摘要 :
Electronic commerce covers trading activities that are supported by information and communication technologies. Digital commerce defines a particular subset of electronic commerce. There are only digital products or digital servic...
展开
Electronic commerce covers trading activities that are supported by information and communication technologies. Digital commerce defines a particular subset of electronic commerce. There are only digital products or digital services involved and every auxiliary used for trading is digital, either. Distributed digital commerce in particular is an approach to relocate digital commerce from client-server structures towards decentralized architectures. This paper targets on distributed digital commerce. It develops a reference model to describe processes involved in digital trading. Furthermore, they are mapped onto decentralized systems and their characteristics. Digital marketplaces are central instances coordinating digital commerce. They are both examined and harmonized with the process model. In particular, characteristics of distributed digital marketplaces are drawn up for they are essentially in the decentralized approach. Finally, the concept of digital money is considered. It can be used forpayment without involving a server-based bank and therefore supports the decentralized idea.
收起
摘要 :
This paper will discuss the use of SOLAR-CATS, a teaching tool for large size computer laboratories and small size seminar classes. SOLAR-CATS uses a peer-to-peer (P2P) technology and does not need a server. SOLAR-CATS includes fu...
展开
This paper will discuss the use of SOLAR-CATS, a teaching tool for large size computer laboratories and small size seminar classes. SOLAR-CATS uses a peer-to-peer (P2P) technology and does not need a server. SOLAR-CATS includes functions such as the remote operation of an application program on every PC in the class from one PC in the class, the sending of an image on one display in the class to all other class members' display, the interactive operation of an application with all class members, and the recording and replaying of operations on SOLAR-CATS. We have been using SOLAR-CATS for elementary computer literacy classes for several years. Each class contains about 50 students. Each student in the class could see small size letters and pictures on the display in front of him/her. We did not require support from the laboratory's manager to install the SOLAR-CATS program and to maintain the program. The program was distributed by us using USB keys. We also have used SOLAR-CATS for a smaller (three-eight students) seminar class. Students and the teacher could enjoyably deal with a subject by interacting with the class members.
收起
摘要 :
This paper will discuss the use of SOLAR-CATS, a teaching tool for large size computer laboratories and small size seminar classes. SOLAR-CATS uses a peer-to-peer (P2P) technology and does not need a server. SOLAR-CATS includes fu...
展开
This paper will discuss the use of SOLAR-CATS, a teaching tool for large size computer laboratories and small size seminar classes. SOLAR-CATS uses a peer-to-peer (P2P) technology and does not need a server. SOLAR-CATS includes functions such as the remote operation of an application program on every PC in the class from one PC in the class, the sending of an image on one display in the class to all other class members' display, the interactive operation of an application with all class members, and the recording and replaying of operations on SOLAR-CATS. We have been using SOLAR-CATS for elementary computer literacy classes for several years. Each class contains about 50 students. Each student in the class could see small size letters and pictures on the display in front of him/her. We did not require support from the laboratory's manager to install the SOLAR-CATS program and to maintain the program. The program was distributed by us using USB keys. We also have used SOLAR-CATS for a smaller (three-eight students) seminar class. Students and the teacher could enjoyably deal with a subject by interacting with the class members.
收起
摘要 :
Popular Peer to Peer (P2P) file-sharing applications like BitTorrent are using segmented file transfer for faster downloads. Peers request chunks of a file from each other and thus retrieve these chunks using cryptographic hashes....
展开
Popular Peer to Peer (P2P) file-sharing applications like BitTorrent are using segmented file transfer for faster downloads. Peers request chunks of a file from each other and thus retrieve these chunks using cryptographic hashes. This concept of simultaneously downloading different portions of the computer file from either multiple servers or a from a single server is a time tested method of improving downloading speeds. This paper presents a peer-assisted parallel downloading system which uses the concept of segmented file transfer to decrease the download time and also aims to be truly decentralised. The proposed system has peers, that can offer high data transfer rates and are in close proximity to the peer interested in downloading the file, themselves download chunks of the file and stream it to the requestor. This allows the utilization of unused bandwidth while reducing the download time. The use of a custom scoring logic which penalises free riders in the network to contribute towards assistance helps maintain balance in the network while reducing the overall time for download for peers with low data transfer rates. Tests show the overall download time for files can be effectively reduced by 15% for peers with poor data transfer rates.
收起
摘要 :
We consider the problem of indexing high-dimensional data for answering (approximate) similarity-search queries. Similarity indexes prove to be important in a wide variety of settings: Web search engines desire fast, parallel, mai...
展开
We consider the problem of indexing high-dimensional data for answering (approximate) similarity-search queries. Similarity indexes prove to be important in a wide variety of settings: Web search engines desire fast, parallel, main-memory-based indexes for similarity search on text data; database systems desire disk-based similarity indexes for high-dimensional data, including text and images; peer-to-peer systems desire distributed similarity indexes with low communication cost. We propose an indexing scheme called LSH Forest which is applicable in all the above contexts. Our index uses the well-known technique of locality-sensitive hashing (LSH), but improves upon previous designs by (a) eliminating the different data-dependent parameters for which LSH must be constantly hand-tuned, and (b) improving on LSH's performance guarantees for skewed data distributions while retaining the same storage and query overhead. We show how to construct this index in main memory, on disk, in parallel systems, and in pcer-to-peer systems. We evaluate the design with experiments on multiple text corpora and demonstrate both the self-tuning nature and the superior performance of LSH Forest.
收起
摘要 :
We consider the problem of indexing high-dimensional data for answering (approximate) similarity-search queries. Similarity indexes prove to be important in a wide variety of settings: Web search engines desire fast, parallel, mai...
展开
We consider the problem of indexing high-dimensional data for answering (approximate) similarity-search queries. Similarity indexes prove to be important in a wide variety of settings: Web search engines desire fast, parallel, main-memory-based indexes for similarity search on text data; database systems desire disk-based similarity indexes for high-dimensional data, including text and images; peer-to-peer systems desire distributed similarity indexes with low communication cost. We propose an indexing scheme called LSH Forest which is applicable in all the above contexts. Our index uses the well-known technique of locality-sensitive hashing (LSH), but improves upon previous designs by (a) eliminating the different data-dependent parameters for which LSH must be constantly hand-tuned, and (b) improving on LSH's performance guarantees for skewed data distributions while retaining the same storage and query overhead. We show how to construct this index in main memory, on disk, in parallel systems, and in pcer-to-peer systems. We evaluate the design with experiments on multiple text corpora and demonstrate both the self-tuning nature and the superior performance of LSH Forest.
收起
摘要 :
Peer-to-Peer (P2P) technique manifests file sharing, distributed computing, and communication. and collaboration between peers in contrast to client/ server architectures. P2P digital society is emerging in our life. It changes ou...
展开
Peer-to-Peer (P2P) technique manifests file sharing, distributed computing, and communication. and collaboration between peers in contrast to client/ server architectures. P2P digital society is emerging in our life. It changes our way of living, work, and play. Meanwhile, the trust is still a core issue in P2P digital society. The objective of this paper is to survey trust in P2P digital society from the point of economics view. Through employing the framework previously proposed, some implications on trust in P2P applications are given from the economics perspective. In this paper, we analyze trust emerging in P2P digital society through the economics perspective from the following levels: technology, product, business process, market, and the macroeconomic.
收起
摘要 :
Peer-to-peer (P2P) based content distribution networks (CDNs), e.g., BitTorrent, are widely used in the today's Internet. Since all peers interested in a specific content provide storage and upload capacity those CDNs facilitate a...
展开
Peer-to-peer (P2P) based content distribution networks (CDNs), e.g., BitTorrent, are widely used in the today's Internet. Since all peers interested in a specific content provide storage and upload capacity those CDNs facilitate a cheap and easy distribution of large amounts of data. However, they generate a lot of costs for Internet Service Providers (ISPs) as normal users also act as a source for downloads. One option for ISPs to encounter the problem of the costly inter-domain traffic is to establish P2P caches. In this study we investigate the potential of those caches in flash-crowd scenarios, i.e., when a large number of peers tries to download the content at the same time. To that end, we perform simulations as well as experiments with real BitTorrent clients. The evaluation shows that ISPs as well as P2P users will benefit from the use of caches.
收起
摘要 :
Peer-to-peer (P2P) based content distribution networks (CDNs), e.g., BitTorrent, are widely used in the today's Internet. Since all peers interested in a specific content provide storage and upload capacity those CDNs facilitate a...
展开
Peer-to-peer (P2P) based content distribution networks (CDNs), e.g., BitTorrent, are widely used in the today's Internet. Since all peers interested in a specific content provide storage and upload capacity those CDNs facilitate a cheap and easy distribution of large amounts of data. However, they generate a lot of costs for Internet Service Providers (ISPs) as normal users also act as a source for downloads. One option for ISPs to encounter the problem of the costly inter-domain traffic is to establish P2P caches. In this study we investigate the potential of those caches in flash-crowd scenarios, i.e., when a large number of peers tries to download the content at the same time. To that end, we perform simulations as well as experiments with real BitTorrent clients. The evaluation shows that ISPs as well as P2P users will benefit from the use of caches.
收起
摘要 :
BitTorrent protocol has been quite successful in capturing majority of Internet traffic since its inception due to its various mechanisms to improve the download performance of the network. The mechanisms like tit-for-tat, optimis...
展开
BitTorrent protocol has been quite successful in capturing majority of Internet traffic since its inception due to its various mechanisms to improve the download performance of the network. The mechanisms like tit-for-tat, optimistic unchoking, anti-snubbing and various piece selection strategy, etc. have been working very well. This work is an attempt to study the performance of BitTorrent protocol and its networking infrastructure through two strategies, namely, (A) Simulations based using BitTorrent patch in ns-2 simulator and (B) Real networks using client implementation based on libtorrent library. Empirical results thus obtained are used to infer various performance parameters of BitTorrent protocols.
收起
原文获取