气相苯加氢低Ni/改性Al2O3催化剂性能评价

通过对γ－Ａｌ２Ｏ３载体进行化学改性处理,把Ｎｉ的含量降低（在５％以内）制得气相苯加氢低Ｎｉ／改性Ａｌ２Ｏ３催化剂。考察反应条件对其催化活性影响,并对催化剂的活性稳定性、耐热性、抗毒物能力进行评价。结果表明：该催化剂的性能良好     

多传感器多目标信号融合算法

多传感器信号融合是数据融合的一个重要方面,ＣｈａｉｒＺ．和ＶａｒｓｈｎｅｙＰ．Ｋ．在这个领域进行了深入研究,提出了基于贝叶斯推理的最佳融合规则,但该推理不能用于多目标的信号判定。推导了用于多目标信号融合的多传感器融合算法,该算法运用假设检验理论,充分考虑了位置数据互联的正确性和目标信号的历史信息,得出了一个可以递推计算的判定准则     

离散滑模变结构控制稳定性分析

对流行的离散变结构控制的两种方案——K.Furuta方案和Wang氏方案进行了研究,发现Wang氏方案中的稳定性定理不能成立,其证明不充分。并通过仿真,给出了反例。文章指出控制结构在A区和B区交替变换过程中,系统状态运动的一个循环过程所对应的转移矩阵A_i~*的谱半径小于1,系统才是渐近稳定的。     

舰船利用柴油机冷却水余热作吸收式制冷空调装置热源的研究

对某型舰利用６—１５０Ｃ柴油发电机冷却水余热作为低品位热源进行溴化锂吸收式制冷进行了热力计算和节能分析。计算及分析结果表明：利用６—１５０Ｃ柴油发电机组冷却水余热作为某型舰吸收式空调机组的热源是可行的,它不仅满足该型舰制冷量的要求,还具有明显的节能效果。     

布尔函数不交化的立方体算法

布尔函数的不交化是进行系统可靠度计算中的重要步骤。本文提出了一种进行布尔函数不交化的立方体算法。基于布尔函数的立方体表示法及不交代数,文中定义了立方体的有关运算法则,建立了立方体矩阵不交化算法,并用算例进行了说明。本算法的实现效率高,操作简便。     

Measuring the Impact of Military Spending: How Far Does a DSGE Model Deviate from Reality?

Dunne, Smith, and Willenbockel (2005) argue that the mainstream growth literature has not found military spending to be a significant determinant of economic growth, yet much of the defense economics literature has noted significant effects. This paper revisits this issue by using a DSGE-VAR approach, combining both theoretical and empirical methods. We present that the DSGE approach (estimated with the Bayesian technique) and the Bayesian VAR with the Minnesota Prior both lead to worse in-sample fit than our proposed DSGE-VAR framework. The DSGE-VAR approach reveals that a positive military spending shock boosts the U.S. economy, increasing per capita real GDP growth, consumption, inflation and interest rate. Our results are robust to alternative model specifications. Future investigations such as exploring an optimal military spending policy could adopt the approach in this paper to determine the best model – empirical, theoretical, or a combination of the two.     

液压驱动型四足机器人对角小跑步态本体水平位置控制方法

为了对对角小跑中四足机器人本体的水平位置进行控制,建立基于沿支撑线方向运动分解的机器人近似动力学模型,将本体和对角支撑腿简化为一个七连杆结构和一个线性倒立摆,并且基于线性倒立摆解析模型提出摆动腿落足点位置计算方法,进而实现对本体水平位置的控制。针对液压作动器伸缩速度受限的问题,利用单腿冗余关节将关节角速度优化问题转化为标准二次型规划问题,通过设计二次型规划问题解法,降低对摆动腿关节角速度的需求,并且避免了传统伪逆方法可能产生的腿部奇异位型。仿真和实验结果表明:该方法能够实现在关节角速度受限的情况下,有效跟踪本体水平位置的期望轨迹。     

Comparison of rank aggregation methods based on inherent ability

Ranking is a common task for selecting and evaluating alternatives. In the past few decades, combining rankings results from various sources into a consensus ranking has become an increasingly active research topic. In this study, we focus on the evaluation of rank aggregation methods. We first develop an experimental data generation method, which can provide ground truth ranking for alternatives based on their “inherent ability.” This experimental data generation method can generate the required individual synthetic rankings with adjustable accuracy and length. We propose characterizing the effectiveness of rank aggregation methods by calculating the Kendall tau distance between the aggregated ranking and the ground truth ranking. We then compare four classical rank aggregation methods and present some useful findings on the relative performances of the four methods. The results reveal that both the accuracy and length of individual rankings have a remarkable effect on the comparison results between rank aggregation methods. Our methods and results may be helpful to both researchers and decision‐makers.     

基于脉冲块追赶的双基地雷达空间同步技术

为解决脉冲追赶技术在双基地雷达空间同步上的应用问题,提出了一种基于脉冲块追赶的双基地雷达空间同步技术,推导了脉冲块追赶时间表的计算公式,提出了以接收机波束形成速率为标准的工程可实现性分析方法,并对脉冲块追赶下的接收波束宽度和波束形成速率进行了仿真分析。仿真结果表明,在相同的双基距离积下,减小发射波束宽度、基线距离、发射脉冲宽度以及增大脉冲块长度可以降低对接收机波束形成的要求,便于工程实现。     

数字化单兵系统作战效能评估

分析了新型数字化单兵系统的功能特点,建立了数字化单兵系统作战效能评估的指标体系,提出一致性排序法与模糊综合评价法相结合的评估方法,采用一致性排序法确定了指标权重,运用模糊综合评价理论对系统效能进行了评估,为数字化单兵系统的应用实践和功能改进提供了理论支持。