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101.
Automatically identifying and extracting the target information of a webpage, especially main text, is a critical task in many web content analysis applications, such as information retrieval and automated screen reading. However, compared with typical plain texts, the structures of information on the web are extremely complex and have no single fixed template or layout. On the other hand, the amount of presentation elements on web pages, such as dynamic navigational menus, flashing logos, and a multitude of ad blocks, has increased rapidly in the past decade. In this paper, we have proposed a statistics-based approach that integrates the concept of fuzzy association rules (FAR) with that of sliding window (SW) to efficiently extract the main text content from web pages. Our approach involves two separate stages. In Stage 1, the original HTML source is pre-processed and features are extracted for every line of text; then, a supervised learning is performed to detect fuzzy association rules in training web pages. In Stage 2, necessary HTML source preprocessing and text line feature extraction are conducted the same way as that of Stage 1, after which each text line is tested whether it belongs to the main text by extracted fuzzy association rules. Next, a sliding window is applied to segment the web page into several potential topical blocks. Finally, a simple selection algorithm is utilized to select those important blocks that are then united as the detected topical region (main texts). Experimental results on real world data show that the efficiency and accuracy of our approach are better than existing Document Object Model (DOM)-based and Vision-based approaches. 相似文献
102.
介绍冶炼烟气制本系统环保治理工程的工艺设计及生产运行情况。污水处理系统采用中和曝气加铁盐除砷工艺,引进了戈尔膜过滤器。尾气处理系统,采用石灰中和法,引进动波洗涤技术和关键设备。环保治理工程投产后,废气均达标排放。 相似文献
103.
探讨价格不确定下,需求-价格相关性与风险态度对决策行为的影响.建立随机需求与随机价格相关情境下基于Copula-CVaR的报童决策模型,Copula函数描述相关性,条件风险价值(CVaR)反映风险态度,证明了模型解的存在性和惟一性.蒙特卡罗模拟发现,需求与价格的相关性与风险态度对决策的交互作用使决策行为发生规律性变化,决策者对价格波动有一定容忍度,需求与价格相关性趋于不相关与完全负相关时市场趋于同质性. 相似文献
104.
新型不锈钢化学抛光剂工艺研究 总被引:1,自引:0,他引:1
叙述了一般不锈钢化学抛光溶液的基本类型和在实际应用中存在的问题。着重论述MW-6不锈钢化学抛光剂的工艺研究过程、工艺条件、质量指标及检测方法,同时介绍了它与传统不锈钢化学抛光剂的比较,经验价值,表面质量控制,应用领域及应用前景。 相似文献
105.
Synthesis of superabsorbent resin (SAR) was achieved by a new method, that of direct UV photopolymerization, and in particular the synthesis of a SAR of acrylic acid–potassium acrylate copolymer by UV photopolymerization was investigated. Influences of ratio (mol) of acrylate monomer to acrylic acid monomer, photoinitiators, crosslinking agents, and exposure time of UV light on the water‐absorbent properties were investigated. The results showed that the water absorbency (Q) of SAR based on Irgacure 1700 or Irgacure 1800 was 545–530 mL/g, but under the same conditions Q was 450 mL/g for the SAR based on Irgacure 651. N,N′‐Methylene bisacrylamide, hydroethyl acrylate, and glycerol were used as crosslinking agents, of which N,N′‐methylene bisacrylamide was the most effective. It crosslinked the molecular chains through attending the copolymerization with acrylic acid (AA) and potassium acrylate. When the exposure time was 5 min, the value of Q was 1368 mL/g (the content of N,N′‐methylene bisacrylamide was 100 ppm). © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1618–1624, 2004 相似文献
106.
An alkali‐soluble, photocrosslinkable polymer was synthesized by esterification of OH groups of acrylic phenolic resin with maleic anhydride. The OH groups were formed by the ring‐opening reaction of epoxy groups of epoxy phenolic resin with acrylic acid. The esterification conditions were studied. The results showed that it is better to use tetramethyl ammonium bromide as catalyst than N,N‐dimethylbenzylamine. The conversion of maleic anhydride in acetone can reach about 80% at 56°C for 4 h. The purified product was characterized by IR, DSC, and TGA. The product containing acrylate and maleic acid monoester groups, above a certain content, can be dissolved in 1% Na2CO3 solution. The photocrosslinkable properties of the product were investigated through selection of photoinitiator, accelarator, crosslinkable diluent monomer, etc. The acrylate and maleic acid monoester group‐containing phenolic resin exhibited very good photocrosslinking behavior, since it contains double bonds from both acrylate groups and maleic acid monoester groups. The activity of photoinitiator decreases in the order: isopropylthioanthraquinone > benzoin ethyl ether (BE) > anthraquinone (AQ) > benzophenone > Michel ketone (MK) > 2,2‐diethoxyacetophenone. The combination of some photoinitiators showed synergistic effects. The order of increasing activity for the accelerator is as follows: MK > ethyl p‐(dimethylamino)benzoate > N,N‐dimethylaniline > triethanolamine. The optimum diluent monomer is trimethylolpropane trimethacrylate. The gel content of the mixture of the resin and trimethylolpropane trimethacrylate could reach 85% using the combined photoinitiators of BE and AQ under UV exposure for 120 s. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1607–1614, 2005 相似文献
107.
108.
The kinetics of curing for a modified bismaleimide (BMI) resin was investigated to ascertain a suitable cure model for the material. The resin system used in this study was composed of 4,4′‐bismaleimidodiphenylmethane (BMIM) and 0,0′‐diallyl bisphenol A (DABPA, DABA). The BMIM was the base monomer and the DABPA was the modified agent. A series of isothermal DSC runs provided information about the kinetics of cure in the temperature range 170–220°C. Regardless of the different temperatures, the shape of the conversion curves was similar, and this modified BMI resin system underwent an nth‐order cure reaction. Kinetic parameters of this BMI resin system, including the reaction model, activation energy, and frequency factor, were calculated. From the experimental data, it was found that the cure kinetics of this resin system can be characterized by a first‐order kinetic model. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3338–3342, 2004 相似文献
109.
Yangyang Ji Jingkui Liang Zhan Chen Sishen Xie 《Journal of the American Ceramic Society》1991,74(2):444-446
The phase relations at a temperature below "subsolidus" in the system Al2 O3 –B2 O3 –Nd2 O3 are reported. Specimens were prepared from various compositions of Al2 O3 , B2 O3 , and Nd2 O3 of purity 99.5%, 99.99%, and 99.9%, respectively, and fired at 1100°C. There are six binary compounds and one ternary compound in this system. The ternary compound, NdAl3 (BO3 )4 (NAB), has a phase transition at 950°C ± 15°C. The high-temperature form of NAB has a second harmonic generation (SHG) efficiency of KH2 PO4 (KDP) of the order of magnitude of the form which has been used as a good self-activated laser material, and the low-temperature form of NAB has no SHG efficiency. 相似文献
110.
Luis F. Hakim Jarod A. McCormick Guo-Dong Zhan Alan W. Weimer Peng Li Steven M. George 《Journal of the American Ceramic Society》2006,89(10):3070-3075
Surface modification of titania nanoparticles was achieved by coating them with ultrathin alumina films using atomic layer deposition. The coating process was performed in a fluidized bed reactor at low pressure and under mechanical vibration. Films were deposited using self-limiting, sequential surface reactions of trimethylaluminum and water. The composition of alumina-coated particles was verified using infrared spectroscopy. The deposited films had an average growth rate of 0.2 nm/coating cycle and were highly uniform and conformal as demonstrated by transmission electron microscopy and X-ray spectroscopy. Deposited alumina films were amorphous as verified through X-ray diffraction and high-resolution electron microscopy. The coating process did not promote particle sintering as validated via particle size and surface area analysis. 相似文献