“信息追询系统”在电子政务中的作用

现有很多办公信息资源没有有效工具进行管理和利用,使信息利用率低下,查询效率低。如果能够在政府现有的服务机构中应用"信息追询系统"技术,那么,政府就有可能用电子政务来完善服务方式,促进政务流程再造,提高公共服务的质量和水平。对信息追询系统在电子政务中的应用进行了论述。

知识经济与高校图书馆的信息服务

分析了高等教育、高校图书馆与知识经济的关系，阐述了高校图书馆的信息服务在知识经济时代如何加快社会化的进程。

Query Expansion for Chinese Information Retrieval by Using a Decaying Co-occurrence Model

Query expansion with thesaurus is one of the useful techniques in modern information retrieval (IR). In this paper, a method of query expansion for Chinese IR by using a decaying co-occurrence model is proposed and realized. The model is an extension of the traditional co-occurrence model by adding a decaying factor that decreases the mutual information when the distance between the terms increases. Experimental results on TREC-9 collections show this query expansion method results in significant improvements over the IR without query expansion.

A method for publishing relational schema into DTD

This paper focuses on exporting relational data into extensible markup language (XML). First, the characteristics of both relational schemas represented by E-R diagrams and XML document type definitions (DTDs) are analyzed. Secondly, the corresponding mapping rules are proposed. At last an algorithm based on edge tables is presented. There are two key points in the algorithm. One is that the edge table is used to store the information of the relational dictionary, and this brings about the efficiency of the algorithm. The other is that structural information can be obtained from the resulting DTDs and other applications can optimize their query processes using the structural information.

Approximate querying between heterogeneous ontologies based on association matrix

An approximate approach of querying between heterogeneous ontology-basedinformation systems based on an association matrix is proposed. First, the association matrix isdefined to describe relations between concepts in two ontologies. Then, a methodof rewriting queriesbased on the association matrix is presented to solve the ontology heterogeneity problem. Itrewrites the queries in one ontology to approximate queries in another ontology based on thesubsumption relations between concepts. The method also uses vectors to represent queries, and thencomputes the vectors with the association matrix; the disjoint relations between concepts can beconsidered by the results. It can get better approximations than the methods currently in use, whichdonot consider disjoint relations. The method can be processed by machines automatically. It issimple to implement and expected to run quite fast.

Measurement of Incompatible Probability in Information Retrieval:A Case Study with User Clicks

The incompatible probability represents an important non-classical phenomenon, and it describes conflicting observed marginal probabilities, which cannot be satisfied with a joint probability. First, the incompatibility of random variables was defined and discussed via the non-positive semi-definiteness of their covariance matrixes. Then, a method was proposed to verify the existence of incompatible probability for variables. A hypothesis testing was also applied to reexamine the likelihood of the observed marginal probabilities being integrated into a joint probability space, thus showing the statistical significance of incompatible probability cases. A case study with user click-through data provided the initial evidence of the incompatible probability in information retrieval (IR), particularly in user interaction. The experiments indicate that both incompatible and compatible cases can be found in IR data, and informational queries are more likely to be compatible than navigational queries. The results inspire new theoretical perspectives of modeling the complex interactions and phenomena in IR.

A new approach to query expansion in information retrieval

To eliminate the mismatch between words of relevant documents and user's query and more seriousnegative effects it has on the performance of information retrieval,a method of query expansion on the ba-sis of new terms co-occurrence representation was put forward by analyzing the process of producingquery.The expansion terms were selected according to their correlation to the whole query.At the sametime,the position information between terms were considered.The experimental result on test retrievalconference(TREC)data collection shows that the method proposed in the paper has made an improve-ment of 5%～19% all the time than the language modeling method without expansion.Compared to thepopular approach of query expansion,pseudo feedback,the precision of the proposed method is competi-tive.

Hash-area-based data dissemination protocol in wireless sensor networks

HashQuery,a Hash-area-based data dissemination protocol,was designed in wireless sensor networks. Using a Hash function which uses time as the key,both mobile sinks and sensors can determine the same Hash area. The sensors can send the information about the events that they monitor to the Hash area and the mobile sinks need only to query that area instead of flooding among the whole network,and thus much energy can be saved. In addition,the location of the Hash area changes over time so as to balance the energy consumption in the whole network. Theoretical analysis shows that the proposed protocol can be energy-efficient and simulation studies further show that when there are 5 sources and 5 sinks in the network,it can save at least 50% energy compared with the existing two-tier data dissemination(TTDD) protocol,especially in large-scale wireless sensor networks.

Bitmap lattice index in road networks

A novel technique called the bitmap lattice index(BLI) is proposed, which combines the advantages of a wireless broadcasting environment with a road network. Existing road networks are based on the on-demand method: a server's workload increases as the query request increases when a server sends a client information. To solve this problem, we propose the BLI. The BLI denotes an object and a node as 0 and 1 in the Hilbert curve(HC) map. The BLI can identify the position of a node and an object through bit information; it can also reduce the broadcasting frequency of a server by reducing the size of the index, thereby decreasing the access latency and query processing times. Moreover, the BLI is highly effective for data filtering, as it can identify the positions of both an object and a node. In a road network, if filtering is done via the Euclidean distance, it may result in an error. To prevent this, we add another validation procedure. The experiment is conducted by applying the BLI to kNN query, and the technique is assessed by a performance evaluation experiment.

Study on spatial temporal model in property management information system

Time is an important dimension for information in the geographical information system. Data, such as the historical state of target property space and related events causing the state to be changed, should be saved as important files. This should be applied to property management. This paper designs and constructs a spatial temporal model, which is suitable to the property data changing management and spatial temporal query by analyzing the basic types and characteristics of property management spatial changing time and date. This model uses current and historical situational layers to organize and set up the relationship between current situation data and historical dates according to spatial temporal topological relations in property entities. By using Map Basic, housing property management and spatial query is realized.

Query Expansion Using Wikipedia and a Concept Base in Cross-language Information Retrieval

The present paper describes the use of online free language resources for translating and expanding queries in CLIR （cross-language information retrieval）. In a previous study, we proposed method queries that were translated by two machine translation systems on the Language Gridem. The queries were then expanded using an online dictionary to translate compound words or word phrases. A concept base was used to compare back translation words with the original query in order to delete mistranslated words. In order to evaluate the proposed method, we constructed a CLIR system and used the science documents of the NTCIR1 dataset. The proposed method achieved high precision. However~ proper nouns （names of people and places） appear infrequently in science documents. In information retrieval, proper nouns present unique problems. Since proper nouns are usually unknown words, they are difficult to find in monolingual dictionaries, not to mention bilingual dictionaries. Furthermore, the initial query of the user is not always the best description of the desired information. In order to solve this problem, and to create a better query representation, query expansion is often proposed as a solution. Wikipedia was used to translate compound words or word phrases. It was also used to expand queries together with a concept base. The NTCIRI and NTCIR 6 datasets were used to evaluate the proposed method. In the proposed method, the CLIR system was implemented with a high rate of precision. The proposed syst had a higher ranking than the NTCIRI and NTCIR6 participation systems.

A minimal-distance overlay for efficiently disseminating replicas in DHT-based P2P networks

In this paper, the problems of redundant traffic and redundant replicas tor efficient object replication in P2P overlay are studies. Firstly, a hierarchical and topology-aware P2P overlay is developed with κ-Medoids partition algorithm to achieve the minimal physical distance of all super peer pairs. Secondly, a new idea of placing at most one replica in a cluster of physically adjacent nodes is introduced to achieve scattered distribution of replicas. Lastly, an efficient replicas-query algorithm based on multiple hash functions is proposed. Theoretical analysis and simulation experiment on several performance metrics are given, and it is verified that the method in this paper can efficiently disseminate replicas across the network, increase query-hit ratio, and decrease redundant messages and storage spaces required.

Design of the visualization of the big data

The arrival of the era of the Internet has brought about the rapid dissemination and spread of a big amount of the information and data. At present, we are surrounded by all kinds of the information, but the rich and diversified information resources also brought about the chaos, so that the query of the messages is no way to start. In fact, the information resources can provide us with more convenience, but we have to spend a lot of energy to organize and filter the information, and the costs and the time of the investment are immeasurable. Usually, the information we want to query is often easy to understand, and the information design uses the more intuitive and vivid computing means to achieve the visualization of the big data, in order to reflect the beauty of the big data.

迅猛发展的Internet及其应用探讨

介绍了Internet的由来与发展现状，特别是全面地介绍了中国Internet的发展现状；讨论了Internet所提供的服务、Internet的应用现状及前景；提出了Internet发展所面临的问题；最后就Internet对我们社会的各种影响进行了探讨。