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Studies on hybridization effects of different geographic populations of Chlamys farreri Ⅱ.The medium-term growth and development of Chlamys farreri populations from China and Russia and their reciprocal crosses 被引量:12
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作者 LiuXiaolin ChangYaqing +3 位作者 XiangJianhai LiFuhua LiuXianjie BrovkinaElenaPavlovna 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2003年第2期255-264,共10页
Based on the research of juvenile (2, 3, 4 months) growth and survival of three populations of two different geographic areas in Chlamys farreri from Russian and China and their F1 hybrids derived from Chinese cultura... Based on the research of juvenile (2, 3, 4 months) growth and survival of three populations of two different geographic areas in Chlamys farreri from Russian and China and their F1 hybrids derived from Chinese cultural population (CC) (?) × Russian population (RW) (?) , Chinese wild population (CW) (?) × Russian population (RW) (?), Russian population (RW) (?) × Chinese wild population (CW) (?) , the study of the medium-term (6, 8, 10, 12 months) growth and development of Chlamys farreri was carried out. The four determined results indicated that there existed different extent heterosis (3% -52%) for the growth in three types of F1 hybrids, and the offspring derived from CC(?) ×R(?) had a stronger heterosis among the crosses at the medium-term; the uptrend among traits are wet weight >shell width>shell length> shell height, Chinese cultural population could be recognized as excellent parent, and seasonal variations influence very much on the daily increment and growth rate of each trait of Chlamys farreri and it is only able to survive and could barely grow in winter (6-8 months), but grows fast in temperate season (10-12 months). 展开更多
关键词 Chlamys farreri POPULATION HYBRIDIZATION medium-term growth and development HETEROSIS
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ANALYSES OF ERRORS IN MEDIUM-TERM NUMERICAL FORECAST PRODUCTS FOR THE SUBTROPICAL HIGH 1998 被引量:1
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作者 王兴荣 姚叶青 +3 位作者 尚瑜 陈晓平 程小泉 率爱梅 《Journal of Tropical Meteorology》 SCIE 2003年第1期105-112,共8页
By statistic and dynamic analyses, we have come to the following conclusions: (1) The ECMWF medium-term numerical forecast can forecast medium-term activity of subtropical high, and the accuracy rate of forecast canno... By statistic and dynamic analyses, we have come to the following conclusions: (1) The ECMWF medium-term numerical forecast can forecast medium-term activity of subtropical high, and the accuracy rate of forecast cannot have large improvement by translational corrections. (2) The important cause for the ECMWF medium-term numerical forecast to have errors in 1998 is that the astronomical tide is not included in the model. (3) Two indexes are found from which it can be judged that ECMWF medium-term numerical forecast will have errors if the astronomical tide is ignored in the model : ① When the 54.7?line under the moon of the nodical month astronomical singularities coincides with the trough-line of the subtropical jet flow from 50癊 to 150癊 on the 500 hPa level at 2000 L.T. of the same day, and is approximately vertical (α>60? with the isotherm, then the day 0 2 days after the appearance of the nodical month astronomical singularities is defined as the initial day. Then in three successive days after the initial day, ECMWF medium-term numerical forecast of the northern latitude of the 588 line at 120 癊 will have continuous errors as large as two latitudes (7/9). Otherwise, it won’t have continuous errors (13/13). ② Otherwise, if the 54.7 ?line is in the range of a low pressure between two high pressures, then there is a dispersive error on the day of the nodical month astronomical singularities (5/7). There is not any error (6/6) otherwise. 展开更多
关键词 ECMWF medium-term numerical forecast subtropical high error analysis astronomical tide analysis of dynamics
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Medium-Term Electric Load Forecasting Using Multivariable Linear and Non-Linear Regression 被引量:2
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作者 Nazih Abu-Shikhah Fawwaz Elkarmi Osama M. Aloquili 《Smart Grid and Renewable Energy》 2011年第2期126-135,共10页
Medium-term forecasting is an important category of electric load forecasting that covers a time span of up to one year ahead. It suits outage and maintenance planning, as well as load switching operation. We propose ... Medium-term forecasting is an important category of electric load forecasting that covers a time span of up to one year ahead. It suits outage and maintenance planning, as well as load switching operation. We propose a new methodol-ogy that uses hourly daily loads to predict the next year hourly loads, and hence predict the peak loads expected to be reached in the next coming year. The technique is based on implementing multivariable regression on previous year's hourly loads. Three regression models are investigated in this research: the linear, the polynomial, and the exponential power. The proposed models are applied to real loads of the Jordanian power system. Results obtained using the pro-posed methods showed that their performance is close and they outperform results obtained using the widely used ex-ponential regression technique. Moreover, peak load prediction has about 90% accuracy using the proposed method-ology. The methods are generic and simple and can be implemented to hourly loads of any power system. No extra in-formation other than the hourly loads is required. 展开更多
关键词 medium-term LOAD Forecasting Electrical PEAK LOAD MULTIVARIABLE Regression And TIME SERIES
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The Relationship Between Abnormal Meiyu and Medium-Term Scale Wave Perturbation Energy Propagation Along the East Asian Subtropical Westerly Jet 被引量:1
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作者 JIN Rong-hua YANG Ning +2 位作者 SUN Xiao-qing LIU Si-jia YIN Shan 《Journal of Tropical Meteorology》 SCIE 2020年第2期125-136,共12页
The East Asian subtropical westerly jet(EASWJ)is one of the most important factors modulating the Meiyu rainfall in the Yangtze-Huaihe River Basin,China.This article analyzed periods of the medium-term EASWJ variation... The East Asian subtropical westerly jet(EASWJ)is one of the most important factors modulating the Meiyu rainfall in the Yangtze-Huaihe River Basin,China.This article analyzed periods of the medium-term EASWJ variation,wave packet distribution and energy propagation of Rossby waves along the EASWJ during Meiyu season,and investigated their possible influence on abnormal Meiyu rain.The results showed that during the medium-term scale atmospheric dynamic process,the evolution of the EASWJ in Meiyu season was mainly characterized by the changes of3-8 d synoptic-scale and 10-15 d low-frequency Rossby waves.The strong perturbation wave packet and energy propagation of the 3-8 d synoptic-scale and 10-15 d low-frequency Rossby waves are mostly concentrated in the East Asian region of 90°-150°E,where the two wave trains of perturbation wave packets and wave-activity flux divergence coexist in zonal and meridional directions,and converge on the EASWJ.Besides,the wave trains of perturbation wave packet and wave-activity flux divergence in wet Meiyu years are more systematically westward than those in dry Meiyu years,and they are shown in the inverse phases between each other.In wet(dry)Meiyu year,the perturbation wave packet high-value area of the 10-15 d low-frequency variability is located between the Aral Sea and the Lake Balkhash(in the northeastern part of China),while over eastern China the wave-activity flux is convergent and strong(divergent and weak),and the high-level jets are strong and southward(weak and northward).Because of the coupling of high and low level atmosphere and high-level strong(weak)divergence on the south side of the jet over the Yangtze-Huaihe River Basin,the low-level southwest wind and vertically ascending motion are strengthened(weakened),which is(is not)conducive to precipitation increase in the Yangtze-Huaihe River Basin.These findings would help to better understand the impact mechanisms of the EASWJ activities on abnormal Meiyu from the perspective of medium-term scale Rossby wave energy propagation. 展开更多
关键词 East Asian subtropical westerly jet(EASWJ) medium-term scale Rossby wave wave packet distribution energy propagation abnormal Meiyu
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Medium-term and Long-term Momentum and Contrarian Effects on China during 1994-2004 被引量:1
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作者 DU Xing-qiang NIE Zhi-ping 《Journal of Modern Accounting and Auditing》 2007年第2期63-69,共7页
We examine momentum and contrarian effects in China's stock market during 1994-2004 and find that no medium momentum effects exist. Meanwhile, contrarian strategy works effectively over the horizon of 18-36 months. 1... We examine momentum and contrarian effects in China's stock market during 1994-2004 and find that no medium momentum effects exist. Meanwhile, contrarian strategy works effectively over the horizon of 18-36 months. 1-month gap for avoiding bid-ask bounce and lead-lag effect make no considerable change to our empirical results. Transaction costs seem to have no significant impact on contrarian strategies' profit. 展开更多
关键词 medium-term momentum long-term momentum contrafian effects transaction costs
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Medium-term forecast of daily passenger volume of high speed railway based on DLP-WNNMedium-term forecast of dailypassenger volume of high speedrailway based on DLP-WNN 被引量:1
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作者 Tangjian Wei Xingqi Yang +1 位作者 Guangming Xu Feng Shi 《Railway Sciences》 2023年第1期121-139,共19页
Purpose – This paper aims to propose a medium-term forecast model for the daily passenger volume of HighSpeed Railway (HSR) systems to predict the daily the Origin-Destination (OD) daily volume formultiple consecutiv... Purpose – This paper aims to propose a medium-term forecast model for the daily passenger volume of HighSpeed Railway (HSR) systems to predict the daily the Origin-Destination (OD) daily volume formultiple consecutivedays (e.g. 120 days).Design/methodology/approach – By analyzing the characteristics of the historical data on daily passengervolume of HSR systems, the date and holiday labels were designed with determined value ranges.In accordance to the autoregressive characteristics of the daily passenger volume of HSR, the Double LayerParallel Wavelet Neural Network (DLP-WNN) model suitable for the medium-term (about 120 d) forecast of thedaily passenger volume of HSR was established. The DLP-WNN model obtains the daily forecast result byweighed summation of the daily output values of the two subnets. Subnet 1 reflects the overall trend of dailypassenger volumes in the recent period, and subnet 2 the daily fluctuation of the daily passenger volume toensure the accuracy of medium-term forecast.Findings – According to the example application, in which the DLP-WNN modelwas used for the medium-termforecast of the daily passenger volumes for 120 days for typical O-D pairs at 4 different distances, the averageabsolute percentage error is 7%-12%, obviously lower than the results measured by the Back Propagation (BP)neural network, the ELM (extreme learning machine), the ELMAN neural network, the GRNN (generalizedregression neural network) and the VMD-GA-BP. The DLP-WNN model was verified to be suitable for themedium-term forecast of the daily passenger volume of HSR.Originality/value – This study proposed a Double Layer Parallel structure forecast model for medium-termdaily passenger volume (about 120 days) of HSR systems by using the date and holiday labels and WaveletNeural Network. The predict results are important input data for supporting the line planning, scheduling andother decisions in operation and management in HSR systems. 展开更多
关键词 High speed railway Passenger flow forecast Daily passenger volume medium-term forecast Wavelet neural network
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Refrigeration Calculation and System Design for Medium-term Genebank of Crop Germplasm Resources in Shandong Province
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作者 李湛 张晓冬 +4 位作者 李润芳 王栋 刘世华 李娜娜 丁汉凤 《Agricultural Science & Technology》 CAS 2016年第8期1929-1932,共4页
Crop germplasm resources are the material basis for the breeding of new varieties, and strategic resources for food production, ecological security and agricultural sustainable development. Constructing a scientific, ... Crop germplasm resources are the material basis for the breeding of new varieties, and strategic resources for food production, ecological security and agricultural sustainable development. Constructing a scientific, environmental-friendly and energy-saving medium-term genebank is essential for preserving crop germplasm resources. However, the construction of medium-term genebank involves a wide range of subjects but lacks unified standard, which might result in many difficulties in the process of construction and application. According to the key parameters of refrigeration system for medium-term genebank, the cooling load was calculated and key system schemes were determined in this paper. Based on the calculation results and designed schemes, the equipment selection was discussed and the standards for construction of bank and monitoring system were proposed with the aim to provide references for germplasm genebank design and equipment selection. 展开更多
关键词 CROP Germplasm resource medium-term genebank Cooling load Equipment selection Shandong Province
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Medium-term surgical outcomes and health-related quality of life after laparoscopic vs open colorectal cancer resection: SF-36 health survey questionnaire
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作者 Chao-Ming Hung Kuo-Chuan Hung +11 位作者 Hon-Yi Shi Shih-Bin Su Hui-Ming Lee Meng-Che Hsieh Cheng-Hao Tseng Shung-Eing Lin Chih-Cheng Chen Chao-Ming Tseng Ying-Nan Tsai Chi-Zen Chen Jung-Fa Tsai Chong-Chi Chiu 《World Journal of Gastrointestinal Endoscopy》 2023年第3期163-176,共14页
BACKGROUND Previous studies that compared the postoperative health-related quality of life(HRQoL)outcomes after receiving laparoscopic resection(LR)or open resection(OR)in patients with colorectal cancer(CRC)have diff... BACKGROUND Previous studies that compared the postoperative health-related quality of life(HRQoL)outcomes after receiving laparoscopic resection(LR)or open resection(OR)in patients with colorectal cancer(CRC)have different conclusions.AIM To explore the medium-term effect of postoperative HRQoL in such patients.METHODS This study randomized 567 patients undergoing non-metastatic CRC surgery managed by one surgeon to the LR or OR groups.HRQoL was assessed during the preoperative period and 3,6,and 12 mo postoperative using a modified version of the 36-Item Short Form(SF-36)Health Survey questionnaire,emphasizing eight specific items.RESULTS This cohort randomly assigned 541 patients to receive LR(n=296)or OR(n=245)surgical procedures.More episodes of postoperative urinary tract infection(P<0.001),wound infection(P<0.001),and pneumonia(P=0.048)were encountered in the OR group.The results demonstrated that the LR group subjectively gained mildly better general health(P=0.045),moderately better physical activity(P=0.006),and significantly better social function recovery(P=0.0001)3 mo postoperatively.Only the aspect of social function recovery was claimed at 6 mo,with a significant advantage in the LR group(P=0.001).No clinical difference was found in HRQoL during the 12 mo.CONCLUSION Our results demonstrated that LR resulted in better outcomes,including intra-operative blood loss,surgery-related complications,course of recovery,and especially some health domains of HRQoL at least within 6 mo postoperatively.Patients should undergo LR if there is no contraindication. 展开更多
关键词 Health-related quality of life medium-term result LAPAROSCOPIC Open surgery Non-metastatic colorectal cancer
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Determination of Regions With Medium-Term Risk of Strong Earthquakes: Pre-warning Active Faults
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作者 Ge Shumo and Wei RuopingSeismological Bureau of Xinjiang Uygur Autonomous Region,Urumqi 830011,China 《Earthquake Research in China》 1996年第1期104-109,共6页
To predict the area with frequent seismicity and the future risky region of strong earthquakes on the time scale of one or several years is a very important and urgent problem that needs to be solved.On the basis of a... To predict the area with frequent seismicity and the future risky region of strong earthquakes on the time scale of one or several years is a very important and urgent problem that needs to be solved.On the basis of active fault research,pre-warning active faults that have been active recently will be discussed; then the medium-term risky region of strong earthquakes will be delimited around the pre-warning active faults.This method proves to be effective. 展开更多
关键词 SEISMIC RISK REGION medium-term prediction ACTIVE FAULT
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Seismicity Quantification and Its Application to Medium-term Earthquake Prediction
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作者 Wang Wei , Liu Zheng , Song Xianyue and Wang ZhengzhengSeismological Bureau of Shanghai Municipality, Shanghai 200062, China Seismological Bureau of Jiangsu Province, Nanjing 210014, China 《Earthquake Research in China》 2000年第1期30-41,共12页
Bed on the analysis of each parameter describing seismicity,we think A(b)-value can betterquantitatively describe the feature of the enhancement and quietness of seismicity in this paper. Thedata of moderate or small ... Bed on the analysis of each parameter describing seismicity,we think A(b)-value can betterquantitatively describe the feature of the enhancement and quietness of seismicity in this paper. Thedata of moderate or small earthquakes during 1972~1996 in North China are used in space scanningof A(b)-value. The result shows that 2~3 years before most strong earthquakes there wereObviously anomaly zones of A(b)-value with very good prediction effect. Some problems about themedium-term prediction by using A(b)-value are also discussed. 展开更多
关键词 ENHANCEMENT and QUIETNESS of SEISMICITY A (b)-value medium-term EARTHQUAKE prediction
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Medium-term Air Quality Benchmarking for Ecosystem Monitoring and Sustainability Planning: Case Study Dallas County (U.S.A.) 2015 to 2020
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作者 David A.Wood 《Research in Ecology》 2021年第4期35-53,共19页
Medium-term air quality assessment,benchmarking it to recent past data can usefully complement short-term air quality index data for monitoring purposes.By using daily and monthly averaged data,medium-term air quality... Medium-term air quality assessment,benchmarking it to recent past data can usefully complement short-term air quality index data for monitoring purposes.By using daily and monthly averaged data,medium-term air quality benchmarking provides a distinctive perspective with which to monitor air quality for sustainability planning and ecosystem perspectives.By normalizing the data for individual air pollutants to a standard scale they can be more easily integrated to generate a daily combined local area benchmark(CLAB).The objectives of the study are to demonstrate that medium-term air quality benchmarking can be tailored to reflect local conditions by selecting the most relevant pollutants to incorporate in the CLAB indicator.Such a benchmark can provide an overall air quality assessment for areas of interest.A case study is presented for Dallas County(U.S.A.)applying the proposed method by benchmarking 2020 data for air pollutants to their trends established for 2015 to 2019.Six air pollutants considered are:ozone,carbon monoxide,nitrogen dioxide,sulfur dioxide,benzene and particulate matter less than 2.5 micrometres.These pollutants are assessed individually and in terms of CLAB,and their 2020 variations for Dallas County compared to daily trends established for years 2015 to 2019.Reductions in benzene and carbon monoxide during much of 2020 are clearly discernible compared to preceding years.The CLAB indicator shows clear seasonal trends for air quality for 2015 to 2019 with high pollution in winter and spring compared to other seasons that is strongly influenced by climatic variations with some anthropogenic inputs.Conducting CLAB analysis on an ongoing basis,using a relevant near-past time interval for benchmarking that covers several years,can reveal useful monthly,seasonal and annual trends in overall air quality.This type of medium-term,benchmarked air quality data analysis is well suited for ecosystem monitoring. 展开更多
关键词 Local air pollution assessment medium-term air quality Local area benchmarking Critical pollutants Seasonal variations in air quality Sustainability planning
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Gravity observations along the eastern margin of the Tibetan Plateau and an application to the Lushan MS 7.0 earthquake 被引量:8
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作者 Wei-feng Liang Yun-feng Zhao +4 位作者 Yun-ma Xu Yi-qing Zhu Shu-song Guo Fang Liu Lian Liu 《Earthquake Science》 2013年第3期251-257,共7页
This paper introduces relative and absolute gravity change observations in the eastern portion of the Tibetan Plateau. We analyze and discuss a change that occurred in 2010 in the gravity along the eastern margin of t... This paper introduces relative and absolute gravity change observations in the eastern portion of the Tibetan Plateau. We analyze and discuss a change that occurred in 2010 in the gravity along the eastern margin of the plateau and the relationship between this change and the 2013 Lushan Ms7.0 earthquake. Our results show that: (1) before the Lushan MsT.0 earthquake, gravity anomalies along the eastern margin of the Tibetan Plateau changed drastically. The Lushan earthquake occurred at the bend of the high gradient zone of gravity var- iation along the southern edge of the Longmenshan fault zone. (2) The 2013 Lushan earthquake occurred less than 100 km away from the epicenter of the 2008 Wenchuan earthquake. Lushan and Wenchuan are located at the center of a four- quadrant section with different gravity anomalies, which may suggest that restoration after the Wenchuan earthquake may have played a role in causing the Lushan earthquake. (3) A medium-term prediction based on changes in gravity anoma- lies was made before the Lushan Ms7.0 earthquake, in par- ticular, a prediction of epicenter location. 展开更多
关键词 The eastern margin of the TibetanPlateau Gravity observation Gravity changeLushan earthquake medium-term prediction
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Earthquake prediction from China's mobile gravity data 被引量:13
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作者 Zhu Yiqing Liu Fang +3 位作者 You Xinzhao Liang Weifeng Zhao Yunfeng Liu Lian 《Geodesy and Geodynamics》 2015年第2期81-90,共10页
The relation between plate tectonics and earthquake evolution is analyzed systematically on the basis of 1998-2010 absolute and relative gravity data from the Crustal Movement Observation Network of China. Most earthq... The relation between plate tectonics and earthquake evolution is analyzed systematically on the basis of 1998-2010 absolute and relative gravity data from the Crustal Movement Observation Network of China. Most earthquakes originated in the plate boundary or within the fault zone. Tectonic deformation was most intense and exhibited discontinuity within the tectonically active fault zone because of the differential movement; the stress accumulation produced an abrupt gravity change, which was further enhanced by the earthquake. The gravity data from China's Mainland since 2000 obviously reflected five major earthquakes (Ms 〉 7), all of which were better reflected than before 2000. Regional gravity anomalies and a gravity gradient change were observed in the area around the epicenter about 2 or 3 years before the earthquake occurred, suggesting that gravity change may be a seismic precursor. Furthermore, in this study, the medium-term predictions of the Ms7.3 Yutian, Ms8.0 Wenchuan, and Ms7.0 Lushan earthquakes are analytically pre- sented and evaluated, especially to estimate location of earthquake. 展开更多
关键词 Chinese mainland Gravity change Tectonic activity Seismic precursor medium-term earthquake prediction Crustal Movement Observation Network of China (CMONC)
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Preliminary Study on Probabilistic Prediction of Seismic Hazard in a Period of 10 Years 被引量:1
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作者 Gao Mengtan and Wang JianInstitute of Geophysics,SSB,Beijing 100081,China 《Earthquake Research in China》 1995年第4期10-17,共8页
Many uncertainty factors need be dealt with in the prediction of seismic hazard for a 10-year period.Restricted by these uncertainties,the result of prediction is also uncertain to a certain extent,so the probabilisti... Many uncertainty factors need be dealt with in the prediction of seismic hazard for a 10-year period.Restricted by these uncertainties,the result of prediction is also uncertain to a certain extent,so the probabilistic analysis method of seismic hazard should be adopted.In consideration of the inhomogeneity of the time,location,and magnitude of future earthquakes and the probabilistic combination of the background of long-term seismic hazard(geology,geophysical field,etc.)and the precursors of earthquake occurrence,a model of probabilistic prediction of seismic hazard in a period of 10 years s proposed.Considering the inhomogeneity of data and earthquake precursors for different regions in China,a simplified model is also proposed in order to satisfy the needs of different regions around the country.A trial in North China is used to discuss the application of the model.The method proposed in this paper can be used in the probabilistic prediction of seismic hazard in a period of 10 years.According to 展开更多
关键词 PROBABILITY MODEL medium-term PREDICTION
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Research on TSIP method for medium-term earthquake prediction
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作者 黄德瑜 朱元清 +1 位作者 陈颙 季颖 《Acta Seismologica Sinica(English Edition)》 CSCD 1995年第4期501-510,共10页
This paper introduces the space increased probability of strong earthquakes (SIP)-a new design based on the algorithm CN of time increased probability of strong earthquake (TIP). The authors have done a prediction res... This paper introduces the space increased probability of strong earthquakes (SIP)-a new design based on the algorithm CN of time increased probability of strong earthquake (TIP). The authors have done a prediction research passing in review of eight strong earthquakes with M>6 in the last 20 years in East China. The result shows that six of the eight strong earthquakes were in the space-time domain of the time and space probability of strong earthquake (TSIP) prediction. The prediction accuracy is 75%, the space-time domain rate of the TSIP precaution is 5%, the diagnosed value of R is 0. 70. So the TSIP as a method of medium-term earthquake prediction has good practicality, efficiency and prospects of applying. 展开更多
关键词 medium-term prediction Algorithm TSIP SEISMICITY
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“Small earthquake modulation window” and its applications in medium-term prediction
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作者 苏鸾声 《Acta Seismologica Sinica(English Edition)》 CSCD 1995年第1期51-56,共6页
Based on the observations of many years, it has been found that “small earthquake modulation windows” exist inthe situation of some special geological structures, which respond sensitively to the variations of regio... Based on the observations of many years, it has been found that “small earthquake modulation windows” exist inthe situation of some special geological structures, which respond sensitively to the variations of regional stressfields and the activities of earthquake swarms greater than moderate strong magnitude, and can supply some precursory information. More than two “small earthquake modulation windows” can also provide a general orientation of the first main earthquake of a earthquake cluster. Compared with “seismic window” based on frequency itis no doubt that the “modulation-window” has an unique characteristic of applicational significance to mediumterm earthquake prediction with a time scale of two or three years. 展开更多
关键词 medium-term prediction small earthquake activity stress rield EARTHQUAKE seismogenic window
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Decision-making model for risk management of cascade hydropower stations
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作者 Pan, Bangchuan Chi, Hong +1 位作者 Xu, Jianguo Qi, Mingliang 《Journal of Southeast University(English Edition)》 EI CAS 2008年第S1期22-26,共5页
In a medium-term electricity market,in order to reduce the risks of price and inflow uncertainties, the cascade hydropower stations may use the options contract with electricity supply companies. A profit-based model ... In a medium-term electricity market,in order to reduce the risks of price and inflow uncertainties, the cascade hydropower stations may use the options contract with electricity supply companies. A profit-based model for risk management of cascade hydropower stations in the medium-term electricity market is presented. The objective function is profit maximization of cascade hydropower stations. In order to avoid the risks of price and inflow uncertainties, two different risk-aversion constraints: a minimum profit constraint and a minimum conditional value-at-risk, are introduced in the model. In addition, the model takes into account technology constraints of the generating units, which includes reservoir flow balance, reservoir capacity limits, water discharge constraints, etc. The model is formulated as a mixed integer nonlinear programming problem. Because the search space of the solution is very large, a genetic algorithm is used to deal with the problem. 展开更多
关键词 cascade hydropower station mixed integer nonlinear programming risk management medium-term electricity market
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The Mid-Term Model Forecast Test of North China Rainstorm from July 19th to 20th, 2016
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作者 Xiakun Zhang Qiqi Liu Manyu Zhang 《Journal of Geoscience and Environment Protection》 2017年第8期166-180,共15页
Heavy rain is a kind of severe weather, often causing floods and serious soil erosion, leading to engineering losses, embankment rupture and crop flooding and other significant economic losses. Especially for some low... Heavy rain is a kind of severe weather, often causing floods and serious soil erosion, leading to engineering losses, embankment rupture and crop flooding and other significant economic losses. Especially for some low-lying terrain areas, rainwater cannot quickly vent caused by farm water and soil moisture being too saturated, so it will cause more geological disasters. This article combines live and forecast data, aiming at the results of the mid-rainstorm forecast in North China during the period of 7.19-2016, and compares with the actual situation of rainstorm. We carry out the mid-term forecast of the rainstorm. The atmosphere is a kind of medium with various fluctuation phenomena, and its physical properties and changes are studied by the analysis of volatility which is an important research method. It is important to improve the accuracy of such severe weather forecasting rainstorms and to take precautionary measures in a timely manner to minimize the losses caused by rainstorms. 展开更多
关键词 Heavy Rain North China medium-term Model FORECAST TEST
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Analysis on Depth Distribution and Precursor Mechanism of Small and Moderate Earthquakes
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作者 Wang JianInstitute of Geophysics, China Seismological Bureau, Beijing 100081, China 《Earthquake Research in China》 2001年第4期406-411,共6页
In this paper, the focus depth distribution of earthquakes with each magnitude has been analyzed. Statistic data show that the lower magnitude is, the wider focus depth distributes. With larger magnitude, the focus te... In this paper, the focus depth distribution of earthquakes with each magnitude has been analyzed. Statistic data show that the lower magnitude is, the wider focus depth distributes. With larger magnitude, the focus tends to be concentrated in upper or middle crustal layers. We analyzed the cause of focus depth distribution and explained the precursor mechanism of small and moderate earthquakes with occurring condition and characteristics of strong earthquakes. The results of this paper may be applied to determine risk sites of strong earthquakes. 展开更多
关键词 SEISMICITY DEPTH distribution PRECURSOR Long- and medium-term EARTHQUAKE prediction
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BM(book-to-market ratio) factor: mediumterm momentum and long-term reversal
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作者 Liu Wei-qi Zhang Jingxing 《Financial Innovation》 2018年第1期1-29,共29页
To explain medium-term momentum and long-term reversal,we use the difference between the optional model and the CAPM model to construct a winner-loser portfolio.According to the CAPM model’s zero explanatory ability ... To explain medium-term momentum and long-term reversal,we use the difference between the optional model and the CAPM model to construct a winner-loser portfolio.According to the CAPM model’s zero explanatory ability with respect to stock market anomalies,we obtain an anomaly interpretative model.This study shows that this anomaly interpretative model can explain stock market perceptions and medium-term momentum.Most importantly,BM is a critical factor in the model’s explanatory ability.We present a robustness test,which includes selecting new sample data,adding new auxiliary variables,changing sample years,and adding industry fixed effects.In general,the BM effect does have considerable explanatory power in medium-term momentum and long-term reversal. 展开更多
关键词 Stock market volatility medium-term momentum long-term reversal holding period formation period book-to-market ratio return on equity
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