UniFAFF: a unified framework for implementing autonomic fault management and failure detection for self‐managing networks

Today's network management, as known within the Fault, Configuration, Accounting, Performance, Security (FCAPS) management framework, is moving towards the definition and implementation of ‘self‐managing’ network functions, with the aim of eliminating or drastically reducing human intervention in some of the complex aspects or daunting tasks of network management. The fault management plane of the FCAPS framework deals with the following functions: fault detection, fault diagnosis, localization or isolation, and fault removal. Task automation is at the very heart of self‐managing (autonomic) nodes and networks, meaning that all functions and processes related to fault management must be automated as much as possible within the functionalities of self‐managing (autonomic) nodes and networks, in order for us to talk about autonomic fault management. At this point in time there are projects calling for implementing new network architectures that are flexible to support on‐demand functional composition for context‐ or situation‐aware networking. A number of such projects have started, under the umbrella of the so‐called clean‐slate network designs. Therefore, this calls for open frameworks for implementing self‐managing (autonomic) functions across each of the traditional FCAPS management planes. This paper presents a unified framework for implementing autonomic fault management and failure detection for self‐managing networks, a framework we are calling UniFAFF. Copyright © 2008 John Wiley & Sons, Ltd.     

Self‐aware management of IP networks with QoS guarantees

Self‐aware management allows the network to react and to adapt to changes of situation. In this paper an architecture is described for self‐aware management of IP networks offering QoS guarantees. This architecture uses policy‐based management and multi‐agent systems. The originality of the present approach lies in the intention to give a real autonomy to the components intervening in the chain of services in terms of internal decisions and configuration. Our solution allows the self‐configuration, self‐provisioning and self‐monitoring of service as well as the proactive service level agreement management. Copyright © 2004 John Wiley & Sons, Ltd.     

A self‐adaptive algorithm for super‐peer selection considering the mobility of peers in cognitive mobile peer‐to‐peer networks

Cognitive peer‐to‐peer networks are obtained from a combination of cognitive networking concepts and peer‐to‐peer networks. These networks are able to improve their performance while operating under dynamic and unknown environments. A cognitive peer‐to‐peer network tries to learn an appropriate configuration for itself considering the unknown physical properties of peers. Cognitive mobile peer‐to‐peer networks refer to cognitive peer‐to‐peer networks which are built over mobile ad hoc networks. In these networks, heterogeneity of the mobility of peers and resource limitation in wireless networks create challenges for network management algorithms. Because of the dynamicity of these networks, the management algorithms should be designated in self‐adaptive manner. In one type of these networks, some peers, called super‐peers, undertake to perform network managerial tasks. The mobility of peers leads to connection failure among peers and reselection of new super‐peers. Therefore, the selection of super‐peers, due to their influential role, requires an algorithm that considers the peers' mobility. Up to now, no self‐adaptive algorithm has been designated for super‐peer selection considering the mobility of peers in a self‐adaptive manner. This paper proposes M‐SSBLA, a self‐adaptive algorithm for super‐peer selection considering the mobility of peers based on learning automata. The proposed algorithm is obtained from cooperation between a learning automata‐based cognitive engine and MIS. MIS is a well‐known super‐peer selection algorithm in mobile peer‐to‐peer networks. We compared the proposed algorithm with recently reported algorithms, especially for a network with high mobility. Simulation results show that the proposed algorithm can cover maximum ordinary‐peer with a few super‐peer and improve robustness against super‐peer failures while decreasing maintenance overhead.     

3D‐Printed MOF‐Derived Hierarchically Porous Frameworks for Practical High‐Energy Density Li–O2 Batteries

Aprotic Li–O₂ batteries are promising candidates for next‐generation energy storage technologies owing to their high theoretical energy densities. However, their practically achievable specific energy is largely limited by the need for porous conducting matrices as cathode support and the passivation of cathode surface by the insulating Li₂O₂ product. Herein, a self‐standing and hierarchically porous carbon framework is reported with Co nanoparticles embedded within developed by 3D‐printing of cobalt‐based metal–organic framework (Co‐MOF) using an extrusion‐based printer, followed by appropriate annealing. The novel self‐standing framework possesses good conductivity and necessary mechanical stability, so that it can act as a porous conducting matrix. Moreover, the porous framework consists of abundant micrometer‐sized pores formed between Co‐MOF‐derived carbon flakes and meso‐ and micropores formed within the flakes, which together significantly benefit the efficient deposition of Li₂O₂ particles and facilitate their decomposition due to the confinement of insulating Li₂O₂ within the pores and the presence of Co electrocatalysts. Therefore, the self‐standing porous architecture significantly enhances the cell's practical specific energy, achieving a high value of 798 Wh kg^?1_cell. This study provides an effective approach to increase the practical specific energy for Li–O₂ batteries by constructing 3D‐printed framework cathodes.     

An immunological approach for file recovery over JXTA peer‐to‐peer framework

Peer‐to‐peer (P2P) file‐sharing systems are characterized by highly replicated content that is distributed among nodes with enormous aggregate resources for storage and communication. File consistency is often compromised by undesirable changes, which should be detected and corrected in a timely fashion. The artificial immune system (AIS) is a novel evolutionary paradigm inspired by aspects of the biological immune system (BIS), such as protection, decentralization, autonomy, and anomaly detection. The AIS paradigm suggests a wide variety of mechanisms for solving complex computer problems. In this paper, we propose the ImmunoJXTA framework for file consistency management and file recovery using the main aspects of AIS in P2P systems. We implemented ImmunoJXTA on the JXTA P2P framework to recover distributed inconsistent files between peers efficiently. Promising results are achieved from experimental runs of the proposed framework. Copyright © 2010 John Wiley & Sons, Ltd.     

Autonomic Self‐Repairing Glassy Materials

A new process that enables glassy materials to self‐repair from mechanical damage is presented in this paper. Contrary to intrinsic self‐healing, which involves overheating to enable crack healing by glass softening, this process is based on an extrinsic effect produced by vanadium boride (VB) particles dispersed within the glass matrix. Self‐repair is obtained through the oxidation of VB particles, and thus without the need to increase the operating temperature. The VB healing agent is selected for its capacity to oxidize at a lower temperature than the softening point of the glass. Thermogravimetric analyses indeed show that VB oxidation is rapid and occurs below the glass transition temperature. Solid‐state nuclear magnetic resonance spectroscopy indicates that VB is oxidized into V₂O₅ and B₂O₃, which enable the local formation of glass. The autonomic self‐healing effect is demonstrated by an in situ experiment visualized using an environmental scanning electron microscope. It is shown that a crack could be healed by the VB oxidation products.     

Framework for distributed autonomic self‐healing in fixed IPv6 networks

A main requirement for the Future Internet is to enable self‐management behaviors facilitating the network to adapt to changing conditions and self‐heal in the face of erroneous states. On the basis of Autonomic Fault‐Management principles, this paper proposes a framework consisting of a set of components operating inside the network elements and allowing the devices to collaboratively realize self‐healing. In that context, Autonomic Fault‐Management is intuitively constituted by the detection of the presence of faulty conditions, followed in turn by the self‐diagnosis and identification of the corresponding root causes, and completed consequently by the removal of the identified root causes and their effects. The proposed framework implements a distributed control loop that interacts with the network operations personnel in case the current erroneous state is not resolvable by means of Autonomic Fault‐Management. We argue that there are a number of mutual benefits between our proposed framework and the IPv6 protocol suite. This is demonstrated by a case study that illustrates these benefits and shows how the capabilities of IPv6 can be enhanced through the self‐healing mechanisms of the proposed framework. Finally, the prototype implementation used for the case study is analyzed in terms of scalability and overhead produced in the network nodes. Copyright © 2013 John Wiley & Sons, Ltd.     

Self‐Limited Epitaxial Growth of Ultrathin Nonlayered CdS Flakes for High‐Performance Photodetectors

2D nonlayered materials that possess appealing properties are entering the researchers' vision. However, direct access to the 2D level of these materials is still a great challenge due to the instrinsic isotropic chemical bond. This work presents the initially self‐limited epitaxial growth of ultrathin nonlayered CdS flakes (as thin as 6 nm) on mica substrate with a large domain size (>40 µm) by employing In₂S₃ as the passivation agent. Besides, the thickness and sizes of the products could be tunable by the addition level of In₂S₃ amount. The growth mechanism is evidenced via experiments and theoretical calculations, which is attributed to the surface distortion effect of In–S motif and the preference of local environments for In on the CdS (0001) surface. The photodetector designed on CdS flake demonstrates a high photoswitching ratio (up to 10³), a high detectivity (D* ≈ 2.71 × 10⁹ Jones), and fast photoresponse speed (τ_R = 14 ms, τ_D = 8 ms). The as‐proposed self‐limited epitaxial growth method opens a new avenue to synthetize 2D nonlayered materials and will promote their further applications in novel optoelectronic devices.     

Task coalition formation and self‐adjustment in the wireless sensor networks

Coalition is an essential mechanism in the multi‐agent systems in the research of task‐oriented area. Self‐interested agents coordinate their behaviors in a coalition to pursue a common goal and obtain payoffs. We propose the clustering‐based coalition formation and self‐adjustment mechanisms for tasks in the wireless sensor network. Before coalition formation, the management center clusters attributes of sensors to reduce the scale of searching space during coalition formation. And then an improved MAX–MIN ant colony optimization algorithm is adopted to resolve the problem of coalition formation. If a coalition member fails to fulfill a task, it can sponsor a negotiation with some noncoalition nodes to execute coalition self‐repairing autonomously. The stimulus‐response mechanism of wasp colony is introduced to determine the probability of response to the task invitation to avoid consuming extra energy. Simulation results show that our model efficiently reduces energy consumption and network traffic, decreases the number of dead nodes, and prolongs the lifetime of the networks. Copyright © 2012 John Wiley & Sons, Ltd.     

XML‐Based Network Management for IP Networks

XML‐based network management, which applies XML technologies to network management, has been proposed as an alternative to existing network management. The use of XML in network management offers many advantages. However, most existing network devices are already embedded with simple network management protocol (SNMP) agents and managed by SNMP managers. For integrated network management, we present the architectures of an XML‐based manager, an XML‐based agent, and an XML/SNMP gateway for legacy SNMP agents. We describe our experience of developing an XML‐based network management system (XNMS), XML‐based agent, and an XML/SNMP gateway. We also verify the effectiveness of our XML‐based agent and XML/SNMP gateway through performance tests. Our experience with developing XNMS and XML‐based agents can be used as a guideline for development of XML‐based management systems that fully take advantage of the strengths of XML technologies.     

Copper(I) Phosphide Nanocrystals for In Situ Self‐Generation Magnetic Resonance Imaging‐Guided Photothermal‐Enhanced Chemodynamic Synergetic Therapy Resisting Deep‐Seated Tumor

Fe‐based Fenton agents can generate highly reactive and toxic hydroxyl radicals (·OH) in the tumor microenvironment (TME) for chemodynamic therapy (CDT) with high specificity. However, the strict condition (lower pH environment: 3–4) of the highly efficient Fenton reaction limits its practical application in the clinic. Development of new CDT agents more suitable for TME is significant and challenging. A highly efficient Cu(I)‐based CDT agent, copper(I) phosphide nanocrystals (CP NCs), which is more adaptable to the pH value of TME than Fe‐based agents, thereby producing more ·OH to trigger the apoptosis of cancer cells, is prepared. Moreover, the excess glutathione (GSH) in TME can reduce the Cu(II) produced by a Fenton‐like reaction to Cu(I), further increasing the generation rate of ·OH and relieving tumor antioxidant ability. Furthermore, owing to their strong absorption in the NIR II region, CP NCs exhibit an excellent photothermal conversion effect, which can further improve the Fenton reaction. What is more, CP NCs can act as in situ self‐generation magnetic resonance imaging (MRI) agents owing to the generation of paramagnetic Cu(II) in response to excess H₂O₂ in the TME. These properties may open up the exploration of copper‐based materials in clinical application of self‐generation imaging‐guided synergetic treatment.     

User‐centric context data collection and provision harnessing Content‐Centric Networking paradigm

A comprehensive context management approach is necessary in the era of ubiquitous technologies, and efficient context data collection is one of the most fundamental and important processes for realizing comprehensive context management. Traditional context data collection approaches are based on Transmission Control Protocol (TCP) or User Datagram Protocol (UDP) over Internet Protocol (IP), which has several disadvantages, such as lack of efficient mobility support, security and data transfer efficiency. Content‐Centric Networking (CCN), on the other hand, provides advantages in terms of mobility, security and bandwidth efficiency in comparison with IP. In this paper, we introduce our user‐centric comprehensive context management framework, and propose a secure and efficient context data collection and provision approach based on the framework using CCN as a network and transport layer. This context collection approach provides a flexible security mechanism by introducing three levels of security type. It also provides bandwidth efficiency by taking advantage of CCN's content caching; performance evaluation results show that our approach can reduce bandwidth consumption up to 99% for pull and up to 46% for push in comparison to a UDP/IP‐based system. Our approach also provides advantages in supporting mobility and leveraging multiple interfaces. Copyright © 2013 John Wiley & Sons, Ltd.     

TpyCo2+‐Based Coordination Polymers by Water‐Induced Gelling Trigged Efficient Oxygen Evolution Reaction

Though the use of conventional self‐assembled architectures in functional applications involving advanced energy chemistries is an important research area, it remains largely unexplored. The self‐assembly of the threefold and sixfold‐symmetric terpyridines (tpy) with Co(II) salts results in a novel morphological and structural characteristics, regardless of the nature of the self‐assembled fragments. Herein, such metallopolymers are achieved by one‐pot synthesis in CH₃OH/CHCl₃ (v/v = 5:1) mixture ambient. It is found, for the first time, that Co‐containing polymers can be well dispersed in deionized water to form gel‐like self‐assemblies that consist of a highly interconnected 3D network and exhibit enhanced electrical conductivity and thus are attractive as electrocatalysts. As expected, the optimized Co‐based polymeric structures exhibit a low overpotential of 320 mV at 10 mA cm^?2 and high stability over 2000 cycles toward oxygen evolution reaction (OER), surpassing commercial RuO₂/C, single‐site Co catalysts, polymer, and metal–organic framework‐based OER catalysts reported to date. X‐ray absorption spectroscopy and density functional theory calculations reveal that the tpy‐Co²⁺ (3N‐Co or tpy‐Co²⁺) configurations act as highly active sites. Importantly, this work demonstrates the functional application of the self‐assembled metallopolymers as electrocatalysts for energy conversion.     

Multifunctional Visible‐Light Powered Micromotors Based on Semiconducting Sulfur‐ and Nitrogen‐Containing Donor–Acceptor Polymer

Photosensitive micromotors that can be remotely controlled by visible light irradiation demonstrate great potential in biomedical and environmental applications. To date, a vast number of light‐driven micromotors are mainly composed from costly heavy and precious metal‐containing multicomponent systems, that limit the modularity of chemical and physical properties of these materials. Herein, a highly efficient photocatalytic micromotors based exclusively on a purely organic polymer framework—semiconducting sulfur‐ and nitrogen‐containing donor–acceptor polymer, is presented. Thanks to precisely tuned molecular architecture, this material has the ability to absorb visible light due to a conveniently situated energy gap. In addition, the donor‐acceptor dyads within the polymer backbone ensure efficient photoexcited charge separation. Hence, these polymer‐based micromotors can move in aqueous solutions under visible light illumination via a self‐diffusiophoresis mechanism. Moreover, these micromachines can degrade toxic organic pollutants and respond to an increase in acidity of aqueous environments by instantaneous colour change. The combination of autonomous motility and intrinsic fluorescence enables these organic micromotors to be used as colorimetric and optical sensors for monitoring of the environmental aqueous acidity. The current findings open new pathways toward the design of organic polymer‐based micromotors with tuneable band gap architecture for fabrication of self‐propelled microsensors for environmental control and remediation applications.     

Understanding and Controlling the Self‐Folding Behavior of Poly (N‐Isopropylacrylamide) Microgel‐Based Devices

Poly(N‐isopropylacrylamide) (pNIPAm) microgel‐based materials can be fabricated that self‐fold into three‐dimensional structures in response to changes in the environmental humidity. The materials are composed of a semi‐rigid polymer substrate coated with a thin layer of Au; the Au layer is subsequently coated with a pNIPAm‐based microgel layer and finally covered with a solution of polydiallyldimethylammonium chloride (pDADMAC). The pDADMAC layer contracts upon drying causing the material to deform (typically bending); this deformation is completely reversible over many cycles as the environmental humidity is systematically varied. Here, by varying the size and aspect ratio of the polymer substrate, it is possible to develop a set of empirical rules that can be applied to predict the material's self‐folding behavior. From these rules, materials that self‐fold from two‐dimensional, flat objects into discrete three‐dimensional structures, which are fully capable of unfolding and folding multiple times in response to humidity, are designed.     

A Self‐Powered Brain‐Linked Vision Electronic‐Skin Based on Triboelectric‐Photodetecing Pixel‐Addressable Matrix for Visual‐Image Recognition and Behavior Intervention

A new self‐powered brain‐linked vision electronic‐skin (e‐skin) for mimicking retina is realized from Polypyrrole/Polydimethysiloxane (Ppy/PDMS) triboelectric‐photodetecting pixel‐addressable matrix. The e‐skin can be driven by human motion, so no external electricity power is needed in both photodetecting and signal transmitting processes. The triboelectric output is significantly dependent on the photo illumination, which can act as visual bionic electric impulse. Taking blue illumination (405 nm) as an example, as the e‐skin is exposed to 100 µW cm^?2 illumination, the output current decreases from 7.5 to 4.9 nA, and the photosensitivity is 34.7. And the photosensitivity of the e‐skin keeps stable with different bending angles and force. The e‐skin is flexible enough to combine with human body and can be driven by blinking eyes to detect UV illumination. In addition, the 4 × 4 photodetecting unit matrix in the e‐skin can map single‐point and multipoint illumination‐stimuli (visual‐image recognition) via the multichannel data acquisition method. Furthermore, the e‐skin can directly transmit photodetecting signals into mouse brain for participating in the perception and behavior intervention. This new self‐powered perception device can lower down the production cost of traditional complex sensory‐substitution system, and can be easily extended to various brain–machine interaction applications.     

A hierarchical mobile‐agent‐based security operation center

The continuous evolvement of the e‐domain has led to a significant increase in the amount of sensitive personal information stored on networked hosts. These hosts are invariably protected by security mechanisms such as intrusion detection systems, Intrusion Prevention System (IPS), antivirus software, firewalls, and so forth. However, they still remain vulnerable to the threat of malicious attacks, theft and intrusion. The high false positive alarm rate of such mechanisms is particularly troublesome because false alarms greatly degrade the efficiency of the security framework. Security operation centers (SOCs) provide an automated solution for analyzing the threat to a network such that appropriate protective measures can be put in place. This paper proposes a novel hierarchical mobile‐agent‐based SOC to overcome the vulnerability of traditional static SOCs to single point of failure attacks. In addition, the network is partitioned into multiple divisions, each with its own alert detection and aggregation methodology to improve the computational efficiency of the data collection and fusion process. The data acquired in the various divisions are fused and correlated in an efficient manner via intrusion detection message exchange format, XML, session and timer methods The experimental results confirm the effectiveness and efficiency of the proposed hierarchical mobile‐agent‐based SOC framework. Copyright © 2012 John Wiley & Sons, Ltd.     

SOS: Self‐organized secure framework for VANET

While authentication is a necessary requirement to provide security in vehicular ad hoc networks, user's personal information such as identity and location must be kept private. The reliance on road side units or centralized trusted authority nodes to provide security services is critical because both are vulnerable, thus cannot be accessed by all users, which mean security absence. In this paper, we introduce a self‐organized secure framework, deployed in vehicular ad hoc networks. The proposed framework solution is designed not only to provide an effective, integrated security and privacy‐preserving mechanism but also to retain the availability of all security services even if there are no road side units at all and/or the trusted authority node is compromised. A decentralized tier‐based security framework that depends on both trusted authority and some fully trusted nodes cooperated to distribute security services is presented. Our approach combines the useful features of both Shamir secret sharing with a trust‐based technique to ensure continuity of achieving all security services. Mathematical analysis of security issues that the proposed framework achieves as well as the availability of offering security services is provided. Proposed framework examination was done to show the performance in terms of storage, computation complexity, and communication overhead as well as its resilience against various types of attacks. Comparisons with different types of security schemes showed that the protocol developed gave better results in most comparison parameters while being unique ensuring continuity of security services delivery.     

Deciphering,Designing, and Realizing Self‐Folding Biomimetic Microstructures Using a Mass‐Spring Model and Inkjet‐Printed,Self‐Folding Hydrogels

Flat, organic microstructures that can self‐fold into 3D microstructures are promising for tissue regeneration, for being capable of distributing living cells in 3D while forming highly complex, biomimetic architectures to assist cells in performing regeneration. However, the design of self‐folding microstructures is difficult due to a lack of understanding of the underlying formation mechanisms. This study helps bridge this gap by deciphering the dynamics of the self‐folding using a mass‐spring model. This numerical study reveals that self‐folding procedure is multi‐modal, which can become random and unpredictable by involving the interplays between internal stresses, external stimulation, imperfection, and self‐hindrance of the folding body. To verify the numerical results, bilayered, hydrogel‐based micropatterns capable of self‐folding are fabricated using inkjet‐printing and tested. The experimental and numerical results are consistent with each other. The above knowledge is applied to designing and fabricating self‐folding microstructures for tissue‐engineering, which successfully creates 3D, cell‐scaled, and biomimetic microstructures, such as microtubes, branched microtubes, and hollow spheres. Embedded in self‐folded microtubes, human mesenchymal stem cells proliferate and form linear cell‐organization mimicking the cell morphology in muscles and tendons. The above knowledge and study platforms can greatly contribute to the research on self‐folding microstructures and applications to tissue regeneration.