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A new grey forecasting model based on BP neural network and Markov chain 被引量:6
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作者 李存斌 王恪铖 《Journal of Central South University of Technology》 EI 2007年第5期713-718,共6页
A new grey forecasting model based on BP neural network and Markov chain was proposed. In order to combine the grey forecasting model with neural network, an important theorem that the grey differential equation is eq... A new grey forecasting model based on BP neural network and Markov chain was proposed. In order to combine the grey forecasting model with neural network, an important theorem that the grey differential equation is equivalent to the time response model, was proved by analyzing the features of grey forecasting model(GM(1,1)). Based on this, the differential equation parameters were included in the network when the BP neural network was constructed, and the neural network was trained by extracting samples from grey system's known data. When BP network was converged, the whitened grey differential equation parameters were extracted and then the grey neural network forecasting model (GNNM(1,1)) was built. In order to reduce stochastic phenomenon in GNNM(1,1), the state transition probability between two states was defined and the Markov transition matrix was established by building the residual sequences between grey forecasting and actual value. Thus, the new grey forecasting model(MNNGM(1,1)) was proposed by combining Markov chain with GNNM(1,1). Based on the above discussion, three different approaches were put forward for forecasting China electricity demands. By comparing GM(1, 1) and GNNM(1,1) with the proposed model, the results indicate that the absolute mean error of MNNGM(1,1) is about 0.4 times of GNNM(1,1) and 0.2 times of GM(I, 1), and the mean square error of MNNGM(1,1) is about 0.25 times of GNNM(1,1) and 0.1 times of GM(1,1). 展开更多
关键词 grey forecasting model neural network Markov chain electricity demand forecasting
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Current State and Prospect of China Natural Gas Industry 被引量:3
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作者 Gao Jie Chen Jianhui +3 位作者 Sun Hui Ge Ye Wei Kaihua Li Bo 《China Oil & Gas》 CAS 2016年第1期22-28,共7页
Natural gas output remained stable growth and reached 130.9 billion cubic meters in 2015, 3% higher than the same period last year. Shale gas saw huge progress. China titus became the third country in the world fu!fil... Natural gas output remained stable growth and reached 130.9 billion cubic meters in 2015, 3% higher than the same period last year. Shale gas saw huge progress. China titus became the third country in the world fu!filling commercial development after U.S. attd Canada. Natural gas import growth and growth rate declined obviously, and the imported pipeline gas and LNG totaled 61.2 billion cubic meters in 2015. Apparent natural gas consumption was 186.5 billion cubic meters in 2015, rising by 4.4% as compared with the same period last year, but it hit a historic low. There is higher dozonward pressure on domestic macro economy in 2016. However, natural gas demand will see more rapid growth, propelled by such favorable factors as gas price regulation and environmental protection policies. It is prospected that natural gas market will take a turn for the better than in 2015, and natural gas supply will still be rich in general in 2016. 展开更多
关键词 China Natural gas CONSUMPTION PRICE City gas Gas power generation Natural gas vehicles
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Challenges and Opportunities of China Oil & Gas Industry
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作者 Qian Xingkun 《China Oil & Gas》 CAS 2015年第2期26-32,共7页
Chinese economy has turned from rapid development into new normal. With economic transition, demand for oil and gas decreases as well. Consumed diesel-gasoline ratio keeps declining, and diesel export increases consid... Chinese economy has turned from rapid development into new normal. With economic transition, demand for oil and gas decreases as well. Consumed diesel-gasoline ratio keeps declining, and diesel export increases considerably. Gas demand grows at medium speed, and supply meets demand in general. Alternative energy dominated by gas and electricity will develop faster. As crude oil import right is gradually liberalized, domestic oil market structure will be changed. Oil price drop brings the best opportunity for oil and gas market reform, and environmental protection becomes main force boosting natural gas development. 展开更多
关键词 OIL natural gas TRANSITION OPPORTUNITY
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Preliminary description of diatom community and its relationship with water physicochemical variables in Qixinghe Wetland 被引量:3
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作者 范亚文 李晶 +1 位作者 门晓宇 刘妍 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2012年第3期379-387,共9页
Wetlands play a very important role in ecosystems. Qixinghe Wetland is a nature reserve area in northeastern China. In this paper, diatom communities and environmental qualities were investigated at eight sites in Qix... Wetlands play a very important role in ecosystems. Qixinghe Wetland is a nature reserve area in northeastern China. In this paper, diatom communities and environmental qualities were investigated at eight sites in Qixinghe Wetland. This study was to examine diatom species patterns in relation to environmental variables in wetlands, and to use diatoms as indicators to water quality in wetlands and wetland classification. Diatoms were sampled in summers and autumns in 2002 and 2004, during which 180 taxa were identified. Environmental variations in pH, temperature, biochemical oxygen demand (BOD), and chemical oxygen demand (COD) were measured. The seasonal composition and abundance of diatoms changed greatly during the study period. The relationship between diatoms and chemical water quality was estimated statistically. Canonical correspondence analysis (CCA) with forward selection and Monte Carlo permutation tests revealed that all water environmental variables changed during the study period (P<0.05). Among all the parameters, variation in BOD among the sites was a very important determinant of species composition according to the CCA, and BOD decreased from 2002 to 2004. Our results suggest that the water quality had improved during the three-year period because of enhanced environmental protection with less human disturbance. We conclude that diatoms can be used to indicate water quality and habitat conditions in this wetland. 展开更多
关键词 DIATOM canonical correspondence analysis (CCA) Qixinghe Wetland
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Trial of Natural Gas Injection Made Success in China
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《China Oil & Gas》 CAS 2005年第2期39-39,共1页
The trial of oil displacement driven by natural gas injection in China has been successfully accomplished recently for the first time in Zhongyuan Oilfield, Henan Province. This technology is ready for oilfield applic... The trial of oil displacement driven by natural gas injection in China has been successfully accomplished recently for the first time in Zhongyuan Oilfield, Henan Province. This technology is ready for oilfield application in July. 展开更多
关键词 中国 石油工业 市场 中原油田
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Analysis on the Charm and Application of Modem Craflwork Art Design
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作者 Li Wuxing 《International Journal of Technology Management》 2013年第9期13-15,共3页
Modern craflwork art, based on traditional craflwork art, with the constant development of the social production level, gradually forms; and they have a very close relationship. But, today' s modern craftwork art is ... Modern craflwork art, based on traditional craflwork art, with the constant development of the social production level, gradually forms; and they have a very close relationship. But, today' s modern craftwork art is not completed by hands and simple tools and doesn' t depend on the limited natural materials to cope with today' s human life needs, but it must be equipped with the beauty wisdom, industrial science and technology, economic ideas and production and manufacturing technology, so that it can produce the modern craftworks full of the era significance. This paper first analyzes the charm of modern craftwork art design, and then explains how to use the modern craftwork art design, which has a certain practical value and reference significance. 展开更多
关键词 modem craftwork art design CHARM APPLICATION INNOVATION
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First ERW Ф610 Steel Tube Production Line Brought on Stream
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《China Oil & Gas》 CAS 2005年第2期57-57,共1页
The first domestic ERWФ610 high-frequency straight-seam steel pipe production line was built in Shanghai Zhongyou TIPO Steel Pipe Co Ltd recently. This steel pipe production line initiated inside China has drawn the ... The first domestic ERWФ610 high-frequency straight-seam steel pipe production line was built in Shanghai Zhongyou TIPO Steel Pipe Co Ltd recently. This steel pipe production line initiated inside China has drawn the attention from many enterprises including PetroChina and CNOOC. It is known that the first batch of products have been transported to the construction site of the West-East Gas Transmission Project. 展开更多
关键词 中国石油天气有限公司 中国海洋石油总公司 油气资源 气运输 市场
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Protective equipment for emergency rescue in alpine-cold region
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作者 Ma Tian Feng Xinxing +1 位作者 Wang Qizhi Hao Limin 《Engineering Sciences》 EI 2013年第2期93-96,共4页
Alpine-cold regions are characterized as hypoxia,strong wind,heavy rain,cold climate,huge temperature difference between day and night,and vertical climate. All these make it difficult for an emergency rescue when a n... Alpine-cold regions are characterized as hypoxia,strong wind,heavy rain,cold climate,huge temperature difference between day and night,and vertical climate. All these make it difficult for an emergency rescue when a natural disaster such as earthquake happens. Based on the characteristics of emergency rescue in alpinecold region,several multifunctional protective equipments have been developed by the Quartermaster Equipment Institute of General Logistics Departmen(tGLD)of the Chinese People's Liberation Army(CPLA). These equipments are lightweight,durable and environment adaptable. 展开更多
关键词 PLATEAU alpine-cold region emergency rescue protective equipment carbon fiber COMPOSITE
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Some Potential Solutions to Global Environment Problems & Energy Crisis: Based on Design
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作者 P.M. Wang G. Liu 《Journal of Environmental Science and Engineering》 2010年第6期55-59,共5页
Nowadays human society enters the 21st century, with the rapid economic and technological development, people's material and spiritual requirements has got great satisfaction. However, natural environmental damage br... Nowadays human society enters the 21st century, with the rapid economic and technological development, people's material and spiritual requirements has got great satisfaction. However, natural environmental damage brought by us is also accelerating. Natural disasters happen frequently, including ecological degradation and deterioration, energy resources crisis, greenhouse effect, earthquakes, tsunamis, volcanoes etc. The global crisis has once again waken-up call to mankind. How to properly solve these crises had become a common and urgent responsibility of mankind. This paper will mainly discuss and seek some new potential methods in solving energy crisis and environmental problems from the perspective of automotive and architecture design. As an architect, how to avoid light pollution and reduce heat absorption of roof, increasing heat reflectance of roof are becoming their main and urgent responsibilities. On the other hand, reducing greenhouse effect, researching and developing new low-carbon, low-emission fuel sources are also becoming automotive designers' obligations. Living in harmony with nature & earth is becoming the common human themes of the 21 st century. 展开更多
关键词 Global crisis product architecture design SOLUTIONS harmony with nature
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朵云印评
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作者 徐庆华 《书法》 2008年第1期81-81,共1页
是印作者对篆刻的空间有极好的感觉,如能得高手指点,前途未可限量。此印章法、刀法取意在齐(白石)、邓(散木)之间,但终因学浅功薄,似有杂陈之感,未臻华境。博学可嘉,然需约取,这中间要在消化融会,作者当体悟之。
关键词 然需 散木 未臻华境 学浅功 印评
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From the lab to the world: The paradigmatic assumption and the functional cognition of avian foraging 被引量:1
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作者 Danielle SULIKOWSKI Darren BURKE 《Current Zoology》 SCIE CAS CSCD 2015年第2期328-340,共13页
Mechanisms of animal learning and memory were traditionally studied without reference to niche-specific functional considerations. More recently, ecological demands have informed such investigations, most notably with... Mechanisms of animal learning and memory were traditionally studied without reference to niche-specific functional considerations. More recently, ecological demands have informed such investigations, most notably with respect to foraging in birds. In parallel, behavioural ecologists, primarily concerned with functional optimization, have begun to consider the role of mechanistic factors, including cognition, to explain apparent deviations from optimal predictions. In the present paper we discuss the application of laboratory-based constructs and paradigms of cognition to the real-world challenges faced by avian foragers. We argue that such applications have been handicapped by what we term the 'paradigmatic assumption' - the assumption that a given laboratory paradigm maps well enough onto a congruent cognitive mechanism (or cognitive ability) to justify confiation of the two. We present evidence against the paradigmatic assumption and suggest that to achieve a profitable integration between function and mechanism, with respect to animal cognition, a new conceptualization of cognitive mechanisms - functional cogni- tion - is required. This new conceptualization should define cognitive mechanisms based on the informational properties of the animal's environment and the adaptive challenges faced. Cognitive mechanisms must be examined in settings that mimic the im- portant aspects of the natural environment, using customized tasks designed to probe defined aspects of the mechanisms' opera- tion. We suggest that this approach will facilitate investigations of the functional and evolutionary relevance of cognitive mecha- nisms, as well as the patterns of divergence, convergence and specialization of cognitive mechanisms within and between species . 展开更多
关键词 Functional cognition Paradigmatic assumption Informational properties Avian foraging
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通信枢纽楼能耗运行分析研究 被引量:2
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作者 樊春锋 伍建萍 《电信工程技术与标准化》 2016年第5期89-92,共4页
如何在业务量不断增加,电源容量无法扩容的情况下,更好地解决供电能力紧张、机房装机位不足、机房散热等问题,是本论文的研究意义所在。本文通过对S省通信枢纽楼能耗运行分析,给出以上难点的合理化建议和建设指导原则。
关键词 枢纽楼 变压器 能耗 红色预警 搬迁
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