2740448
A novel conflict detection and resolution strategy based on TLRSP in replicated mobile database systems
Replication is one of the key technologies in promoting the performance of mobile database systems. In this paper, a novel mobile database replication scheme, the transaction-level result-set propagation (TLRSP) model, is put forward. A conflict detection and resolution strategy based on TLRSP is discussed in detail and its implementation algorithm is proposed. In the TLRSP model, mobile users are allowed to access local replicas of the database and to submit local transactions when the system is disconnected. The locally committed transactions are sent to a fixed database server for conflict reconciliation and result-set incorporation when the system is reconnected. The TLRSP model uses the incremental refreshing method to synchronize database replicas and to maintain the consistency of the replicated mobile database system.
42912843
NChiql: The Chinese Natural Language Interface to Databases
Numerous natural language interface to databases (NLIDBs) developed in the mid-eighties demonstrated impressive characteristic in certain application areas, but NLIDBs did not gained the expected rapid and wide commercial acceptance. We argue that there are two good reasons explain why: limited portability and poor usability. This paper describes the design and implementation of NChiql, a Chinese natural language interface to databases. In order to bright the essence of these problems, we provide an abstract model (AM) in NChiql. We try to give a solution for these problems based on the model in our system. In this paper, we depict a novel method based on database semantics (SCM) to handle the Chinese natural language query, which greatly promotes the system's usability. The experiments show that NChiql has good usability and high correctness.
39614040
The incidence coloring number of Halin graphs and outerplanar graphs
In this paper, we shall prove that the incidence coloring number for Halin graphs of maximum degree greater than or equal to 5 and outerplanar graphs of maximum degree greater than or equal to 4 is equal to the maximum degree of the graph plus 1.
2070714
A large quantity of novel human antisense transcripts detected by LongSAGE
MOTIVATION
Taking advantage of the high sensitivity and specificity of LongSAGE tag for transcript detection and genome mapping, we analyzed the 632 813 unique human LongSAGE tags deposited in public databases to identify novel human antisense transcripts.


RESULTS
Our study identified 45 321 tags that match the antisense strand of 9804 known mRNA sequences, 6606 of which contain antisense ESTs and 3198 are mapped only by SAGE tags. Quantitative analysis showed that the detected antisense transcripts are present at levels lower than their counterpart sense transcripts. Experimental results confirmed the presence of antisense transcripts detected by the antisense tags. We also constructed an antisense tag database that can be used to identify the antisense SAGE tags originated from the antisense strand of known mRNA sequences included in the RefSeq database.


CONCLUSIONS
Our study highlights the benefits of exploring SAGE data for comprehensive identification of human antisense transcripts and demonstrates the prevalence of antisense transcripts in the human genome.
4775385
A fine-grained replacement strategy for XML query cache
Caching popular queries and reusing results of previously computed queries is one important query optimization technique, especially in modern distributed environments such as the WWW. Based on the recent proliferation of XML data and the emergence of the XQuery language, we are thus developing a query- based caching system for XQuery queries, called ACE-XQ. ACE-XQ applies innovative query containment and rewriting strategies to answer incoming user queries based on the cached XQueries, whenever possible, instead of accessing remote XML data sources.To manage the space of the cache, a straightforward application of traditional replacement strategies would correspond to removing a complete cached query and its derived XML document as a whole when space needs to be freed. This coarse granularity however does not match well with the typical access pattern of web searches where new queries often partially overlap with cached queries.In this paper, we propose a novel replacement strategy appropriate for such query-based XML caching systems. In particular, we collect user access statistics at the granularity of the XML path structure instead of the complete XML query regions. We then apply a more fine-grained replacement strategy that purges XML fragments off a cached region instead of the whole XML document and accordingly adjusts the query descriptor. This may better capture the user access patterns since more frequently used XML document fragments are likely to remain in the cache while other less beneficial parts are purged. This approach has been implemented in our ACE-XQ System. Preliminary experiment results illustrate the performance improvement achievable by our fine-grained replacement strategy over the one which replaces a whole XML view at a time when the cache size is relatively large.
18781726
Watermarking scheme capable of resisting attacks based on availability of inserter
Attacks based on the presence ofwatermark inserter are easy to perf orm since they make use ofsimilarity between an original watermark and additionally added ones by using the same inserter and key. In this paper, a novel watermarking scheme capable ofresisting inserter attacks is proposed. Watermark signals corresponding to the same key are mutually independent ifthey are randomly selected using the described technique. Thus the inserter attack is invalidated. Performance ofthe proposed method is studied, and simulation experiments presented. ? 2002 Elsevier Science B.V. All rights reserved.
27992571
Segmentation of SAR images
Abstract This paper presents a new algorithm for segmentation of SAR images based on threshold estimation using the histogram. The speckle distribution in the SAR image is modeled by a Gamma function. Thus, the SAR image histogram exhibits a combination of Gamma distributions. The maximum likelihood technique is therefore used to estimate the histogram parameters. This technique requires knowledge of the number of modes of the histogram, the number of looks of the SAR image, and the initial parameters of the histogram. The second derivative of the histogram is used to estimate the number of modes. We use two methods to estimate the number of looks. Initial parameters are estimated at the maximum of the Gamma function. Thresholds are selected at the valleys of a multi-modal histogram by minimizing the discrimination error between the classes of pixels in the image. The algorithm is applied to several RADARSAT SAR images with different number of looks. The results obtained are promising.