99 research outputs found

    An office document retrieval system with the capability of processing incomplete and vague queries

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    TEXPROS (TEXt PROcessing System) is an intelligent document processing system. The system is a combination of filing and retrieval systems, which supports storing, classifying, categorizing, retrieving and reproducing documents, as well as extracting, browsing, retrieving and synthesizing information from a variety of documents. This dissertation presents a retrieval system for TEXPROS, which is capable of processing incomplete or vague queries and providing semantically meaningful responses to the users. The design of the retrieval system is highly integrated with various mechanisms for achieving these goals. First, a system catalog including a thesaurus is used to store the knowledge about the database. Secondly, there is a query transformation mechanism which consists of context construction and algebraic query formulation modules. Given an incomplete query, the context construction module searches the system for the required terms and constructs a query that has a complete representation. The resulting query is then formulated into an algebraic query. Thirdly, in practice, the user may not have a precise notion of what he is looking for. A browsing mechanism is employed for such situations to assist the user in the retrieval process. With the browser, vague queries can be entered into the system until sufficient information is obtained to the extent that the user is able to construct a query for his request. Finally, when processing of queries responds with an empty answer to the user, a query generalization mechanism is used to give the user a cooperative explanation for the empty answer. The generalizations of any given failed queries (i.e., with an empty answer) are derived by applying both the folder and type substitutions and weakening the search criteria in the original query. An efficient way is investigated for determining whether the empty answer is genuine and whether the original query reflects erroneous presuppositions, and therefore answering any failed query with a meaningful and cooperative response. It incorporates with a methodical approach to reducing the search space of generalized subqueries by analyzing the results of executing the query generalization and by efficiently applying the possible substitutions in a query to generate a small subset of relevant subqueries which are to be evaluated

    Electron Transfer Dynamics and Electrocatalytic Oxygen Evolution Activities of the Co3O4 Nanoparticles Attached to Indium Tin Oxide by Self-Assembled Monolayers

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    The Co3O4 nanoparticle-modified indium tin oxide-coated glass slide (ITO) electrodes are successfully prepared using dicarboxylic acid as the self-assembled monolayer through a surface esterification reaction. The ITO-SAM-Co3O4 (SAM = dicarboxylic acid) are active to electrochemically catalyze oxygen evolution reaction (OER) in acid. The most active assembly, with Co loading at 3.31 × 10-8 mol cm-2, exhibits 374 mV onset overpotential and 497 mV overpotential to reach 1 mA cm-2 OER current in 0.1 M HClO4. The electron transfer rate constant (k) is acquired using Laviron\u27s approach, and the results show that k is not affected by the carbon chain lengths of the SAM (up to 18 -CH2 groups) and that an increase in the average diameter of Co3O4 nanoparticles enhances the k. In addition, shorter carbon chains and smaller Co3O4 nanoparticles can increase the turn-over frequency (TOF) of Co sites toward OER. The Co3O4 nanoparticles tethered to the ITO surface show both a higher number of electrochemically active Co sites and a higher TOF of OER than the Co3O4 nanoparticles bound to ITO using Nafion

    Engineering pressure retarded osmosis membrane bioreactor (PRO-MBR) for simultaneous water and energy recovery from municipal wastewater

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    Osmotic membrane bioreactors (OMBR) have gained increasing interest in wastewater treatment and reclamation due to their high product water quality and fouling resistance. However, high energy consumption (mostly by draw solution recovery) restricted the wider application of OMBR. Herein, we propose a novel pressure retarded osmosis membrane bioreactor (PRO-MBR) for improving the economic feasibility. In comparison with conventional FO-MBR, PRO-MBR exhibited similar excellent contaminants removal performance and comparable water flux. More importantly, a considerable amount of energy can be recovered by PRO-MBR (4.1 kWh/100 m2·d), as a result of which, 10.02% of the specific energy consumption (SEC) for water recovery was reduced as compared with FO-MBR (from 1.42 kWh/m3 to 1.28 kWh/m3). Membrane orientation largely determined the performance of PRO-MBR, higher power density was achieved in AL-DS orientation (peak value of 3.4 W/m2) than that in AL-FS orientation (peak value of 1.4 W/m2). However, PRO-MBR suffered more severe and complex membrane fouling when operated in AL-DS orientation, because the porous support layer was facing sludge mixed liquor. Further investigation revealed fouling was mostly reversible for PRO-MBR, it exhibited similar flux recoverability (92.4%) to that in FO-MBR (95.1%) after osmotic backwash. Nevertheless, flux decline due to membrane fouling is still a restricting factor to power generation of PRO-MBR, its power density was decreased by 38.2% in the first 60 min due to the formation of fouling. Overall, in perspective of technoeconomic feasibility, the PRO-MBR demonstrates better potential than FO-MBR in wastewater treatment and reclamation and deserves more research attention in the future.This work was supported by the National Natural Science Foundation of China [grant number 51978312]; the Six Major Talent Peaks of Jiangsu Province [grant number 2018-JNHB-014]; and the Program to Cultivate Middle-aged and Young Science Leaders of Colleges and Universities of Jiangsu Province

    Compact CCA2-secure Hierarchical Identity-Based Broadcast Encryption for Fuzzy-entity Data Sharing

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    With the advances of cloud computing, data sharing becomes easier for large-scale enterprises. When deploying privacy and security schemes in data sharing systems, fuzzy-entity data sharing, entity management, and efficiency must take into account, especially when the system is asked to share data with a large number of users in a tree-like structure. (Hierarchical) Identity-Based Encryption is a promising candidate to ensure fuzzy-entity data sharing functionalities while meeting the security requirement, but encounters efficiency difficulty in multi-user settings. This paper proposes a new primitive called Hierarchical Identity-Based Broadcast Encryption (HIBBE) to support multi-user data sharing mechanism. Similar to HIBE, HIBBE organizes users in a tree-like structure and users can delegate their decryption capability to their subordinates. Unlike HIBE merely allowing a single decryption path, HIBBE enables encryption to any subset of the users and only the intended users (and their supervisors) can decrypt. We define Ciphertext Indistinguishability against Adaptively Chosen-Identity-Vector-Set and Chosen-Ciphertext Attack (IND-CIVS-CCA2) for HIBBE, which capture the most powerful attacks in the real world. We achieve this goal in the standard model in two steps. We first construct an efficient HIBBE Scheme (HIBBES) against Adaptively Chosen-Identity-Vector-Set and Chosen-Plaintext Attack (IND-CIVS-CPA) in which the attacker is not allowed to query the decryption oracle. Then we convert it into an IND-CIVS-CCA2 scheme at only a marginal cost, i.e., merely adding one on-the-fly dummy user at the first depth of hierarchy in the basic scheme without requiring any other cryptographic primitives. Our CCA2-secure scheme natively allows public ciphertext validity test, which is a useful property when a CCA2-secure HIBBES is used to design advanced protocols and auditing mechanisms for HIBBE-based data sharing

    Interfacial nucleation in iPP/PB-1 blends promotes the formation of polybutene-1 trigonal crystals

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    The formation of trigonal Form I\ub4 crystals of polybutene-1 (PB-1) directly from melt has drawn much attention in past decades. In this study, we investigate the fractionated crystallization behavior of PB-1 within droplets formed by blending PB-1 with an excess of isotactic polypropylene (iPP) employing DSC, SEM, in situ synchrotron WAXD and FT-IR. When PB-1 is dispersed into a large number of small size droplets, the heterogeneous nucleation of Form II crystals can be inhibited because the number of droplets is larger than that of active nucleation sites for Form II (i.e., active heterogeneities originally present in bulk PB-1). The nucleation of the finely dispersed PB-1 droplets does not occur homogenously, but at the interface with the iPP matrix, which induces the crystallization of the droplets into Form I\ub4. The crystallization rate of Form I\ub4 at different temperatures was determined by Fourier transform infrared spectroscopy. It was found that trigonal Form I\ub4 crystallizes faster when the content of PB-1 in the blend is lower, and the specific interfacial surface area is larger. The opposite effect has been observed for the kinetics of the metastable Form II formation. It is therefore suggested that Form I\ub4 crystallization is driven by the nucleation of PB-1 at the crystalline iPP surface, which competes with the crystallization of Form II induced by nucleating heterogeneities present in PB-1 droplets

    Cardiomyocyte-Restricted Deletion of PPARβ/δ in PPARα-Null Mice Causes Impaired Mitochondrial Biogenesis and Defense, but No Further Depression of Myocardial Fatty Acid Oxidation

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    It is well documented that PPARα and PPARβ/δ share overlapping functions in regulating myocardial lipid metabolism. However, previous studies demonstrated that cardiomyocyte-restricted PPARβ/δ deficiency in mice leads to severe cardiac pathological development, whereas global PPARα knockout shows a benign cardiac phenotype. It is unknown whether a PPARα-null background would alter the pathological development in mice with cardiomyocyte-restricted PPARβ/δ deficiency. In the present study, a mouse model with long-term PPARβ/δ deficiency in PPARα-null background showed a comparably reduced cardiac expression of lipid metabolism to those of single PPAR-deficient mouse models. The PPARα-null background did not rescue or aggravate the cardiac pathological development linked to cardiomyocyte-restricted PPARβ/δ deficiency. Moreover, PPARα-null did not alter the phenotypic development in adult mice with the short-term deletion of PPARβ/δ in their hearts, which showed mitochondrial abnormalities, depressed cardiac performance, and cardiac hypertrophy with attenuated expression of key factors in mitochondrial biogenesis and defense. The present study demonstrates that cardiomyocyte-restricted deletion of PPARβ/δ in PPARα-null mice causes impaired mitochondrial biogenesis and defense, but no further depression of fatty acid oxidation. Therefore, PPARβ/δ is essential for maintaining mitochondrial biogenesis and defense in cardiomyocytes independent of PPARα

    Electronic Enterprise Engineering - An Outline of an Architecture

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    In this paper we put forth a vision for organizations to fully embrace computer support. We propose a business-process oriented architecture for Electronic Enterprise Engineering (EEE) that will enable enterprises to manage and evolve all technological and organizational processes effectively; integrate and manage all enterprise information electronically; and empower knowledge workers at all levels with broad decision support capabilities. Our goal is for the EEE architecture to empower an enterprise to make the best use of its informational assets to operate effectively in this new era of electronic commerce. As part of this project we are developing a standard-based, customizable, integrated tool set called the Support Environment for Enterprise Engineering (SEEE). This paper presents the current SEEE architecture and shouts how it supports the three EEE goals

    Artificial trans-encoded small non-coding RNAs specifically silence the selected gene expression in bacteria

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    Recently, many small non-coding RNAs (sRNAs) with important regulatory roles have been identified in bacteria. As their eukaryotic counterparts, a major class of bacterial trans-encoded sRNAs acts by basepairing with target mRNAs, resulting in changes in translation and stability of the mRNA. RNA interference (RNAi) has become a powerful gene silencing tool in eukaryotes. However, such an effective RNA silencing tool remains to be developed for prokaryotes. In this study, we described first the use of artificial trans-encoded sRNAs (atsRNAs) for specific gene silencing in bacteria. Based on the common structural characteristics of natural sRNAs in Gram-negative bacteria, we developed the designing principle of atsRNA. Most of the atsRNAs effectively suppressed the expression of exogenous EGFP gene and endogenous uidA gene in Escherichia coli. Further studies demonstrated that the mRNA base pairing region and AU rich Hfq binding site were crucial for the activity of atsRNA. The atsRNA-mediated gene silencing was Hfq dependent. The atsRNAs led to gene silencing and RNase E dependent degradation of target mRNA. We also designed a series of atsRNAs which targeted the toxic genes in Staphyloccocus aureus, but found no significant interfering effect. We established an effective method for specific gene silencing in Gram-negative bacteria
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