旋流环形堰竖井泄洪洞三维流场数值模拟

旋流环形堰竖井泄洪洞是一种新型的环境友好的内消能工, 跟传统环形堰竖井泄洪洞相比, 泄洪洞的流态和 消能防蚀机理明显不同。作为一种新型布置形式, 其复杂的水流特性并不是十分清楚。依托于广东清远抽水蓄能 电站下水库泄洪洞工程, 基于RNG k2E双方程湍流数学模型, 并结合VOF( Volume Of Fluid) 方法, 对下库旋流环形 堰竖井泄洪洞进水口、竖井旋流泄洪洞、出口的复杂水流进行了三维数值模拟, 并对部分水力参数的特性进行了解 析计算, 获得了流态、压力、流速、空化数等水力要素的变化规律。模拟结果表明, 数值计算结果与物理模型试验成 果吻合较好。并通过数值模拟验证了该新型内消能工的泄流能力和高消能效率。     

Tracking and grasping of moving target based on accelerated geometric particle filter on colored image

Visual tracking and grasping of moving object is a challenging task in the field of robotic manipulation, which also has great potential in applications such as human-robot collaboration. Based on the particle filtering framework and position-based visual servoing, this paper proposes a new method for visual tracking and grasping of randomly moving objects. A geometric particle filter tracker is established for visual tracking. In order to deal with the tracking efficiency issue for particle filter, edge detection and morphological dilation are employed to reduce the computation burden of geometric particle filtering. Meanwhile, the HSV image feature is employed instead of the grayscale feature to improve the tracking algorithm's robustness to illumination change.A grasping strategy combining tracking and interception is adopted along with the position-based visual servoing(PBVS)method to achieve stable grasp of the target. Comprehensive comparisons on open source dataset and a large number of experiments on real robot system are conducted, which demonstrate the proposed method has competitive performance in random moving object tracking and grasping.     

铁路能源统计管理信息系统的分析与设计

本文分析了铁路能源统计管理信息系统，介绍了系统设计思想和技术要点，以及开发过程中的心得体会。     

飞机BIT与ATE的综合设计技术研究

测试性／机内测试（BIT）对现代武器装备特别是作战飞机的可用性有着重大的影响。具有良好测试性的系统和设备，可以及时、快速地发现并准确地隔离其存在的故障，提高系统的任务可靠性及安全性。随着航空技术不断发展，特别是具有综合化航空电子系统、数字电传操纵系统的飞机的出现，机载嵌入式计算机和电子设备的使用目益增多，功能更为复杂，导致对设备维修性、测试性要求越来越高。第三代飞机的电子系统和非电系统都采用了大量的机内测试（BIT）设计，外场的大量故障由BIT检测，大大减少了外场地面保障设备的数量，缩短了外场排除故障和维修时间，提高了飞机的可用性。     

Comparing logic coverage criteria on test case prioritization

Logic coverage criteria have been widely used in the testing of safety-critical software.In the past few years,fault-based logic coverage criteria have been studied intensively both in theory and in practice.However,there is a lack of authentic evidence of the comparison of fault-based logic coverage criteria with other logic coverage criteria,such as branch coverage and modified condition/decision coverage(MC/DC).In this paper,we present a comprehensive empirical study that compares these logic coverage criteria on test case prioritization,which is currently a hot topic in software testing.Several useful conclusions are drawn from our research:(1) Fine-grained coverage criteria are always more effective and efficient.(2) The effectiveness of fault-based logic coverage criteria is not significantly different from that of MC/DC in terms of statistics,but the former is more stable.(3) A random strategy is more effective than branch coverage if a certain number of test cases are redundant.     

基于0.5谐次扭振的内燃机故障诊断研究

依据内燃机轴系测点扭振与各缸激振力矩的关系式,利用0．5谐次扭振的幅值与相位特性,进行内燃机各缸作功状态监测和拉缸故障诊断。以6135柴油机为对象的应用研究验证利用0．5谐次扭振确定故障阈值方法的实用性和诊断准确性。对6240柴油机的实例分析表明,不仅可以利用0．5谐次扭振相位角准确判断出内燃机拉缸缸号,还可利用其幅值反映拉缸故障程度。因此,利用0．5谐次扭振对内燃机进行一级诊断和三级诊断具有较强的工程应用价值。