Replacing points by compacta in neural network approximation

It is shown that cartesian product and pointwise-sum with a fixed compact set preserve various approximation-theoretic properties. Results for pointwise-sum are proved for F-spaces and so hold for any normed linear space, while the other results hold in general metric spaces. Applications are given to approximation of L_p-functions on the d-dimensional cube, 1?p<∞, by linear combinations of half-space characteristic functions; i.e., by Heaviside perceptron networks.     

Liquid–Liquid Extraction and Solid Phase Extraction for Urinary Organic Acids: A Comparative Study from a Resource Constraint Setting

Pre analytical process of extraction for accurate detection of organic acids is a crucial step in diagnosis of organic acidemias by GCMS analysis. This process is accomplished either by solid phase extraction (SPE) or by liquid–liquid extraction (LLE). Both extraction procedures are used in different metabolic laboratories all over the world. In this study we compared these two extraction procedures in respect of precision, accuracy, percent recovery of metabolites, number of metabolites isolated, time and cost in a resource constraint setup. We observed that the mean recovery from SPE was 84.1 % and by LLE it was 77.4 % (p value <0.05). Moreover, the average number of metabolites isolated by SPE and LLE was 161.8 ± 18.6 and 140.1 ± 20.4 respectively. The processing cost of LLE was economical. In a cost constraint setting using LLE may be the practical option if used for organic acid analysis.     

高校本科生科研的意义、现状与措施

从教学过程、人才培养、科研成果三个角度阐述了本科生科研的意义,并对我国目前高校本科生科研情况作了调查与分析,在此基础上,提出了本列生科研的保障措施。     

Secondary immunization inhibits drug induced apoptosis<Emphasis Type="Italic">in vivo</Emphasis>

Immunization with a proper dose of an antigenic stimulus leads to cell proliferation and antibody response of circulating lymphocytes. We have previously observed that Secondary immunized spleenocytes resist ceramide-mediated apoptosisin vitro. Our present study is aimed at investigating thein vivo effect of immunization on apoptosis. Mice were subjected to either Primary or Secondary dose with Tetanus Toxoid. Unimmunized spleenocytes served as controls. Unimmunized, Primary and Secondary immunized mice were later exposed to chemotherapeutic drugs such as Etoposide/Methotrexate/Vincristine to induce apoptosis. Apoptosis was studied by using the Feulgen reaction on 5μ thin parafin sections of spleen. It was observed that Secondary immunized mice showed a lower percentage of apoptosis as compared to Primary or Unimmunized mice that was subjected to either of the chemotherapeutic drugs. It was thus concluded that Secondary immunization inhibits the process of chemotherapeutic drug induced apoptosis in vivo.     

Building parallel corpora by automatic title alignment using length-based and text-based approaches

Cross-lingual semantic interoperability has drawn significant attention in recent digital library and World Wide Web research as the information in languages other than English has grown exponentially. Cross-lingual information retrieval (CLIR) across different European languages, such as English, Spanish, and French, has been widely explored; however, CLIR across European languages and Oriental languages is still in the initial stage. To cross language boundary, corpus-based approach is promising to overcome the limitation of the knowledge-based and controlled vocabulary approaches but collecting parallel corpora between European language and Oriental language is not an easy task. Length-based and text-based approaches are two major approaches to align parallel documents. In this paper, we investigate several techniques using these approaches and compare their performances in aligning English and Chinese titles of parallel documents available on the Web.     

团队知识扩散的行为难题与组织学习的内在逻辑

通过对团队知识扩散相关表征的界定,确定了复杂环境下团队知识共享与整合的基本认知。与此同时,对知识扩散行为难题的剖析,引出组织学习是影响其有效配置的内在动力。在此基础上,从学习能力、学习平台、学习效用以及学习氛围等方面充实了团队知识扩散的相关思路。     

Analyzing imbalance among homogeneous index servers in a web search system

The performance of parallel query processing in a cluster of index servers is crucial for modern web search systems. In such a scenario, the response time basically depends on the execution time of the slowest server to generate a partial ranked answer. Previous approaches investigate performance issues in this context using simulation, analytical modeling, experimentation, or a combination of them. Nevertheless, these approaches simply assume balanced execution times among homogeneous servers (by uniformly distributing the document collection among them, for instance)—a scenario that we did not observe in our experimentation. On the contrary, we found that even with a balanced distribution of the document collection among index servers, correlations between the frequency of a term in the query log and the size of its corresponding inverted list lead to imbalances in query execution times at these same servers, because these correlations affect disk caching behavior. Further, the relative sizes of the main memory at each server (with regard to disk space usage) and the number of servers participating in the parallel query processing also affect imbalance of local query execution times. These are relevant findings that have not been reported before and that, we understand, are of interest to the research community.     

Unique-order interpolative coding for fast querying and space-efficient indexing in information retrieval systems

This paper presents a size reduction method for the inverted file, the most suitable indexing structure for an information retrieval system (IRS). We notice that in an inverted file the document identifiers for a given word are usually clustered. While this clustering property can be used in reducing the size of the inverted file, good compression as well as fast decompression must both be available. In this paper, we present a method that can facilitate coding and decoding processes for interpolative coding using recursion elimination and loop unwinding. We call this method the unique-order interpolative coding. It can calculate the lower and upper bounds of every document identifier for a binary code without using a recursive process, hence the decompression time can be greatly reduced. Moreover, it also can exploit document identifier clustering to compress the inverted file efficiently. Compared with the other well-known compression methods, our method provides fast decoding speed and excellent compression. This method can also be used to support a self-indexing strategy. Therefore our research work in this paper provides a feasible way to build a fast and space-economical IRS.