To explore the feasibility of the full automatic animal experimental cabin to establish the animal models in normobaric/hypobaric hypoxic and high carbon dioxide environment. Methods： Sixty SPF-class male DS rats wer...To explore the feasibility of the full automatic animal experimental cabin to establish the animal models in normobaric/hypobaric hypoxic and high carbon dioxide environment. Methods： Sixty SPF-class male DS rats were divided into 2 groups, 20 for normobaric, hypoxic conditions and the other 40 for hypobaric, hypoxic conditions. For each group, the pulmonary arterial pressure and carotid arterial pressure indicators of rats were examined by using the physiological multi-detector, and the pulmonary vascular changes in the structure were observed. Results： The normobaric/hypobaric hypoxic with high carbon dioxide environment can promote the formation of pulmonary hypertension and accelerate changes in pulmonary vascular remodeling, and promote the right ventricular hypertrophy. Conclusion： Clinical applications showed that the animal experimental cabin has observed and controlled accurately. The result was safe, reliable and reproducible. The cabin can successfully establish the pulmonary hypertension model in normobaric/hypobaric hypoxic with high carbon dioxide environment, and in order to study the physiological mechanism of a variety of circulation and respiratory diseases caused by lack of oxygen, which provided an experimental technology platform for clinical research.展开更多
For program behavior-based anomaly detection, the only way to ensure accurate monitoring is to construct an efficient and precise program behavior model. A new program behavior-based anomaly detection model, called co...For program behavior-based anomaly detection, the only way to ensure accurate monitoring is to construct an efficient and precise program behavior model. A new program behavior-based anomaly detection model, called combined pushdown automaton (CPDA) model was proposed, which is based on static binary executable analysis. The CPDA model incorporates the optimized call stack walk and code instrumentation technique to gain complete context information. Thereby the proposed method can detect more attacks, while retaining good performance.展开更多
The paper presents an improved cellular automaton model according to the feature of evacuation near the outlet. We studied friction and turning factors that affect pedestrian evacuation speed. By using mathematical me...The paper presents an improved cellular automaton model according to the feature of evacuation near the outlet. We studied friction and turning factors that affect pedestrian evacuation speed. By using mathematical methods to derive expressions of friction function and turning function. The average pedestrian outflow of the simulation that includes the effect of both the frictional function and the turning function agrees well with experiment result. On the contrary, the simulation results that only include the effect of the frictional function are not corresponding to the experiment results well. Simulation results show that friction and turning can not be ignored. By analyzing the simulation results, it verified that the model can accurately reflect the actual evacuation process and has practical value.展开更多
Like other optical astrometric techniques,the Photographic Zenith Tube(PZT) has played a key role in the past observations of the Earth rotation,and it also has a potential to be applied to several other observations ...Like other optical astrometric techniques,the Photographic Zenith Tube(PZT) has played a key role in the past observations of the Earth rotation,and it also has a potential to be applied to several other observations by taking advantage of automatic observations with self compensation of tilt of the tube.We here propose In-situ Lunar Orientation Measurement(ILOM) to study lunar rotational dynamics by direct observations of the lunar rotation from the lunar surface by using a small telescope like PZT with an accuracy of 1 milli-seconds of arc(1 mas) in the post-SELENE mission.Our second application is to obtain local gravity field on the Earth by combining deflection of the vertical measured by PZT and the position measured by Global Positioning System(GPS) or Global Navigation Satellite System(GNSS).The accuracy required for this purpose is not as strict as ILOM.We have already developed a Bread Board Model(BBM) of the telescope for ILOM and made some experiments in order to know the performance of the driving mechanism under a similar condition to the lunar environment showing high vacuum,large temperature change and dusty condition.We have also shown that it is possible to correct the effects of uniform temperature change upon the optical system by using a simple model with an accuracy of better than 1 mas.This model has the potential to attain the accuracy of 1 mas,based on the results of the experiments and the simulations.展开更多
In order to satisfy the safety-critical requirements,the train control system(TCS) often employs a layered safety communication protocol to provide reliable services.However,both description and verification of the sa...In order to satisfy the safety-critical requirements,the train control system(TCS) often employs a layered safety communication protocol to provide reliable services.However,both description and verification of the safety protocols may be formidable due to the system complexity.In this paper,interface automata(IA) are used to describe the safety service interface behaviors of safety communication protocol.A formal verification method is proposed to describe the safety communication protocols using IA and translate IA model into PROMELA model so that the protocols can be verified by the model checker SPIN.A case study of using this method to describe and verify a safety communication protocol is included.The verification results illustrate that the proposed method is effective to describe the safety protocols and verify deadlocks,livelocks and several mandatory consistency properties.A prototype of safety protocols is also developed based on the presented formally verifying method.展开更多
文摘To explore the feasibility of the full automatic animal experimental cabin to establish the animal models in normobaric/hypobaric hypoxic and high carbon dioxide environment. Methods： Sixty SPF-class male DS rats were divided into 2 groups, 20 for normobaric, hypoxic conditions and the other 40 for hypobaric, hypoxic conditions. For each group, the pulmonary arterial pressure and carotid arterial pressure indicators of rats were examined by using the physiological multi-detector, and the pulmonary vascular changes in the structure were observed. Results： The normobaric/hypobaric hypoxic with high carbon dioxide environment can promote the formation of pulmonary hypertension and accelerate changes in pulmonary vascular remodeling, and promote the right ventricular hypertrophy. Conclusion： Clinical applications showed that the animal experimental cabin has observed and controlled accurately. The result was safe, reliable and reproducible. The cabin can successfully establish the pulmonary hypertension model in normobaric/hypobaric hypoxic with high carbon dioxide environment, and in order to study the physiological mechanism of a variety of circulation and respiratory diseases caused by lack of oxygen, which provided an experimental technology platform for clinical research.
文摘For program behavior-based anomaly detection, the only way to ensure accurate monitoring is to construct an efficient and precise program behavior model. A new program behavior-based anomaly detection model, called combined pushdown automaton (CPDA) model was proposed, which is based on static binary executable analysis. The CPDA model incorporates the optimized call stack walk and code instrumentation technique to gain complete context information. Thereby the proposed method can detect more attacks, while retaining good performance.
文摘The paper presents an improved cellular automaton model according to the feature of evacuation near the outlet. We studied friction and turning factors that affect pedestrian evacuation speed. By using mathematical methods to derive expressions of friction function and turning function. The average pedestrian outflow of the simulation that includes the effect of both the frictional function and the turning function agrees well with experiment result. On the contrary, the simulation results that only include the effect of the frictional function are not corresponding to the experiment results well. Simulation results show that friction and turning can not be ignored. By analyzing the simulation results, it verified that the model can accurately reflect the actual evacuation process and has practical value.
基金supported by the Advanced Technology Center (Grant No. 2009-101)supported by the National Natural Science Foundation of China (Grant No. 10973031)+1 种基金Chinese National High-Tech Project (Grant No. 2009AA122206)the Grant-in-Aid for Scientific Research (B) (Grant No. 22340128)
文摘Like other optical astrometric techniques,the Photographic Zenith Tube(PZT) has played a key role in the past observations of the Earth rotation,and it also has a potential to be applied to several other observations by taking advantage of automatic observations with self compensation of tilt of the tube.We here propose In-situ Lunar Orientation Measurement(ILOM) to study lunar rotational dynamics by direct observations of the lunar rotation from the lunar surface by using a small telescope like PZT with an accuracy of 1 milli-seconds of arc(1 mas) in the post-SELENE mission.Our second application is to obtain local gravity field on the Earth by combining deflection of the vertical measured by PZT and the position measured by Global Positioning System(GPS) or Global Navigation Satellite System(GNSS).The accuracy required for this purpose is not as strict as ILOM.We have already developed a Bread Board Model(BBM) of the telescope for ILOM and made some experiments in order to know the performance of the driving mechanism under a similar condition to the lunar environment showing high vacuum,large temperature change and dusty condition.We have also shown that it is possible to correct the effects of uniform temperature change upon the optical system by using a simple model with an accuracy of better than 1 mas.This model has the potential to attain the accuracy of 1 mas,based on the results of the experiments and the simulations.
基金supported by the New Century Excellent Researcher Award Program from Ministry of Education of China (Grant No. NCET-07-0059)the Fundamental Research Funds for the Central Universities (Grant No.2011YJS006)+1 种基金the National High Technology Research and DevelopmentProgram of China ("863" Program) (Grant No. 2011AA010104)the State Key Laboratory of Rail Traffic Control and Safety Research Project(Grant Nos. RCS2008ZZ001, RCS2008ZZ005)
文摘In order to satisfy the safety-critical requirements,the train control system(TCS) often employs a layered safety communication protocol to provide reliable services.However,both description and verification of the safety protocols may be formidable due to the system complexity.In this paper,interface automata(IA) are used to describe the safety service interface behaviors of safety communication protocol.A formal verification method is proposed to describe the safety communication protocols using IA and translate IA model into PROMELA model so that the protocols can be verified by the model checker SPIN.A case study of using this method to describe and verify a safety communication protocol is included.The verification results illustrate that the proposed method is effective to describe the safety protocols and verify deadlocks,livelocks and several mandatory consistency properties.A prototype of safety protocols is also developed based on the presented formally verifying method.
