According to a lot of practical data in Liujialiang Mine and reliability theory and result of computer simulation, operation regularity of fully mechanized sublevel caving mining production system in the condition of ...According to a lot of practical data in Liujialiang Mine and reliability theory and result of computer simulation, operation regularity of fully mechanized sublevel caving mining production system in the condition of gently inclined complicated geological structure and production shortcomings are found out and reliability of system and output of the working face are predicted finally.展开更多
This research measures the reliability of audit firms in predicting bankruptcy for United States （US） listed financial institutions. The object of analysis is the going concern opinion （GCO）, widely considered as ...This research measures the reliability of audit firms in predicting bankruptcy for United States （US） listed financial institutions. The object of analysis is the going concern opinion （GCO）, widely considered as a bankruptcy warning signal to stakeholders. The sample is composed of 42 US listed financial companies that filed for Chapter 11 between 1998 and 2011. To highlight the differences between bankrupting and healthy firms, a matching sample composed of 42 randomly picked healthy US listed financial companies is collected. We concentrate on financial institutions, whereas the existing literature pays considerably greater attention to the industrial sector. This research imbalance is remarkable and particularly unexpected in the wake of recent financial scandals. Literature points out two main approaches on bankruptcy prediction： （1） purely mathematical; and （2） approaches based on a combination of auditor knowledge, expertise, and experience. The use of data mining techniques allows us to benefit from the best features of both approaches. Statistical tools used in the analysis are： Logit regression, support vector machines （SVMs）, and an AdaBoost meta-algorithm. Findings show a quite low reliability of GCOs in predicting bankruptcy. It is likely that auditors consider further information in supporting their audit opinions, aside from financial-economic ratios. The scant predictive ability of auditors might be due to critical relationships with distressed clients, as suggested by recent literature.展开更多
Dependability analysis is an important step in designing and analyzing safety computer systems and protection systems.Introducing multi-processor and virtual machine increases the system faults' complexity,diversi...Dependability analysis is an important step in designing and analyzing safety computer systems and protection systems.Introducing multi-processor and virtual machine increases the system faults' complexity,diversity and dynamic,in particular for software-induced failures,with an impact on the overall dependability.Moreover,it is very different for safety system to operate successfully at any active phase,since there is a huge difference in failure rate between hardware-induced and softwareinduced failures.To handle these difficulties and achieve accurate dependability evaluation,consistently reflecting the construct it measures,a new formalism derived from dynamic fault graphs(DFG) is developed in this paper.DFG exploits the concept of system event as fault state sequences to represent dynamic behaviors,which allows us to execute probabilistic measures at each timestamp when change occurs.The approach automatically combines the reliability analysis with the system dynamics.In this paper,we describe how to use the proposed methodology drives to the overall system dependability analysis through the phases of modeling,structural discovery and probability analysis,which is also discussed using an example of a virtual computing system.展开更多
文摘According to a lot of practical data in Liujialiang Mine and reliability theory and result of computer simulation, operation regularity of fully mechanized sublevel caving mining production system in the condition of gently inclined complicated geological structure and production shortcomings are found out and reliability of system and output of the working face are predicted finally.
文摘This research measures the reliability of audit firms in predicting bankruptcy for United States （US） listed financial institutions. The object of analysis is the going concern opinion （GCO）, widely considered as a bankruptcy warning signal to stakeholders. The sample is composed of 42 US listed financial companies that filed for Chapter 11 between 1998 and 2011. To highlight the differences between bankrupting and healthy firms, a matching sample composed of 42 randomly picked healthy US listed financial companies is collected. We concentrate on financial institutions, whereas the existing literature pays considerably greater attention to the industrial sector. This research imbalance is remarkable and particularly unexpected in the wake of recent financial scandals. Literature points out two main approaches on bankruptcy prediction： （1） purely mathematical; and （2） approaches based on a combination of auditor knowledge, expertise, and experience. The use of data mining techniques allows us to benefit from the best features of both approaches. Statistical tools used in the analysis are： Logit regression, support vector machines （SVMs）, and an AdaBoost meta-algorithm. Findings show a quite low reliability of GCOs in predicting bankruptcy. It is likely that auditors consider further information in supporting their audit opinions, aside from financial-economic ratios. The scant predictive ability of auditors might be due to critical relationships with distressed clients, as suggested by recent literature.
基金This work was supported in part by National Natural Science Foundation of China under grant No.61272411 and National 973 Basic Research Program of China under grant No.2014CB340600
文摘Dependability analysis is an important step in designing and analyzing safety computer systems and protection systems.Introducing multi-processor and virtual machine increases the system faults' complexity,diversity and dynamic,in particular for software-induced failures,with an impact on the overall dependability.Moreover,it is very different for safety system to operate successfully at any active phase,since there is a huge difference in failure rate between hardware-induced and softwareinduced failures.To handle these difficulties and achieve accurate dependability evaluation,consistently reflecting the construct it measures,a new formalism derived from dynamic fault graphs(DFG) is developed in this paper.DFG exploits the concept of system event as fault state sequences to represent dynamic behaviors,which allows us to execute probabilistic measures at each timestamp when change occurs.The approach automatically combines the reliability analysis with the system dynamics.In this paper,we describe how to use the proposed methodology drives to the overall system dependability analysis through the phases of modeling,structural discovery and probability analysis,which is also discussed using an example of a virtual computing system.
