To test self healing capability of asphalt binders,three asphalt specimens(pure asphalt,modified asphalt and aged asphalt) were prepared.Every specimen was tested by dynamic shear rheometer(DSR).The temperature sw...To test self healing capability of asphalt binders,three asphalt specimens(pure asphalt,modified asphalt and aged asphalt) were prepared.Every specimen was tested by dynamic shear rheometer(DSR).The temperature sweeps result indicates that both aging and SBS modifying influence the self healing capability of asphalt binder.The fatigue-heal-fatigue test was introduced to study the self healing capability of asphalt in its serving periods.Furthermore,three different periods(0.5 h,1 h,3 h) were set up to study the influence of rest time on fatigue time.It is concluded that longer rest time,less load will delay the appearance of cracks and extend the service life of asphalt binders.展开更多
The self-healing action of a permeable crystalline coating on the po rous mortar was investigated by two times impermeability test. Moreover, the sel f-healing mechanism of cement-based materials with the permeable cr...The self-healing action of a permeable crystalline coating on the po rous mortar was investigated by two times impermeability test. Moreover, the sel f-healing mechanism of cement-based materials with the permeable crystalline c oating was studied by SEM. The results indicate that the permeable crystalline c oating not only seals the pores and cracks in mortar during its curing process, but also heals the permeable pathway caused by first impermeability test or crac ks produced by freeze-thaw cycles. Therefore, cement-based materials can be im proved by the permeable crystalline coating for the self-healing function. SEM images prove that the self-healing function is realized by generating a great q uantity of non-soluble dendritic crystalline within the pores and cracks, which prevents the penetration of water and other liquids.展开更多
In order to inhibit and remove the thin ice and extend the lifetime of the damaged bridge, the self-healing mechanism and hydrophobic performance of asphalt modified by siloxane and polyurethane (ASP) were studied by ...In order to inhibit and remove the thin ice and extend the lifetime of the damaged bridge, the self-healing mechanism and hydrophobic performance of asphalt modified by siloxane and polyurethane (ASP) were studied by dynamic shear rheology (DSR), fluorescence microscope (FM), atomic force microscope (AFM), the fracture-healing-re-fracture test and molecular simulations. The experimental results indicated that the selfhealing capability of ASP increased with increasing heating time and temperature. Furthermore, the addition of siloxane could improve the reaction energy barrier and complex modulus, and it is believed that the self-healing is a viscosity driven process, consisting of two parts namely crack closure and properties recovery. Contact angle of ASP increased with the increasing siloxane content and it deduced that the siloxane could improve the hydrophobic performance of ASP and the ASP molecule model could simulate well the self-healing mechanism and hydrophobic performance of ASP.展开更多
The complete deposition distribution process of calcium carbonate is summarized in three directions of cracks. Distribution of calcium carbonate in the self-healing process of microbial concrete is studied in detail, ...The complete deposition distribution process of calcium carbonate is summarized in three directions of cracks. Distribution of calcium carbonate in the self-healing process of microbial concrete is studied in detail, with the help of a variety of analytical techniques. The results show that carbonate deposits along the x-axis direction of the cracks. The farther from the crack surfaces of concrete matrix in x-axis direction, the more the content of the substrate, the less content of calcium carbonate. Gradual accumulation of calcium carbonate along the y-axis direction is like building a house with bricks. Different repair points are gradually connected, and ultimately the whole of cracks are completely filled. In the z-axis direction, calcium deposits on the surface of fracture direction, when the crack is filled on the surface, because the internal crack hypoxia in the depths of cracks hardly produces calcium carbonate.展开更多
The urea-formaldehyde(UF) capsules filled with a healing agent, a mixture of epoxy resins(epoxy 711 and E-51) as core material, were produced by means of one step in-situ polymerization. The characteristics of the...The urea-formaldehyde(UF) capsules filled with a healing agent, a mixture of epoxy resins(epoxy 711 and E-51) as core material, were produced by means of one step in-situ polymerization. The characteristics of these microcapsules were studied via scanning electron microscopy(SEM), particle size analysis, FTIR and DSC/TGA. The results show that the dispersed and integrated microcapsules of 5 μm in shell thickness were synthesized successfully. The capsules were produced with diameters ranging from 10 to 250 μm via controlling agitation rate. Young's modulus of the capsule was a little lower than those of the epoxy resins, but the microcapsules having such a shell thickness were robust enough to survive handling during manufacturing self-healing composites. When damage occurred in the epoxy matrix, the crack could rupture the microcapsule to make the repairing agent release.展开更多
The phosphated and cerium nitrate post-sealed galvanized steel was firstly scratched to expose zinc layer and then placed in neutral salt spray (NSS) chamber for different durations. The microstructure and compositi...The phosphated and cerium nitrate post-sealed galvanized steel was firstly scratched to expose zinc layer and then placed in neutral salt spray (NSS) chamber for different durations. The microstructure and compositions of the scratches were investigated using SEM and EDS. The phases of the corrosion products were examined through XRD. The self-healing mechanism of the composite coatings was discussed. The experimental results show that the composite coatings have an excellent corrosion resistance. The corrosion products increase with corrosion time and finally cover the whole scratch. They contain phosphorous, cerium, oxygen, chloride and zinc, and are fine needle and exceedingly compact. The composite coatings are favorable self-healing. During corrosion, the self-healing ions such as Ce3+, Ce4+, PO43-, Zn2+ in the composite coatings were dissolved, migrated, recombined, and covered the exposed zinc, impeding zinc corrosion. The self-healing process of the scratches on the composite coatings can be divided into three stages, about 2 h, 4 h, and 24 h, respectively.展开更多
Cracks can deteriorate mechanical properties and/or durability of concrete. A few studies have shown that, cracks can autogenously heal under a certain conditions besides the traditional passive repair with a delibera...Cracks can deteriorate mechanical properties and/or durability of concrete. A few studies have shown that, cracks can autogenously heal under a certain conditions besides the traditional passive repair with a deliberate external intervention. For underground concrete structures, the presence of water, as a necessity for chemical reactions of the healing additives, is beneficial to healing concrete. In this paper, a natural healing method by mineral additives was developed according to the chemical and physical characteristics of underground environment. The healing capacity of three different crystalline mineral materials classified namely, carbonate, calcium sulphoaluminate expansive agent and natural metakaolin due to permeation- crystallization, expansion and pozzolanic reaction, has been assessed from the mechanical properties, referring to the relative elastic modulus, the strength restoration, and the water permeability of the healed specimens. In addition, the morphology of the healing products in the vicinity of the crack was observed. The results indicate that the specimens incorporated with the three mineral additives show different healing capacity according to the improved mechanical properties and permeability. The permeability of the host matrix decreased a lot after crack healing by natural metakaolin followed by carbonate whereas no noticeable improvement of water permeability has been observed for the specimens mixed with expansive agent. The specimens incorporated with carbonate show the best mechanical restoration in terms of relative elastic modulus and compressive strength. Although the dominate element is CaCO3 by reaction of CO32-, either from the dissolved CO2 or from the additives, and Ca2+ in the cementitious system to fill the cracks, the healing capacity depends greatly on the morphology and the properties of the newly formed products.展开更多
In order to improve the performance of non-asbestos composite auto brake pads that are composed of matrix resin, reinforced material and fillers, a novel method with new technology of self-heal microcapsules was propo...In order to improve the performance of non-asbestos composite auto brake pads that are composed of matrix resin, reinforced material and fillers, a novel method with new technology of self-heal microcapsules was proposed. Nano reinforced fillers' effects were also considered in the experiment project. Five recipe designs for new composite auto brake pads were carried out and cor-responding samples were prepared as well. The friction coefficient and wearing properties at certain temperature, impact intensity and hardness were comparatively studied. Investigations indicate that properties of such composite auto brake pads meet the requirements of the national standards while microcapsule's weight content varies from 5.5wt%-1.09wt% of matrix resin and microcapsule's loca-tion varies in the pads. Nano reinforced fillers have the effects of increasing composites' impact in-tensity and hardness. Application of self-healing microcapsules in auto brake pads is feasible.展开更多
A hybrid epoxy resin with intrinsic self healing properties has been prepared from a bifunctional Diels-Alder (DA) adduct. The obtained network, based on conventional Diglycidyl ether of BisphenolA (DGEBA) and DA epox...A hybrid epoxy resin with intrinsic self healing properties has been prepared from a bifunctional Diels-Alder (DA) adduct. The obtained network, based on conventional Diglycidyl ether of BisphenolA (DGEBA) and DA epoxy, leads to simultaneous tuning of physical-chemical properties and healing capability. The self-repairing behavior has been verified by means of scratch recovery observation and micromechanical analysis. A satisfactory morphological and mechanical recovery has been achieved by thermal stimulus, leading to very promising application in the field of adhesives and structural applications.展开更多
This paper discusses the applications of a hybrid multi-agent framework for self-healing applications in an intelligent smart grid system following catastrophic disturbances such as loss of generators or during system...This paper discusses the applications of a hybrid multi-agent framework for self-healing applications in an intelligent smart grid system following catastrophic disturbances such as loss of generators or during system fault.The proposed hybrid multi-agent framework is a hybrid of both centralized and decentralized scheme to allow distributed intelligent agent in the smart grid system to make fast local decision while allowing the slower central controller to judge the effectiveness of the decision made by the local agents and to suggest more optimal solutions.展开更多
The complexity of computer architectures, software, web applications, and its large spread worldwide using the internet and the rapid increase in the number of users in companion with the increase of maintenance cost ...The complexity of computer architectures, software, web applications, and its large spread worldwide using the internet and the rapid increase in the number of users in companion with the increase of maintenance cost are all factors guided many researchers to develop software, web applications and systems that have the ability of self-healing. The aim of the self healing software feature is to fast recover the application and keep it running and available for 24/7 as optimal as possible. This survey provides an overview of self-healing software and system that is especially useful in all of those situations in which the involvement of humans is costly and hard to recover and needs to be automated with self healing. There are different aspects which will make us understand the different benefits of these self-healing systems. Finally, the approaches, techniques, mechanisms and individual characteristics of self healing are classified in different tables and then summarized.展开更多
Resilient Packet Ring (RPR) is a Media Access Control (MAC) layer protocol that operates over a double counter-rotating ring network topology. RPR is designed to enhance Synchronous Digital Hierarchy(SDH) in order to ...Resilient Packet Ring (RPR) is a Media Access Control (MAC) layer protocol that operates over a double counter-rotating ring network topology. RPR is designed to enhance Synchronous Digital Hierarchy(SDH) in order to handle data traffic more efficiently. Since Intelligent Protection Switching(IPS) is one of the key technologies in ring networks, RPR provides two intelligent protection algorithms: steering and wrapping. While wrapping in RPR in essence inherits the automatic protection switching(APS) algorithm of SDH, it also wastes the bandwidth on the wrapping ringlets and may result in severe congestion. Whereas steering in RPR provides high bandwidth utilization, its switching speed is low, because it is indeed a high layer's restoration algorithm. In this paper, integrated self-healing(ISH) algorithm as an effective algorithm for RPR is proposed, which synthesizes the merits of the two algorithms by transporting healing signal and computing routing in MAC layer. At last, the performance of ISH algorithm is analyzed and simulated.展开更多
The sensing coverage of a wireless sensor network is an important measure of the quality of service. It is desirable to develop energy efficient methods for relocating mobile sensors in order to achieve optimum sensin...The sensing coverage of a wireless sensor network is an important measure of the quality of service. It is desirable to develop energy efficient methods for relocating mobile sensors in order to achieve optimum sensing coverage. This paper introduces an average distance based self-relocation and self-healing algorithm for randomly deployed mobile sensor networks. No geo-location or relative location information is needed by this algorithm thereby no hardware such as GPS is required. The tradeoff is that sensors need to move longer distance in order to achieve certain coverage. Simulations are conducted in order to evaluate the proposed relocation and self-healing algorithms. An average of 94% coverage is achieved in the cases that we are examined with or without obstacles.展开更多
A new family of transparent,biocompatible,self-adhesive,and self-healing elastomer has been developed by a convenient and efficient one-pot reaction between poly(acrylic acid)(PAA)and hydroxyl-terminated polydimethyls...A new family of transparent,biocompatible,self-adhesive,and self-healing elastomer has been developed by a convenient and efficient one-pot reaction between poly(acrylic acid)(PAA)and hydroxyl-terminated polydimethylsiloxane(PDMSOH).The condensation reaction between PAA and PDMS-OH has been confirmed by attenuated total reflection Fourier transform infrared(ATR-FTIR)spectra.The prepared PAA-PDMS elastomers possess robust mechanical strength and strong adhesiveness to human skin,and they have fast self-healing ability at room temperature(in^10 s with the efficiency of 98%).Specifically,strain sensors were fabricated by assembling PAA-PDMS as packaging layers and polyetherimide-reduced graphene oxide(PEI-rGO)as strain-sensing layers.The PAA-PDMS/PEI-rGO sensors are stably and reliably responsive to slight physical deformations,and they can be attached onto skin directly to monitor the body’s motions.Meanwhile,strain sensors can self-heal quickly and completely,and they can be reused for the motion detecting after shallowly scratching the surface.This work provides new opportunities to manufacture high performance self-adhesive and self-healing materials.展开更多
Defects in protective-coating systems on steel surfaces are inevitable in practical engineering applications.A composite coating system,including a primer,middle coat and topcoat,were used to protect carbon steel from...Defects in protective-coating systems on steel surfaces are inevitable in practical engineering applications.A composite coating system,including a primer,middle coat and topcoat,were used to protect carbon steel from corrosion in a marine environment.Two environmental additives,glass fi bers and thiourea,were applied in the middle coat to modify the coating system.The long-term corrosion durability and self-healing ability of the scratched coating system were evaluated by multiple methods.Results of the electrochemical technologies indicated that the coating system that contained 0.5 wt.%fi bers and 0.5 wt.%thiourea presented good corrosion protection and self-healing for carbon steel when immersed in 3.5%Na Cl for 120 d.Evolution of localized corrosion factors with time,as obtained from the current distribution showed that fi bers combined with thiourea could inhibit the occurrence of local corrosion in scratched coating systems and retarded the corrosion development signifi cantly.Surface characterization suggested that adequate thiourea could be absorbed uniformly on fi bers for a long time to play an important role in protecting the carbon steel.Finally,schematic models were established to demonstrate the action of fi bers and thiourea on the exposed surface of the carbon steel and the scratched coating system in the entire deterioration process.展开更多
Based on ATM Multi section backup VP self healing scheme, analysis of cell loss probability under finite buffer is made by use of queue system method. Optimal buffer size can be fixed on.
To employ the network resources more effectively and fl exibly,cloud radio access network(C-RAN) adopts centralized network construction and management. Since the new network characteristics,the self-healing is reliab...To employ the network resources more effectively and fl exibly,cloud radio access network(C-RAN) adopts centralized network construction and management. Since the new network characteristics,the self-healing is reliable distinguish compared with previous studies. This paper drives a solution for selfhealing based on cooperative transmission and power adjustment under C-RAN self-healing management architecture. This compensation model with the aim to maximize the number of connected UEs and optimize power regulation is solved by Benders' decomposition algorithm. And through the simulation,this paper verifies the speediness and effectiveness of this scheme.展开更多
An important area of focus in complex systems development is the capability to adapt to variable runtime environ- mental resources and to accommodate runtime system failures. The research in this area is broadly terme...An important area of focus in complex systems development is the capability to adapt to variable runtime environ- mental resources and to accommodate runtime system failures. The research in this area is broadly termed as “Self Healing” and has recently aroused increasing attention to complex systems. Digital libraries have gained popularity because of the richer fea- tures they provide compared to traditional libraries. As more users begin to use digital libraries, addressing downtimes of these valuable resources has become a high priority. Operating and providing access to digital content to anyone, anytime from any- where in the world, results in a continued rise of administrative overhead for system monitoring and needs continuous human intervention. Given the volume of information and the huge infrastructure of modern libraries, continuous manual system ad- ministration is quite costly and not feasible. In this paper we propose a self healing digital library system as the solution to this problem and present the approach of adding self healing capabilities to an existing digital library project, the Digital Library of India (DLI). We also propose a self healing framework that enables successful reuse of our approach to other architecturally similar digital library systems.展开更多
基金Funded by the Scientific Research Foundation for Dr,Wuhan University of Technology,Wuhan,China
文摘To test self healing capability of asphalt binders,three asphalt specimens(pure asphalt,modified asphalt and aged asphalt) were prepared.Every specimen was tested by dynamic shear rheometer(DSR).The temperature sweeps result indicates that both aging and SBS modifying influence the self healing capability of asphalt binder.The fatigue-heal-fatigue test was introduced to study the self healing capability of asphalt in its serving periods.Furthermore,three different periods(0.5 h,1 h,3 h) were set up to study the influence of rest time on fatigue time.It is concluded that longer rest time,less load will delay the appearance of cracks and extend the service life of asphalt binders.
基金Funded by the Scientific and Technological Project of Hubei Province(2004BCS005)
文摘The self-healing action of a permeable crystalline coating on the po rous mortar was investigated by two times impermeability test. Moreover, the sel f-healing mechanism of cement-based materials with the permeable crystalline c oating was studied by SEM. The results indicate that the permeable crystalline c oating not only seals the pores and cracks in mortar during its curing process, but also heals the permeable pathway caused by first impermeability test or crac ks produced by freeze-thaw cycles. Therefore, cement-based materials can be im proved by the permeable crystalline coating for the self-healing function. SEM images prove that the self-healing function is realized by generating a great q uantity of non-soluble dendritic crystalline within the pores and cracks, which prevents the penetration of water and other liquids.
基金Funded by the National Natural Science Foundation of China(No.51808329)Science and Technology Department of Shanxi Province International Cooperation(No.201603D421027)the Special Project of Commercialization of Shanxi Province Research Foundation(No.201804D131034)
文摘In order to inhibit and remove the thin ice and extend the lifetime of the damaged bridge, the self-healing mechanism and hydrophobic performance of asphalt modified by siloxane and polyurethane (ASP) were studied by dynamic shear rheology (DSR), fluorescence microscope (FM), atomic force microscope (AFM), the fracture-healing-re-fracture test and molecular simulations. The experimental results indicated that the selfhealing capability of ASP increased with increasing heating time and temperature. Furthermore, the addition of siloxane could improve the reaction energy barrier and complex modulus, and it is believed that the self-healing is a viscosity driven process, consisting of two parts namely crack closure and properties recovery. Contact angle of ASP increased with the increasing siloxane content and it deduced that the siloxane could improve the hydrophobic performance of ASP and the ASP molecule model could simulate well the self-healing mechanism and hydrophobic performance of ASP.
基金Funded by the National Natural Science Foundation of China(No.51178104)333 Project of JiangsuPhD Program’s Foundation of Ministry of Education of China(No.20110092110033)
文摘The complete deposition distribution process of calcium carbonate is summarized in three directions of cracks. Distribution of calcium carbonate in the self-healing process of microbial concrete is studied in detail, with the help of a variety of analytical techniques. The results show that carbonate deposits along the x-axis direction of the cracks. The farther from the crack surfaces of concrete matrix in x-axis direction, the more the content of the substrate, the less content of calcium carbonate. Gradual accumulation of calcium carbonate along the y-axis direction is like building a house with bricks. Different repair points are gradually connected, and ultimately the whole of cracks are completely filled. In the z-axis direction, calcium deposits on the surface of fracture direction, when the crack is filled on the surface, because the internal crack hypoxia in the depths of cracks hardly produces calcium carbonate.
基金Supported by the National Natural Science Foundation of China(Nos.50775222 and 50735006)
文摘The urea-formaldehyde(UF) capsules filled with a healing agent, a mixture of epoxy resins(epoxy 711 and E-51) as core material, were produced by means of one step in-situ polymerization. The characteristics of these microcapsules were studied via scanning electron microscopy(SEM), particle size analysis, FTIR and DSC/TGA. The results show that the dispersed and integrated microcapsules of 5 μm in shell thickness were synthesized successfully. The capsules were produced with diameters ranging from 10 to 250 μm via controlling agitation rate. Young's modulus of the capsule was a little lower than those of the epoxy resins, but the microcapsules having such a shell thickness were robust enough to survive handling during manufacturing self-healing composites. When damage occurred in the epoxy matrix, the crack could rupture the microcapsule to make the repairing agent release.
基金Funded by the National Natural Science Foundation(No.501408517)the Natural Science Foundation of Fujian Province(No.2012J05099)the Pre-research Project of National Natural Science Fund of Xiamen University of Technology(No.XYK201410)
文摘The phosphated and cerium nitrate post-sealed galvanized steel was firstly scratched to expose zinc layer and then placed in neutral salt spray (NSS) chamber for different durations. The microstructure and compositions of the scratches were investigated using SEM and EDS. The phases of the corrosion products were examined through XRD. The self-healing mechanism of the composite coatings was discussed. The experimental results show that the composite coatings have an excellent corrosion resistance. The corrosion products increase with corrosion time and finally cover the whole scratch. They contain phosphorous, cerium, oxygen, chloride and zinc, and are fine needle and exceedingly compact. The composite coatings are favorable self-healing. During corrosion, the self-healing ions such as Ce3+, Ce4+, PO43-, Zn2+ in the composite coatings were dissolved, migrated, recombined, and covered the exposed zinc, impeding zinc corrosion. The self-healing process of the scratches on the composite coatings can be divided into three stages, about 2 h, 4 h, and 24 h, respectively.
基金Funded by National Basic Research Program of China(973 Program)(No.2011CB013805)National Natural Science Foundation of China(Nos.51278360,51478348,51308407)National Key Project of Scientific and Technical Supporting Programs of China(No.2014BAL03B02)
文摘Cracks can deteriorate mechanical properties and/or durability of concrete. A few studies have shown that, cracks can autogenously heal under a certain conditions besides the traditional passive repair with a deliberate external intervention. For underground concrete structures, the presence of water, as a necessity for chemical reactions of the healing additives, is beneficial to healing concrete. In this paper, a natural healing method by mineral additives was developed according to the chemical and physical characteristics of underground environment. The healing capacity of three different crystalline mineral materials classified namely, carbonate, calcium sulphoaluminate expansive agent and natural metakaolin due to permeation- crystallization, expansion and pozzolanic reaction, has been assessed from the mechanical properties, referring to the relative elastic modulus, the strength restoration, and the water permeability of the healed specimens. In addition, the morphology of the healing products in the vicinity of the crack was observed. The results indicate that the specimens incorporated with the three mineral additives show different healing capacity according to the improved mechanical properties and permeability. The permeability of the host matrix decreased a lot after crack healing by natural metakaolin followed by carbonate whereas no noticeable improvement of water permeability has been observed for the specimens mixed with expansive agent. The specimens incorporated with carbonate show the best mechanical restoration in terms of relative elastic modulus and compressive strength. Although the dominate element is CaCO3 by reaction of CO32-, either from the dissolved CO2 or from the additives, and Ca2+ in the cementitious system to fill the cracks, the healing capacity depends greatly on the morphology and the properties of the newly formed products.
基金Funded by the Beijing Talent and Innovation Project (No. 2006)
文摘In order to improve the performance of non-asbestos composite auto brake pads that are composed of matrix resin, reinforced material and fillers, a novel method with new technology of self-heal microcapsules was proposed. Nano reinforced fillers' effects were also considered in the experiment project. Five recipe designs for new composite auto brake pads were carried out and cor-responding samples were prepared as well. The friction coefficient and wearing properties at certain temperature, impact intensity and hardness were comparatively studied. Investigations indicate that properties of such composite auto brake pads meet the requirements of the national standards while microcapsule's weight content varies from 5.5wt%-1.09wt% of matrix resin and microcapsule's loca-tion varies in the pads. Nano reinforced fillers have the effects of increasing composites' impact in-tensity and hardness. Application of self-healing microcapsules in auto brake pads is feasible.
文摘A hybrid epoxy resin with intrinsic self healing properties has been prepared from a bifunctional Diels-Alder (DA) adduct. The obtained network, based on conventional Diglycidyl ether of BisphenolA (DGEBA) and DA epoxy, leads to simultaneous tuning of physical-chemical properties and healing capability. The self-repairing behavior has been verified by means of scratch recovery observation and micromechanical analysis. A satisfactory morphological and mechanical recovery has been achieved by thermal stimulus, leading to very promising application in the field of adhesives and structural applications.
基金funded by the ARC Linkage Grant LP LP0991428a URC Research Partnerships Grants Scheme, from the University of Wollongong
文摘This paper discusses the applications of a hybrid multi-agent framework for self-healing applications in an intelligent smart grid system following catastrophic disturbances such as loss of generators or during system fault.The proposed hybrid multi-agent framework is a hybrid of both centralized and decentralized scheme to allow distributed intelligent agent in the smart grid system to make fast local decision while allowing the slower central controller to judge the effectiveness of the decision made by the local agents and to suggest more optimal solutions.
文摘The complexity of computer architectures, software, web applications, and its large spread worldwide using the internet and the rapid increase in the number of users in companion with the increase of maintenance cost are all factors guided many researchers to develop software, web applications and systems that have the ability of self-healing. The aim of the self healing software feature is to fast recover the application and keep it running and available for 24/7 as optimal as possible. This survey provides an overview of self-healing software and system that is especially useful in all of those situations in which the involvement of humans is costly and hard to recover and needs to be automated with self healing. There are different aspects which will make us understand the different benefits of these self-healing systems. Finally, the approaches, techniques, mechanisms and individual characteristics of self healing are classified in different tables and then summarized.
文摘Resilient Packet Ring (RPR) is a Media Access Control (MAC) layer protocol that operates over a double counter-rotating ring network topology. RPR is designed to enhance Synchronous Digital Hierarchy(SDH) in order to handle data traffic more efficiently. Since Intelligent Protection Switching(IPS) is one of the key technologies in ring networks, RPR provides two intelligent protection algorithms: steering and wrapping. While wrapping in RPR in essence inherits the automatic protection switching(APS) algorithm of SDH, it also wastes the bandwidth on the wrapping ringlets and may result in severe congestion. Whereas steering in RPR provides high bandwidth utilization, its switching speed is low, because it is indeed a high layer's restoration algorithm. In this paper, integrated self-healing(ISH) algorithm as an effective algorithm for RPR is proposed, which synthesizes the merits of the two algorithms by transporting healing signal and computing routing in MAC layer. At last, the performance of ISH algorithm is analyzed and simulated.
文摘The sensing coverage of a wireless sensor network is an important measure of the quality of service. It is desirable to develop energy efficient methods for relocating mobile sensors in order to achieve optimum sensing coverage. This paper introduces an average distance based self-relocation and self-healing algorithm for randomly deployed mobile sensor networks. No geo-location or relative location information is needed by this algorithm thereby no hardware such as GPS is required. The tradeoff is that sensors need to move longer distance in order to achieve certain coverage. Simulations are conducted in order to evaluate the proposed relocation and self-healing algorithms. An average of 94% coverage is achieved in the cases that we are examined with or without obstacles.
基金supported by the National Science Funds for Excellent Young Scholars of China (Grant No. 61822106)National Science Funds for Creative Research Groups of China (Grant No. 61421002)+1 种基金Natural Science Foundation of China (Grant No. 61671115)Opening Project of State Key Laboratory of Polymer Materials Engineering (Sichuan University) (Grant No. sklpme 2018-4-28)
文摘A new family of transparent,biocompatible,self-adhesive,and self-healing elastomer has been developed by a convenient and efficient one-pot reaction between poly(acrylic acid)(PAA)and hydroxyl-terminated polydimethylsiloxane(PDMSOH).The condensation reaction between PAA and PDMS-OH has been confirmed by attenuated total reflection Fourier transform infrared(ATR-FTIR)spectra.The prepared PAA-PDMS elastomers possess robust mechanical strength and strong adhesiveness to human skin,and they have fast self-healing ability at room temperature(in^10 s with the efficiency of 98%).Specifically,strain sensors were fabricated by assembling PAA-PDMS as packaging layers and polyetherimide-reduced graphene oxide(PEI-rGO)as strain-sensing layers.The PAA-PDMS/PEI-rGO sensors are stably and reliably responsive to slight physical deformations,and they can be attached onto skin directly to monitor the body’s motions.Meanwhile,strain sensors can self-heal quickly and completely,and they can be reused for the motion detecting after shallowly scratching the surface.This work provides new opportunities to manufacture high performance self-adhesive and self-healing materials.
基金Supported by the Open Project of Key Laboratory of Marine New Materials of CNITECH(No.LMMT-KFKT-2014-008)the National Basic Research Program of China(973 Program)(No.2014CB643304)
文摘Defects in protective-coating systems on steel surfaces are inevitable in practical engineering applications.A composite coating system,including a primer,middle coat and topcoat,were used to protect carbon steel from corrosion in a marine environment.Two environmental additives,glass fi bers and thiourea,were applied in the middle coat to modify the coating system.The long-term corrosion durability and self-healing ability of the scratched coating system were evaluated by multiple methods.Results of the electrochemical technologies indicated that the coating system that contained 0.5 wt.%fi bers and 0.5 wt.%thiourea presented good corrosion protection and self-healing for carbon steel when immersed in 3.5%Na Cl for 120 d.Evolution of localized corrosion factors with time,as obtained from the current distribution showed that fi bers combined with thiourea could inhibit the occurrence of local corrosion in scratched coating systems and retarded the corrosion development signifi cantly.Surface characterization suggested that adequate thiourea could be absorbed uniformly on fi bers for a long time to play an important role in protecting the carbon steel.Finally,schematic models were established to demonstrate the action of fi bers and thiourea on the exposed surface of the carbon steel and the scratched coating system in the entire deterioration process.
文摘Based on ATM Multi section backup VP self healing scheme, analysis of cell loss probability under finite buffer is made by use of queue system method. Optimal buffer size can be fixed on.
基金partially the 863 program (2014AA01A701)National Nature Science Foundation of China (61271187)
文摘To employ the network resources more effectively and fl exibly,cloud radio access network(C-RAN) adopts centralized network construction and management. Since the new network characteristics,the self-healing is reliable distinguish compared with previous studies. This paper drives a solution for selfhealing based on cooperative transmission and power adjustment under C-RAN self-healing management architecture. This compensation model with the aim to maximize the number of connected UEs and optimize power regulation is solved by Benders' decomposition algorithm. And through the simulation,this paper verifies the speediness and effectiveness of this scheme.
文摘An important area of focus in complex systems development is the capability to adapt to variable runtime environ- mental resources and to accommodate runtime system failures. The research in this area is broadly termed as “Self Healing” and has recently aroused increasing attention to complex systems. Digital libraries have gained popularity because of the richer fea- tures they provide compared to traditional libraries. As more users begin to use digital libraries, addressing downtimes of these valuable resources has become a high priority. Operating and providing access to digital content to anyone, anytime from any- where in the world, results in a continued rise of administrative overhead for system monitoring and needs continuous human intervention. Given the volume of information and the huge infrastructure of modern libraries, continuous manual system ad- ministration is quite costly and not feasible. In this paper we propose a self healing digital library system as the solution to this problem and present the approach of adding self healing capabilities to an existing digital library project, the Digital Library of India (DLI). We also propose a self healing framework that enables successful reuse of our approach to other architecturally similar digital library systems.