An objective identification technique is used to detect regional extreme low temperature events （RELTE） in China during 1960-2009. Their spatial-temporal characteristics are analyzed. The results indicate that the l...An objective identification technique is used to detect regional extreme low temperature events （RELTE） in China during 1960-2009. Their spatial-temporal characteristics are analyzed. The results indicate that the lowest temperatures of RELTE, together with the frequency distribution of the geometric latitude center, exhibit a double-peak feature. The RELTE frequently happen near the geometric area of 30°N and 42°N before the mid-1980s, but shifted afterwards to 30°N. During 1960-2009, the frequency~ intensity, and the maximum impacted area of RELTE show overall decreasing trends. Due to the contribution of RELTE, with long duratioh and large spatial range, which account for 10% of the total RELTE, there is a significant turning point in the late 1980s. A change to a much more steady state after the late 1990s is identified. In addition, the integrated indices of RELTE are classified and analyzed.展开更多
Many techniques have been used in the courts to demonstrate the criticalities of a delay event on the project schedule. At this time, there is no standard method to analyze a delay claim. This paper first introduced a...Many techniques have been used in the courts to demonstrate the criticalities of a delay event on the project schedule. At this time, there is no standard method to analyze a delay claim. This paper first introduced a fictional case study that has most types of delay and acceleration events that might be faced on a real project. The case study is applied to all current techniques of delay claims that have been identified from previous studies. The comparison uses the delay claim issues as criteria to evaluate all the delay claim techniques from the case study results. The case study result and discussion demonstrate that the Day-by-Day technique satisfies all the desired criteria while other techniques lack some.展开更多
Recently,virtualization technologies have been widely used in industry.In order to monitor the security of target systems in virtualization environments,conventional methods usually put the security monitoring mechani...Recently,virtualization technologies have been widely used in industry.In order to monitor the security of target systems in virtualization environments,conventional methods usually put the security monitoring mechanism into the normal functionality of the target systems.However,these methods are either prone to be tempered by attackers or introduce considerable performance overhead for target systems.To address these problems,in this paper,we present a concurrent security monitoring method which decouples traditional serial mechanisms,including security event collector and analyzer,into two concurrent components.On one hand,we utilize the SIM framework to deploy the event collector into the target virtual machine.On the other hand,we combine the virtualization technology and multi-core technology to put the event analyzer into a trusted execution environment.To address the synchronization problem between these two concurrent components,we make use of Lamport's ring buffer algorithm.Based on the Xen hypervisor,we have implemented a prototype system named COMO.The experimental results show that COMO can monitor the security of the target virtual machine concurrently within a little performance overhead.展开更多
Building construction site plays an important role in the economic aspect of a region. So any disruption due to hazard event like earthquake can cause several direct and indirect damages. Direct damages can lead to th...Building construction site plays an important role in the economic aspect of a region. So any disruption due to hazard event like earthquake can cause several direct and indirect damages. Direct damages can lead to the loss of equipments and qualified persons. Indirect damages can lead to inflation and loss of purchasing power. To deal with that situation, parameters that govern the vulnerability of building construction site have been identified. Using a MCDM （multiple criteria decision making） method, the priority order of these parameters has been set. Then a PVI （partial vulnerability index） and a GVI （global vulnerability index） are proposed. These indexes allow the classification of building construction sites according to their intrinsic vulnerability and seismic vulnerability respectively that is through the use of a given classification. Several Algerian building construction sites belonging to different seismic zones were considered in order to show the applicability of the method.展开更多
Targeted observation is an observation strategy by which the concerned phenomenon is observed. In geoscienee, targeted ob- servation is mainly related to the forecasts of weather events or predictions of climate event...Targeted observation is an observation strategy by which the concerned phenomenon is observed. In geoscienee, targeted ob- servation is mainly related to the forecasts of weather events or predictions of climate events. This paper will first review the history of targeted observation, and then introduce the main methods used in targeted observation. The discussion on the theo- retical basis of targeted observation includes its advantages and limitations. After presenting the current situation of domestic and international targeted observations in atmospheric and oceanic sciences, the methods used for targeted observation, and their effect evaluation and testing are mainly discussed here. Finally, the author presents his suggestion about the prospect of further development in the field, and how to extend the method of targeted observation to deal with numerical model errors.展开更多
基金supported by the Special Scientific Research Projects for Public Interest(No.GYHY201006021 and GYHY201106016)the National Natural Science Foundation of China(No.41205040 and 40930952)
文摘An objective identification technique is used to detect regional extreme low temperature events （RELTE） in China during 1960-2009. Their spatial-temporal characteristics are analyzed. The results indicate that the lowest temperatures of RELTE, together with the frequency distribution of the geometric latitude center, exhibit a double-peak feature. The RELTE frequently happen near the geometric area of 30°N and 42°N before the mid-1980s, but shifted afterwards to 30°N. During 1960-2009, the frequency~ intensity, and the maximum impacted area of RELTE show overall decreasing trends. Due to the contribution of RELTE, with long duratioh and large spatial range, which account for 10% of the total RELTE, there is a significant turning point in the late 1980s. A change to a much more steady state after the late 1990s is identified. In addition, the integrated indices of RELTE are classified and analyzed.
文摘Many techniques have been used in the courts to demonstrate the criticalities of a delay event on the project schedule. At this time, there is no standard method to analyze a delay claim. This paper first introduced a fictional case study that has most types of delay and acceleration events that might be faced on a real project. The case study is applied to all current techniques of delay claims that have been identified from previous studies. The comparison uses the delay claim issues as criteria to evaluate all the delay claim techniques from the case study results. The case study result and discussion demonstrate that the Day-by-Day technique satisfies all the desired criteria while other techniques lack some.
基金supported in part by National Natural Science Foundation of China(NSFC)under Grant No.61100228 and 61202479the National High-tech R&D Program of China under Grant No.2012AA013101+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences under Grant No.XDA06030601 and XDA06010701Open Found of Key Laboratory of IOT Application Technology of Universities in Yunnan Province Grant No.2015IOT03
文摘Recently,virtualization technologies have been widely used in industry.In order to monitor the security of target systems in virtualization environments,conventional methods usually put the security monitoring mechanism into the normal functionality of the target systems.However,these methods are either prone to be tempered by attackers or introduce considerable performance overhead for target systems.To address these problems,in this paper,we present a concurrent security monitoring method which decouples traditional serial mechanisms,including security event collector and analyzer,into two concurrent components.On one hand,we utilize the SIM framework to deploy the event collector into the target virtual machine.On the other hand,we combine the virtualization technology and multi-core technology to put the event analyzer into a trusted execution environment.To address the synchronization problem between these two concurrent components,we make use of Lamport's ring buffer algorithm.Based on the Xen hypervisor,we have implemented a prototype system named COMO.The experimental results show that COMO can monitor the security of the target virtual machine concurrently within a little performance overhead.
文摘Building construction site plays an important role in the economic aspect of a region. So any disruption due to hazard event like earthquake can cause several direct and indirect damages. Direct damages can lead to the loss of equipments and qualified persons. Indirect damages can lead to inflation and loss of purchasing power. To deal with that situation, parameters that govern the vulnerability of building construction site have been identified. Using a MCDM （multiple criteria decision making） method, the priority order of these parameters has been set. Then a PVI （partial vulnerability index） and a GVI （global vulnerability index） are proposed. These indexes allow the classification of building construction sites according to their intrinsic vulnerability and seismic vulnerability respectively that is through the use of a given classification. Several Algerian building construction sites belonging to different seismic zones were considered in order to show the applicability of the method.
基金sponsored by the National Natural Science Foundation of China(Grant No.41230420)the National Basic Research Program of China(Grant No.2012CB417404)
文摘Targeted observation is an observation strategy by which the concerned phenomenon is observed. In geoscienee, targeted ob- servation is mainly related to the forecasts of weather events or predictions of climate events. This paper will first review the history of targeted observation, and then introduce the main methods used in targeted observation. The discussion on the theo- retical basis of targeted observation includes its advantages and limitations. After presenting the current situation of domestic and international targeted observations in atmospheric and oceanic sciences, the methods used for targeted observation, and their effect evaluation and testing are mainly discussed here. Finally, the author presents his suggestion about the prospect of further development in the field, and how to extend the method of targeted observation to deal with numerical model errors.
