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AN EMPIRICAL ANALYSIS OF SAMPLING INTERVAL FOR EXCHANGE RATE FORECASTING WITH NEURAL NETWORKS

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Journal of Systems Science & Complexity 2003年第2期16卷 165-176页

作者： K.K.Lai Y.Nakamori WANGShouyang DepartmentofManagementsciences CityUniversityofHongKongTatCheeAvenueKowloonHongKong schoolofKnowledgeScience JapanAdvancedInstituteofScienceandTechnology1-1AsahidaiTatsunokuchiIshikawa923-1292Japan InstituteofSystemsScience AcademyofMathematicsandSystemsSciencesChineseAcademyofSciencesBeijing100080China

Artificial neural networks (ANNs) have been widely used as a promising alternative approach for forecast task because of their several distinguishing features. In this paper, we investigate the effect of different sampling intervals on predictive performance of ANNs in forecasting exchange rate time series. It is shown that selection of an appropriate sampling interval would permit the neural network to model adequately the financial time series. Too short or too long a sampling interval does not provide good forecasting accuracy. In addition, we discuss the effect of forecasting horizons and input nodes on the prediction performance of neural networks.

关键词： Neural networks sampling interval exchange rate forecasting.

Sugarcane leaves-derived polyphenols alleviate metabolic syndrome and modulate gut microbiota of ob/ob mice

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Food Science and Human Wellness 2024年第2期13卷 633-648页

作者： Li Sun Tao Wang Baosong Chen Cui guo Shanshan Qiao Jinghan Lin Huan Liao Huanqin Dai Bin Wang Jingzu Sun Hongwei Liu State Key Laboratory of Mycology Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China Savaid Medicine school University of Chinese Academy of SciencesBeijing 100101China Guangxi Academy of sciences Nanning 530007China

Sugarcane leaves-derived polyphenols(SLP)have been demonstrated to have diverse health-promoting benefits,but the mechanism of action has not been fully *** study aimed to investigate the anti-metabolic disease effects of SLP and the underlying mechanisms in *** the current study,we prepared the SLP mainly consisting of three flavonoid glycosides,three phenol derivatives,and two lignans including one new compound,and further demonstrated that SLP reduced body weight gain and fat accumulation,improved glucose and lipid metabolism disorders,ameliorated hepatic steatosis,and regulated short-chain fatty acids(SCFAs)production and secondary bile acids metabolism in ob/ob ***,SLP largely altered the gut microbiota composition,especially enriching the commensal bacteria Akkermansia muciniphila and Bacteroides *** gavage with the above two strains ameliorated metabolic syndrome(MetS),regulated secondary bile acid metabolism,and increased the production of SCFAs in high-fat diet(HFD)-induced obese *** results demonstrated that SLP could be used as a prebiotic to attenuate MetS via regulating gut microbiota composition and further activating the secondary bile acids-mediated gut-adipose axis.

关键词： Sugarcane leaves-derived polyphenols Metabolic syndrome Bacteroides acidifaciens Akkermansia muciniphila Secondary bile acids metabolism

Intracerebroventricular administration of leptin increase physical activity but has no effect on metabolism in cold-acclimated rats

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Intracerebroventricular administration of leptin increase ph...

第七届全国野生动物生态与资源保护学术研讨会

作者： Gang-Bin tang~a,Kui Li~b,Xiang-Fang tang~b,De-Hua Wang~(a*) (a State Key Laboratory of Integrated Management of Pest Insects and Rodents,Institute of Zoology, Chinese Academy of sciences,{3. 100101,{4. b State Key Laboratory of Animal Nutrition, Institute of Animal sciences,Chinese Academy of Agricultural sciences,{3. 100193.{4.)

Chronic cold exposure stimulates thermogenesis in brown adipose tissue,resulting in fat mobilization and compensatory ***,these physiological events are accompanied by a remarkable reduction in serum leptin ***,the be...

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Intelligent Decision Support System for Subway Incident Solving

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Intelligent Decision Support System for Subway Incident Solv...

2004.全科学与技术国际会议

作者： CUI Yanping1 tang Zhenmin2 & WU Xu1 (1 school of Traffic and Transport {3. Jiaotong {4. beijing 10004. china) (2 school of Electrical Engineering {3. Jiaotong {4. beijing 10004. china)

Subway incident is a serious problem of great concern for most metropolitan subway management authorities. The high economic, social and psychological impact associated with the incident has prompted

关键词： decision support system (DSS) subway incident solving case-based reasoning context

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大学生的压力与心理健康(英)

心理学报 2003年第2期35卷 222-230页

作者：李虹林崇德清华大学教育研究所北京100084 北京师范大学心理学院北京100875

目的是探讨大学校园压力对大学生心理健康的影响。其意义在于根据压力与心理健康的不同关系,有的放矢地制定干预策略,使大学生在压力之下仍然能够保持心理健康。大学校园压力被定义为学习压力,个人压力和消极生活事件,并由相应的量表所... 详细信息

目的是探讨大学校园压力对大学生心理健康的影响。其意义在于根据压力与心理健康的不同关系,有的放矢地制定干预策略,使大学生在压力之下仍然能够保持心理健康。大学校园压力被定义为学习压力,个人压力和消极生活事件,并由相应的量表所测量。心理健康被定义为:一般健康状况和自尊,也由相应的量表所测量。研究问题是:(1)大学校园压力对大学生的心理健康是否有负面影响?(2)学习压力对大学生的心理健康是否有负面影响?(3.个人压力对大学生的心理健康是否有负面影响?(4.消极生活事件对大学生的心理健康是否有负面影响?同时建立了4.相应的理论假设。研究所采用的是横断和相关设计原则,并采用回溯性调查问卷方法对来自北京市3.高校的788名大学生进行了研究。研究结果证明了全部4.理论假设。研究结论是:大学校园压力对大学生的心理健康有负面影响,而与心理问题呈正相关。

关键词：大学校园压力心理健康大学生

Neutron Halo in Deformed Nuclei

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Neutron Halo in Deformed Nuclei

第十三届全国核结构研讨会暨第九次全国“核结构与量子力学”专题讨论会

作者： Shan-Gui Zhou~(1,2 1)) Jie Meng~(3.4.1,2) P.Ring~5 En-Guang Zhao~(1,2,3. 1(Institute of Theoretical Physics,Chinese Academy of sciences,beijing 100190,{4.) 2(Center of Theoretical Nuclear Physics,National Laboratory of Heavy Ion Accelerator,Lanzhou 73.000,{4.) 3.school of Physics,Peking university,beijing 100871,{4.) 4.school of Physics and Nuclear Engineering Science,Beihang university,beijing 100191,{4.) 5(Physikdepartment,Technische Universitat Munchen,8574. Garching,Germany)

Halo phenomena in nuclei are driving forces for the development of the physics with radioactive ion beams. They are threshold effects and have been first observed in the weakly bound system *** that most open shell nuclei are deformed,the interplay between deformation and weak binding raises interesting questions,such as whether or not there exist halos in deformed nuclei and,if yes,what are their new features. In order to describe adequately the halo phenomena in deformed nuclei,contributions of the halo,deformation effects,and large spatial extensions of these systems should be considered in a fully self-consistent way.A deformed relativistic Hartree Bogoliubov（DRHB） theory has been developed in which the DRHB equations are solved in a spherical Woods-Saxon basis with the proper asymptotic behavior at large distance from the nuclear center.

关键词： Neutron halo deformed nuclei shape decoupling relativistic Hatree-Bogoliubov model

Perceived Institutional Supportiveness and Innovation Capability Building: A Study in Emerging Market-Based Science Park Firms

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Perceived Institutional Supportiveness and Innovation Capabi...

第四届（2009）中国管理学年会--技术与创新管理分会场

作者： Yinghui Cao Guanghua school of Management Peking university, beijing, {3. 100871 Changhui Zhou Guanghua school of Management Peking university, beijing, {3. 100871

Adopting an interactive approach, we extend the existing research in understanding the driving mechanism of innovation capability building activities in transitional economies by positing that external institutional environment and internal firm-specific characteristics jointed determine innovation capability building activities in terms of patenting propensity. Using data from a nationwide survey of technology- based firms in china’s national science parks, we empirically investigate the moderating effect of firm evolutional paths and coordination processes on the relationship between perceived institutional supportiveness and patenting propensity.

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A Strategy for the Proliferation of Ulva prolifera,Main Causative Species of Green Tides,with Formation of Sporangia by Fragmentation

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A Strategy for the Proliferation of Ulva prolifera,Main Caus...

庆祝中国藻类学会成立3.周年暨第十五次学术讨论会

作者： Shan Gao~a Xiaoyuan Chen~a Qianqian Yi~a Guangce Wang~(b 1) Guanghua Pan~a Apeng Lin~(b c) and Guang Peng~b a College of Marine Science and Engineering Tianjin university of Science and Technology Tianjin 3.04.7 china b Institute of Oceanology Chinese Academy of sciences (IOCAS) Qingdao 266071 china c graduate school Chinese Academy of sciences beijing 10003. china

＜正＞Ulva prolifera,a common green seaweed,is one of the causative species of green tides that occurred frequently along the shores of Qingdao in 2008 and had detrimental effects on the preparation for the 2008 beijing Olympic Games sailing competition,since more than 3.%of the area of the Games was *** view of the rapid accumulation of the vast biomass of floating *** in green tides,we investigated the formation of sporangia in disks of different diameters excised from U. prolifera,changes of the photosynthetic properties of cells during sporangia formation, and development of *** results suggested that the disks less than 1.00 mm in diameter were optimal for the formation of sporangia,but there was a small amount of spore release in these *** highest percentage of area of spore release occurred in 2.50 mm diameter *** contrast,sporangia were formed only at the cut edges of larger disks（3.00 mm,3.50 mm and 4.00 mm diameter）.Additionally,the majority of spores liberated from the disks appeared vigorous and developed successfully into new *** results implied that fragments of the appropriate size from the *** thalli broken by a variety of factors via producing spores gave rise to the rapid proliferation of the seaweed under field conditions,which may be one of the most important factors to the rapid accumulation of the vast biomass of *** in green tides occurred in Qingdao,2008.

关键词： Ulva prolifera Rapid proliferation Sporangia Spore development

Analyses of Forest Diseases and Insect Pests

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Forest Ecosystems 2003年第S1期 45-53页

作者： Gao Lan Zhao Tiezhen school of Economics and Management,beijing Forestry university,beijing 10008{4.P.R.china

The paper first carries out time and spatial analyses of forest diseases and insect pests and points out that the mostserious year is 1989,the most serious region is central-south,the disaster areas are increasing as a whole and insect pests account forlarger than forest *** a comparison of its loss analysis,it concludes that disaster occurrence area is larger than preventionand cure area;The former is larger than reforestation *** reasons are worsened ecological environment,unreasonablemanagement,feeble management institutions,ignored prevention and cure,diseased legal system,short of funds,and so *** to these,the paper puts forward related countermeasures to reduce forest diseases and insect pests.

关键词： forest diseases and insect pests time analysis spatial analysis loss comparison