17783880
TCUAP: A Novel Approach of Text Clustering Using Asymmetric Proximity
Text documents have sparse data spaces and current existing methods of text clustering use symmetry proximity to measure the correlation of documents. In this paper, we propose a novel approach to strengthen the discriminative feature of document objects, which uses asymmetric proximity for text clustering. We present a measure of asymmetric proximity between documents and between clusters. TCUAP is an agglomerative hierarchical clustering algorithm and carries on the clustering analysis by strong components of sparse matrix. The experimental evaluation on textual data sets demonstrates the validity and efficiency of our approach. The result shows that the measure of asymmetric proximity possesses higher accuracy than that of symmetry proximity.
2193712
Similarity Joins of Text with Incomplete Information Formats
Similarity join over text is important in text retrieval and query. Due to the incomplete formats of information representation, such as abbreviation and short word, similarity joins should address an asymmetric feature that these incomplete formats may contain only partial information of their original representation. Current approaches, including cosine similarity with q-grams, can hardly deal with the asymmetric feature of similarity between words and their incomplete formats. In order to find this type of incomplete format information with asymmetric features, we develop a new similarity join algorithm, namely IJoin. A novel matching scheme is proposed to identify the overlap between two entities with incomplete formats. Other than q-grams, we reconnect the sequence of words in a string to reserve the abbreviated information. Based on the asymmetric features of similar entities with incomplete formats, we adopt a new similarity function. Furthermore, an efficient algorithm is implemented by using the join operation in SQL, which reduces pairs of tuples in similarity comparison. The experimental evaluation demonstrates the effectiveness and the efficiency of our approach.
701055
Practical Security Improvement of PKCS#5
A public key infrastructure (PKI) is being deployed in a field of network security. PKCS#5 is one of the most popular standards in PKI framework, intended for the practical implementation of password-based cryptography. So, the PKCS#5 encryption must be useful for general software applications within multimedia systems. However, it has a critical weak point in terms of security such as being vulnerable to off-line attacks due to the password-derived encryption key. In this paper, we observe a practical and simple method to improve security of the PKCS#5 encryption without modifying the installed base. The idea is to hide a salt by exploiting several existing schemes.
52830861
A Coarse-Grained Parallel Algorithm for Maximal Cliques in Circle Graphs
We present a parallel algorithm for generating the maximal cliques of a circle graph with n vertices and m edges. We consider the Coarse-Grained Multicomputer Model (CGM) and show that the proposed algorithm requires O(log p) communication rounds, where p is the number of processors, independent of n. The main contribution is the use of a new technique based on the unrestricted depth search for the design of CGM algorithms.
16958952
An efficient parallel garbage collection system and ITS correctness proof
Abstract : An efficient system to perform garbage collection in parallel with list operations is proposed and its correctness is proven. The system consists of two independent processes sharing a common memory. One process is performed by the list processor (LP) for list processing and the other by the garbage collector (GC) for marking active nodes and collecting garbage nodes. The system is derived by using both the correctness and efficiency arguments. Assuming that memory references are indivisible the system satisfies the following properties: No critical sections are needed in the entire system. The time to perform the marking phase by the GC is independent of the size of memory, but depends only on the number of active nodes. Nodes on the free list need not be marked during the marking phase by the GC. Minimum overheads are introduced to the LP. Only two extra bits for encoding four colors are needed for each node. Efficiency results show that the parallel system is usually significantly more efficient in terms of storage and time than the sequential stack algorithm. (Author)
17234328
A CGM/BSP Parallel Similarity Algorithm
We present a CGM/BSP algorithm for computing an alignment (or string editing) between two strings A and C, with jAj = m and jCj = n. The algorithm requires O(p) communication rounds and O( p ) local computing time, on a distributed memory parallel computer of p processors each with O(nm=p) memory. We also present implementation results obtained on Beowulf machine with 64 nodes. Topic of interest: Algorithms and applications in Bioinformatics