地面终端站KSA(Ka-band Single Access)高速卫星数据传输接收系统基带数据的处理既要实现基带数据记录存储、实时转发和事后按可控制的帧频转发等业务,又要满足返向高速基带输出的处理时延不大于40ms实时性需求。针对基带数据的处理业...地面终端站KSA(Ka-band Single Access)高速卫星数据传输接收系统基带数据的处理既要实现基带数据记录存储、实时转发和事后按可控制的帧频转发等业务,又要满足返向高速基带输出的处理时延不大于40ms实时性需求。针对基带数据的处理业务多样性和实时性之间的矛盾,提出了一种基于CPCI(Compact Peripheral Component Interconnect)结构且满足基带数据的处理应用业务多样性和高实时性的处理架构,实现了一种高速卫星信号基带数据实时处理平台。经搭建测试平台并拷机500h,该架构下的处理平台能够稳定地实时处理600Mb/s卫星基带数据的所有业务类型,并在地面终端站KSA卫星信号数据传输系统中得到了工程实践验证。展开更多
<span style="font-family:Verdana;"><strong>Introduction: </strong>Coronavirus Disease 2019 (COVID-19) is a viral infection that was first reported in Wuhan, China on 31 December 2019. This ...<span style="font-family:Verdana;"><strong>Introduction: </strong>Coronavirus Disease 2019 (COVID-19) is a viral infection that was first reported in Wuhan, China on 31 December 2019. This study aimed to clarify the epidemiology and clinical characteristics of 500 first COVID-19 in the Najran region, Saudi Arabia. <strong>Material and Methods:</strong> A multi-center retrospective study design was employed to study the first 500 confirmed COVID-19 positive cases in Najran province, Kingdom of Saudi Arabia (KSA). Data were collected from 1 March 2020 until 1 July 2020 and provided by the Infection Prevention and Control (IPC) department from the hospitals. Included cases were confirmed using real-time reverse transcriptase-polymerase chain reaction (RT-PCR). Demographic, vital signs, symptoms, incubation period, travel or exposure history medical history, and comorbidities were collected. Logistic regression analysis was used to explore the association between potential risk factors associated with symptoms occurrence of COVID-19. <strong>Results:</strong> The median age of 500 COVID-19 patients was 31 years;333 (66.6%) males. A total of 34 (6.8%) were Healthcare Workers (HCWs). Out of the 500 patients, 180 (36%) had at least one comorbid disease. The most common symptoms on admission were fever 281 (56.2%), cough 266 (53.2%), shortness of breath 166 (33.2%), and malaise 113 (22.6%). Most of the patients presented with mild disease severity 310 (62%). Nationality, age, and Diabetes Miletus (DM) were independently and significantly associated with being symptomatic (P < 0.05). Compared to Saudi nationals, other nationality patients were most likely to have symptoms (<em>β</em> = 2.968, CI = 2.002 - 4.400, P = 0.0010). For every 1 year increase in age, the risk of being symptomatic increased by 5.8% (<em>β</em> = 1.045, CI = 1.033 - 1.058, P = 0.001). Compared with non-DM patients, DM patients had a 4.05 times higher risk (<em>β</em> = 4.05, CI = 2.188 - 7.507, P = 0.001) of getting symptoms. <strong>Conclusions:</strong> The study concluded that the majority of the COVID-19 patients were symptomatic or had mild disease severity. Age, nationality, and DM were the important risk factors in being symptomatic.</span>展开更多
The aim of this study is to identify the relationship between Vegetation Cover (VC) and the land Surface Temperature (LST), using satellite data of Wadi Bisha, south the Kingdome of Saudi Arabia (KSA). The Landsat 7 T...The aim of this study is to identify the relationship between Vegetation Cover (VC) and the land Surface Temperature (LST), using satellite data of Wadi Bisha, south the Kingdome of Saudi Arabia (KSA). The Landsat 7 Thematic Mapper (ETM) thermal band (band 6) was used for calculating the (LST) values. The near-infrared (NIR) and red band (bands 3 and 4 respectively) were used for estimating the vegetation cover. ERDAS Imagine 9.3 and ArcGIS 10.2 were used in the current study. The results of the study show that the increase of vegetation cover (VC) coincides with decrease of (LST), while the decrease in vegetation cover is linked with increase of (LST). It was found that there was no vegetation observed in areas practiced the highest temperature of 49℃, while areas of lowest temperature of 28℃ were characterized by dense vegetation cover. Thus, a quite significant correlation is approved between the (VC) and the (LST), based on the validation of (50) locations. It was concluded that availability and continuity of Satellite remote sensing data was required for elaborating a continuous monitoring of vegetation cover conditions and mapping was recommended in Wadi Bisha. Operational monitoring is recommended to ensure the adoption of flexible land cover validation protocols.展开更多
文摘<span style="font-family:Verdana;"><strong>Introduction: </strong>Coronavirus Disease 2019 (COVID-19) is a viral infection that was first reported in Wuhan, China on 31 December 2019. This study aimed to clarify the epidemiology and clinical characteristics of 500 first COVID-19 in the Najran region, Saudi Arabia. <strong>Material and Methods:</strong> A multi-center retrospective study design was employed to study the first 500 confirmed COVID-19 positive cases in Najran province, Kingdom of Saudi Arabia (KSA). Data were collected from 1 March 2020 until 1 July 2020 and provided by the Infection Prevention and Control (IPC) department from the hospitals. Included cases were confirmed using real-time reverse transcriptase-polymerase chain reaction (RT-PCR). Demographic, vital signs, symptoms, incubation period, travel or exposure history medical history, and comorbidities were collected. Logistic regression analysis was used to explore the association between potential risk factors associated with symptoms occurrence of COVID-19. <strong>Results:</strong> The median age of 500 COVID-19 patients was 31 years;333 (66.6%) males. A total of 34 (6.8%) were Healthcare Workers (HCWs). Out of the 500 patients, 180 (36%) had at least one comorbid disease. The most common symptoms on admission were fever 281 (56.2%), cough 266 (53.2%), shortness of breath 166 (33.2%), and malaise 113 (22.6%). Most of the patients presented with mild disease severity 310 (62%). Nationality, age, and Diabetes Miletus (DM) were independently and significantly associated with being symptomatic (P < 0.05). Compared to Saudi nationals, other nationality patients were most likely to have symptoms (<em>β</em> = 2.968, CI = 2.002 - 4.400, P = 0.0010). For every 1 year increase in age, the risk of being symptomatic increased by 5.8% (<em>β</em> = 1.045, CI = 1.033 - 1.058, P = 0.001). Compared with non-DM patients, DM patients had a 4.05 times higher risk (<em>β</em> = 4.05, CI = 2.188 - 7.507, P = 0.001) of getting symptoms. <strong>Conclusions:</strong> The study concluded that the majority of the COVID-19 patients were symptomatic or had mild disease severity. Age, nationality, and DM were the important risk factors in being symptomatic.</span>
文摘The aim of this study is to identify the relationship between Vegetation Cover (VC) and the land Surface Temperature (LST), using satellite data of Wadi Bisha, south the Kingdome of Saudi Arabia (KSA). The Landsat 7 Thematic Mapper (ETM) thermal band (band 6) was used for calculating the (LST) values. The near-infrared (NIR) and red band (bands 3 and 4 respectively) were used for estimating the vegetation cover. ERDAS Imagine 9.3 and ArcGIS 10.2 were used in the current study. The results of the study show that the increase of vegetation cover (VC) coincides with decrease of (LST), while the decrease in vegetation cover is linked with increase of (LST). It was found that there was no vegetation observed in areas practiced the highest temperature of 49℃, while areas of lowest temperature of 28℃ were characterized by dense vegetation cover. Thus, a quite significant correlation is approved between the (VC) and the (LST), based on the validation of (50) locations. It was concluded that availability and continuity of Satellite remote sensing data was required for elaborating a continuous monitoring of vegetation cover conditions and mapping was recommended in Wadi Bisha. Operational monitoring is recommended to ensure the adoption of flexible land cover validation protocols.
