Cavo, Michele; Boccadoro, Mario

    2015-04-17

    A still not well defined proportion of patients with multiple myeloma (MM) and eligible for autologous stem cell transplantation (AuSCT) fails to mobilize CD34+ peripheral blood stem cells (PBSC) at all or to collect an adequate number for a safe procedure or sufficient for multiple transplants. These so-called "poor-mobilizers" are difficult to be predicted, due to marked difference across previous heterogeneous studies. We aimed to develop a method based on simple clinical parameters for predicting unsuccessful (<2×10(6)/kg) or sub-optimal (<5×10(6)/kg) collections of CD34+ PBSC in newly diagnosed MM patients eligible for AuSCT, treated with novel agents and receiving an homogeneous mobilizing therapy with cyclophosphamide and granulocyte-colony stimulating factor (G-CSF). To this purpose, 1,348 patients enrolled in five consecutive Italian clinical trials were retrospectively analysed. Age, baseline low peripheral blood cell counts, use of lenalidomide, and haematological toxicity developed during induction were taken into account as possible factors associated with poor mobilization. Overall, 280 patients (20.8%) showed either sub-optimal (167 patients, 12.4%) or unsuccessful (113 patients, 8.4%) collections. All analysed parameters negatively influenced the procedure, but only age and haematological toxicity during induction maintained their significance at multivariate analysis. Based on ordinal logistic regression model, we constructed a risk heat-map where the four parameters were pooled and weighted according to their relevance as single or combined variables. This model was predictive for different probabilities of failure, suboptimal or optimal outcomes. We found that about one fifth of newly diagnosed MM fails to collect an adequate number of PBSC. Our model, based on a large group of patients treated frontline with novel agents and receiving the most popular mobilizing approach currently employed in Europe, is applicable in individual subjects and

  18. 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....

  19. Agents That Negotiate Proficiently with People

    Science.gov (United States)

    Kraus, Sarit

    Negotiation is a process by which interested parties confer with the aim of reaching agreements. The dissemination of technologies such as the Internet has created opportunities for computer agents to negotiate with people, despite being distributed geographically and in time. The inclusion of people presents novel problems for the design of autonomous agent negotiation strategies. People do not adhere to the optimal, monolithic strategies that can be derived analytically, as is the case in settings comprising computer agents alone. Their negotiation behavior is affected by a multitude of social and psychological factors, such as social attributes that influence negotiation deals (e.g., social welfare, inequity aversion) and traits of individual negotiators (e.g., altruism, trustworthiness, helpfulness). Furthermore, culture plays an important role in their decision making and people of varying cultures differ in the way they make offers and fulfill their commitments in negotiation.

  20. Staging Mobilities

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    that mobility 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......In recent years, the social sciences have taken a “mobilities turn.” There has been a developing realisation that mobilities do not “just happen.” Mobilities are carefully and meticulously designed, planned and staged (from above). However, they are equally importantly acted out, performed...... 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...