This paper proposes a novel approach to comment spam identification based on content analysis. Three main features including the number of links, content repetitiveness, and text similarity are used for comment spam i...This paper proposes a novel approach to comment spam identification based on content analysis. Three main features including the number of links, content repetitiveness, and text similarity are used for comment spam identification. In practice, content repetitiveness is determined by the length and frequency of the longest common substring. Furthermore, text similarity is calculated using vector space model. The precisions of preliminary experiments on comment spam identification conducted on Chinese and English are as high as 93% and 82% respectively. The results show the validity and language independency of this approach. Compared with conventional spam filtering approaches, our method requires no training, no rule sets and no link relationships. The proposed approach can also deal with new comments as well as existing comments.展开更多
Growth of population and extensive industrial development had increases solid wastes and pollutants in many parts of the world. Due to the economic and technologic limitations not all waste can be easily turn to other...Growth of population and extensive industrial development had increases solid wastes and pollutants in many parts of the world. Due to the economic and technologic limitations not all waste can be easily turn to other sort of materials or energy. As a result so, we still have to rely on the common solution to bury as to excrete urban wastes. Selection of an appropriate site for this process in a big city like Mashad in Iran is an important task which needs a cautious, strategic planning and investigations at various levels. With regards to this issue it is necessary to have a comprehensive volume of spatial information of the surrounding area and a proper analysis and spatial exploration need to be done. The methodology being implemented utilized geospatial technology for the management and visualization of spatial data while fuzzy logic is used in searching the best location for site selection. In this paper the basic elements of the fuzzy logic methodology as well as its potential in the specific problem are described. A case study for Mashad city is elaborated. The results drawn up by fuzzy logic are compared with that of the traditional Boolean approach in the decision making process.展开更多
Municipal solid wastes from industrial plants were pyrolyzed in a fixed bed reactor to evaluate the influence of paper/plastic ratio and reaction time both on product quantity and quality. Raw materials have been pyro...Municipal solid wastes from industrial plants were pyrolyzed in a fixed bed reactor to evaluate the influence of paper/plastic ratio and reaction time both on product quantity and quality. Raw materials have been pyrolyzed under nitrogen in a 3.0 dm^3 autoclave. Results show considerable differences in yields and quality of products obtained by pyrolysis of wastes with different paper content. Light and heavy oils were mixtures of organic compounds containing valuable hydrocarbons and oxygenated chemicals, while chars were rather composed of inorganic compounds from the raw materials. Longer reaction time of pyrolysis had produced higher non-condensable gas, water and light oil. Gases contained CO, CO2 and hydrocarbons, but the concentrations were very function of reaction time and paper/plastic ratio. Light and heavy oils showed similarities with middle distillates and heavy oils in refinery, the high paper content of the raw materials was unfavourable for longer storage of waste derived oils.展开更多
基金Supported by the National Natural Science Foundation of China (No.60736044, 60803094)
文摘This paper proposes a novel approach to comment spam identification based on content analysis. Three main features including the number of links, content repetitiveness, and text similarity are used for comment spam identification. In practice, content repetitiveness is determined by the length and frequency of the longest common substring. Furthermore, text similarity is calculated using vector space model. The precisions of preliminary experiments on comment spam identification conducted on Chinese and English are as high as 93% and 82% respectively. The results show the validity and language independency of this approach. Compared with conventional spam filtering approaches, our method requires no training, no rule sets and no link relationships. The proposed approach can also deal with new comments as well as existing comments.
文摘Growth of population and extensive industrial development had increases solid wastes and pollutants in many parts of the world. Due to the economic and technologic limitations not all waste can be easily turn to other sort of materials or energy. As a result so, we still have to rely on the common solution to bury as to excrete urban wastes. Selection of an appropriate site for this process in a big city like Mashad in Iran is an important task which needs a cautious, strategic planning and investigations at various levels. With regards to this issue it is necessary to have a comprehensive volume of spatial information of the surrounding area and a proper analysis and spatial exploration need to be done. The methodology being implemented utilized geospatial technology for the management and visualization of spatial data while fuzzy logic is used in searching the best location for site selection. In this paper the basic elements of the fuzzy logic methodology as well as its potential in the specific problem are described. A case study for Mashad city is elaborated. The results drawn up by fuzzy logic are compared with that of the traditional Boolean approach in the decision making process.
文摘Municipal solid wastes from industrial plants were pyrolyzed in a fixed bed reactor to evaluate the influence of paper/plastic ratio and reaction time both on product quantity and quality. Raw materials have been pyrolyzed under nitrogen in a 3.0 dm^3 autoclave. Results show considerable differences in yields and quality of products obtained by pyrolysis of wastes with different paper content. Light and heavy oils were mixtures of organic compounds containing valuable hydrocarbons and oxygenated chemicals, while chars were rather composed of inorganic compounds from the raw materials. Longer reaction time of pyrolysis had produced higher non-condensable gas, water and light oil. Gases contained CO, CO2 and hydrocarbons, but the concentrations were very function of reaction time and paper/plastic ratio. Light and heavy oils showed similarities with middle distillates and heavy oils in refinery, the high paper content of the raw materials was unfavourable for longer storage of waste derived oils.
