<strong>Background:</strong> <span style="font-family:Verdana;">In-hospital mortality is high in low-income countries. Currently, little is known in Cameroon concerning the characteristics ...<strong>Background:</strong> <span style="font-family:Verdana;">In-hospital mortality is high in low-income countries. Currently, little is known in Cameroon concerning the characteristics of patients who die in cardiology units. Our objectives were to determine the in-hospital mortality rate;describe </span><span style="font-family:Verdana;">th</span><span style="font-family:;" "=""><span style="font-family:Verdana;">e general characteristics of death patients, and factors associated with mortality. </span><b><span style="font-family:Verdana;">Material and Methods: </span></b><span style="font-family:Verdana;">We conducted a retrospective cross-sectional study by reviewing the medical records of all patients admitted to the cardiology unit of the Yaoundé Central Hospital (CHY) between January 2018 </span></span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;">January 2019. The files of all death patients were studied for socio-demographical, clinical and therapeutical variables. Bivariate analysis was conducted to order to check the association between independents variables and time of death. A p-value <</span><span style="font-family:Verdana;"> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">0.05 was considered statistically significant. </span><b><span style="font-family:Verdana;">Results: </span></b><span style="font-family:Verdana;">A total number of 860 patients were admitted in the cardiology unit of CHY during the study period. Amongst the 860 patients admitted 78 had a fatal outcome, hence, an in-hospital mortality rate of 9.06%. The male gender was predominant amongst the deceased patients (n = 45). The mean age at death was 69 ± 15.19 years. The median time before death was 6 days and they ranged between 1 to 25 days. Hypertension was the most frequent comorbidity (65.4%). Stroke was the principal cause of admission (40.3%), whereas the main presenting complaint was dyspnea (26.9%). Before being admitted to the cardiology department, the majority of the deceased patients were from the emergency department. The major clinical sign of death was respiratory distress (39.74%). Shock on admission was the sole factor found to be associated with the mean time of death (p = 0.012). The patient</span></span><span style="font-family:Verdana;">s</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> with deep venous thrombosis compared to other diagnoses were less like to die early (r = 16, p = 0.016). </span><b><span style="font-family:Verdana;">Conclusion: </span></b><span style="font-family:Verdana;">The patient admitted in the cardiology unit of Yaoundé Central Hospital died mainly from stroke and the death is earlier when the patient has signs of shock on admission. These results emphasize the need for a good primary evaluation at the emergency room, to better manage patients with cardiovascular diseases in the cardiology ward.</span></span>展开更多
The uncertainty analysis is an effective sensitivity analysis method for system model analysis and optimization. However,the existing single-factor uncertainty analysis methods are not well used in the logistic suppor...The uncertainty analysis is an effective sensitivity analysis method for system model analysis and optimization. However,the existing single-factor uncertainty analysis methods are not well used in the logistic support systems with multiple decision-making factors. The multiple transfer parameters graphical evaluation and review technique（MTP-GERT） is used to model the logistic support process in consideration of two important factors, support activity time and support activity resources, which are two primary causes for the logistic support process uncertainty. On this basis,a global sensitivity analysis（GSA） method based on covariance is designed to analyze the logistic support process uncertainty. The aircraft support process is selected as a case application which illustrates the validity of the proposed method to analyze the support process uncertainty, and some feasible recommendations are proposed for aircraft support decision making on carrier.展开更多
Cloud computing plays a significant role in modern information technology, providing organizations with numerous benefits, including flexibility, scalability, and cost-efficiency. However, it has become essential for ...Cloud computing plays a significant role in modern information technology, providing organizations with numerous benefits, including flexibility, scalability, and cost-efficiency. However, it has become essential for organizations to ensure the security of their applications, data, and cloud-based networks to use cloud services effectively. This systematic literature review aims to determine the latest information regarding cloud computing security, with a specific emphasis on threats and mitigation strategies. Additionally, it highlights some common threats related to cloud computing security, such as distributed denial-of-service (DDoS) attacks, account hijacking, malware attacks, and data breaches. This research also explores some mitigation strategies, including security awareness training, vulnerability management, security information and event management (SIEM), identity and access management (IAM), and encryption techniques. It discusses emerging trends in cloud security, such as integrating artificial intelligence (AI) and machine learning (ML), serverless computing, and containerization, as well as the effectiveness of the shared responsibility model and its related challenges. The importance of user awareness and the impact of emerging technologies on cloud security have also been discussed in detail to mitigate security risks. A literature review of previous research and scholarly articles has also been conducted to provide insights regarding cloud computing security. It shows the need for continuous research and innovation to address emerging threats and maintain a security-conscious culture in the company.展开更多
在遥感影像配准过程中,通常假设控制点是“完美的”。然而,在实际情况中,由于控制点本身不可避免的带有一定的误差导致这种假设在一定情况下并不成立,并且将会影响遥感影像几何校正的精度。普通最小二乘方法OLS(O rd inary Least Square...在遥感影像配准过程中,通常假设控制点是“完美的”。然而,在实际情况中,由于控制点本身不可避免的带有一定的误差导致这种假设在一定情况下并不成立,并且将会影响遥感影像几何校正的精度。普通最小二乘方法OLS(O rd inary Least Square)是遥感影像配准常用的校正估计模型,令人遗憾的是,在控制点存在误差的情况下,它的估计是有偏的,并且不能够正确传递和估计校正影像的误差大小。引入一致校正最小二乘方法CALS(ConsistentAd justed Least Squares),在此基础上提出的一个改进的方法,称之为松弛一致校正最小二乘方法RCALS(Relaxed ConsistentAd justed Least Squares)。这类回归模型具有改正控制点(解释变量)中的误差和跟踪回归模型中的误差传递的能力。为了验证CALS和RCALS模型的有效性,本文利用模拟影像进行分析。这里着重分析OLS,CALS和RCALS模型在几何校正过程中的比较。结果表明,RCALS和CALS的结果优于OLS估计结果。展开更多
文摘<strong>Background:</strong> <span style="font-family:Verdana;">In-hospital mortality is high in low-income countries. Currently, little is known in Cameroon concerning the characteristics of patients who die in cardiology units. Our objectives were to determine the in-hospital mortality rate;describe </span><span style="font-family:Verdana;">th</span><span style="font-family:;" "=""><span style="font-family:Verdana;">e general characteristics of death patients, and factors associated with mortality. </span><b><span style="font-family:Verdana;">Material and Methods: </span></b><span style="font-family:Verdana;">We conducted a retrospective cross-sectional study by reviewing the medical records of all patients admitted to the cardiology unit of the Yaoundé Central Hospital (CHY) between January 2018 </span></span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;">January 2019. The files of all death patients were studied for socio-demographical, clinical and therapeutical variables. Bivariate analysis was conducted to order to check the association between independents variables and time of death. A p-value <</span><span style="font-family:Verdana;"> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">0.05 was considered statistically significant. </span><b><span style="font-family:Verdana;">Results: </span></b><span style="font-family:Verdana;">A total number of 860 patients were admitted in the cardiology unit of CHY during the study period. Amongst the 860 patients admitted 78 had a fatal outcome, hence, an in-hospital mortality rate of 9.06%. The male gender was predominant amongst the deceased patients (n = 45). The mean age at death was 69 ± 15.19 years. The median time before death was 6 days and they ranged between 1 to 25 days. Hypertension was the most frequent comorbidity (65.4%). Stroke was the principal cause of admission (40.3%), whereas the main presenting complaint was dyspnea (26.9%). Before being admitted to the cardiology department, the majority of the deceased patients were from the emergency department. The major clinical sign of death was respiratory distress (39.74%). Shock on admission was the sole factor found to be associated with the mean time of death (p = 0.012). The patient</span></span><span style="font-family:Verdana;">s</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> with deep venous thrombosis compared to other diagnoses were less like to die early (r = 16, p = 0.016). </span><b><span style="font-family:Verdana;">Conclusion: </span></b><span style="font-family:Verdana;">The patient admitted in the cardiology unit of Yaoundé Central Hospital died mainly from stroke and the death is earlier when the patient has signs of shock on admission. These results emphasize the need for a good primary evaluation at the emergency room, to better manage patients with cardiovascular diseases in the cardiology ward.</span></span>
基金supported by the National Natural Science Foundation of China(71171008)
文摘The uncertainty analysis is an effective sensitivity analysis method for system model analysis and optimization. However,the existing single-factor uncertainty analysis methods are not well used in the logistic support systems with multiple decision-making factors. The multiple transfer parameters graphical evaluation and review technique（MTP-GERT） is used to model the logistic support process in consideration of two important factors, support activity time and support activity resources, which are two primary causes for the logistic support process uncertainty. On this basis,a global sensitivity analysis（GSA） method based on covariance is designed to analyze the logistic support process uncertainty. The aircraft support process is selected as a case application which illustrates the validity of the proposed method to analyze the support process uncertainty, and some feasible recommendations are proposed for aircraft support decision making on carrier.
文摘Cloud computing plays a significant role in modern information technology, providing organizations with numerous benefits, including flexibility, scalability, and cost-efficiency. However, it has become essential for organizations to ensure the security of their applications, data, and cloud-based networks to use cloud services effectively. This systematic literature review aims to determine the latest information regarding cloud computing security, with a specific emphasis on threats and mitigation strategies. Additionally, it highlights some common threats related to cloud computing security, such as distributed denial-of-service (DDoS) attacks, account hijacking, malware attacks, and data breaches. This research also explores some mitigation strategies, including security awareness training, vulnerability management, security information and event management (SIEM), identity and access management (IAM), and encryption techniques. It discusses emerging trends in cloud security, such as integrating artificial intelligence (AI) and machine learning (ML), serverless computing, and containerization, as well as the effectiveness of the shared responsibility model and its related challenges. The importance of user awareness and the impact of emerging technologies on cloud security have also been discussed in detail to mitigate security risks. A literature review of previous research and scholarly articles has also been conducted to provide insights regarding cloud computing security. It shows the need for continuous research and innovation to address emerging threats and maintain a security-conscious culture in the company.
文摘在遥感影像配准过程中,通常假设控制点是“完美的”。然而,在实际情况中,由于控制点本身不可避免的带有一定的误差导致这种假设在一定情况下并不成立,并且将会影响遥感影像几何校正的精度。普通最小二乘方法OLS(O rd inary Least Square)是遥感影像配准常用的校正估计模型,令人遗憾的是,在控制点存在误差的情况下,它的估计是有偏的,并且不能够正确传递和估计校正影像的误差大小。引入一致校正最小二乘方法CALS(ConsistentAd justed Least Squares),在此基础上提出的一个改进的方法,称之为松弛一致校正最小二乘方法RCALS(Relaxed ConsistentAd justed Least Squares)。这类回归模型具有改正控制点(解释变量)中的误差和跟踪回归模型中的误差传递的能力。为了验证CALS和RCALS模型的有效性,本文利用模拟影像进行分析。这里着重分析OLS,CALS和RCALS模型在几何校正过程中的比较。结果表明,RCALS和CALS的结果优于OLS估计结果。
