Orbit Weighting Scheme in the Context of Vector Space Information Retrieval

This study introduces the Orbit Weighting Scheme(OWS),a novel approach aimed at enhancing the precision and efficiency of Vector Space information retrieval(IR)models,which have traditionally relied on weighting schemes like tf-idf and BM25.These conventional methods often struggle with accurately capturing document relevance,leading to inefficiencies in both retrieval performance and index size management.OWS proposes a dynamic weighting mechanism that evaluates the significance of terms based on their orbital position within the vector space,emphasizing term relationships and distribution patterns overlooked by existing models.Our research focuses on evaluating OWS’s impact on model accuracy using Information Retrieval metrics like Recall,Precision,InterpolatedAverage Precision(IAP),andMeanAverage Precision(MAP).Additionally,we assessOWS’s effectiveness in reducing the inverted index size,crucial for model efficiency.We compare OWS-based retrieval models against others using different schemes,including tf-idf variations and BM25Delta.Results reveal OWS’s superiority,achieving a 54%Recall and 81%MAP,and a notable 38%reduction in the inverted index size.This highlights OWS’s potential in optimizing retrieval processes and underscores the need for further research in this underrepresented area to fully leverage OWS’s capabilities in information retrieval methodologies.

High-Level Security Dimension Evaluation of Blockchain BaaS System and Key Technology

In recent years,blockchain technology integration and application has gradually become an important driving force for new technological innovation and industrial transformation.While blockchain technology and applications are developing rapidly,the emerging security risks and obstacles have gradually become prominent.Attackers can still find security issues in blockchain systems and conduct attacks,causing increasing losses from network attacks every year.In response to the current demand for blockchain application security detection and assessment in all industries,and the insufficient coverage of existing detection technologies such as smart contract detectiontechnology,this paper proposes a blockchain core technology security assessment system model,and studies the relevant detection and assessment key technologies and systems.A security assessment scheme based on a smart contract and consensus mechanism detection scheme is designed.And the underlying blockchain architecture supports the traceability of detection results using super blockchains.Finally,the functionality and performance of the system were tested,and the test results show that the model and solutions proposed in this paper have good feasibility.

Sharing of Encrypted Lock Keys in the Blockchain-Based Renting House System from Time- and Identity-Based Proxy Reencryption

To design an efficient protocol for sharing the encrypted lock keys in the renting house system,we introduce a new notion called time-and identitybased proxy reencryption(TIPRE)and the blockchain platform.Our CPA secure TIPRE scheme is constructed from Green et al.’s identity-based proxy reencryption scheme by adding the time property.In every time period,a time stamp authority generates a public key embedded with the current time stamp for each user.In our protocol for the renting house system,the TIPRE scheme is the primary building block,and the blockchain platform serves instead of a trusted third party,such as a real estate agency between landlords and tenants.The TIPRE scheme allows the landlord to change the lock key at each time period for safety.The blockchain platform allows the landlords and tenants to directly interact,and all of the interactions are recorded in the blockchain database to provide the desired security requirements,such as nonrepudiation and unforgeability.Finally,we provide the secure analysis of our protocol and test its performance by implementing it in the MacBook Pro and the Intel Edison development platforms.

A Novel GLS Consensus Algorithm for Alliance Chain in Edge Computing Environment

Edge computing devices are widely deployed.An important issue that arises is in that these devices suffer from security attacks.To deal with it,we turn to the blockchain technologies.The note in the alliance chain need rules to limit write permissions.Alliance chain can provide security management functions,using these functions to meet the management between the members,certification,authorization,monitoring and auditing.This article mainly analyzes some requirements realization which applies to the alliance chain,and introduces a new consensus algorithm,generalized Legendre sequence(GLS)consensus algorithm,for alliance chain.GLS algorithms inherit the recognition and verification efficiency of binary sequence ciphers in computer communication and can solve a large number of nodes verification of key distribution issues.In the alliance chain,GLS consensus algorithm can complete node address hiding,automatic task sorting,task automatic grouping,task node scope confirmation,task address binding and stamp timestamp.Moreover,the GLS consensus algorithm increases the difficulty of network malicious attack.

The Digital Fingerprinting Method for Static Images Based on Weighted Hamming Metric and on Weighted Container Model

The algorithm of fingerprint constructing for still images based on weighted image structure model is proposed. The error correcting codes that are perfect in weighted Hamming metric are used as a base for fingerprint constructing.

A Motivate Mechanism for Large-Scale P2P Content Delivery System

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.

The New Attribute-Based Generalized Signcryption Scheme

An attribute-based generalized signcryption scheme based on bilinear pairing has been proposed. By changing attributes, encryption-only mode, signature-only mode, and signcryption mode can be switch adaptively. It shows that the scheme achieves the semantic security under the decisional bilinear Diffie- Hellman assumption and achieves the unforgeability under the computational Diffie-Hellman assumption. It is more efficient than traditional way and can be used to secure the big data in networks.

A Lightweight Authentication Protocol Scheme for RFID Security

Lightweight and safety are two essential features for large-scale application of radio frequency identification （RFID） tags. Based on the analysis of potential safety problem of RFID and the characteristics of existing typical authentication protocol, a new low-cost RFID tags authentication protocol was proposed. The performance of the new protocol was analyzed. The results show that the protocol can resist replay attacks and concurrent attacks and has nontracking, authenticity, and service availability. In addition, the protocol can also reduce the storage of tags and computation burden to meet the application requirements of low-cost tags.

Weak invertibility of linear finite automata (I)——Classification and enumeration of transfer functions

Let 3V denote the set of all possible transfer function matrices of weakly invertible linear finite automata over a given finite field F. A classification and an enumeration on the infinite set are given.

Dynamic clustering of distributed source coding in wireless sensor networks

There are correlations of data in adjacent sensor nodes in wireless sensor networks （WSNs）. Distributed source coamg （DSC） is an idea to improve the energy efficiency in WSNs by compressing the sensor data with correlations to others, When utilizing the DSC, the network architecture that, deciding which nodes to transmit the side information and which nodes to compress according to the correlations, influences the compression efficiency significantly. Comparing with former schemes that have no adaptations, a dynamic clustering scheme is presented in this article, with which the network is partitioned to clusters adaptive to the topology and the degree of correlations. The simulation indicates that the proposed scheme has higher efficiency than static clustering schemes.

RDDP:An Efficient MDS Array Code on Toleration Triple Node Failures in Storage System

It is well known that erasure coding can be used in storage systems to efficiently store data while protecting against failures. Conventionally, the design of erasure codes has focused on the tradeoff between redundancy and reliability. Under this criterion, an maximum distance separable（MDS） code has optimal redundancy. In this paper, we address a new class of MDS array codes for tolerating triple node failures by extending the row di- agonal parity（RDP） code, named the RDDP（row double diagonal parity） code. The RDDP code takes advantages of good perform- ances of the RDP code with balanced I/0. A specific triple-erasure decoding algorithm to reduce decoding complexity is depicted by geometric graph, and it is easily implemented by software and hardware. The theoretical analysis shows that the comprehensive properties of the RDDP code are optimal, such as encoding and decoding efficiency, update efficiency and I/0 balance performance.

Notes on q-ary interleaved sequences

(f(x), m)-interleaved sequences over Fq have been proposed and studied. Roughly speaking, an (f(x), m)-interleaved sequence is a sequence which is made of (or say, interleaved by) m component sequences with a common characteristic polynomial (f(x)(∈Fq [x]). in this note, (7(x), m)-interleaved sequences are studied further. As a result, it is made clear how their minimal characteristic polynomials, linear spans and periods are determined by their component sequences. And also, their period distribution and the number of (f(x), m)-interleaved sequences with maximal linear spans are derived. Furthermore, a large number of interleaved sequences with the lowest correlation among ali the (f(x), m)-interleaved sequences are constructed.

Dynamic resource allocation in cloud download service

Cloud download service, as a new application which downloads the requested content offiine and reserves it m cloud storage until users retrieve it, has recently become a trend attracting millions of users in China. In the face of the dilemma between the growth of download requests and the limitation of storage resource, the cloud servers have to design an efficient resource allocation scheme to enhance the utilization of storage as well as to satisfy users＇ needs like a short download time. When a user＇s churn behavior is considered as a Markov chain process, it is found that a proper allocation of download speed can optimize the storage resource utilization. Accordingly, two dynamic resource allocation schemes including a speed switching （SS） scheme and a speed increasing （SI） scheme are proposed. Both theoretical analysis and simulation results prove that our schemes can effectively reduce the consumption of storage resource and keep the download time short enough for a good user experience.