LNG冷能利用方案的本质安全性评价

为了获得本质安全性较高的LNG冷能利用方案,利用本质安全指标法评价了3个可选方案,根据评价结果对方案进行了优选。首先介绍了本质安全及典型的指标型本质安全评价方法,阐述了本质安全指标法的结构及其评分体系;应用本质安全指标法分别评价了LNG与空气换热,LNG与污氮换热,LNG与氮气、空气换热3个LNG冷能回收利用方案,得到它们的本质安全指标值分别为21,20,18;结果表明LNG与氮气、空气换热方案的本质安全指标值最低,即其本质安全性最高,主要原因是用氮气作中间介质能够消除潜在的LNG与空气、或污氮混合而引发爆炸的可能性;最后,确定该方案的本质安全性最佳,并给出了该方案的流程图。本研究改良了LNG冷能利用方案的本质安全性并对方案的优选提供了数据支持。     

基于蓝牙技术的智能车实时监测系统的研究

研究开发了以Freescale公司MC9S12DG128单片机为核心控制单元的智能车无线监测系统。系统主要由传感器模块、数据采集与处理模块、UART通讯模块、蓝牙通讯模块、上位机模块组成。详细介绍了以上4个模块的设计开发。经过测试表明,此系统工作稳定,对于摄像头图像的显示,速度曲线的绘制,PID参数修正等功能完全满足智能车调试的需求。     

ADAPTIVE RANKS CLONE AND k‐NEAREST NEIGHBOR LIST–BASED IMMUNE MULTI‐OBJECTIVE OPTIMIZATION

Artificial immune systems (AIS) are computational systems inspired by the principles and processes of the vertebrate immune system. The AIS‐based algorithms typically exploit the immune system's characteristics of learning and adaptability to solve some complicated problems. Although, several AIS‐based algorithms have proposed to solve multi‐objective optimization problems (MOPs), little focus have been placed on the issues that adaptively use the online discovered solutions. Here, we proposed an adaptive selection scheme and an adaptive ranks clone scheme by the online discovered solutions in different ranks. Accordingly, the dynamic information of the online antibody population is efficiently exploited, which is beneficial to the search process. Furthermore, it has been widely approved that one‐off deletion could not obtain excellent diversity in the final population; therefore, a k‐nearest neighbor list (where k is the number of objectives) is established and maintained to eliminate the solutions in the archive population. The k‐nearest neighbors of each antibody are founded and stored in a list memory. Once an antibody with minimal product of k‐nearest neighbors is deleted, the neighborhood relations of the remaining antibodies in the list memory are updated. Finally, the proposed algorithm is tested on 10 well‐known and frequently used multi‐objective problems and two many‐objective problems with 4, 6, and 8 objectives. Compared with five other state‐of‐the‐art multi‐objective algorithms, namely NSGA‐II, SPEA2, IBEA, HYPE, and NNIA, our method achieves comparable results in terms of convergence, diversity metrics, and computational time.     

雷达视频回波信号实时采集、压缩转发装置

介绍了一种基于FPGA和DSP的六通道雷达视频回波实时信号采集、压缩转发装置,该装置单通道采样率为20MSPS,采样精度为12bit,采集后的数据经过DSP压缩处理后再转化为2Mbps的PCM码流,实时发送给遥测发射机进行遥测下传和实时检测;并对相位一致性控制、基于流水线的数据处理方法等关键技术做了详细介绍;该装置已成功应用于某飞行器综合匹配试验,其性能和指标均优于应用要求。     

Stable local dimensionality reduction approaches

Dimensionality reduction is a big challenge in many areas. A large number of local approaches, stemming from statistics or geometry, have been developed. However, in practice these local approaches are often in lack of robustness, since in contrast to maximum variance unfolding (MVU), which explicitly unfolds the manifold, they merely characterize local geometry structure. Moreover, the eigenproblems that they encounter, are hard to solve. We propose a unified framework that explicitly unfolds the manifold and reformulate local approaches as the semi-definite programs instead of the above-mentioned eigenproblems. Three well-known algorithms, locally linear embedding (LLE), laplacian eigenmaps (LE) and local tangent space alignment (LTSA) are reinterpreted and improved within this framework. Several experiments are presented to demonstrate the potential of our framework and the improvements of these local algorithms.     

A decision support system for fisheries management using operations research and systems science approach

In this paper, we present a general framework, using a systems science approach, for developing a decision support system (DSS) for fisheries management. Decision support systems are quantitative tools for managers to evaluate outcomes of their policies prior to implementation. Our fishery model considers multiple stocks and fisheries simultaneously in balancing catch among targeted and protected fish abundances. Since in the Northeastern US multispecies fishery the distribution of abundance, catch-per-unit-effort and bycatch vary geographically, we focus on a spatial management approach to address their spatial variability. The core component of this DSS applies operations research techniques of simulation and optimization to determine the optimal inter-annual and intra-annual fishing plans in terms of fishing efforts in each sub-area and the time period. The result is the recommended amount to catch from each fish species at each sub-area at any time period so that while management objectives for sustainability of fish stocks are satisfied, the value of landings is maximized. The graphical user interface of the proposed DSS helps users to define inputs, to set constraints and sub-area boundaries, and to visualize the outcomes.     

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.     

智能磁致伸缩液位测量仪设计

针对当前液位测量监测系统中存在的多种问题,设计了一种高精度的智能磁致伸缩液位测量仪.系统采用ARM Cortex-M4系列的EK-TM4C1294NCPDTI芯片作为核心控制处理器,包含电源模块、时钟模块、激励信号模块、信号检测模块、以太网接口模块、故障报警模块、数据存储模块等.实现了测量精度高、稳定性好、人机交互友好,具有网络化通信功能的智能液位测量仪.     

基于混合聚类的城市道路多时段控制研究*

多方案控制具有简单实用、可靠性好,稳定性高,性价比高等的优点,在城市交通控制中得到了广泛应用。本研究在利用指数平滑异同移动平均法对缺失交通数据进行修补的基础上,运用快速聚类与系统聚类相结合的混合聚类方法对交通数据进行分析,并以经典的Silhouttte评价指标作为聚类终止条件,同时兼顾/考虑了交通数据时序性,消除聚类结果中的三类“奇异点”,最后利用交通信号配时软件SYNCHRO制定了相应时段的控制方案。相关的案例分析显示,优化后的多时段控制方案可以更好地适应交通流的波动,车均延误减少9.79%,其中时序性考虑可以有效改善控制方案频繁切换对交通流的扰动,避免其负效应对混合聚类改善效果的影响。