为了更好地满足云计算中用户的服务质量(quality of service,QoS)需求,合理利用云数据中心的资源,以任务的执行时间和虚拟机的负载均衡作为优化的目标对象,提出了一种基于烟花算法(fireworks algorithm,FWA)的多目标优化调度模型。烟花...为了更好地满足云计算中用户的服务质量(quality of service,QoS)需求,合理利用云数据中心的资源,以任务的执行时间和虚拟机的负载均衡作为优化的目标对象,提出了一种基于烟花算法(fireworks algorithm,FWA)的多目标优化调度模型。烟花算法是一种启发式算法,利用爆炸算子、高斯变异和选择策略能较快地寻找到全局最优解。通过在Cloudsim上与粒子群优化算法(PSO)和遗传算法(GA)进行有效性和执行时间上的对比,结果表明烟花算法在不同实验次数下可持续得到最优适应度值,而且在种群规模不断扩大时,烟花算法的执行时间没有陡然增加,明显优于PSO算法和GA算法。展开更多
目的了解学龄前儿童日常身体活动现状,进一步研究身体活动与执行功能之间的相关性。方法2018年5-7月在北京地区抽取3家幼儿园,采用方便抽样方法抽取中班儿童201人,连续3d佩戴加速度计ActiGraph GT9X,采用早期儿童执行功能测量工具包(Ear...目的了解学龄前儿童日常身体活动现状,进一步研究身体活动与执行功能之间的相关性。方法2018年5-7月在北京地区抽取3家幼儿园,采用方便抽样方法抽取中班儿童201人,连续3d佩戴加速度计ActiGraph GT9X,采用早期儿童执行功能测量工具包(Early Years Toolbox,EYT)进行工作记忆、抑制控制和转换三项执行功能测试,采用自编问卷调查受试儿童的屏幕时间。结果学龄前儿童每日中高强度身体活动、总身体活动时间分别为(95.65±29.02)min、(204.58±46.91)min,男女之间每日轻度、中度、剧烈、中高强度以及总身体活动时间存在差异(U=2593.00,2136.00,2440.00,t=4.09,3.68,P<0.05)。每日屏幕时间为(72.84±51.79)min,男女之间差异无统计学意义(P>0.05)。工作记忆、抑制控制、转换三项执行功能测试得分依次是2.40±0.80、0.76±0.16、14.08±3.49,男女之间差异无统计学意义(P>0.05)。身体活动与EYT测试得分相关性分析发现在4岁组儿童中针对转换的测试得分与每日高强度身体活动时间存在显著相关性(r=0.199,P=0.040)。进一步以屏幕时间、每日总身体活动时间,每日中高强度身体活动时间达标与否进行分组,未发现各组间EYT测试得分差异有统计学意义(P>0.05)。结论学龄前儿童存在身体活动不足的状况,身体活动和执行功能之间存在相关性,且这种相关性与身体活动的强度有关。展开更多
Purpose: Although exercise and sleep duration habits are associated with cognitive function, their beneficial effects on cognitive function remain unclear. We aimed to examine the effect of sleep duration and daily ph...Purpose: Although exercise and sleep duration habits are associated with cognitive function, their beneficial effects on cognitive function remain unclear. We aimed to examine the effect of sleep duration and daily physical activity on cognitive function, elucidating the neural mechanisms using near-infrared spectroscopy(NIRS).Methods: A total of 23 healthy young adults(age 22.0 ± 2.2 years) participated in this study. Exercise amount was assessed using a uniaxial accelerometer. We evaluated total sleep time(TST) and sleep efficiency by actigraphy. Cognitive function was tested using the N-back task, the Wisconsin Card Sorting Test(WCST), and the Continuous Performance Test—Identical Pairs(CPT-IP), and the cortical oxygenated hemoglobin levels during a word fluency task were measured with NIRS.Results: Exercise amount was significantly correlated with reaction time on 0- and 1-back tasks(r = —0.602, p = 0.002; r = —0.446, p = 0.033,respectively), whereas TST was significantly correlated with % corrects on the 2-back task(r = 0.486, p = 0.019). Multiple regression analysis,including exercise amount, TST, and sleep efficiency, revealed that exercise amount was the most significant factor for reaction time on 0- and 1-back tasks(b = —0.634, p = 0.002; b = —0.454, p = 0.031, respectively), and TST was the most significant factor for % corrects on the 2-back task(b = 0.542, p = 0.014). The parameter measured by WCST and CPT-IP was not significantly correlated with TST or exercise amount. Exercise amount, but not TST, was significantly correlated with the mean area under the NIRS curve in the prefrontal area(r = 0.492, p = 0.017).Conclusion: Exercise amount and TST had differential effects on working memory and cortical activation in the prefrontal area. Daily physical activity and appropriate sleep duration may play an important role in working memory.展开更多
In many real-time resource-constrained embedded systems, highly-predictable system behavior is a key design requirement. The “time-triggered co-operative” (TTC) scheduling algorithm provides a good match for a wide ...In many real-time resource-constrained embedded systems, highly-predictable system behavior is a key design requirement. The “time-triggered co-operative” (TTC) scheduling algorithm provides a good match for a wide range of low-cost embedded applications. As a consequence of the resource, timing, and power constraints, the implementation of such algorithm is often far from trivial. Thus, basic implementation of TTC algorithm can result in excessive levels of task jitter which may jeopardize the predictability of many time-critical applications using this algorithm. This paper discusses the main sources of jitter in earlier TTC implementations and develops two alternative implementations – based on the employment of “sandwich delay” (SD) mechanisms – to reduce task jitter in TTC system significantly. In addition to jitter levels at task release times, we also assess the CPU, memory and power requirements involved in practical implementations of the proposed schedulers. The paper concludes that the TTC scheduler implementation using “multiple timer interrupt” (MTI) technique achieves better performance in terms of timing behavior and resource utilization as opposed to the other implementation which is based on a simple SD mechanism. Use of MTI technique is also found to provide a simple solution to “task overrun” problem which may degrade the performance of many TTC systems.展开更多
Consensus of creativity research suggests that the measurement of both originality and valuableness is necessary when designing creativity tasks.However,few studies have emphasized valuableness when exploring underlyi...Consensus of creativity research suggests that the measurement of both originality and valuableness is necessary when designing creativity tasks.However,few studies have emphasized valuableness when exploring underlying neural substrates of creative thinking.The present study employs product-based creativity tasks that measure both originality and valuableness in an exploration of the dynamic relationship between the default mode(DMN),executive control(ECN),and salience(SN)networks through time windows.This methodology highlights relevance,or valuableness,in creativity evaluation as opposed to divergent thinking tasks solely measuring originality.The researchers identified seven brain regions belonging to the ECN,DMN,and SN as regions of interest(ROIs),as well as four representative seeds to analyze functional connectivity in 25 college student participants.Results showed that all of the identified ROIs were involved during the creative task.The insula,precuneus,and ventrolateral prefrontal cortex(vlPFC)remained active across all stages of product-based creative thinking.Moreover,the connectivity analyses revealed varied interaction patterns of DMN,ECN,and SN at different thinking stages.The integrated findings of the whole brain,ROI,and connectivity analyses suggest a trend that the DMN and SN(which relate to bottom-up thinking)attenuate as time proceeds,whereas the vlPFC(which relates to top-down thinking)gets stronger at later stages;these findings reflect the nature of our creativity tasks and decision-making of valuableness in later stages.Based on brain region activation throughout execution of the task,we propose that product-based creative process may include three stages:exploration and association,incubation and insight,and finally,evaluation and decision making.This model provides a thinking frame for further research and classroom instruction.展开更多
OSEK/VDX(open systems and the corresponding interfaces for automobile electronic/vehicle distributed execu-tive)OS规范描述了一个嵌入式实时操作系统,对系统服务调用的上下文做了严格的限制。违反系统服务调用规范是一种很隐...OSEK/VDX(open systems and the corresponding interfaces for automobile electronic/vehicle distributed execu-tive)OS规范描述了一个嵌入式实时操作系统,对系统服务调用的上下文做了严格的限制。违反系统服务调用规范是一种很隐蔽的错误,不会被编译器发现。提出一种OSEK/VDX OS系统服务调用规范一致性的检测方法,利用森林图描述用户自定义代码中的函数及其调用关系,采用矩阵描述OSEK/VDX OS系统服务调用的规则,遍历该森林图的函数调用路径,对于每条路径,结合该规则矩阵判断其规范一致性。实验和分析表明该方法能有效地检测用户自定义代码中隐藏的违反OSEK/VDX OS系统服务调用规范的错误。展开更多
文摘为了更好地满足云计算中用户的服务质量(quality of service,QoS)需求,合理利用云数据中心的资源,以任务的执行时间和虚拟机的负载均衡作为优化的目标对象,提出了一种基于烟花算法(fireworks algorithm,FWA)的多目标优化调度模型。烟花算法是一种启发式算法,利用爆炸算子、高斯变异和选择策略能较快地寻找到全局最优解。通过在Cloudsim上与粒子群优化算法(PSO)和遗传算法(GA)进行有效性和执行时间上的对比,结果表明烟花算法在不同实验次数下可持续得到最优适应度值,而且在种群规模不断扩大时,烟花算法的执行时间没有陡然增加,明显优于PSO算法和GA算法。
文摘目的了解学龄前儿童日常身体活动现状,进一步研究身体活动与执行功能之间的相关性。方法2018年5-7月在北京地区抽取3家幼儿园,采用方便抽样方法抽取中班儿童201人,连续3d佩戴加速度计ActiGraph GT9X,采用早期儿童执行功能测量工具包(Early Years Toolbox,EYT)进行工作记忆、抑制控制和转换三项执行功能测试,采用自编问卷调查受试儿童的屏幕时间。结果学龄前儿童每日中高强度身体活动、总身体活动时间分别为(95.65±29.02)min、(204.58±46.91)min,男女之间每日轻度、中度、剧烈、中高强度以及总身体活动时间存在差异(U=2593.00,2136.00,2440.00,t=4.09,3.68,P<0.05)。每日屏幕时间为(72.84±51.79)min,男女之间差异无统计学意义(P>0.05)。工作记忆、抑制控制、转换三项执行功能测试得分依次是2.40±0.80、0.76±0.16、14.08±3.49,男女之间差异无统计学意义(P>0.05)。身体活动与EYT测试得分相关性分析发现在4岁组儿童中针对转换的测试得分与每日高强度身体活动时间存在显著相关性(r=0.199,P=0.040)。进一步以屏幕时间、每日总身体活动时间,每日中高强度身体活动时间达标与否进行分组,未发现各组间EYT测试得分差异有统计学意义(P>0.05)。结论学龄前儿童存在身体活动不足的状况,身体活动和执行功能之间存在相关性,且这种相关性与身体活动的强度有关。
基金supported by the Japan Society for the Promotion of Science, KAKENHI (25282210,15H05935)by Grants-in-Aid from the Comprehensive Research on Disability Health and Welfare+3 种基金the Ministry of Health,Labor and Welfare of Japanthe Academic Frontier Project for Private UniversitiesComparative Cognitive Science InstitutesMeijo University
文摘Purpose: Although exercise and sleep duration habits are associated with cognitive function, their beneficial effects on cognitive function remain unclear. We aimed to examine the effect of sleep duration and daily physical activity on cognitive function, elucidating the neural mechanisms using near-infrared spectroscopy(NIRS).Methods: A total of 23 healthy young adults(age 22.0 ± 2.2 years) participated in this study. Exercise amount was assessed using a uniaxial accelerometer. We evaluated total sleep time(TST) and sleep efficiency by actigraphy. Cognitive function was tested using the N-back task, the Wisconsin Card Sorting Test(WCST), and the Continuous Performance Test—Identical Pairs(CPT-IP), and the cortical oxygenated hemoglobin levels during a word fluency task were measured with NIRS.Results: Exercise amount was significantly correlated with reaction time on 0- and 1-back tasks(r = —0.602, p = 0.002; r = —0.446, p = 0.033,respectively), whereas TST was significantly correlated with % corrects on the 2-back task(r = 0.486, p = 0.019). Multiple regression analysis,including exercise amount, TST, and sleep efficiency, revealed that exercise amount was the most significant factor for reaction time on 0- and 1-back tasks(b = —0.634, p = 0.002; b = —0.454, p = 0.031, respectively), and TST was the most significant factor for % corrects on the 2-back task(b = 0.542, p = 0.014). The parameter measured by WCST and CPT-IP was not significantly correlated with TST or exercise amount. Exercise amount, but not TST, was significantly correlated with the mean area under the NIRS curve in the prefrontal area(r = 0.492, p = 0.017).Conclusion: Exercise amount and TST had differential effects on working memory and cortical activation in the prefrontal area. Daily physical activity and appropriate sleep duration may play an important role in working memory.
文摘In many real-time resource-constrained embedded systems, highly-predictable system behavior is a key design requirement. The “time-triggered co-operative” (TTC) scheduling algorithm provides a good match for a wide range of low-cost embedded applications. As a consequence of the resource, timing, and power constraints, the implementation of such algorithm is often far from trivial. Thus, basic implementation of TTC algorithm can result in excessive levels of task jitter which may jeopardize the predictability of many time-critical applications using this algorithm. This paper discusses the main sources of jitter in earlier TTC implementations and develops two alternative implementations – based on the employment of “sandwich delay” (SD) mechanisms – to reduce task jitter in TTC system significantly. In addition to jitter levels at task release times, we also assess the CPU, memory and power requirements involved in practical implementations of the proposed schedulers. The paper concludes that the TTC scheduler implementation using “multiple timer interrupt” (MTI) technique achieves better performance in terms of timing behavior and resource utilization as opposed to the other implementation which is based on a simple SD mechanism. Use of MTI technique is also found to provide a simple solution to “task overrun” problem which may degrade the performance of many TTC systems.
文摘Consensus of creativity research suggests that the measurement of both originality and valuableness is necessary when designing creativity tasks.However,few studies have emphasized valuableness when exploring underlying neural substrates of creative thinking.The present study employs product-based creativity tasks that measure both originality and valuableness in an exploration of the dynamic relationship between the default mode(DMN),executive control(ECN),and salience(SN)networks through time windows.This methodology highlights relevance,or valuableness,in creativity evaluation as opposed to divergent thinking tasks solely measuring originality.The researchers identified seven brain regions belonging to the ECN,DMN,and SN as regions of interest(ROIs),as well as four representative seeds to analyze functional connectivity in 25 college student participants.Results showed that all of the identified ROIs were involved during the creative task.The insula,precuneus,and ventrolateral prefrontal cortex(vlPFC)remained active across all stages of product-based creative thinking.Moreover,the connectivity analyses revealed varied interaction patterns of DMN,ECN,and SN at different thinking stages.The integrated findings of the whole brain,ROI,and connectivity analyses suggest a trend that the DMN and SN(which relate to bottom-up thinking)attenuate as time proceeds,whereas the vlPFC(which relates to top-down thinking)gets stronger at later stages;these findings reflect the nature of our creativity tasks and decision-making of valuableness in later stages.Based on brain region activation throughout execution of the task,we propose that product-based creative process may include three stages:exploration and association,incubation and insight,and finally,evaluation and decision making.This model provides a thinking frame for further research and classroom instruction.
文摘OSEK/VDX(open systems and the corresponding interfaces for automobile electronic/vehicle distributed execu-tive)OS规范描述了一个嵌入式实时操作系统,对系统服务调用的上下文做了严格的限制。违反系统服务调用规范是一种很隐蔽的错误,不会被编译器发现。提出一种OSEK/VDX OS系统服务调用规范一致性的检测方法,利用森林图描述用户自定义代码中的函数及其调用关系,采用矩阵描述OSEK/VDX OS系统服务调用的规则,遍历该森林图的函数调用路径,对于每条路径,结合该规则矩阵判断其规范一致性。实验和分析表明该方法能有效地检测用户自定义代码中隐藏的违反OSEK/VDX OS系统服务调用规范的错误。
