Multiyear observed time series of wind speed for selected points of the Arctic region (data of station network from the Kola Peninsula to the Chukotka Peninsula) are used to highlight the important peculiarities of wi...Multiyear observed time series of wind speed for selected points of the Arctic region (data of station network from the Kola Peninsula to the Chukotka Peninsula) are used to highlight the important peculiarities of wind speed extreme statistics. How largest extremes could be simulated by climate model (the INM-CM4 model data from the Historical experiment of the CMIP5) is also discussed. Extreme value analysis yielded that a volume of observed samples of wind speeds are strictly divided into two sets of variables. Statistical properties of one population are sharply different from another. Because the common statistical conditions are the sign of identity of extreme events we therefore hypothesize that two groups of extreme wind events adhere to different circulation processes. A very important message is that the procedure of selection can be realized easily based on analysis of the cumulative distribution function. The authors estimate the properties of the modelled extremes and conclude that they consist of only the samples, adhering to one group. This evidence provides a clue that atmospheric model with a coarse spatial resolution does not simulate special mechanism responsible for appearance of largest wind speed extremes. Therefore, the tasks where extreme wind is needed cannot be explicitly solved using the output of climate model. The finding that global models are unable to capture the wind extremes is already well known, but information that they are members of group with the specific statistical conditions provides new knowledge. Generally, the implemented analytical approach allows us to detect that the extreme wind speed events adhere to different statistical models. Events located above the threshold value are much more pronounced than representatives of another group (located below the threshold value) predicted by the extrapolation of law distributions in their tail. The same situation is found in different areas of science where the data referring to the same nomenclature are adhering to different statistical models. This result motivates our interest on our ability to detect, analyze, and understand such different extremes.展开更多
Dear Sir,Iam Dr.Kavitha S,from the Department of Electronics and Communication Engineering,Nandha Engineering College,Erode,Tamil Nadu,India.I write to present the detection of glaucoma using extreme learning machine(...Dear Sir,Iam Dr.Kavitha S,from the Department of Electronics and Communication Engineering,Nandha Engineering College,Erode,Tamil Nadu,India.I write to present the detection of glaucoma using extreme learning machine(ELM)and fractal feature analysis.Glaucoma is the second most frequent cause of permanent blindness in industrial展开更多
The extreme temperature differences in fiat steel box girder of a cable-stayed bridge were studied.Firstly,by using the long-term measurement data collected by the structural health monitoring system installed on the ...The extreme temperature differences in fiat steel box girder of a cable-stayed bridge were studied.Firstly,by using the long-term measurement data collected by the structural health monitoring system installed on the Runyang Cable-stayed Bridge,the daily variations as well as seasonal ones of measured temperature differences in the box girder cross-section area were summarized.The probability distribution models of temperature differences were further established and the extreme temperature differences were estimated with a return period of 100 years.Finally,the temperature difference models in cross-section area were proposed for bridge thermal design.The results show that horizontal temperature differences in top plate and vertical temperature differences between top plate and bottom plate are considerable.All the positive and negative temperature differences can be described by the weighted sum of two Weibull distributions.The maximum positive and negative horizontal temperature differences in top plate are 10.30 ℃ and -13.80 ℃,respectively.And the maximum positive and negative vertical temperature differences between top plate and bottom plate are 17.30 ℃ and-3.70 ℃,respectively.For bridge thermal design,there are two vertical temperature difference models between top plate and bottom plate,and six horizontal temperature difference models in top plate.展开更多
Objective To discuss the etiology,course of diseases and prognosis of symmetry peripheral entrapment enuropathies of upper extremity. Methods The etiology, clinical scale and resluts of 14 cases were analyzed betwen 1...Objective To discuss the etiology,course of diseases and prognosis of symmetry peripheral entrapment enuropathies of upper extremity. Methods The etiology, clinical scale and resluts of 14 cases were analyzed betwen 1999 and April 2002. Results In the bilateral tunnel syndrome, the excellent and good rate was 60% at the original side and 80% at the contralateral side occurred later. In the bilateral carpal tunnel syndrome, the excellent and good rate was 67% at the original side and 89% at the contralateral side occurred later. Conclusion The main etiological factor of the bilateral cubital tunnel syndrome was the elbow eversion deformity. The lesions of synovium contributed mainly to the symmetry carpal tunnel syndrome. The symmetry peripheral entrapment neuropathies of upper extremity should be operated on as soon as possible when diagnosis had been made for enhancement of treatment outcome. 5 refs,2 tabs.展开更多
We performed long-term wind-wave hindcast in the Yellow Sea and the Bohai Sea from the year 1988 to 2002, and then analyzed the regional wave climate. Comparisons between model results and satellite data are generally...We performed long-term wind-wave hindcast in the Yellow Sea and the Bohai Sea from the year 1988 to 2002, and then analyzed the regional wave climate. Comparisons between model results and satellite data are generally consistent on monthly mean significant wave height. Then we discuss the temporal and spatial characteristics of the climatological monthly mean significant wave heights and mean wave periods. The climatologically spatial patterns are observed as increasing from northwest to southeast and from offshore to deep-water area for both significant wave height and mean wave period, and the patterns are highly related to the wind forcing and local topography. Seasonal variations of wave parameters are also significant. Furthermore, we compute the extreme values of wind and significant wave height using statistical methods. Results reveal the spatial patterns of N-year return significant wave height in the Yellow Sea and the Bohai Sea, and we discuss the relationship between extreme values of significant wave height and wind forcing.展开更多
This study aims to identify the factors that robustly contribute to Bitcoin liquidity,employing a rich range of potential determinants that represent unique characteristics of the cryptocurrency industry,investor atte...This study aims to identify the factors that robustly contribute to Bitcoin liquidity,employing a rich range of potential determinants that represent unique characteristics of the cryptocurrency industry,investor attention,macroeconomic fundamentals,and global stress and uncertainty.To construct liquidity metrics,we compile 60-min high-frequency data on the low,high,opening,and closing exchange rates of Bitcoin against the US dollar.Our empirical investigation is based on the extreme bounds analysis(EBA),which can resolve model uncertainty issues.The results of Leamer’s version of the EBA suggest that the realized volatility of Bitcoin is the sole variable relevant to explaining liquidity.With the Sala-i-Martin’s variant of EBA,however,four more variables,(viz.Bitcoin’s negative returns,trading volume,hash rates,and Google search volume)are also labeled as robust determinants.Accordingly,our evidence confirms that Bitcoin-specific factors and developments,rather than global macroeconomic and financial variables,matter for explaining its liquidity.The findings are largely insensitive to our proxy of liquidity and to the estimation method used.展开更多
Wave climate plays an important role in the air-sea interaction over marginal seas. Extreme wave height provides fundamental information for various ocean engineering practices, such as hazard mitigation, coastal stru...Wave climate plays an important role in the air-sea interaction over marginal seas. Extreme wave height provides fundamental information for various ocean engineering practices, such as hazard mitigation, coastal structure design, and risk assessment. In this paper, we implement a third generation wave model and conduct a high-resolution wave hindcast over the East China Sea to reconstruct a 15-year wave field from 1988 to 2002 for derivation of monthly mean wave parameters and analysis of extreme wave conditions. The numerical results of the wave field are validated through comparison with satellite altimetry measurements, low-resolution reanalysis, and the ocean wave buoy record. The monthly averaged wave height and wave period show seasonal variation and refined spatial patterns of surface waves in the East China Sea. The climatological significant wave height and mean wave period decrease from the open ocean in the southeast toward the continental area in the northwest, with the pattern generally following the bathymetry. Extreme analysis on the significant wave height at the buoy station indicates the hindcast data underestimate the extreme values relative to the observations. The spatial pattern of extreme wave height shows single peak emerges at the southwest of Ryukyu Island although a wind forcing with multi-core structure at the extreme is applied.展开更多
文摘Multiyear observed time series of wind speed for selected points of the Arctic region (data of station network from the Kola Peninsula to the Chukotka Peninsula) are used to highlight the important peculiarities of wind speed extreme statistics. How largest extremes could be simulated by climate model (the INM-CM4 model data from the Historical experiment of the CMIP5) is also discussed. Extreme value analysis yielded that a volume of observed samples of wind speeds are strictly divided into two sets of variables. Statistical properties of one population are sharply different from another. Because the common statistical conditions are the sign of identity of extreme events we therefore hypothesize that two groups of extreme wind events adhere to different circulation processes. A very important message is that the procedure of selection can be realized easily based on analysis of the cumulative distribution function. The authors estimate the properties of the modelled extremes and conclude that they consist of only the samples, adhering to one group. This evidence provides a clue that atmospheric model with a coarse spatial resolution does not simulate special mechanism responsible for appearance of largest wind speed extremes. Therefore, the tasks where extreme wind is needed cannot be explicitly solved using the output of climate model. The finding that global models are unable to capture the wind extremes is already well known, but information that they are members of group with the specific statistical conditions provides new knowledge. Generally, the implemented analytical approach allows us to detect that the extreme wind speed events adhere to different statistical models. Events located above the threshold value are much more pronounced than representatives of another group (located below the threshold value) predicted by the extrapolation of law distributions in their tail. The same situation is found in different areas of science where the data referring to the same nomenclature are adhering to different statistical models. This result motivates our interest on our ability to detect, analyze, and understand such different extremes.
文摘Dear Sir,Iam Dr.Kavitha S,from the Department of Electronics and Communication Engineering,Nandha Engineering College,Erode,Tamil Nadu,India.I write to present the detection of glaucoma using extreme learning machine(ELM)and fractal feature analysis.Glaucoma is the second most frequent cause of permanent blindness in industrial
基金Project(51178100)supported by the National Natural Science Foundation of ChinaProject(1105007001)supported by the Foundation of the Priority Academic Development Program of Higher Education Institute of Jiangsu Province,ChinaProject(3205001205)supported by the Teaching and Research Foundation for Excellent Young Teachers of Southeast University,China
文摘The extreme temperature differences in fiat steel box girder of a cable-stayed bridge were studied.Firstly,by using the long-term measurement data collected by the structural health monitoring system installed on the Runyang Cable-stayed Bridge,the daily variations as well as seasonal ones of measured temperature differences in the box girder cross-section area were summarized.The probability distribution models of temperature differences were further established and the extreme temperature differences were estimated with a return period of 100 years.Finally,the temperature difference models in cross-section area were proposed for bridge thermal design.The results show that horizontal temperature differences in top plate and vertical temperature differences between top plate and bottom plate are considerable.All the positive and negative temperature differences can be described by the weighted sum of two Weibull distributions.The maximum positive and negative horizontal temperature differences in top plate are 10.30 ℃ and -13.80 ℃,respectively.And the maximum positive and negative vertical temperature differences between top plate and bottom plate are 17.30 ℃ and-3.70 ℃,respectively.For bridge thermal design,there are two vertical temperature difference models between top plate and bottom plate,and six horizontal temperature difference models in top plate.
文摘Objective To discuss the etiology,course of diseases and prognosis of symmetry peripheral entrapment enuropathies of upper extremity. Methods The etiology, clinical scale and resluts of 14 cases were analyzed betwen 1999 and April 2002. Results In the bilateral tunnel syndrome, the excellent and good rate was 60% at the original side and 80% at the contralateral side occurred later. In the bilateral carpal tunnel syndrome, the excellent and good rate was 67% at the original side and 89% at the contralateral side occurred later. Conclusion The main etiological factor of the bilateral cubital tunnel syndrome was the elbow eversion deformity. The lesions of synovium contributed mainly to the symmetry carpal tunnel syndrome. The symmetry peripheral entrapment neuropathies of upper extremity should be operated on as soon as possible when diagnosis had been made for enhancement of treatment outcome. 5 refs,2 tabs.
基金The National Natural Science Foundation of China under contract Nos 41476021 and 41321004the Strategic Priority Research Program of the Chinese Academy of Sciences under contract No.XDA11010104the project of Indo-Pacific Ocean Environment Variation and Air-sea Interaction under contract No.GASI-IPOVAI-04
文摘We performed long-term wind-wave hindcast in the Yellow Sea and the Bohai Sea from the year 1988 to 2002, and then analyzed the regional wave climate. Comparisons between model results and satellite data are generally consistent on monthly mean significant wave height. Then we discuss the temporal and spatial characteristics of the climatological monthly mean significant wave heights and mean wave periods. The climatologically spatial patterns are observed as increasing from northwest to southeast and from offshore to deep-water area for both significant wave height and mean wave period, and the patterns are highly related to the wind forcing and local topography. Seasonal variations of wave parameters are also significant. Furthermore, we compute the extreme values of wind and significant wave height using statistical methods. Results reveal the spatial patterns of N-year return significant wave height in the Yellow Sea and the Bohai Sea, and we discuss the relationship between extreme values of significant wave height and wind forcing.
文摘This study aims to identify the factors that robustly contribute to Bitcoin liquidity,employing a rich range of potential determinants that represent unique characteristics of the cryptocurrency industry,investor attention,macroeconomic fundamentals,and global stress and uncertainty.To construct liquidity metrics,we compile 60-min high-frequency data on the low,high,opening,and closing exchange rates of Bitcoin against the US dollar.Our empirical investigation is based on the extreme bounds analysis(EBA),which can resolve model uncertainty issues.The results of Leamer’s version of the EBA suggest that the realized volatility of Bitcoin is the sole variable relevant to explaining liquidity.With the Sala-i-Martin’s variant of EBA,however,four more variables,(viz.Bitcoin’s negative returns,trading volume,hash rates,and Google search volume)are also labeled as robust determinants.Accordingly,our evidence confirms that Bitcoin-specific factors and developments,rather than global macroeconomic and financial variables,matter for explaining its liquidity.The findings are largely insensitive to our proxy of liquidity and to the estimation method used.
基金supported by the National Natural Science Foundation of China(Grant Nos.41476021,41576013&41321004)the National High Technology Research and Development Program of China(Grant No.2013AA122803)National Program on Global Change and Air-Sea Interaction(Grant No.GASI-IPOVAI-04)
文摘Wave climate plays an important role in the air-sea interaction over marginal seas. Extreme wave height provides fundamental information for various ocean engineering practices, such as hazard mitigation, coastal structure design, and risk assessment. In this paper, we implement a third generation wave model and conduct a high-resolution wave hindcast over the East China Sea to reconstruct a 15-year wave field from 1988 to 2002 for derivation of monthly mean wave parameters and analysis of extreme wave conditions. The numerical results of the wave field are validated through comparison with satellite altimetry measurements, low-resolution reanalysis, and the ocean wave buoy record. The monthly averaged wave height and wave period show seasonal variation and refined spatial patterns of surface waves in the East China Sea. The climatological significant wave height and mean wave period decrease from the open ocean in the southeast toward the continental area in the northwest, with the pattern generally following the bathymetry. Extreme analysis on the significant wave height at the buoy station indicates the hindcast data underestimate the extreme values relative to the observations. The spatial pattern of extreme wave height shows single peak emerges at the southwest of Ryukyu Island although a wind forcing with multi-core structure at the extreme is applied.
