OpenMP compiler for distributed memory architectures

OpenMP is an emerging industry standard for shared memory architectures. While OpenMP has advantages on its ease of use and incremental programming, message passing is today still the most widely-used programming model for distributed memory architectures. How to effectively extend OpenMP to distributed memory architectures has been a hot spot. This paper proposes an OpenMP system, called KLCoMP, for distributed memory architectures. Based on the partially replicating shared arrays memory model, we propose ...     

Impacts of geographical knowledge, spatial ability and environmental cognition on image searches supported by GIS software

Google Earth search function was used to study the impacts of small-scale spatial ability, large-scale environmental cognition, and geographical knowledge on new technology usage. The participants were 153 junior high students from central Taiwan. Geography grades served as indicators of prior knowledge, mental rotation and abstract reasoning skills as indicators of spatial ability, and sketch maps of school neighborhoods as indicators of environmental cognition (including landmark representation, intersection representation, and frame of reference). Lastly, the authors announced the landmarks searching worksheet and asked the participants to accomplish 16 familiar and unfamiliar landmark searching tasks using Google Earth with keyword search function disabled. The result showed the strongest predictor of landmark searching performance is ‘frame of reference’ in environmental cognition, followed by ‘mental rotation’ of spatial ability, ‘landmark representation’ of environmental cognition, and geographical knowledge. Google Earth landmark searches require complex cognitive processing; therefore, our conclusion is that GIS-supported image search activities give students good practice of active knowledge construction.     

小缓存高速网络的拥塞控制算法

传统高带宽拥塞控制算法不适用于小缓存高速网络。针对该问题提出端算法与中间节点结合的拥塞控制算法,根据缓存区占用大小调整调节因子a、保障因子c,自适应增加或减少窗口大小。实验结果表明,该算法可以在小缓存高速网络中实现高带宽利用率、快速收敛和不同RTT流的公平性。     

基于RT-Ethernet的井下防越级系统仿真研究

针对目前煤矿井下供电系统越级跳闸问题,搭建基于实时以太网的井下电网防越级系统,该系统以安装有TwinCAT软件的工业PC作为主站,以PLC控制器作为从站.主站完成对从站PLC控制器的配置,从站之间利用上下级闭锁的方式实现防越级功能.通过模拟井下供电网络短路故障,研究井下电网防越级功能的实现及RT-Ethernet的通信实时性.试验结果表明,在发生短路故障时,该系统能够快速准确地切除井下电网中的故障线路,实现防越级功能.     

高速电磁阀的动态特性

高速电磁阀是重要的液压执行元件,因此其响应速度尤为重要.首先分析高速电磁阀的原理结构,再对电学、磁学、运动学进行建模,研究不同参数下系统的响应速度与时间的关系.研究结果表明:采用的控制变量仿真法可以清晰地看出不同参数对系统动态参数的影响,其中起励电压、线圈匝数与占空比对响应的影响比较明显,为项目研究提供参考.     

Variability in decision-making and critical cue use by different road users at rail level crossings

Collisions at rail level crossings (RLXs) are typically high-severity and high-cost, often involving serious injuries, fatalities and major disruptions to the transport network. Most research examining behaviour at RLXs has focused exclusively on drivers and consequently there is little knowledge on how other road users make decisions at RLXs. We collected drivers’, motorcyclists’, bicyclists’ and pedestrians’ self-reported daily experiences at RLXs for two weeks, focusing on behaviour, decision-making and information use in the presence of a train and/or activated RLX signals. Both information use and behaviour differed between road users. Visual information (e.g. flashing lights) was more influential for motorists, whereas pedestrians and cyclists relied more on auditory information (e.g. bells). Pedestrians were also more likely to violate active RLX warnings and/or cross before an approaching train. These results emphasise the importance of adopting holistic RLX design approaches that support cognition and behaviour across for all road users.

Practitioner Summary: This study explores how information use and decision-making at rail level crossings (RLXs) differ between road user groups, using a two-week self-report study. Most users make safe decisions, but pedestrians are most likely to violate RLX warnings. Information use (visual vs. auditory) also differs substantially between road user groups.     

Continuous output‐feedback control for a class of switched high‐order planar systems and its application

This paper deals with the problem of continuous output‐feedback stabilization for a class of switched high‐order planar systems under arbitrary switchings. Based on the common Lyapunov function design method, by using the adding a power integrator technique and designing an implementable observer, a continuous output‐feedback controller is constructed such that the closed‐loop system is global stabilization and the output can be regulated to the origin. As an application, the developed strategy is utilized to the control design for the continuous stirred tank reactor with two modes feed stream. The simulation results verify the efficiency of the proposed design scheme. Copyright © 2017 John Wiley & Sons, Ltd.     

A small‐area and low‐power data driver IC using two‐stage DAC with a capacitor array for active matrix flat‐panel displays

A small‐area and low‐power data driver integrated circuit (IC) using a two‐stage digital‐to‐analog converter (DAC) with a capacitor array is proposed for active matrix flat‐panel displays. The proposed data driver IC employs a capacitor array in the two‐stage DAC so as to reduce the DAC area and eliminate the need for a resistor string, which has high‐power consumption. To verify the proposed two‐stage DAC, a 20‐channel data driver IC with the proposed 10‐bit two‐stage DAC was fabricated using a 0.18‐μm complementary metal–oxide–semiconductor process with 1.8 and 6 V complementary metal–oxide–semiconductor devices. The proposed 10‐bit two‐stage DAC occupies only 43.8% of the area of a conventional 10‐bit two‐stage DAC. The measurement results show that the differential nonlinearity and integral nonlinearity are +0.58/?0.52 least significant bit and +0.62/?0.59 least significant bit, respectively. The measured interchannel deviation of the voltage outputs is 8.8 mV, and the measured power consumption of the 20‐channel data driver IC is reduced to 7.1 mW, which is less than half of the power consumed by the conventional one.     

Development of active matrix LCD for use in high‐resolution adaptive headlights

Conventional adaptive driving beam headlamps are limited in achieving still higher quantities of switchable pixels by the number of LEDs and movable elements needed. In this paper, it is shown that by integrating an active matrix liquid crystal display module, it is possible to realize fully adaptive high‐resolution headlights without mechanical elements and a finite number of LED with 30 k switchable pixels.     

小型高分辨率中阶梯光栅光谱仪光学设计

为了克服传统光栅光谱仪小体积与高分辨率无法共存的缺点,提出一种以中阶梯光栅为核心色散元件、反射棱镜为辅助色散元件的光谱仪光学设计方法.具体分析了中阶梯光栅的基本原理,从光路设计和元件参数设计两方面进行仪器光学设计,最后设计了一个焦距为150 mm、光谱范围为200 nm～600 nm、理论光谱分辨能力为0.1 nm的中阶梯光栅光谱仪,仿真和实验表明,设计的光谱仪在Hg灯253.652 nm处光谱分辨能力为0.023 9 nm,在Hg灯546.074 nm处光谱分辨能力为0.061 nm,满足设计指标要求.