BACKGROUND： Recent researches demonstrate that damage of executive function is an early manifestation of vascular cognitive disorder. OBJECTIVE： To investigate the executive functions of patients with transient isch...BACKGROUND： Recent researches demonstrate that damage of executive function is an early manifestation of vascular cognitive disorder. OBJECTIVE： To investigate the executive functions of patients with transient ischemic attack （TIA）. DESIGN： Case control. SETTING： Department of Neurology, the First Affiliated Hospital of Xinxiang Medical College. PARTICIPANTS： A total of 83 TIA patients （46 males and 37 females, aged 32 - 74 years） were selected from Department of Neurology, the First Affiliated Hospital of Xinxiang Medical College from July 2005 to December 2006. The diagnosis of TIA was established by the criteria of cerebrovascular diseases made by the Fourth National Cerebrovascular Disease Meeting. In these cases, forty-five patients （54%） were involved in internal carotid artery, and thirty-eight patients （46%） were involved in vertebral basilar system. Fifty healthy adults （Control group： 28 males and 22 females, aged 32 - 74 years） were chosen from retiree in community and family of patients. All of them were right-handedness, without cerebrovascular disease, cerebral trauma, inborn oligophrenia, and heating and visual disorders; also they had no anxiety and depression nearly one week. In addition, all the subjects cooperated with examination. METHODS： After TIA diagnosis, all patients received neuropsychological examination, including attention and inhibition, working memory, flexibility, planning and diversion, based on Stroop tests （C and CW） and the Wisconsin card sorting tests （WCST）. ① WCST test： The edition revised by Nelson was used. We would take the times of sorting, incorrect response, persistent incorrect response, and randomly incorrect response as the index of evaluation.② Stroop tests： The edition revised by Trenarry was used and this test had two types： form color and form color-word. Their incorrect response and response time were recorded for data analysis in the end. MAIN OUTCOME MEASURES： Results of WCST test and Stroop tests. RESULTS： A total of 83 TIA patients and 50 healthy subjects were involved in the final analysis. Items of Stroop tests, including response time of Stroop-C test, incorrect response of Stroop-C test, response time of Stroop-CW test and incorrect response of Stroop-CW test, and items of WCST, including incorrect response, persistent incorrect response and random incorrect response, between internal carotid artery system and vertebral basilar artery system were （93.87±24.39） s, 3.16±3.97, （228.46±68.13） s, 12.91 ± 10.56, 55.42± 20.38, 26.58± 10.41, 28.62±11.22; （96.76±24.75） s, 3.89±4.77, （223.46±72.54） s, 18.71 ± 13.80, 52.47 ±22.25, 28.82± 16.20, 23.39±9.72, respectively; this was higher than those in the control group [（52.10± 12.18） s, 1.68± 1.97, （134.86±34.15） s, 4.22±4.21, 32.46± 17.97, 14.42±8.47, 18.24± 10.24, P 〈 0.05 - 0.01]. Times of sorting of WCST between internal carotid artery system and vertebral basilar artery system were obviously lower than those in the control group （8.27±2.73, 8.66±2.77, 11.22±2.41, P 〈 0.01）. However, there were no significant differences between internal carotid artery system and vertebral basilar artery system （P 〉 0.05）. CONCLUSION： Patients with TIA have executive dysfunctions, and the dysfunctions have no difference between internal carotid artery system and vertebral basilar artery system.展开更多
Abstract Accurate aerodynamic models are the basis of flight simulation and control law design. Mathematically modeling unsteady aerodynamics at high angles of attack bears great difficulties in model structure determ...Abstract Accurate aerodynamic models are the basis of flight simulation and control law design. Mathematically modeling unsteady aerodynamics at high angles of attack bears great difficulties in model structure determination and parameter estimation due to little understanding of the flow mechanism. Support vector machines （SVMs） based on statistical learning theory provide a novel tool for nonlinear system modeling. The work presented here examines the feasibility of applying SVMs to high angle.-of-attack unsteady aerodynamic modeling field. Mainly, after a review of SVMs, several issues associated with unsteady aerodynamic modeling by use of SVMs are discussed in detail, such as sele, ction of input variables, selection of output variables and determination of SVM parameters. The least squares SVM （LS-SVM） models are set up from certain dynamic wind tunnel test data of a delta wing and an aircraft configuration, and then used to predict the aerodynamic responses in other tests. The predictions are in good agreement with the test data, which indicates the satisfving learning and generalization performance of LS-SVMs.展开更多
Side channel attack may result in user key leakage as scan test techniques are applied for crypto-graphic chips. Many secure scan designs have been proposed to protect the user key. This paper meticulously selects thr...Side channel attack may result in user key leakage as scan test techniques are applied for crypto-graphic chips. Many secure scan designs have been proposed to protect the user key. This paper meticulously selects three current scan test techniques, analyses their advantages and disadvantages and also compares them in security and area overhead. Users can choose one of them according to the requirements and further combination can be implemented to achieve better performance.展开更多
The frequent attacks on network infrastructure, using various forms of denial of service attacks, have led to an increased need for developing new techniques for analyzing network traffic. If efficient analysis tools ...The frequent attacks on network infrastructure, using various forms of denial of service attacks, have led to an increased need for developing new techniques for analyzing network traffic. If efficient analysis tools were available, it could become possible to detect the attacks and to take action to weaken those attacks appropriately before they have had time to propagate across the network. In this paper, we propose an SNMP MIB oriented approach for detecting attacks, which is based on two-tier GCT by analyzing causal relationship between attacking variable at the attacker and abnormal variable at the target. According to the abnormal behavior at the target, GCT is executed initially to determine preliminary attacking variable, which has whole causality with abnormal variable in network behavior. Depending on behavior feature extracted from abnormal behavior, we can recognize attacking variable by using GCT again, which has local causality with abnormal variable in local behavior. Proactive detecting rules can be constructed with the causality between attacking variable and abnormal variable, which can be used to give alarms in network management system. The results of experiment showed that the approach with two-tier GCT was proved to detect attacks early, with which attack propagation could be slowed through early detection.展开更多
The number and creativity of side channel attacks have increased dramatically in recent years. Of particular interest are attacks leveraging power line communication to 1) gather information on power consumption from ...The number and creativity of side channel attacks have increased dramatically in recent years. Of particular interest are attacks leveraging power line communication to 1) gather information on power consumption from the victim and 2) exfiltrate data from compromised machines. Attack strategies of this nature on the greater power grid and building infrastructure levels have been shown to be a serious threat. This project further explores this concept of a novel attack vector by creating a new type of penetration testing tool: an USB power adapter capable of remote monitoring of device power consumption and communicating through powerline communications.展开更多
针对先进高性能飞行器对高精度大气数据的测控需求,研发设计了一套适用于亚声速飞行器的嵌入式大气数据传感(flush air data sensing,FADS)系统。该系统首先基于数值建模技术建立了FADS系统模型的压力数据库,并针对建模数据精度及风洞...针对先进高性能飞行器对高精度大气数据的测控需求,研发设计了一套适用于亚声速飞行器的嵌入式大气数据传感(flush air data sensing,FADS)系统。该系统首先基于数值建模技术建立了FADS系统模型的压力数据库,并针对建模数据精度及风洞试验校准数据分析了Ma=0.2~0.4对应的压力误差限;其次,开发了攻角实时解算算法,并集成到工程原理样机中;最后基于风洞试验和飞行试验对FADS系统的实时解算算法及样机进行了系统评估,并通过事后模型算法对攻角进行重新解算以评估攻角实时解算算法的可靠性。结果表明:(1)与机载惯性导航系统等其他独立测试系统解算的数据相比,飞行试验中FADS系统采用的攻角实时解算方法精度整体较好,攻角误差小于1°,在关键段小于0.5°;基于不同模型建立的FADS系统攻角解算方法得到的攻角数值基本一致,证实了开发的实时解算算法的可靠性。(2)基于风洞试验及飞行试验数据对算法误差限的考核结果显示,飞行试验初始阶段实时解算的攻角值产生波动是压力输入波动误差限较大造成的,高空低速时的压力波动幅值大是实时解算攻角值偏差较大的主要原因;建立的FADS系统的攻角解算方法在算法误差限范围内的压力波动对攻角解算值影响较小,但超过算法误差限的压力波动对攻角解算值影响显著。高空低速飞行器FADS系统对测压传感器精度水平及工程实施水平要求较高,在实际工程应用中应尽量保证测压传感器的精度水平。展开更多
针对亚声速飞行器对高精度飞行参数的测控需求,研发了一套亚声速嵌入式大气数据传感(flush air data sensing,FADS)系统,集成工程样机,并通过风洞试验及飞行试验进行系统考核评估。基于计算流体动力学(computational fluid dynamics,CFD...针对亚声速飞行器对高精度飞行参数的测控需求,研发了一套亚声速嵌入式大气数据传感(flush air data sensing,FADS)系统,集成工程样机,并通过风洞试验及飞行试验进行系统考核评估。基于计算流体动力学(computational fluid dynamics,CFD)方法首先建立FADS系统压力数据库,并通过风洞试验考核了模型算法在低亚声速时的误差限;其次,集成融合实时解算算法的FADS工程原理样机;最后通过飞行试验考核了工程样机的工程适用性。结果表明:(1)与机载的其他独立测试系统相比,FADS攻角实时解算精度高,攻角偏差≤1°,关键段攻角偏差≤0.5°;事后重建的攻角数据与飞行试验FADS系统实时解算数据一致,证实FADS实时攻角解算方法可靠;(2)风洞及飞行试验校核数据表明,FADS实时攻角输出数据在飞行试验初始段的波动是由输入压力波动较大导致,特别是在高空低速段,输入压力波动幅值超过算法的误差限,导致实时攻角解算数值波动较大;(3)CFD仿真结果表明,输入压力波动位于算法误差限内对攻角输出精度影响较小,超过算法误差限的压力幅值波动对实时攻角输出精度影响极大。高空低速飞行器FADS系统对压力传感器等硬件精度及工程实现水平要求较高,应尽量保证工程实施精度。展开更多
基金High-educational Talents Starting Foundation of Xinxiang Medical College
文摘BACKGROUND： Recent researches demonstrate that damage of executive function is an early manifestation of vascular cognitive disorder. OBJECTIVE： To investigate the executive functions of patients with transient ischemic attack （TIA）. DESIGN： Case control. SETTING： Department of Neurology, the First Affiliated Hospital of Xinxiang Medical College. PARTICIPANTS： A total of 83 TIA patients （46 males and 37 females, aged 32 - 74 years） were selected from Department of Neurology, the First Affiliated Hospital of Xinxiang Medical College from July 2005 to December 2006. The diagnosis of TIA was established by the criteria of cerebrovascular diseases made by the Fourth National Cerebrovascular Disease Meeting. In these cases, forty-five patients （54%） were involved in internal carotid artery, and thirty-eight patients （46%） were involved in vertebral basilar system. Fifty healthy adults （Control group： 28 males and 22 females, aged 32 - 74 years） were chosen from retiree in community and family of patients. All of them were right-handedness, without cerebrovascular disease, cerebral trauma, inborn oligophrenia, and heating and visual disorders; also they had no anxiety and depression nearly one week. In addition, all the subjects cooperated with examination. METHODS： After TIA diagnosis, all patients received neuropsychological examination, including attention and inhibition, working memory, flexibility, planning and diversion, based on Stroop tests （C and CW） and the Wisconsin card sorting tests （WCST）. ① WCST test： The edition revised by Nelson was used. We would take the times of sorting, incorrect response, persistent incorrect response, and randomly incorrect response as the index of evaluation.② Stroop tests： The edition revised by Trenarry was used and this test had two types： form color and form color-word. Their incorrect response and response time were recorded for data analysis in the end. MAIN OUTCOME MEASURES： Results of WCST test and Stroop tests. RESULTS： A total of 83 TIA patients and 50 healthy subjects were involved in the final analysis. Items of Stroop tests, including response time of Stroop-C test, incorrect response of Stroop-C test, response time of Stroop-CW test and incorrect response of Stroop-CW test, and items of WCST, including incorrect response, persistent incorrect response and random incorrect response, between internal carotid artery system and vertebral basilar artery system were （93.87±24.39） s, 3.16±3.97, （228.46±68.13） s, 12.91 ± 10.56, 55.42± 20.38, 26.58± 10.41, 28.62±11.22; （96.76±24.75） s, 3.89±4.77, （223.46±72.54） s, 18.71 ± 13.80, 52.47 ±22.25, 28.82± 16.20, 23.39±9.72, respectively; this was higher than those in the control group [（52.10± 12.18） s, 1.68± 1.97, （134.86±34.15） s, 4.22±4.21, 32.46± 17.97, 14.42±8.47, 18.24± 10.24, P 〈 0.05 - 0.01]. Times of sorting of WCST between internal carotid artery system and vertebral basilar artery system were obviously lower than those in the control group （8.27±2.73, 8.66±2.77, 11.22±2.41, P 〈 0.01）. However, there were no significant differences between internal carotid artery system and vertebral basilar artery system （P 〉 0.05）. CONCLUSION： Patients with TIA have executive dysfunctions, and the dysfunctions have no difference between internal carotid artery system and vertebral basilar artery system.
文摘Abstract Accurate aerodynamic models are the basis of flight simulation and control law design. Mathematically modeling unsteady aerodynamics at high angles of attack bears great difficulties in model structure determination and parameter estimation due to little understanding of the flow mechanism. Support vector machines （SVMs） based on statistical learning theory provide a novel tool for nonlinear system modeling. The work presented here examines the feasibility of applying SVMs to high angle.-of-attack unsteady aerodynamic modeling field. Mainly, after a review of SVMs, several issues associated with unsteady aerodynamic modeling by use of SVMs are discussed in detail, such as sele, ction of input variables, selection of output variables and determination of SVM parameters. The least squares SVM （LS-SVM） models are set up from certain dynamic wind tunnel test data of a delta wing and an aircraft configuration, and then used to predict the aerodynamic responses in other tests. The predictions are in good agreement with the test data, which indicates the satisfving learning and generalization performance of LS-SVMs.
文摘Side channel attack may result in user key leakage as scan test techniques are applied for crypto-graphic chips. Many secure scan designs have been proposed to protect the user key. This paper meticulously selects three current scan test techniques, analyses their advantages and disadvantages and also compares them in security and area overhead. Users can choose one of them according to the requirements and further combination can be implemented to achieve better performance.
文摘The frequent attacks on network infrastructure, using various forms of denial of service attacks, have led to an increased need for developing new techniques for analyzing network traffic. If efficient analysis tools were available, it could become possible to detect the attacks and to take action to weaken those attacks appropriately before they have had time to propagate across the network. In this paper, we propose an SNMP MIB oriented approach for detecting attacks, which is based on two-tier GCT by analyzing causal relationship between attacking variable at the attacker and abnormal variable at the target. According to the abnormal behavior at the target, GCT is executed initially to determine preliminary attacking variable, which has whole causality with abnormal variable in network behavior. Depending on behavior feature extracted from abnormal behavior, we can recognize attacking variable by using GCT again, which has local causality with abnormal variable in local behavior. Proactive detecting rules can be constructed with the causality between attacking variable and abnormal variable, which can be used to give alarms in network management system. The results of experiment showed that the approach with two-tier GCT was proved to detect attacks early, with which attack propagation could be slowed through early detection.
文摘The number and creativity of side channel attacks have increased dramatically in recent years. Of particular interest are attacks leveraging power line communication to 1) gather information on power consumption from the victim and 2) exfiltrate data from compromised machines. Attack strategies of this nature on the greater power grid and building infrastructure levels have been shown to be a serious threat. This project further explores this concept of a novel attack vector by creating a new type of penetration testing tool: an USB power adapter capable of remote monitoring of device power consumption and communicating through powerline communications.
文摘针对先进高性能飞行器对高精度大气数据的测控需求,研发设计了一套适用于亚声速飞行器的嵌入式大气数据传感(flush air data sensing,FADS)系统。该系统首先基于数值建模技术建立了FADS系统模型的压力数据库,并针对建模数据精度及风洞试验校准数据分析了Ma=0.2~0.4对应的压力误差限;其次,开发了攻角实时解算算法,并集成到工程原理样机中;最后基于风洞试验和飞行试验对FADS系统的实时解算算法及样机进行了系统评估,并通过事后模型算法对攻角进行重新解算以评估攻角实时解算算法的可靠性。结果表明:(1)与机载惯性导航系统等其他独立测试系统解算的数据相比,飞行试验中FADS系统采用的攻角实时解算方法精度整体较好,攻角误差小于1°,在关键段小于0.5°;基于不同模型建立的FADS系统攻角解算方法得到的攻角数值基本一致,证实了开发的实时解算算法的可靠性。(2)基于风洞试验及飞行试验数据对算法误差限的考核结果显示,飞行试验初始阶段实时解算的攻角值产生波动是压力输入波动误差限较大造成的,高空低速时的压力波动幅值大是实时解算攻角值偏差较大的主要原因;建立的FADS系统的攻角解算方法在算法误差限范围内的压力波动对攻角解算值影响较小,但超过算法误差限的压力波动对攻角解算值影响显著。高空低速飞行器FADS系统对测压传感器精度水平及工程实施水平要求较高,在实际工程应用中应尽量保证测压传感器的精度水平。
文摘针对亚声速飞行器对高精度飞行参数的测控需求,研发了一套亚声速嵌入式大气数据传感(flush air data sensing,FADS)系统,集成工程样机,并通过风洞试验及飞行试验进行系统考核评估。基于计算流体动力学(computational fluid dynamics,CFD)方法首先建立FADS系统压力数据库,并通过风洞试验考核了模型算法在低亚声速时的误差限;其次,集成融合实时解算算法的FADS工程原理样机;最后通过飞行试验考核了工程样机的工程适用性。结果表明:(1)与机载的其他独立测试系统相比,FADS攻角实时解算精度高,攻角偏差≤1°,关键段攻角偏差≤0.5°;事后重建的攻角数据与飞行试验FADS系统实时解算数据一致,证实FADS实时攻角解算方法可靠;(2)风洞及飞行试验校核数据表明,FADS实时攻角输出数据在飞行试验初始段的波动是由输入压力波动较大导致,特别是在高空低速段,输入压力波动幅值超过算法的误差限,导致实时攻角解算数值波动较大;(3)CFD仿真结果表明,输入压力波动位于算法误差限内对攻角输出精度影响较小,超过算法误差限的压力幅值波动对实时攻角输出精度影响极大。高空低速飞行器FADS系统对压力传感器等硬件精度及工程实现水平要求较高,应尽量保证工程实施精度。
