信号交叉口行人相位配时方法

以信号交叉口行人相位配时为研究对象,针对信号交叉口行人和机动车对配时要求不一致以及我国行人相位清空时间不足的问题,借鉴HCM中行人绿灯最小时间和行人闪时间的计算公式,利用交通流理论,分析了行人相位和机动车相位关系,并建立了不同情况下行人信号配时方法,尤其是行人绿灯时间的调整方法.讨论了不同中央分隔带形式和宽度的行人过街方式,对计算参数的取值进行了研究,在此基础上,给出了不同情况下建议的行人配时计算模型.     

一种单点多相公交信号优先控制策略

为满足交叉口短时间内多个方向有公交车到达时的信号优先需求,提出了一种单点多相公交信号优先策略.针对不同相位公交优先申请间的冲突,提出了“就近原则”以合理安排各公交车的优先级别并确定最佳优先顺序.为避免出现过饱和现象,提出了一种有限优先策略,即在各相位饱和度不超过0.95的情况下,采用绿灯延长、绿灯提前启亮给予具有最高优...     

Effects of reinforcer delay and variability in a successive-encounters procedure

Pigeons responded in a successive-encounters procedure that consisted of a search period, a choice period, and a handling period. The search period was either a fixed-interval or a mixed-interval schedule presented on the center key of a three-key chamber. Upon completion of the search period, the center key was turned off and the two side keys were lit. A pigeon could either accept a delay followed by food (by pecking the right key) or reject this option and return to the search period (by pecking the left key). During the choice period, a red right key represented the long alternative (a long handling delay followed by food), and a green right key represented the short alternative (a short handling delay followed by food). The experiment consisted of a series of comparisons for which optimal diet theory predicted no changes in preference for the long alternative (because the overall rates of reinforcement were unchanged), whereas the hyperbolic-decay model predicted changes in preference (because the delays to the next possible reinforcer were varied). In all comparisons, the results supported the predictions of the hyperbolic-decay model, which states that the value of a reinforcer is inversely related to the delay between a choice response and reinforcer delivery.     

交叉口多相位信号设置及通行能力研究(英文)

采用停车线法建立了多相位信号交叉口通行能力模型,并对直行车道和左转车道均为一条以及直行车道为2条而左转车道为一条这2种常见状态下建立的模型进行了简化,结果表明信号交叉口通行能力主要和信号周期长度、相位配置、交叉口几何设计和车辆跟车时距等因素有关.考虑车辆到达率时的信号周期长度和相位配时设置问题,建立了基于各相位剩余时间均衡的优化模型,并采用拉格朗日乘子法对优化模型进行求解,从而确定出信号周期最佳时长以及各相位时长的计算模型,并对模型进行了简化.所建立周期和相位时长的计算模型较现有的模型更简便实用.最后,选取了一个实际的交叉口,用所建立的模型对其周期和相位时长进行了设计.     

信号交叉口行人穿越时间模型研究

为了研究信号交叉口行人穿越时间的特性规律,应用间隙理论和实际观测数据,建立了行人穿越的概率统计模型．进而建立了3种不同穿越条件下行人穿越数的估算模型．在此基础上,构建了行人平均过街时间模型、第85分位行人过街时间模型和第90分位行人过街时间模型．采用定量分析和模型实证分析方法,发现行人穿越的主要影响因素有：人行过街横道长度、车头时距小于临界间隙的概率以及交叉口内的转弯车辆数．结果表明模型估计误差均小于5％．     

带孔洞立体截交线和相贯线的“分部作图法”

受组合体读图的形体分析法启发,提出求解带孔洞立体截交线和相贯线的分部作图法,将带孔洞立体分为外部形体和内部孔洞两部分,分别求出其截交线或者相贯线,然后再对外部形体和内部孔洞的轮廓线进行整理,并结合4个例子详细介绍了作图过程.     

Abel范畴子对象的交在radical中的两个应用

首先讨论了Abel范畴中子对象的交与商对象之间的关系,而后利用子对象的交与和,给出Abel范畴子对象radical的另一等价刻画以及计算商对象的rdical的公式．     

Plotting intersections along the political axis: The interior voice of dissenting mathematics teachers

The supposed apolitical nature of mathematics is an institutional frame that functions to sustain specific power structures within schools. This paper disrupts the common assumption that mathematics (as a body of knowledge constructed in situated historical moments)is free from entrenched ideological motives. Using narrative inquiry, the paper examines the ways in which novice mathematics teachers negotiate the intersection of curriculum and institutional politics. After outlining a theoretical framework, the paper performs a story entitled ‘political text’ which reveals the plaintive, dissenting voice of a novice teacher as she negotiates the friction between her life history and the ossified canonicity of mathematics curriculum. Through the critical and reflexive voice of the novice teacher, the naturalized concepts of counting and measurement are playfully revisioned. The frequent silencing of such oppositional readings underscores the deeply embedded conflict between voice and text in the contemporary mathematics classroom.     

一类非线性时滞差分方程的振动性

考虑非线性时滞差分方程xn+1=xnexp[rn（1-xn-k）]n=0,1,2,…;x-k,…,x-1≥0,x0>0其中|rn|是非负实数列,k是正整数,本文获得了方程的每个正解关于正平衡点振动的充分条件.     

Children's perception of gap affordances: bicycling across traffic-filled intersections in an immersive virtual environment

This study examined gap choices and crossing behavior in children and adults using an immersive, interactive bicycling simulator. Ten- and 12-year-olds and adults rode a bicycle mounted on a stationary trainer through a virtual environment consisting of a street with 6 intersections. Participants faced continuous cross traffic traveling at 25 mph or 35 mph and waited for gaps they judged were adequate for crossing. Children and adults chose the same size temporal gaps, but children left far less time to spare between themselves and the approaching vehicle when they crossed the intersection. Relative to adults, children delayed in getting started and took longer to reach the roadway. Discussion focuses on developmental changes in how children coordinate self movement with object movement.     

Origins of language delay in abused infants

This paper presents a reanalysis of data collected in a study of abusing mother-infant pairs, emphasizing the failure of infants with a history of physical abuse to develop appropriate language skills. Bayley Mental Development indices of abused infants decreased with age. This decrease was attributable largely to the failure of abused infants to pass verbal items. None of the abused children had any verbal communication skills. Results are discussed in relation to patterns of maternal ignoring and lack of verbal stimulation.     

Stability analysis of CPLL with loop delay

In this paper,a discrete-time analysis of the third-order charge-pump based phase-locked loops (CPLLs) is presented in the presence of loop delay.The z-domain analysis of the closed-loop transfer function is derived and compared with the traditional s-domain method.The simulation results under SPECTRE show that,due to the sampling nature of CPLL,the traditional s-domain analysis is unable to predict its jitter peaking accurately,especially when the loop delay is taken into consideration.The impact of loop delay on the stability of the third-order CPLL system is further analyzed based on the proposed way.The stability limit of the wide bandwidth CPLL with loop delay is calculated.The circuit simulation results agree well with mathematical analysis.     

午时太阳位置分析

分析正午时太阳在天空中的方位,利用太阳周日运动轨迹及太阳与本地法线的相对位置变化来判断午时太阳的准确位置.最终得出太阳午时位于正南或正北.     

讨论一类有状态依赖时滞和连续时滞积分微分方程系统正周期解的存在性

利用重合度理论讨论了一类状态依赖时滞和连续时滞积分方程所描述的多物种生态竞争系统正周期解的存在性,得到了保证周期解存在的充分性条件.     

Effects of CS preexposure on inhibition of delay

Two experiments examined the effects of preexposure to a stimulus on the subsequent acquisition of conditioned suppression by rats. Variations in the level of suppression within conditioning trials were noted so thatinhibition of delay (taken here to mean less suppression at the beginning of a trial than at the end) could be detected. Inhibition of delay was observed both during the acquisition of suppression and (in Experiment 1) when suppression began to wane with continued postasymptotic training. Preexposure to the to-be-conditioned stimulus retarded acquisition of suppression and slowed the appearance of inhibition of delay both in acquisition and (in Experiment 1) in postasymptotic performance. Experiment 2 demonstrated that inhibition of delay was attenuated during conditioning that followed preexposure in which the stimulus was paired with a weak reinforcer. These results provide no support for the suggestion that preexposure to a stimulus retards later conditioning because it allows the subject to acquire information about stimulus duration that in turn fosters the development of inhibition of delay. Rather, they are compatible with the suggestion that preexposure causes the stimulus to lose associability.     

带有随机延滞的GARCH模型的几何遍历性

在非线性时间序列的基础上,建立了延滞是有限状态空间上马尔可夫链的GARCH模型.在新的模型中考虑了环境对延滞的影响.带有随机延滞的GARCH模型有更好的应用价值.     

高校档案工作滞后的主要成因与对策刍议

当前,高校档案工作与高等教育事业发展和高校整体实力的提升不同步、不协调.高等教育管理体制改革和高校大规模扩招以来,我国的高等教育事业实现了跨越式发展,高校整体发展水平也有了较大幅度的提升,但相比之下,高校档案工作的发展却步履缓慢、基础薄弱.文章就影响当前高校档案工作滞后的原因作一些初浅的分析.     

Simultaneous and successive contrast with delay of reward

In Experiment I, rats showed no evidence of a successive negative contrast effect (NCE) when shifted from immediate reward to a 15-sec delay of reward. Experiment II provided a direct comparison of NCE in both successive and simultaneous paradigms. As in Experiment I, there was no evidence of a successive NCE, but a reliable simultaneous NCE was observed. These results add support for the view that simultaneous and successive NCEs are not due to a single, common process.