期刊文献+
共找到29篇文章
< 1 2 >
每页显示 20 50 100
基于上下文重构的短文本情感极性判别研究 被引量:21
1
作者 杨震 赖英旭 +1 位作者 段立娟 李玉鑑 《自动化学报》 EI CSCD 北大核心 2012年第1期55-67,共13页
文本对象所固有的多义性,面对短文本特征稀疏和上下文缺失的情况,现有处理方法无法明辨语义,形成了底层特征和高层表达之间巨大的语义鸿沟.本文尝试借由时间、空间、联系等要素挖掘文本间隐含的关联关系,重构文本上下文范畴,提升情感极... 文本对象所固有的多义性,面对短文本特征稀疏和上下文缺失的情况,现有处理方法无法明辨语义,形成了底层特征和高层表达之间巨大的语义鸿沟.本文尝试借由时间、空间、联系等要素挖掘文本间隐含的关联关系,重构文本上下文范畴,提升情感极性分类性能.具体做法对应一个两阶段处理过程:1)基于短文本的内在联系将其初步重组成上下文(领域);2)将待处理短文本归入适合的上下文(领域)进行深入处理.首先给出了基于NaiveBayes分类器的短文本情感极性分类基本框架,揭示出上下文(领域)范畴差异对分类性能的影响.接下来讨论了基于领域归属划分的文本情感极性分类增强方法,并将领域的概念扩展为上下文关系,提出了基于特殊上下文关系的文本情感极性判别方法.同时为了解决由于信息缺失所造成的上下文重组困难,给出基于遗传算法的任意上下文重组方案.理论分析表明,满足限制条件的前提下,基于上下文重构的情感极性判别方法能够同时降低抽样误差(Sample error)和近似误差(Approximation error).真实数据集上的实验结果也验证了理论分析的结论. 展开更多
关键词 舆情分析 短文本处理 情感计算 误差分析 遗传算法
下载PDF
基于字符串相似性聚类的网络短文本舆情热点发现技术 被引量:25
2
作者 杨震 段立娟 赖英旭 《北京工业大学学报》 EI CAS CSCD 北大核心 2010年第5期669-673,共5页
将每个短文本文档看成一个由文字、数字和标点构成的字符串,并基于字符串自身的特性直接计算其相似性,在此基础上进行短文本层次化聚类,进而发现网络舆情热点.由于这种方法免去特征提取和文本表示过程,在一定程度上避免了传统方法在短... 将每个短文本文档看成一个由文字、数字和标点构成的字符串,并基于字符串自身的特性直接计算其相似性,在此基础上进行短文本层次化聚类,进而发现网络舆情热点.由于这种方法免去特征提取和文本表示过程,在一定程度上避免了传统方法在短文本表示时特征向量稀疏的不足,有效解决了短文本内容聚类问题.实验结果表明,本文提出方法有效. 展开更多
关键词 舆情分析 短文本处理 层次聚类
下载PDF
不同盐分胁迫对美洲红树耐盐性和耐旱性的影响 被引量:1
3
作者 张金香 钱金娥 《防护林科技》 2006年第2期1-2,共2页
为了提高树木对干旱、盐碱环境的适应性,苗木时期人为制造一定程度的不良环境,锻炼苗木对不良环境的适应能力,从而提高造林后林分的效益和稳定性。该试验分为前处理和本处理,前处理设淡水区、1/2海水区(含盐1.7%)和海水区(含盐3.4%),生... 为了提高树木对干旱、盐碱环境的适应性,苗木时期人为制造一定程度的不良环境,锻炼苗木对不良环境的适应能力,从而提高造林后林分的效益和稳定性。该试验分为前处理和本处理,前处理设淡水区、1/2海水区(含盐1.7%)和海水区(含盐3.4%),生长45 d后,进行本处理,统一用含盐浓度7%的盐水进行浇灌。结果表明:经过前处理的1/2海水区中生长的苗木其叶、茎、根的生长量均超过淡水区中生长的苗木。说明一定程度的耐盐锻炼能够增强苗木对盐碱、干旱环境的适应能力。 展开更多
关键词 美洲红树 处理 本处理 适应性
下载PDF
Surface treatment effect on the photocatalytic hydrogen generation of CdS/ZnS core-shell microstructures 被引量:7
4
作者 苏进展 张涛 +2 位作者 王璐 师进文 陈玉彬 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2017年第3期489-497,共9页
CdS/ZnS core-shell microparticles were prepared by a simple two-step method combining ultrasonic spray pyrolysis and chemical bath deposition.The core-shell structures showed enhanced photocatalytic properties compare... CdS/ZnS core-shell microparticles were prepared by a simple two-step method combining ultrasonic spray pyrolysis and chemical bath deposition.The core-shell structures showed enhanced photocatalytic properties compared with those of CdS or ZnS spherical particles.CdS/ZnS photocatalysts with different amount of ZnS loaded as shells were prepared by adjusting the concentrations of Zn and S precursors during synthesis.The optical properties and photocatalytic activity for hydrogen production were investigated and the amount of ZnS loaded as shell was optimized.Thermal annealing and hydrothermal sulfurization treatments were applied to the core-shell structure and both treatments enhanced the material's photocatalytic activity and stability by eliminating crystalline defects and surface states.The result showed that thermal annealing treatment improved the bulk crystallinity and hydrothermal sulfurization improved the surface properties.The sample subjected to both treatments showed the highest photocatalytic activity.These results indicate that CdS/ZnS core-shell microspheres are a simple structure that can be used as efficient photocatalysts.The hydrothermal sulfurization treatment may also be a useful surface treatment for metal sulfide photocatalysts.The simple two-step method provides a promising approach to the large-scale synthesis of core-shell microsphere catalysts. 展开更多
关键词 Core-shell microstructure PHOTOCATALYSIS Surface treatment Hydrogen production Low-cost synthesis
下载PDF
依靠国内力量建设RH精炼工程
5
作者 陈骥 程煌 《重型机械》 2005年第6期6-10,共5页
通过对比国内外RH装置的发展现状,特别是重点分析国内在RH精炼领域生产工艺、设备设计和设备制造的技术水平,论证了国内已经完全有能力建设具有自己特色RH精炼装置。
关键词 真空脱气 蒸汽喷射泵 本处理 冶金模型
下载PDF
An improved TF-IDF approach for text classification 被引量:5
6
作者 张云涛 龚玲 王永成 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2005年第1期49-55,共7页
This paper presents a new improved term frequency/inverse document frequency (TF-IDF) approach which uses confidence, support and characteristic words to enhance the recall and precision of text classification. Synony... This paper presents a new improved term frequency/inverse document frequency (TF-IDF) approach which uses confidence, support and characteristic words to enhance the recall and precision of text classification. Synonyms defined by a lexicon are processed in the improved TF-IDF approach. We detailedly discuss and analyze the relationship among confidence, recall and precision. The experiments based on science and technology gave promising results that the new TF-IDF approach improves the precision and recall of text classification compared with the conventional TF-IDF approach. 展开更多
关键词 Term frequency/inverse document frequency (TF-IDF) Text classification CONFIDENCE SUPPORT Characteristic words
下载PDF
Realtime Vision-Based Surface Defect Inspection of Steel Balls 被引量:3
7
作者 王仲 邢芊 +1 位作者 付鲁华 孙虹 《Transactions of Tianjin University》 EI CAS 2015年第1期76-82,共7页
In the proposed system for online inspection of steel balls, a diffuse illumination is developed to enhance defect appearances and produce high quality images. To fully view the entire sphere, a novel unfolding method... In the proposed system for online inspection of steel balls, a diffuse illumination is developed to enhance defect appearances and produce high quality images. To fully view the entire sphere, a novel unfolding method is put forward based on geometrical analysis, which only requires one-dimensional movement of the balls and a pair of cameras to capture images from different directions. Moreover, a realtime inspection algorithm is customized to improve both accuracy and efficiency. The precision and recall of the sample set were 87.7% and 98%, respectively. The average time cost on image processing and analysis for a steel ball was 47 ms, and the total time cost was less than 200 ms plus the cost of image acquisition and balls' movement. The system can sort 18 000 balls per hour with a spatial resolution higher than 0.01 mm. 展开更多
关键词 machine vision steel ball defect inspection image processing
下载PDF
Music of the Arab-Anglicans in Israel: Dynamics of Ethno-Religious Identity 被引量:1
8
作者 Alexander Rosenblatt 《Sociology Study》 2014年第7期649-659,共11页
The paper focuses on music of the contemporary Arab-Anglican communities in Israel in their dynamics over the last years. The analysis is based on field recordings and other ethnography collected by the author in 2006... The paper focuses on music of the contemporary Arab-Anglican communities in Israel in their dynamics over the last years. The analysis is based on field recordings and other ethnography collected by the author in 2006-2011. The music of the contemporary Arab-Anglican churches in Israel comprises different styles, which might be decoded as indices of group identity, and transmits different signifiers of belonging to diverse branches of the contemporary world Anglican tradition. A remarkable feature of this Christian community is the ongoing shift of subaltern identities when their most "Western" component--association with a particular sub-division of the Church--receives its musical expression by means of "local motif', that is, the tunes associated with regional repertories. The dynamics of ethno-religious identity of Arab-Anglicans in Israel manifests itself through several tendencies, such as ecumenical tendency and some other trends. Though the study is situated in the context of an interdisciplinary academic discourse, music is the main text addressed. "Reading" this music allowed the author to uncover tenets, trends, and interrelations within the communities under study. 展开更多
关键词 Arab-Anglicans group identity subaltern identity local motif
下载PDF
Pearson's Correlation Coefficient: A More Realistic Threshold for Applications on Autonomous Robotics 被引量:3
9
作者 Arthur de Miranda Neto 《Computer Technology and Application》 2014年第2期69-72,共4页
Many applications for control of autonomous platform are being developed and one important aspect is the excess of information, frequently redundant, that imposes a great computational cost in data processing. Taking ... Many applications for control of autonomous platform are being developed and one important aspect is the excess of information, frequently redundant, that imposes a great computational cost in data processing. Taking into account the temporal coherence between consecutive frames, the PCC (Pearson's Correlation Coefficient) was proposed and applied as: discarding criteria methodology, dynamic power management solution, environment observer method which selects automatically only the regions-of-interest; and taking place in the obstacle avoidance context, as a method for collision risk estimation for vehicles in dynamic and unknown environments. Even if the PCC is a great tool to help the autonomous or semi-autonomous navigation, distortions in the imaging system, pixel noise, slight variations in the object's position relative to the camera, and other factors produce a false PCC threshold. Whereas there are homogeneous regions in the image, in order to obtain a more realistic Pearson's correlation, we propose to use some prior known environment information. 展开更多
关键词 PERCEPTION real time mobile robots Pearson's correlation.
下载PDF
TWO-STAGE SENTENCE SELECTION APPROACH FOR MULTI-DOCUMENT SUMMARIZATION
10
作者 Zhang Shu Zhao Tiejun Zheng Dequan Zhao Hua 《Journal of Electronics(China)》 2008年第4期562-567,共6页
Compared with the traditional method of adding sentences to get summary in multi-document summarization,a two-stage sentence selection approach based on deleting sentences in acandidate sentence set to generate summar... Compared with the traditional method of adding sentences to get summary in multi-document summarization,a two-stage sentence selection approach based on deleting sentences in acandidate sentence set to generate summary is proposed,which has two stages,the acquisition of acandidate sentence set and the optimum selection of sentence.At the first stage,the candidate sentenceset is obtained by redundancy-based sentence selection approach.At the second stage,optimum se-lection of sentences is proposed to delete sentences in the candidate sentence set according to itscontribution to the whole set until getting the appointed summary length.With a test corpus,theROUGE value of summaries gotten by the proposed approach proves its validity,compared with thetraditional method of sentence selection.The influence of the token chosen in the two-stage sentenceselection approach on the quality of the generated summaries is analyzed. 展开更多
关键词 TWO-STAGE Sentence selection approach Multi-document summarization
下载PDF
Speed, Uncertainty, and Origin of Disaster
11
作者 Thomas Hauer 《Journal of Philosophy Study》 2015年第6期282-286,共5页
Progress and disaster are two sides of the same coin. Text analyzes the two main themes. Firstly, the treatise attempts at a philosophical analysis of the categories--speed and disaster in Paul Virilio dromology. The ... Progress and disaster are two sides of the same coin. Text analyzes the two main themes. Firstly, the treatise attempts at a philosophical analysis of the categories--speed and disaster in Paul Virilio dromology. The development of high technical speeds would thus result in the disappearance of consciousness as the direct perception of phenomena that inform us of our own existence. Dromological research by Paul Virilio presents a critical analysis of the consequences for our perception and logistics caused by polar inertia, inertia of absolute speed. The second part of the study discusses the word--accident. Accident is inseparable from the speed. Virilio's texts deal with the impact of speed, disaster, and accident on the contemporary world. Speed and accident create a new form of uncertainty in society. 展开更多
关键词 DISASTER SPEED ACCIDENT post-democracy dromology UNCERTAINTY
下载PDF
Differentiated Use of the Cross-Lingual Strategy in Foreign Language Teaching: A Grounded Theory
12
作者 Seyyed Ali Ostovar-Namaghi Shabnam Norouzi 《Sino-US English Teaching》 2015年第12期916-926,共11页
Despite its potential in foreign language education, the cross-lingual strategy has been marginalized and stigmatized in many EFL contexts including language education in private language schools of Iran. This study a... Despite its potential in foreign language education, the cross-lingual strategy has been marginalized and stigmatized in many EFL contexts including language education in private language schools of Iran. This study aims to uncover the facilitative role of the cross-lingual strategy in foreign language instruction by theorizing experienced language teachers' practice. To this end, some experienced teachers were selected in line with the sampling procedures of Grounded Theory from famous English language institutes of Tehran, the capital city of lran. Iterative data collection and analysis revealed that first language use can be differentiated based on learners' level of proficiency. For the beginners, it can be used to present classroom management rules, provide learners with the necessary classroom language and establish rapport. Similarly, at intermediate level LI can be used to check mastery over the teaching points, give vocabulary equivalents, and explain writing rules. As for advanced learners, it can be used to explain the subtleties of grammar and provide learners with ideas to participate in classroom discussion and text processing. 展开更多
关键词 first language use qualitative study foreign language instruction proficiency level
下载PDF
Low-cost cloud computing solution for geo-information processing 被引量:3
13
作者 高培超 刘钊 +1 位作者 谢美慧 田琨 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第12期3217-3224,共8页
Cloud computing has emerged as a leading computing paradigm,with an increasing number of geographic information(geo-information) processing tasks now running on clouds.For this reason,geographic information system/rem... Cloud computing has emerged as a leading computing paradigm,with an increasing number of geographic information(geo-information) processing tasks now running on clouds.For this reason,geographic information system/remote sensing(GIS/RS) researchers rent more public clouds or establish more private clouds.However,a large proportion of these clouds are found to be underutilized,since users do not deal with big data every day.The low usage of cloud resources violates the original intention of cloud computing,which is to save resources by improving usage.In this work,a low-cost cloud computing solution was proposed for geo-information processing,especially for temporary processing tasks.The proposed solution adopted a hosted architecture and can be realized based on ordinary computers in a common GIS/RS laboratory.The usefulness and effectiveness of the proposed solution was demonstrated by using big data simplification as a case study.Compared to commercial public clouds and dedicated private clouds,the proposed solution is more low-cost and resource-saving,and is more suitable for GIS/RS applications. 展开更多
关键词 cloud computing geo-information processing geo-processing
下载PDF
Influence of Three Protein Sources on Performance of Grasscutters (Thryonomys swinderianus) Fed Diets with or without Fishmeal
14
作者 Victoria Attoh-Kotoku Dagbui Kofi Emmanuel +2 位作者 Donkoh Armstrong Atuahene Comfort Charity Akpadie Winfred 《Journal of Agricultural Science and Technology(A)》 2015年第7期621-625,共5页
An 8-week feeding trial was conducted to assess the effect of soybean meal (SBM), groundnut meal (GNM) and blood meal (BM) addition in diets with or without (1%) fishmeal on the performance, N-digestibility an... An 8-week feeding trial was conducted to assess the effect of soybean meal (SBM), groundnut meal (GNM) and blood meal (BM) addition in diets with or without (1%) fishmeal on the performance, N-digestibility and cost of production of growing grasscutters. Fifty-four grasscutters (9-week-old) of mixed sexes were randomly assigned to six dietary treatments, using a completely randomized design (CRD) in a 2 × 3 factorial arrangement, with three grasscutters per treatment and three replicates each. Treatments 1-3 (TI-T3) contained no fishmeal, whilst treatments 4-6 (T4-T6) had 1% fishmeal added. The diets were formulated to be isocaloric and isonitrogenous. N-digestibility was significantly high for SBM diets with or without fishmeal, 83.91% and 82.19%, respectively, followed by BM diets. Average daily gain (ADG) was significantly (P 〈 0.05) high (12.95 g) for BM diet without fishmeal. Feed cost per kg diet was the lowest (US$0.195) for the same BM diet. The results indicated that the inclusion of SBM and BM in the diet of grasscutters with or without 1% fishmeal could improve performance and it may be the most economical for feeding BM in the diet without fishmeal. 展开更多
关键词 Alternative feed DIGESTIBILITY economic viability FISHMEAL greater cane rat protein sources.
下载PDF
Design and implementation of a large-scale multi-class text classifier
15
作者 于水 张亮 马范援 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2005年第6期690-695,共6页
Although, researchers in the ATC field have done a wide range of work based on SVM, almost all existing approaches utilize an empirical model of selection algorithms. Their attempts to model automatic selection in pra... Although, researchers in the ATC field have done a wide range of work based on SVM, almost all existing approaches utilize an empirical model of selection algorithms. Their attempts to model automatic selection in practical, large-scale, text classification systems have been limited. In this paper, we propose a new model selection algorithm that utilizes the DDAG learning architecture. This architecture derives a new large-scale text classifier with very good performance. Experimental results show that the proposed algorithm has good efficiency and the necessary generalization capability while handling large-scale multi-class text classification tasks. 展开更多
关键词 model selection DAGSVM automatic text classification
下载PDF
Exploring Criminology in Literary Texts: Robert Browning --An Example
16
作者 Afra Saleh Alshiban 《Journal of Literature and Art Studies》 2012年第4期454-463,共10页
The association between literature and criminology is undeniable, and yet, for too long, those studying crime and literature respectively have failed to see the connection between the two, or dismissed it as being irr... The association between literature and criminology is undeniable, and yet, for too long, those studying crime and literature respectively have failed to see the connection between the two, or dismissed it as being irrelevant. This study explores literary pieces, which deal exclusively with murder in order to prove that the two disciplines literature and criminology, are intimately connected and essentially inseparable. Some literary pieces which deal with identifying the thought processes of murderers have been so insightful that crime experts applied them to certain high-profile cases. That so much violent crime is depicted in literature should stimulate further research into the links between criminology and literature. Robert Browning's “The Laboratory: Ancien Regime” (1844) is selected as a case study in order to demonstrate how criminological theories can successfully be applied to literary pieces. Browning's protagonist will prove to be a fictional manifestation of a female sadistic criminal as defined by psychiatrist/criminologist Paul De River in his criminology/sexology textbook for law enforcement personnel The Sexual Criminal(1949) . 展开更多
关键词 cross-disciplinary approach LITERATURE CRIMINOLOGY interchangeable CORRELATED DISCIPLINES fictional manifestation
下载PDF
Revision of stratified OWL ontologiesbased on integer linear programming
17
作者 Ji Qiu Qi Guilin Boutouhami Khaoula 《Journal of Southeast University(English Edition)》 EI CAS 2020年第1期1-7,共7页
To revise stratified web ontology language(OWL)ontologies,the kernel revision operator is extended by defining novel conflict stratification and the incision function based on integer linear programming(ILP).The ILP-b... To revise stratified web ontology language(OWL)ontologies,the kernel revision operator is extended by defining novel conflict stratification and the incision function based on integer linear programming(ILP).The ILP-based model considers an optimization problem of minimizing a linear objective function which is suitable for selecting the minimal number of axioms to remove when revising ontologies.Based on the incision function,a revision algorithm is proposed to apply ILP to all minimal incoherence-preserving subsets(MIPS).Although this algorithm can often find a minimal number of axioms to remove,it is very time-consuming to compute MIPS.Thus,an adapted revision algorithm to deal with unsatisfiable concepts individually is also given.Experimental results reveal that the proposed ILP-based revision algorithm is much more efficient than the commonly used algorithm based on the hitting set tree.In addition,the adapted algorithm can achieve higher efficiency,while it may delete more axioms. 展开更多
关键词 ontology revision inconsistency handling semantic web integer linear programming
下载PDF
Spatial Data Process Using Python Script and Visual Programming Language in ArcGIS
18
作者 Pil Kwon 《Computer Technology and Application》 2013年第6期275-283,共9页
Data are limitless. But those are usually not formed or created in our needs. Most of data providers deliver their data in Microsoft Excel spreadsheet, which is compatible with ArcGIS, the most widely used GIS (Geogr... Data are limitless. But those are usually not formed or created in our needs. Most of data providers deliver their data in Microsoft Excel spreadsheet, which is compatible with ArcGIS, the most widely used GIS (Geographic Information System) software in GIS sector. However, those table data contain much unnecessary information that do not need for a certain project. Using the raw data can increase processing times and reduce performance of geoprocessing tools. This study shows steps of how the raw data are being processed using ArcGIS ModelBuilder and Python script. 展开更多
关键词 ARCGIS ARCMAP GIS Local Moran's I ModelBuilder PYTHON Python script visual programming language.
下载PDF
A SUBARRAY-SYNTHESIS BASED 2D DOA ESTIMATION METHOD
19
作者 Xu Wenlong Jiang Wei Li Zengfu Shang Yong Xiang Haige 《Journal of Electronics(China)》 2006年第5期645-649,共5页
In some satellite communications, we need to perform Direction Of Arrival (DOA) angle estima- tion under the restriction that the number of receivers is less than that of the array elements in an array antenna. To sol... In some satellite communications, we need to perform Direction Of Arrival (DOA) angle estima- tion under the restriction that the number of receivers is less than that of the array elements in an array antenna. To solve the conundrum, a method named subarray-synthesis-based Two-Dimensional DOA (2D DOA) angle estimation is proposed. In the method, firstly, the array antenna is divided into a series of subarray antennas based on the total number of receivers; secondly, the subarray antennas’ output covariance matrices are esti- mated; thirdly, an equivalent covariance matrix is synthesized based on the subarray output covariance matri- ces; then 2D DOA estimation is performed. Monte Carlo simulations showed that the estimation method is ef- fective. 展开更多
关键词 Spatial signal processing Direction Of Arrival (DOA) estimation Eigenspace decomposition Time Division Multiplex (TDM) Subarray synthesis
下载PDF
Processing of 8-Channel Synchronous Electro-Cardiograph
20
作者 赵捷 韩月秋 《Journal of Beijing Institute of Technology》 EI CAS 2002年第1期66-70,共5页
A real time algorithm is presented here to recognize and analyze 8 channel simultaneous electro cardiograph(ECG). The algorithm transforms 8 channel simultaneous ECG into three orthogonal vectors and spatial veloc... A real time algorithm is presented here to recognize and analyze 8 channel simultaneous electro cardiograph(ECG). The algorithm transforms 8 channel simultaneous ECG into three orthogonal vectors and spatial velocity first, then forms the spatial velocity sample, and uses this spatial velocity sample to recognize each beat. The algorithm computes the averaged parameters by using averaged spatial velocity and the averaged ECG and the current parameters by using the current beat period and current width of QRS. The algorithm can recognize P, QRS and T onsets and ends of simultaneous 12 lead ECG precisely, and some arrhythmias such as premature ventricular beat, ventricular escape beat, R on T, bigeminy, trigeminy. The algorithm software works well on a real 8 channel ECG system and meets the demands of designing. 展开更多
关键词 multi lead electro cardiograph embedded system real time computer processing
下载PDF
上一页 1 2 下一页 到第
使用帮助 返回顶部