Newly-established data on onshore deliverable US dollar-RMB forwards and the Shanghai lnterbank Offered Rate from Oetober 2006 to April 2009 reveal significant violations of covered interest rate parity. This paper ex...Newly-established data on onshore deliverable US dollar-RMB forwards and the Shanghai lnterbank Offered Rate from Oetober 2006 to April 2009 reveal significant violations of covered interest rate parity. This paper explains the cause of this anomaly. Deviations in the forward market are caused by an increase in US dollar-to-RMB conversion restrictions. Given that Chinese monetary authorities want to prevent market participants from taking advantage of the predictable appreciation of the RMB, China＇s State Administration of Foreign Exchange has to tighten up the control on US dollar-to-RMB conversions. Under the tightened conversion restrictions, similar deviations will resurface in the forward market whenever hot money inflow increases. One way to avoid covered interest rate parity violations in the forward market is to decrease hot money inflow into China by maintaining a stable and credible exchange rate policy.展开更多
局地微地形产生的微气象环境是造成气象预报误差的重要因素之一,也是导致覆冰预报准确性不高的主要原因。该研究利用高精度MODIS系统15 s(约500 m)地形数据驱动中尺度天气研究和预报(weather research and forecasting,WRF)模式,并使用...局地微地形产生的微气象环境是造成气象预报误差的重要因素之一,也是导致覆冰预报准确性不高的主要原因。该研究利用高精度MODIS系统15 s(约500 m)地形数据驱动中尺度天气研究和预报(weather research and forecasting,WRF)模式,并使用基于决策树的梯度提升框架(light gradient boosting machine,LightGBM)对WRF预报进行订正,通过局地个例评估订正后的覆冰预测效果。结果表明:在假设条件下,过冷液滴覆冰速率随温度降低先快速增加,后增长速率保持不变,且液滴粒径越大,完全冻结所需温度越低;WRF-LightGBM订正算法在山区微地形下有效提升了温度预报准确度,典型冬季寒潮条件下预测温度与实际温度的误差在2℃以内,预报准确率为76%;以典型区域杆塔覆冰为例,输入订正后的温度和相对湿度数据后,覆冰融化时段被消除,覆冰厚度曲线与实际基本一致,增长速率接近一致。展开更多
文摘Newly-established data on onshore deliverable US dollar-RMB forwards and the Shanghai lnterbank Offered Rate from Oetober 2006 to April 2009 reveal significant violations of covered interest rate parity. This paper explains the cause of this anomaly. Deviations in the forward market are caused by an increase in US dollar-to-RMB conversion restrictions. Given that Chinese monetary authorities want to prevent market participants from taking advantage of the predictable appreciation of the RMB, China＇s State Administration of Foreign Exchange has to tighten up the control on US dollar-to-RMB conversions. Under the tightened conversion restrictions, similar deviations will resurface in the forward market whenever hot money inflow increases. One way to avoid covered interest rate parity violations in the forward market is to decrease hot money inflow into China by maintaining a stable and credible exchange rate policy.
文摘局地微地形产生的微气象环境是造成气象预报误差的重要因素之一,也是导致覆冰预报准确性不高的主要原因。该研究利用高精度MODIS系统15 s(约500 m)地形数据驱动中尺度天气研究和预报(weather research and forecasting,WRF)模式,并使用基于决策树的梯度提升框架(light gradient boosting machine,LightGBM)对WRF预报进行订正,通过局地个例评估订正后的覆冰预测效果。结果表明:在假设条件下,过冷液滴覆冰速率随温度降低先快速增加,后增长速率保持不变,且液滴粒径越大,完全冻结所需温度越低;WRF-LightGBM订正算法在山区微地形下有效提升了温度预报准确度,典型冬季寒潮条件下预测温度与实际温度的误差在2℃以内,预报准确率为76%;以典型区域杆塔覆冰为例,输入订正后的温度和相对湿度数据后,覆冰融化时段被消除,覆冰厚度曲线与实际基本一致,增长速率接近一致。
