针对目前联盟链共识算法存在共识效率低和主节点选举过于集中的问题,提出一种基于信誉审查与工作量证明相结合的联盟区块链共识算法PRW(Proof of Review and Work)。引入了公有链中工作量证明的思想,通过同时考虑联盟区块链共识节点当...针对目前联盟链共识算法存在共识效率低和主节点选举过于集中的问题,提出一种基于信誉审查与工作量证明相结合的联盟区块链共识算法PRW(Proof of Review and Work)。引入了公有链中工作量证明的思想,通过同时考虑联盟区块链共识节点当前信誉审查情况与算力化的权益实现一致化共识,平衡系统集中化趋势,从而促进联盟区块链公平可持续发展。实验结果显示,经过改进后的PRW共识算法在提高节点出块效率的同时平衡了记账权竞争。展开更多
The spatio-temporal analysis of the performance of the March to May</span><span style="font-family:""> (MAM) <span>2020 rainfall and its societal implications to Northern Coastal Tanza...The spatio-temporal analysis of the performance of the March to May</span><span style="font-family:""> (MAM) <span>2020 rainfall and its societal implications to Northern Coastal Tanzania</span> (NCT) including Zanzibar was investigated. The uniqueness of the October to December, 2019 (OND) rainfall and the extension of the January to February, 2020 rainfall in Zanzibar which coincided with MAM 2020 rainfall was among the issues which prolonged MAM 2020 rainfall in NCT and Zanzibar. The National Center for Environmental Prediction (NCEP) in collaboration with National Center for Atmospheric Research (NCAR)</span><span style="font-family:"">.</span><span style="font-family:""> Reanalysis 1 datasets of <i>u</i> (zonal)</span><span style="font-family:""> </span><span style="font-family:"">and <i>v</i> (meridional)</span><span style="font-family:""> </span><span style="font-family:"">winds</span><span style="font-family:"">,</span><span style="font-family:""> sea surface temperatures anomalies, relative humidity, amount of precipitable water and ocean net flux were</span><span style="font-family:""><span style="background-image:initial;background-position:initial;background-size:initial;background-repeat:initial;background-attachment:initial;background-origin:initial;background-clip:initial;"> </span></span><span style="background-color:;"></span><span style="font-family:""><span style="background:yellow;"></span><span>analyzed. Other datasets include the Tanzania Meteorological Authority (TMA) observed rainfall</span> records</span><span style="font-family:"">,</span><span style="font-family:""> maximum and minimum temperature</span><span style="font-family:"">s</span><span style="font-family:"">. Moreover, <span>TMA and Intergovernmental Climate Prediction and Analysis Cente</span>r (ICPAC)</span><span style="font-family:"">.</span><span style="font-family:""> MAM 2020 rainfall and temperature forecast reports were interpreted. Gridded and observed datasets were calculated into monthly and seasonal averages. As for observed data, long</span><span style="font-family:"">-</span><span style="font-family:"">term monthly and MAM percentage changes were calculated. Besides, </span><span style="font-family:"">the </span><span style="font-family:"">correlation between rainfall anomalies with an area</span><span style="font-family:"">-</span><span style="font-family:"">averaged SST<sub>A</sub> for defined regions and stations in Zanzibar w</span><span style="font-family:"">as</span><span style="font-family:""> performed. Lastly, the calculated monthly and seasonal rainfall was compared to MAM periods of 2016, 2017, 2018 and 2019. Results revealed that consecutive five MAM seasonal rainfall was among the highest ones in records with that of 2020 being exceptional. These MAM seasons had percentage contribution ranged from 68% - 212%, 150% - 304%, 22% - 163% and 57% - 170% for stations in Zanzibar and 130% - 230%, 57% - 168% and 230% - 706% for NCT station, respectively. Compared to previous MAM seasons of 2016-2019, MAM 2020 rainfall season was spatially well distributed in our study area with rainfall rang</span><span style="font-family:"">ing</span><span style="font-family:""> from 1200 to 2100 mm and up to 900 in most Zanzibar and NCT stations. Indeed, the study revealed that the observed highest rainfall and flooding was enhanced by wet seasons of MAM 2019, OND 2019 and DFJ (2019-2020). Other dynamics which accelerated MAM 2020 rainfall were the higher SST<sub>A</sub> ranged f<span>rom 0.5<span style="white-space:nowrap;">°</span>C - 1.5<span style="white-space:nowrap;">°</span>C and 1.5<span style="white-space:nowrap;">°</span>C - 2.5<span style="white-space:nowrap;">°</span>C over Southwestern Indian Ocean </span>(SWIO) and coastal Tanzania</span><span style="font-family:""> and</span><span style="font-family:""> the increased trend of area</span><span style="font-family:"">-</span><span style="font-family:"">averaged SST<sub>A</sub> on various SWIO blocks. </span><span style="font-family:"">Besides,</span><span style="font-family:""> parameters including Rhum, PWR and wind regimes were supporting the MAM 2020 rainfall. The socio-economic implications of these rains were strong and spatially well distributed in Zanzibar. For instance, a death toll of about 10 people, </span><span style="font-family:"">a </span><span style="font-family:"">great number of road culverts were washed away, </span><span style="font-family:"">and </span><span style="font-family:"">about 3600 houses </span><span style="font-family:"">were </span><span style="font-family:"">fallen or damaged, leading to </span><span style="font-family:"">a </span><span style="font-family:"">significant number of homeless people. As for NCT</span><span style="font-family:"">,</span><span style="font-family:""> the catastrophes include loss of lives</span><span style="font-family:"">,</span><span style="font-family:""> increased water levels over Lake <span>Victoria leading to flooded islands and re</span></span><span style="font-family:""> </span><span style="font-family:"">allocation of more than 1000 </span><span style="font-family:"">people. In Kenya</span><span style="font-family:"">,</span><span style="font-family:""> more than 116 people died and 40,000 people were displaced. Conclusively</span><span style="font-family:"">,</span><span style="font-family:""> the study has shown the unique<span>ness (<i>i</i>.<i>e</i>.</span></span><span style="font-family:"">,</span><span style="font-family:""> strength and societal implications) of MAM 2020 compared to </span><span style="font-family:"">other seasons;hence more studies on understanding the factors affecting extreme rainfall seasons in East Africa are required</span><span style="font-family:"">.展开更多
文摘针对目前联盟链共识算法存在共识效率低和主节点选举过于集中的问题,提出一种基于信誉审查与工作量证明相结合的联盟区块链共识算法PRW(Proof of Review and Work)。引入了公有链中工作量证明的思想,通过同时考虑联盟区块链共识节点当前信誉审查情况与算力化的权益实现一致化共识,平衡系统集中化趋势,从而促进联盟区块链公平可持续发展。实验结果显示,经过改进后的PRW共识算法在提高节点出块效率的同时平衡了记账权竞争。
文摘The spatio-temporal analysis of the performance of the March to May</span><span style="font-family:""> (MAM) <span>2020 rainfall and its societal implications to Northern Coastal Tanzania</span> (NCT) including Zanzibar was investigated. The uniqueness of the October to December, 2019 (OND) rainfall and the extension of the January to February, 2020 rainfall in Zanzibar which coincided with MAM 2020 rainfall was among the issues which prolonged MAM 2020 rainfall in NCT and Zanzibar. The National Center for Environmental Prediction (NCEP) in collaboration with National Center for Atmospheric Research (NCAR)</span><span style="font-family:"">.</span><span style="font-family:""> Reanalysis 1 datasets of <i>u</i> (zonal)</span><span style="font-family:""> </span><span style="font-family:"">and <i>v</i> (meridional)</span><span style="font-family:""> </span><span style="font-family:"">winds</span><span style="font-family:"">,</span><span style="font-family:""> sea surface temperatures anomalies, relative humidity, amount of precipitable water and ocean net flux were</span><span style="font-family:""><span style="background-image:initial;background-position:initial;background-size:initial;background-repeat:initial;background-attachment:initial;background-origin:initial;background-clip:initial;"> </span></span><span style="background-color:;"></span><span style="font-family:""><span style="background:yellow;"></span><span>analyzed. Other datasets include the Tanzania Meteorological Authority (TMA) observed rainfall</span> records</span><span style="font-family:"">,</span><span style="font-family:""> maximum and minimum temperature</span><span style="font-family:"">s</span><span style="font-family:"">. Moreover, <span>TMA and Intergovernmental Climate Prediction and Analysis Cente</span>r (ICPAC)</span><span style="font-family:"">.</span><span style="font-family:""> MAM 2020 rainfall and temperature forecast reports were interpreted. Gridded and observed datasets were calculated into monthly and seasonal averages. As for observed data, long</span><span style="font-family:"">-</span><span style="font-family:"">term monthly and MAM percentage changes were calculated. Besides, </span><span style="font-family:"">the </span><span style="font-family:"">correlation between rainfall anomalies with an area</span><span style="font-family:"">-</span><span style="font-family:"">averaged SST<sub>A</sub> for defined regions and stations in Zanzibar w</span><span style="font-family:"">as</span><span style="font-family:""> performed. Lastly, the calculated monthly and seasonal rainfall was compared to MAM periods of 2016, 2017, 2018 and 2019. Results revealed that consecutive five MAM seasonal rainfall was among the highest ones in records with that of 2020 being exceptional. These MAM seasons had percentage contribution ranged from 68% - 212%, 150% - 304%, 22% - 163% and 57% - 170% for stations in Zanzibar and 130% - 230%, 57% - 168% and 230% - 706% for NCT station, respectively. Compared to previous MAM seasons of 2016-2019, MAM 2020 rainfall season was spatially well distributed in our study area with rainfall rang</span><span style="font-family:"">ing</span><span style="font-family:""> from 1200 to 2100 mm and up to 900 in most Zanzibar and NCT stations. Indeed, the study revealed that the observed highest rainfall and flooding was enhanced by wet seasons of MAM 2019, OND 2019 and DFJ (2019-2020). Other dynamics which accelerated MAM 2020 rainfall were the higher SST<sub>A</sub> ranged f<span>rom 0.5<span style="white-space:nowrap;">°</span>C - 1.5<span style="white-space:nowrap;">°</span>C and 1.5<span style="white-space:nowrap;">°</span>C - 2.5<span style="white-space:nowrap;">°</span>C over Southwestern Indian Ocean </span>(SWIO) and coastal Tanzania</span><span style="font-family:""> and</span><span style="font-family:""> the increased trend of area</span><span style="font-family:"">-</span><span style="font-family:"">averaged SST<sub>A</sub> on various SWIO blocks. </span><span style="font-family:"">Besides,</span><span style="font-family:""> parameters including Rhum, PWR and wind regimes were supporting the MAM 2020 rainfall. The socio-economic implications of these rains were strong and spatially well distributed in Zanzibar. For instance, a death toll of about 10 people, </span><span style="font-family:"">a </span><span style="font-family:"">great number of road culverts were washed away, </span><span style="font-family:"">and </span><span style="font-family:"">about 3600 houses </span><span style="font-family:"">were </span><span style="font-family:"">fallen or damaged, leading to </span><span style="font-family:"">a </span><span style="font-family:"">significant number of homeless people. As for NCT</span><span style="font-family:"">,</span><span style="font-family:""> the catastrophes include loss of lives</span><span style="font-family:"">,</span><span style="font-family:""> increased water levels over Lake <span>Victoria leading to flooded islands and re</span></span><span style="font-family:""> </span><span style="font-family:"">allocation of more than 1000 </span><span style="font-family:"">people. In Kenya</span><span style="font-family:"">,</span><span style="font-family:""> more than 116 people died and 40,000 people were displaced. Conclusively</span><span style="font-family:"">,</span><span style="font-family:""> the study has shown the unique<span>ness (<i>i</i>.<i>e</i>.</span></span><span style="font-family:"">,</span><span style="font-family:""> strength and societal implications) of MAM 2020 compared to </span><span style="font-family:"">other seasons;hence more studies on understanding the factors affecting extreme rainfall seasons in East Africa are required</span><span style="font-family:"">.
