According to the consequences of software failures, software faults remaining in safety-critical systems can be classified into two sets： common faults and fatal faults. Common faults cause slight loss when they are ...According to the consequences of software failures, software faults remaining in safety-critical systems can be classified into two sets： common faults and fatal faults. Common faults cause slight loss when they are activated. A fatal fault can lead to significant loss, and even damage the safety-crltical system entirely when it is activated. A software reliability growth model for safety-critical systems is developed based on G - 0 model. And a software cost model is proposed too. The cost model considers maintenance and risk costs due to software failures. The optimal release policies are discussed to minimize the total software cost. A numerical exampie is provided to illustrate how to use the results we obtained.展开更多
Objective： Assess clinical efficacy and safety analysis of laparoscopic-assisted vaginal surgery and laparoscopic-alone surgery in treatment of endometrial cancer. Methods： select 76 cases of endometrial cancer pati...Objective： Assess clinical efficacy and safety analysis of laparoscopic-assisted vaginal surgery and laparoscopic-alone surgery in treatment of endometrial cancer. Methods： select 76 cases of endometrial cancer patients, divided into two groups, 40 in laparoscopic-alone group and 36 in laparoscopic-assisted group, and compare operation time, intraoperative blood loss, intraoperative complications, postoperative complications, lymph node number, anal exhaust time, indwelling catheter days and hospitalization days by group. Result： compared with laparoscopic-alone surgery, laparoscopic-assisted vaginal surgery has certain advantages in reducing intraoperative blood loss, intraoperative and postoperative complications, anal exhaust time, indwelling catheter days and hospitalization days. Discussion： laparoscopic-assisted vaginal surgery is a relatively safe, effective and good economic benefit surgical method in treatment of endometrial cancer.展开更多
This article expounds and proves the basic model of the inconsistency of the security supervision policy and makes an analysis in the method of game theory on the inconsistency of the security transaction-tax-rate pol...This article expounds and proves the basic model of the inconsistency of the security supervision policy and makes an analysis in the method of game theory on the inconsistency of the security transaction-tax-rate policy, concludes that the security supervision department is inclined to increase or decrease the security transaction tax rate, thus points out ways for supervision department to surmount this difficulty.展开更多
Low energy arc discharge characteristics was analyzed based on dynamic V-A characteristics model. It draws conclusions that discharge time relates to the source voltage and the product of inductance and stable current...Low energy arc discharge characteristics was analyzed based on dynamic V-A characteristics model. It draws conclusions that discharge time relates to the source voltage and the product of inductance and stable current, discharge time will increase when the source voltage increases; current reduce rate is in inverse proportion to the value of inductance; arc resistance when the arc occurs is the ratio of minimum arcing voltage to stable current. It also gains the expressions of arc resistance and arc power, arc resistance and arc power both increase as the source voltage increases and decrease as the value of inductance increases. Conclusions above mentioned are helpful to design intrinsically safe circuits.展开更多
traditional In this paper, two drawbacks pseudo-static method （vertical of the slice method） in the slope stability evaluation have been studied. First, the sliding mass is divided into vertical slices according to...traditional In this paper, two drawbacks pseudo-static method （vertical of the slice method） in the slope stability evaluation have been studied. First, the sliding mass is divided into vertical slices according to this method, which is irrational to some extent in the seismic design of slope. Second, only peak ground acceleration （PGA） is considered, and the effects of shaking frequency and duration on slope stability are neglected. And then, based on the theory of elastic wave and the summarized geological model, this paper put forwards an improved method of pseudo-method by using the theory of elastic wave and Hilbert-Huang transform. The improved pseudostatic method gives reasonable considerations to the time-frequency effects of seismic wave and its rationality has been verified by the shaking table test. This method can evaluate the safety of a slope, the happening time and the scale of landslides. At the same time, this method also can improve the high accuracy of the evaluation of the safety of the slope.展开更多
Traditional control does not pay much attention to information security problems in system identification enough, which are important in practical applications. This paper focuses on the security problem of input info...Traditional control does not pay much attention to information security problems in system identification enough, which are important in practical applications. This paper focuses on the security problem of input information in a class of system identification problems with noise and binary-valued observations, presents a cryptography based security protocol, and improves it in the range of allowed errors. During solving the identification problem, the improved security protocol can ensure that the input information is not leaked, and thus, can deal with passive attacks effectively. Besides, a quantitative relationship among the input information, the public key in encryption and the number of partieipailts in the improved protocol is shown. Finally, the simulation results show that, the identification algorithm can still achieve the estimation accuracy by adding the improved security protocol. However, compared with the original identification algorithm, the time complexity of the algorithm with the improved security protocol increases.展开更多
基金Sponsored by the Ph.D. Programs Foundation of Ministry of Education of China (Grant No. 20020213017).
文摘According to the consequences of software failures, software faults remaining in safety-critical systems can be classified into two sets： common faults and fatal faults. Common faults cause slight loss when they are activated. A fatal fault can lead to significant loss, and even damage the safety-crltical system entirely when it is activated. A software reliability growth model for safety-critical systems is developed based on G - 0 model. And a software cost model is proposed too. The cost model considers maintenance and risk costs due to software failures. The optimal release policies are discussed to minimize the total software cost. A numerical exampie is provided to illustrate how to use the results we obtained.
文摘Objective： Assess clinical efficacy and safety analysis of laparoscopic-assisted vaginal surgery and laparoscopic-alone surgery in treatment of endometrial cancer. Methods： select 76 cases of endometrial cancer patients, divided into two groups, 40 in laparoscopic-alone group and 36 in laparoscopic-assisted group, and compare operation time, intraoperative blood loss, intraoperative complications, postoperative complications, lymph node number, anal exhaust time, indwelling catheter days and hospitalization days by group. Result： compared with laparoscopic-alone surgery, laparoscopic-assisted vaginal surgery has certain advantages in reducing intraoperative blood loss, intraoperative and postoperative complications, anal exhaust time, indwelling catheter days and hospitalization days. Discussion： laparoscopic-assisted vaginal surgery is a relatively safe, effective and good economic benefit surgical method in treatment of endometrial cancer.
文摘This article expounds and proves the basic model of the inconsistency of the security supervision policy and makes an analysis in the method of game theory on the inconsistency of the security transaction-tax-rate policy, concludes that the security supervision department is inclined to increase or decrease the security transaction tax rate, thus points out ways for supervision department to surmount this difficulty.
文摘Low energy arc discharge characteristics was analyzed based on dynamic V-A characteristics model. It draws conclusions that discharge time relates to the source voltage and the product of inductance and stable current, discharge time will increase when the source voltage increases; current reduce rate is in inverse proportion to the value of inductance; arc resistance when the arc occurs is the ratio of minimum arcing voltage to stable current. It also gains the expressions of arc resistance and arc power, arc resistance and arc power both increase as the source voltage increases and decrease as the value of inductance increases. Conclusions above mentioned are helpful to design intrinsically safe circuits.
基金supported in part by National Science Foundation of China (Contract NO. 41030742)Guangxi Science Foundation and the Program for Science & Technology of Henan Province in China (Grant No. 142300410200)
文摘traditional In this paper, two drawbacks pseudo-static method （vertical of the slice method） in the slope stability evaluation have been studied. First, the sliding mass is divided into vertical slices according to this method, which is irrational to some extent in the seismic design of slope. Second, only peak ground acceleration （PGA） is considered, and the effects of shaking frequency and duration on slope stability are neglected. And then, based on the theory of elastic wave and the summarized geological model, this paper put forwards an improved method of pseudo-method by using the theory of elastic wave and Hilbert-Huang transform. The improved pseudostatic method gives reasonable considerations to the time-frequency effects of seismic wave and its rationality has been verified by the shaking table test. This method can evaluate the safety of a slope, the happening time and the scale of landslides. At the same time, this method also can improve the high accuracy of the evaluation of the safety of the slope.
基金supported by the National Key Basic Research Program of China(973 Program)under Grant No.2014CB845301the National Natural Science Foundation of China under Grant No.61227902
文摘Traditional control does not pay much attention to information security problems in system identification enough, which are important in practical applications. This paper focuses on the security problem of input information in a class of system identification problems with noise and binary-valued observations, presents a cryptography based security protocol, and improves it in the range of allowed errors. During solving the identification problem, the improved security protocol can ensure that the input information is not leaked, and thus, can deal with passive attacks effectively. Besides, a quantitative relationship among the input information, the public key in encryption and the number of partieipailts in the improved protocol is shown. Finally, the simulation results show that, the identification algorithm can still achieve the estimation accuracy by adding the improved security protocol. However, compared with the original identification algorithm, the time complexity of the algorithm with the improved security protocol increases.
