With the maturation of P2P technology, there are more and more challenges to the protection of digital rights. DRM for traditional Client/Server model can not satisfy the requirement of digital right protection of P2P...With the maturation of P2P technology, there are more and more challenges to the protection of digital rights. DRM for traditional Client/Server model can not satisfy the requirement of digital right protection of P2P network. With practical application of P2P network technology and new generational DRM technology, the article proposes a DRM model for P2P system based on trust degree. The proposed model shares the secret key to the trusty peers and affords necessary security ensure for digital content delivery based on P2P technology. Mathematic analyses and simulations show that, compared to the current DRM model, the proposed model is more robust toleration of transmit and security.展开更多
The key problem in unstructured P2P system is how to control "Flood".Some studies focus on constructing more efficient topology while others focus on better query algorithms.This paper presents HICUS(Hierarc...The key problem in unstructured P2P system is how to control "Flood".Some studies focus on constructing more efficient topology while others focus on better query algorithms.This paper presents HICUS(Hierarchical Interest-driven Community-based Unstructured System) motivated by a basic thought-whether the resources correlate with topology distinguishes structured and unstruc-tured P2P essentially.By introducing hierarchical "interest",HICUS organizes a quasi-structured topology through a pure distributed way,and provides a new platform for query algorithms.We study the procedure and performance of topology organization,and the simulations show that HICUS forms a small-world which can significantly improve the routing efficiency.展开更多
为应对配电网络低碳化运行的挑战,并充分挖掘系统中分布式资源的灵活调控潜力,文中构建一种基于电碳综合边际定价的虚拟电厂(virtual power plant,VPP)双层点对点(peer-to-peer,P2P)交易模型。上层由配电网运营商(distribution system o...为应对配电网络低碳化运行的挑战,并充分挖掘系统中分布式资源的灵活调控潜力,文中构建一种基于电碳综合边际定价的虚拟电厂(virtual power plant,VPP)双层点对点(peer-to-peer,P2P)交易模型。上层由配电网运营商(distribution system operator,DSO)建立基于碳排放流(carbon emission flow,CEF)技术的碳感知最优潮流模型,在此基础上计算出电碳综合边际价格,DSO可利用该价格信号协调VPP低碳调度。下层组建多VPP合作联盟,可将电动汽车规模化整合并引入碳信号引导的电动汽车灵活调度机制,建立基于贡献度的非对称纳什议价交易模型,各VPP在价格信号的引导下平衡个体与联盟利益,制定生产与交易的最优策略。然后,采用自适应交替方向乘子法(adaptive-scaling alternating direction method of multipliers,AS-ADMM)对模型进行求解,解决变量耦合导致的收敛速度问题。最后,采用改进的IEEE 33节点配电系统进行仿真验证。案例分析结果表明,所提交易模型可以通过提高分布式能源利用效率并优化负荷分布,在降低VPP运营成本的同时减少配电网碳排放。展开更多
P2P2B模式下云服务投入是工业互联网(industrial internet of things,IIoT)平台的关键战略决策之一.构建由IIoT平台、龙头企业、潜在客户构成的演化博弈模型,研究IIoT平台在公有云研发投入和私有云研发投入中的策略选择,及其与龙头企业...P2P2B模式下云服务投入是工业互联网(industrial internet of things,IIoT)平台的关键战略决策之一.构建由IIoT平台、龙头企业、潜在客户构成的演化博弈模型,研究IIoT平台在公有云研发投入和私有云研发投入中的策略选择,及其与龙头企业的生态合作问题.结果表明:虽然公有云存在数据泄露隐患,但较高的规模收益仍会吸引IIoT平台投入公有云研发,而平台搭建期内龙头企业的高合作意愿会促使平台投入私有云,随着龙头企业合作研发的比例增加,平台又将改变其投入策略.驱动龙头企业合作的因素可以是成本收益、技术提升等直接因素,也可以是规模收益、数据泄露概率等间接因素.最后,基于平台生命周期探讨了初创期、平台搭建期与生态系统期IIoT平台的系统稳定策略,并得到相应的管理启示.展开更多
Multimedia teaching managemem system based on SIP ＆ P2P is proposed on account of the existing deficiency on video teaching of distance education. The designed P2P-SIP system applies SIP protocol to realize the under...Multimedia teaching managemem system based on SIP ＆ P2P is proposed on account of the existing deficiency on video teaching of distance education. The designed P2P-SIP system applies SIP protocol to realize the underlying DHT, which guarantees zero-configuration, robustness and adaptability in P2P system. And maximum improvement in performance of the networks for multimedia system can be implemented by rapid networking and information sharing technology of the underlying P2P networks as well as fast call and location technology of SIP system. Experiments indicates that multimedia teaching management system based on SIP ＆ P2P could meet the requirement of system design on data latency and calling location.展开更多
随着能源系统互联化和能源交易市场化的高度发展,通过多综合能源系统(Multi-Integrated Energy System,MIES)的区域互联使综合能源系统(Integrated Energy System,IES)的能源利用率更高效、经济收益更可观。首先,文中构建多能源市场背...随着能源系统互联化和能源交易市场化的高度发展,通过多综合能源系统(Multi-Integrated Energy System,MIES)的区域互联使综合能源系统(Integrated Energy System,IES)的能源利用率更高效、经济收益更可观。首先,文中构建多能源市场背景下的MIES合作联盟的能量共享架构,建立MIES之间的电能和备用点对点(Point To Point,P2P)交易模型;其次,对新能源出力的不确定性,电价及备用价格波动风险进行分析,文中采用条件风险价值(Conditional Value-at-Risk,CVaR)理论,构建风险成本函数,并将其纳入综合运行成本模型;最后,选择交替方向乘子法(Alternating Direction Method Of Multipliers,ADMM)进行分布式求解,并通过算例分析验证模型的正确性与合理性,实现MIES运行成本的最小化和支付收益最大化,体现不同条件风险厌恶系数对MIES的影响。展开更多
A hierarchical peer-to-peer（P2P）model and a data fusion method for network security situation awareness system are proposed to improve the efficiency of distributed security behavior monitoring network.The single po...A hierarchical peer-to-peer（P2P）model and a data fusion method for network security situation awareness system are proposed to improve the efficiency of distributed security behavior monitoring network.The single point failure of data analysis nodes is avoided by this P2P model,in which a greedy data forwarding method based on node priority and link delay is devised to promote the efficiency of data analysis nodes.And the data fusion method based on repulsive theory-Dumpster/Shafer（PSORT-DS）is used to deal with the challenge of multi-source alarm information.This data fusion method debases the false alarm rate.Compared with improved Dumpster/Shafer（DS）theoretical method based on particle swarm optimization（PSO）and classical DS evidence theoretical method,the proposed model reduces false alarm rate by 3%and 7%,respectively,whereas their detection rate increases by 4%and 16%,respectively.展开更多
We consider the problem of efficiently computing distributed geographical k-NN queries in an unstructured peer-to-peer （P2P） system, in which each peer is managed by an individual organization and can only communica...We consider the problem of efficiently computing distributed geographical k-NN queries in an unstructured peer-to-peer （P2P） system, in which each peer is managed by an individual organization and can only communicate with its logical neighboring peers. Such queries are based on local filter query statistics, and require as less communication cost as possible which makes it more difficult than the existing distributed k-NN queries. Especially, we hope to reduce candidate peers and degrade communication cost. In this paper, we propose an efficient pruning technique to minimize the number of candidate peers to be processed to answer the k-NN queries. Our approach is especially suitable for continuous k-NN queries when updating peers, including changing ranges of peers, dynamically leaving or joining peers, and updating data in a peer. In addition, simulation results show that the proposed approach outperforms the existing Minimum Bounding Rectangle （MBR）-based query approaches, especially for continuous queries.展开更多
This paper presents a P2P VOD system based on RF-IPS algorithm, and this system consists of two parts, server-side and clients. We put emphasis on the piece selection module of server-side, and in this part we cite th...This paper presents a P2P VOD system based on RF-IPS algorithm, and this system consists of two parts, server-side and clients. We put emphasis on the piece selection module of server-side, and in this part we cite the RF-IPS algorithm proposed in the past. In the piece selection module, we also proposed a weighting function except the RF-IPS algorithm. Using this function we will find the best server peers effectively and quickly, it will enhance the performance of this system. We carry on experiments on RF-IPS algorithm, and the results show this algorithm is efficient. Overall, we believe that the RF-IPS algorithm is feasible to further improve system performance and provide a cost-effective P2P VOD service with acceptable user experience.展开更多
More and more modern group oriented collaborativeapplications use the peer-to-peer(P2P)paradigm tobe independent of expensive infrastructures as theyare,for instance,provided for audio and video conferencesby H.323 sy...More and more modern group oriented collaborativeapplications use the peer-to-peer(P2P)paradigm tobe independent of expensive infrastructures as theyare,for instance,provided for audio and video conferencesby H.323 systems.Decentralized collaborativeP2P solutions require appropriate mechanismsto protect group privacy and data integrity.A centralizedclient/server based video conference system canbe well shielded in a standard manner,whilst thereare no off-the-shelf approaches to secure a P2P videoconference up to now.The paper addresses this issueand presents a flexible security architecture.Usingthe BRAVIS system[4]as an example it shows howthe architecture can be embedded into a P2P videoconferencing system.展开更多
For lack of effective resource adjustment method, the supply-demand relationship of each resource in P2P content delivery system are often unbalanced. Especially after a popular content releasing, a burst of downloade...For lack of effective resource adjustment method, the supply-demand relationship of each resource in P2P content delivery system are often unbalanced. Especially after a popular content releasing, a burst of downloaders often can＇t find sufficient uploaders and their request may starve the upload capacity of server. Therefore the overall system QoS may be degraded. To tackle such issue, this paper proposes a download rate accelerate mechanism, called motivate mechanism. With it, the system can quickly find out the files becoming insufficient by monitoring the operating status of the files hourly, Then it promptly increase the number of copies of those files by using free rider nodes so that the whole system QoS is maintained and the system performance is improved. The experiment results on the practical operating system of Tencent demonstrated that the proposed mechanism increases the download rate, saves the traffic on the server and optimizes the system performance.展开更多
In peer-to-peer (P2P) reputation systems,each peer's trustworthiness is evaluated based on its pseudonym's rating values given by other peers. Since it is assumed that each peer has a long lived pseudonym,all ...In peer-to-peer (P2P) reputation systems,each peer's trustworthiness is evaluated based on its pseudonym's rating values given by other peers. Since it is assumed that each peer has a long lived pseudonym,all the transactions conducted by the same peer may be linked by its pseudonym. Therefore,one of the fundamental challenges in P2P reputation systems is to protect peers' identity privacy. In this paper,we present two independent anonymity protocols to achieve all the peers' anonymity by changing pseudonym with the help of a trusted third party (TTP) server. Compared with RuP (Reputation using Pseudonym),an existing representative scheme,our protocols reduce the server's cost in two different ways. First,we propose a protocol using blind signature scheme as in RuP. The protocol improves the blind signature scheme and assessment of macro-node values,and reduces the server's cost by half in terms of encryption and decryption operations and message overhead. Second,we propose another protocol,group-confusion protocol,to further reduce the server's cost.展开更多
IIn order to improve the performance of wireless distributed peer-to-peer(P2P)files sharing systems,a general system architecture and a novel peer selecting model based on fuzzy cognitive maps(FCM)are proposed in this...IIn order to improve the performance of wireless distributed peer-to-peer(P2P)files sharing systems,a general system architecture and a novel peer selecting model based on fuzzy cognitive maps(FCM)are proposed in this paper.The new model provides an effective approach on choosing an optimal peer from several resource discovering results for the best file transfer.Compared with the traditional min-hops scheme that uses hops as the only selecting criterion,the proposed model uses FCM to investigate the complex relationships among various relative factors in wireless environments and gives an overall evaluation score on the candidate.It also has strong scalability for being independent of specified P2P resource discovering protocols.Furthermore,a complete implementation is explained in concrete modules.The simulation results show that the proposed model is effective and feasible compared with min-hops scheme,with the success transfer rate increased by at least 20% and transfer time improved as high as 34%.展开更多
HitPeers conotitute a scalable and highly efficient P2P file sharing system in which all the data file can be shared. The center of HitPeers is the Category Tree (CT). CT collects the published information with catego...HitPeers conotitute a scalable and highly efficient P2P file sharing system in which all the data file can be shared. The center of HitPeers is the Category Tree (CT). CT collects the published information with category. It is flexible enough to let users customize their own local CT. Its hierarchy helps users to find the information they desire most conveniently. To increase the robustness and retain the efficiency, HitPeers will divide the tree into disjoint parts. Every part is a subtree. Some special nodes named Onodes will take charge of the subtree and play the role of a service provider. HitPeers produce more and more Onodes to meet the service demands in the internet scale distributed environment. This paper will show the profile of the whole system.展开更多
A P2P scientific collaboration is a P2P network whose members can share documents, co-compile papers and codes, and communicate with each other instantly. From the simulation experiment we found that P2P collaboration...A P2P scientific collaboration is a P2P network whose members can share documents, co-compile papers and codes, and communicate with each other instantly. From the simulation experiment we found that P2P collaboration system is a power-law network with a tail between -2 and -3.We utilized the algorithm that searches by high-degree shortcuts to improve the scalability of p2p collaboration system. The experimental result shows that the algorithm works better than random walk algorithm.展开更多
基金Supported by the National Natural Science Foun-dation of China (60502024) the Natural Science Foundation of HubeiProvince (2005ABA267) +1 种基金the Electronic Development Foundation ofMinistry of InformationIndustry of China theInnovation FundforTechnology Based Firms of Ministry of Science and Technology ofChina (04C26214201284)
文摘With the maturation of P2P technology, there are more and more challenges to the protection of digital rights. DRM for traditional Client/Server model can not satisfy the requirement of digital right protection of P2P network. With practical application of P2P network technology and new generational DRM technology, the article proposes a DRM model for P2P system based on trust degree. The proposed model shares the secret key to the trusty peers and affords necessary security ensure for digital content delivery based on P2P technology. Mathematic analyses and simulations show that, compared to the current DRM model, the proposed model is more robust toleration of transmit and security.
基金Supported by the National Natural Science Foundation of China (No.60602018 and 60772033)
文摘The key problem in unstructured P2P system is how to control "Flood".Some studies focus on constructing more efficient topology while others focus on better query algorithms.This paper presents HICUS(Hierarchical Interest-driven Community-based Unstructured System) motivated by a basic thought-whether the resources correlate with topology distinguishes structured and unstruc-tured P2P essentially.By introducing hierarchical "interest",HICUS organizes a quasi-structured topology through a pure distributed way,and provides a new platform for query algorithms.We study the procedure and performance of topology organization,and the simulations show that HICUS forms a small-world which can significantly improve the routing efficiency.
文摘为应对配电网络低碳化运行的挑战,并充分挖掘系统中分布式资源的灵活调控潜力,文中构建一种基于电碳综合边际定价的虚拟电厂(virtual power plant,VPP)双层点对点(peer-to-peer,P2P)交易模型。上层由配电网运营商(distribution system operator,DSO)建立基于碳排放流(carbon emission flow,CEF)技术的碳感知最优潮流模型,在此基础上计算出电碳综合边际价格,DSO可利用该价格信号协调VPP低碳调度。下层组建多VPP合作联盟,可将电动汽车规模化整合并引入碳信号引导的电动汽车灵活调度机制,建立基于贡献度的非对称纳什议价交易模型,各VPP在价格信号的引导下平衡个体与联盟利益,制定生产与交易的最优策略。然后,采用自适应交替方向乘子法(adaptive-scaling alternating direction method of multipliers,AS-ADMM)对模型进行求解,解决变量耦合导致的收敛速度问题。最后,采用改进的IEEE 33节点配电系统进行仿真验证。案例分析结果表明,所提交易模型可以通过提高分布式能源利用效率并优化负荷分布,在降低VPP运营成本的同时减少配电网碳排放。
文摘P2P2B模式下云服务投入是工业互联网(industrial internet of things,IIoT)平台的关键战略决策之一.构建由IIoT平台、龙头企业、潜在客户构成的演化博弈模型,研究IIoT平台在公有云研发投入和私有云研发投入中的策略选择,及其与龙头企业的生态合作问题.结果表明:虽然公有云存在数据泄露隐患,但较高的规模收益仍会吸引IIoT平台投入公有云研发,而平台搭建期内龙头企业的高合作意愿会促使平台投入私有云,随着龙头企业合作研发的比例增加,平台又将改变其投入策略.驱动龙头企业合作的因素可以是成本收益、技术提升等直接因素,也可以是规模收益、数据泄露概率等间接因素.最后,基于平台生命周期探讨了初创期、平台搭建期与生态系统期IIoT平台的系统稳定策略,并得到相应的管理启示.
文摘Multimedia teaching managemem system based on SIP ＆ P2P is proposed on account of the existing deficiency on video teaching of distance education. The designed P2P-SIP system applies SIP protocol to realize the underlying DHT, which guarantees zero-configuration, robustness and adaptability in P2P system. And maximum improvement in performance of the networks for multimedia system can be implemented by rapid networking and information sharing technology of the underlying P2P networks as well as fast call and location technology of SIP system. Experiments indicates that multimedia teaching management system based on SIP ＆ P2P could meet the requirement of system design on data latency and calling location.
文摘随着能源系统互联化和能源交易市场化的高度发展,通过多综合能源系统(Multi-Integrated Energy System,MIES)的区域互联使综合能源系统(Integrated Energy System,IES)的能源利用率更高效、经济收益更可观。首先,文中构建多能源市场背景下的MIES合作联盟的能量共享架构,建立MIES之间的电能和备用点对点(Point To Point,P2P)交易模型;其次,对新能源出力的不确定性,电价及备用价格波动风险进行分析,文中采用条件风险价值(Conditional Value-at-Risk,CVaR)理论,构建风险成本函数,并将其纳入综合运行成本模型;最后,选择交替方向乘子法(Alternating Direction Method Of Multipliers,ADMM)进行分布式求解,并通过算例分析验证模型的正确性与合理性,实现MIES运行成本的最小化和支付收益最大化,体现不同条件风险厌恶系数对MIES的影响。
基金Supported by the National Natural Science Foundation of China(61370212)the Research Fund for the Doctoral Program of Higher Education of China(20122304130002)+1 种基金the Natural Science Foundation of Heilongjiang Province(ZD 201102)the Fundamental Research Fund for the Central Universities(HEUCFZ1213,HEUCF100601)
文摘A hierarchical peer-to-peer（P2P）model and a data fusion method for network security situation awareness system are proposed to improve the efficiency of distributed security behavior monitoring network.The single point failure of data analysis nodes is avoided by this P2P model,in which a greedy data forwarding method based on node priority and link delay is devised to promote the efficiency of data analysis nodes.And the data fusion method based on repulsive theory-Dumpster/Shafer（PSORT-DS）is used to deal with the challenge of multi-source alarm information.This data fusion method debases the false alarm rate.Compared with improved Dumpster/Shafer（DS）theoretical method based on particle swarm optimization（PSO）and classical DS evidence theoretical method,the proposed model reduces false alarm rate by 3%and 7%,respectively,whereas their detection rate increases by 4%and 16%,respectively.
基金the Program for New Century Excellent Talents in Universities(Grant No.NCET-06-0290)the National Natural Science Foundation of China(Grant Nos.60503036,and 60773221)+1 种基金the National High-Tech Development 863 Program of China(Grant No.2006AA09Z139)the Fok Ying Tong Education Foundation Award(Grant No.104027)
文摘We consider the problem of efficiently computing distributed geographical k-NN queries in an unstructured peer-to-peer （P2P） system, in which each peer is managed by an individual organization and can only communicate with its logical neighboring peers. Such queries are based on local filter query statistics, and require as less communication cost as possible which makes it more difficult than the existing distributed k-NN queries. Especially, we hope to reduce candidate peers and degrade communication cost. In this paper, we propose an efficient pruning technique to minimize the number of candidate peers to be processed to answer the k-NN queries. Our approach is especially suitable for continuous k-NN queries when updating peers, including changing ranges of peers, dynamically leaving or joining peers, and updating data in a peer. In addition, simulation results show that the proposed approach outperforms the existing Minimum Bounding Rectangle （MBR）-based query approaches, especially for continuous queries.
文摘This paper presents a P2P VOD system based on RF-IPS algorithm, and this system consists of two parts, server-side and clients. We put emphasis on the piece selection module of server-side, and in this part we cite the RF-IPS algorithm proposed in the past. In the piece selection module, we also proposed a weighting function except the RF-IPS algorithm. Using this function we will find the best server peers effectively and quickly, it will enhance the performance of this system. We carry on experiments on RF-IPS algorithm, and the results show this algorithm is efficient. Overall, we believe that the RF-IPS algorithm is feasible to further improve system performance and provide a cost-effective P2P VOD service with acceptable user experience.
文摘More and more modern group oriented collaborativeapplications use the peer-to-peer(P2P)paradigm tobe independent of expensive infrastructures as theyare,for instance,provided for audio and video conferencesby H.323 systems.Decentralized collaborativeP2P solutions require appropriate mechanismsto protect group privacy and data integrity.A centralizedclient/server based video conference system canbe well shielded in a standard manner,whilst thereare no off-the-shelf approaches to secure a P2P videoconference up to now.The paper addresses this issueand presents a flexible security architecture.Usingthe BRAVIS system[4]as an example it shows howthe architecture can be embedded into a P2P videoconferencing system.
基金National Science Foundation Project of P.R.China，China Postdoctoral Science Foundation，the Fundamental Research Funds for the Central Universities
文摘For lack of effective resource adjustment method, the supply-demand relationship of each resource in P2P content delivery system are often unbalanced. Especially after a popular content releasing, a burst of downloaders often can＇t find sufficient uploaders and their request may starve the upload capacity of server. Therefore the overall system QoS may be degraded. To tackle such issue, this paper proposes a download rate accelerate mechanism, called motivate mechanism. With it, the system can quickly find out the files becoming insufficient by monitoring the operating status of the files hourly, Then it promptly increase the number of copies of those files by using free rider nodes so that the whole system QoS is maintained and the system performance is improved. The experiment results on the practical operating system of Tencent demonstrated that the proposed mechanism increases the download rate, saves the traffic on the server and optimizes the system performance.
基金the National High Technology Research and Development Program (863) of China(No. 07QA14033)the National Natural Science Foundation of China(No.60702047)
文摘In peer-to-peer (P2P) reputation systems,each peer's trustworthiness is evaluated based on its pseudonym's rating values given by other peers. Since it is assumed that each peer has a long lived pseudonym,all the transactions conducted by the same peer may be linked by its pseudonym. Therefore,one of the fundamental challenges in P2P reputation systems is to protect peers' identity privacy. In this paper,we present two independent anonymity protocols to achieve all the peers' anonymity by changing pseudonym with the help of a trusted third party (TTP) server. Compared with RuP (Reputation using Pseudonym),an existing representative scheme,our protocols reduce the server's cost in two different ways. First,we propose a protocol using blind signature scheme as in RuP. The protocol improves the blind signature scheme and assessment of macro-node values,and reduces the server's cost by half in terms of encryption and decryption operations and message overhead. Second,we propose another protocol,group-confusion protocol,to further reduce the server's cost.
基金Sponsored by the National Natural Science Foundation of China(Grant No.60672124 and 60832009)Hi-Tech Research and Development Program(National 863 Program)(Grant No.2007AA01Z221)
文摘IIn order to improve the performance of wireless distributed peer-to-peer(P2P)files sharing systems,a general system architecture and a novel peer selecting model based on fuzzy cognitive maps(FCM)are proposed in this paper.The new model provides an effective approach on choosing an optimal peer from several resource discovering results for the best file transfer.Compared with the traditional min-hops scheme that uses hops as the only selecting criterion,the proposed model uses FCM to investigate the complex relationships among various relative factors in wireless environments and gives an overall evaluation score on the candidate.It also has strong scalability for being independent of specified P2P resource discovering protocols.Furthermore,a complete implementation is explained in concrete modules.The simulation results show that the proposed model is effective and feasible compared with min-hops scheme,with the success transfer rate increased by at least 20% and transfer time improved as high as 34%.
文摘HitPeers conotitute a scalable and highly efficient P2P file sharing system in which all the data file can be shared. The center of HitPeers is the Category Tree (CT). CT collects the published information with category. It is flexible enough to let users customize their own local CT. Its hierarchy helps users to find the information they desire most conveniently. To increase the robustness and retain the efficiency, HitPeers will divide the tree into disjoint parts. Every part is a subtree. Some special nodes named Onodes will take charge of the subtree and play the role of a service provider. HitPeers produce more and more Onodes to meet the service demands in the internet scale distributed environment. This paper will show the profile of the whole system.
文摘A P2P scientific collaboration is a P2P network whose members can share documents, co-compile papers and codes, and communicate with each other instantly. From the simulation experiment we found that P2P collaboration system is a power-law network with a tail between -2 and -3.We utilized the algorithm that searches by high-degree shortcuts to improve the scalability of p2p collaboration system. The experimental result shows that the algorithm works better than random walk algorithm.
