Purpose: To evaluate respiratory-triggered three-dimensional (3D) true steady-state free-precession (SSFP) projection magnetic resonance angiographic sequences with time-spatial labeling inversion pulse (Time-SLIP) fo...Purpose: To evaluate respiratory-triggered three-dimensional (3D) true steady-state free-precession (SSFP) projection magnetic resonance angiographic sequences with time-spatial labeling inversion pulse (Time-SLIP) for visualizing the hepatic arteries and to optimize the image acquisition protocol. Materials and Methods: A 1.5-T clinical magnetic resonance imager was used to perform abdominal magnetic resonance angiography (MRA) in 25 consecutive patients before transcatheter arterial chemoembolization or surgery. We compared two selective space-labeling inversion pulse (tag pulse) patterns (Patterns I and II, oblique and parallel tag pulses, respectively). Two experienced radiologists evaluated the number of hepatic arterial branches visible on the acquired MRA images, and the results were referenced with those on images from intra-arterial digital subtraction angiography. Results: Images were acquired from all patients. The two radiologists clearly visualized branches of the left and right hepatic arteries. More peripheral hepatic arterial branches were identified in MRA images captured by using tag pulse Pattern I than in those acquired by using Pattern II (P P > 0.05). Conclusion: Non-contrast-enhanced Time-SLIP hepatic MRA with true SSFP allowed selective visualization of peripheral hepatic vessels.展开更多
In this study,we investigate the extent to which sustainability disclosures in the narrative sections of European banks’annual reports improve analysts’forecasting accuracy.We capture sustainability disclosures with...In this study,we investigate the extent to which sustainability disclosures in the narrative sections of European banks’annual reports improve analysts’forecasting accuracy.We capture sustainability disclosures with a machine learning approach and use forecast errors as a proxy for analysts’forecast accuracy.Our results suggest that sustainability disclosures significantly improve analysts’forecasting accuracy by reducing forecast errors.In a further analysis,we also find that the introduction of Directive 2014/95/European Union is associated with increased disclosure content,which reduces forecast error.Collectively,our results suggest that sustainability disclosures improve forecast accuracy,and the introduction of the new EU directive strengthens this improvement.These results hold after several robustness tests.Our findings have important implications for market participants and policymakers.展开更多
利用GIS所提供的三维可视化功能,建立起矿山治理恢复后的具有真实感的三维景观模型,对评价规划方案、展示规划效果、通过三维可视化的形式反映矿山环境治理恢复前后的景观变化具有重要意义。ArcView 3D Analyst是ArcView GIS的扩充模块,...利用GIS所提供的三维可视化功能,建立起矿山治理恢复后的具有真实感的三维景观模型,对评价规划方案、展示规划效果、通过三维可视化的形式反映矿山环境治理恢复前后的景观变化具有重要意义。ArcView 3D Analyst是ArcView GIS的扩充模块,在ArcView 3D Analyst基础上建立了采空塌陷区的回填、削坡设计及其治理后矿山绿化等矿山治理恢复设计的三维景观模拟。展开更多
以湛江金沙湾海滩养护前后不同时期沉积物粒度监测数据、海底高程扫描数据和遥感影像为依据,运用Arc GIS 3D Analyst进行沉积物和海底地形分析,得出湛江市金沙湾海滩养护工程实施前后不同时期海底沉积物、地形表面和动态剖面变化情况。...以湛江金沙湾海滩养护前后不同时期沉积物粒度监测数据、海底高程扫描数据和遥感影像为依据,运用Arc GIS 3D Analyst进行沉积物和海底地形分析,得出湛江市金沙湾海滩养护工程实施前后不同时期海底沉积物、地形表面和动态剖面变化情况。结果表明,湛江金沙湾海滩侵蚀区域集中在风车广场对出海域和原红嘴鸥码头附近,后期应重点考虑对此区域进行修复重建。展开更多
Based on the company's disclosure of key customer information,the impact of corporate customer concentration on analyst forecast was studied,and we further studied the impact of detailed customer names on analyst ...Based on the company's disclosure of key customer information,the impact of corporate customer concentration on analyst forecast was studied,and we further studied the impact of detailed customer names on analyst forecasts. It is found that:(i) customer concentration significantly affects the accuracy of analyst forecasts. The higher the customer concentration is,the lower the accuracy of analyst forecasts is;(ii) Voluntary disclosure of customer names can provide incremental information to analysts and mitigate the negative impact of customer concentration on the accuracy of analyst forests;(iii) further research has found that the incremental information brought by the state-owned enterprises' disclosure of the customer names to analysts is more obvious; disclosure of customer names by companies with high environmental uncertainty is more likely to be of concern to analysts; and star analysts have a higher ability to interpret customer names than non-star analysts.展开更多
This paper used the A-shares listed companies in China as samples,constructed a comprehensive indicator of investor attention,and conducted an empirical analysis on the correlations among investor attention,analyst op...This paper used the A-shares listed companies in China as samples,constructed a comprehensive indicator of investor attention,and conducted an empirical analysis on the correlations among investor attention,analyst optimism,and stock price crash risk.The results indicated that investor attention aggravates the stock price crash risk and has a positive effect on analyst optimism.Meanwhile,the analyst optimism plays a mediating role in the positive correlation between investor attention and stock price crash risk.In addition to that,institutional investor attention also has direct and indirect effects on the crash risk.展开更多
As Hainan Island belonged to tropical monsoon influenced region, vegetation coverage was high. It is accessible to acquire the vegetation index information from remote sensing images, but predicting the average vegeta...As Hainan Island belonged to tropical monsoon influenced region, vegetation coverage was high. It is accessible to acquire the vegetation index information from remote sensing images, but predicting the average vegetation index in spatial distributing trend is not available. Under the condition that the average vegetation index values of observed stations in different seasons were known, it was possible to qualify the vegetation index values in study area and predict the NDVI (Normal Different Vegetation Index) change trend. In order to learn the variance trend of NDVI and the relationships between NDVI and temperature, precipitation, and land cover in Hainan Island, in this paper, the average seasonal NDVI values of 18 representative stations in Hainan Island were derived by a standard 10-day composite NDVI generated from MODIS imagery. ArcGIS Geostatistical Analyst was applied to predict the seasonal NDVI change trend by the Kriging method in Hainan Island. The correlation of temperature, precipitation, and land cover with NDVI change was analyzed by correlation analysis method. The results showed that the Kriging method of ARCGIS Geostatistical Analyst was a good way to predict the NDVI change trend. Temperature has the primary influence on NDVI, followed by precipitation and land-cover in Hainan Island.展开更多
文摘Purpose: To evaluate respiratory-triggered three-dimensional (3D) true steady-state free-precession (SSFP) projection magnetic resonance angiographic sequences with time-spatial labeling inversion pulse (Time-SLIP) for visualizing the hepatic arteries and to optimize the image acquisition protocol. Materials and Methods: A 1.5-T clinical magnetic resonance imager was used to perform abdominal magnetic resonance angiography (MRA) in 25 consecutive patients before transcatheter arterial chemoembolization or surgery. We compared two selective space-labeling inversion pulse (tag pulse) patterns (Patterns I and II, oblique and parallel tag pulses, respectively). Two experienced radiologists evaluated the number of hepatic arterial branches visible on the acquired MRA images, and the results were referenced with those on images from intra-arterial digital subtraction angiography. Results: Images were acquired from all patients. The two radiologists clearly visualized branches of the left and right hepatic arteries. More peripheral hepatic arterial branches were identified in MRA images captured by using tag pulse Pattern I than in those acquired by using Pattern II (P P > 0.05). Conclusion: Non-contrast-enhanced Time-SLIP hepatic MRA with true SSFP allowed selective visualization of peripheral hepatic vessels.
文摘In this study,we investigate the extent to which sustainability disclosures in the narrative sections of European banks’annual reports improve analysts’forecasting accuracy.We capture sustainability disclosures with a machine learning approach and use forecast errors as a proxy for analysts’forecast accuracy.Our results suggest that sustainability disclosures significantly improve analysts’forecasting accuracy by reducing forecast errors.In a further analysis,we also find that the introduction of Directive 2014/95/European Union is associated with increased disclosure content,which reduces forecast error.Collectively,our results suggest that sustainability disclosures improve forecast accuracy,and the introduction of the new EU directive strengthens this improvement.These results hold after several robustness tests.Our findings have important implications for market participants and policymakers.
文摘利用GIS所提供的三维可视化功能,建立起矿山治理恢复后的具有真实感的三维景观模型,对评价规划方案、展示规划效果、通过三维可视化的形式反映矿山环境治理恢复前后的景观变化具有重要意义。ArcView 3D Analyst是ArcView GIS的扩充模块,在ArcView 3D Analyst基础上建立了采空塌陷区的回填、削坡设计及其治理后矿山绿化等矿山治理恢复设计的三维景观模拟。
文摘以湛江金沙湾海滩养护前后不同时期沉积物粒度监测数据、海底高程扫描数据和遥感影像为依据,运用Arc GIS 3D Analyst进行沉积物和海底地形分析,得出湛江市金沙湾海滩养护工程实施前后不同时期海底沉积物、地形表面和动态剖面变化情况。结果表明,湛江金沙湾海滩侵蚀区域集中在风车广场对出海域和原红嘴鸥码头附近,后期应重点考虑对此区域进行修复重建。
文摘Based on the company's disclosure of key customer information,the impact of corporate customer concentration on analyst forecast was studied,and we further studied the impact of detailed customer names on analyst forecasts. It is found that:(i) customer concentration significantly affects the accuracy of analyst forecasts. The higher the customer concentration is,the lower the accuracy of analyst forecasts is;(ii) Voluntary disclosure of customer names can provide incremental information to analysts and mitigate the negative impact of customer concentration on the accuracy of analyst forests;(iii) further research has found that the incremental information brought by the state-owned enterprises' disclosure of the customer names to analysts is more obvious; disclosure of customer names by companies with high environmental uncertainty is more likely to be of concern to analysts; and star analysts have a higher ability to interpret customer names than non-star analysts.
文摘This paper used the A-shares listed companies in China as samples,constructed a comprehensive indicator of investor attention,and conducted an empirical analysis on the correlations among investor attention,analyst optimism,and stock price crash risk.The results indicated that investor attention aggravates the stock price crash risk and has a positive effect on analyst optimism.Meanwhile,the analyst optimism plays a mediating role in the positive correlation between investor attention and stock price crash risk.In addition to that,institutional investor attention also has direct and indirect effects on the crash risk.
文摘As Hainan Island belonged to tropical monsoon influenced region, vegetation coverage was high. It is accessible to acquire the vegetation index information from remote sensing images, but predicting the average vegetation index in spatial distributing trend is not available. Under the condition that the average vegetation index values of observed stations in different seasons were known, it was possible to qualify the vegetation index values in study area and predict the NDVI (Normal Different Vegetation Index) change trend. In order to learn the variance trend of NDVI and the relationships between NDVI and temperature, precipitation, and land cover in Hainan Island, in this paper, the average seasonal NDVI values of 18 representative stations in Hainan Island were derived by a standard 10-day composite NDVI generated from MODIS imagery. ArcGIS Geostatistical Analyst was applied to predict the seasonal NDVI change trend by the Kriging method in Hainan Island. The correlation of temperature, precipitation, and land cover with NDVI change was analyzed by correlation analysis method. The results showed that the Kriging method of ARCGIS Geostatistical Analyst was a good way to predict the NDVI change trend. Temperature has the primary influence on NDVI, followed by precipitation and land-cover in Hainan Island.
