Passive localization by a single moving observer using TOA only with unknown SRI: Observability analysis and algorithm

Passive localization by a single moving observer using Time of Arrival (TOA) only with an unknown Signal Repetition Interval (SRI) is investigated in this paper. Observability analysis is performed first. The observability condition for uniquely determining the emitter position and SRI is derived. The conditional Cramer-Rao Lower Bound (CRLB) is also analyzed. It is found that the ambiguity of the SRI integer of the first TOA does not affect the theoretical estimation precision of the emitter position and SRI. A Reference-Fixed Differential TOA (RFDTOA)-based Iterative Maximum Likelihood Estimator (IMLE) is proposed, which only needs O(M) computational operations. Theoretical analysis and simulation results show that the Mean Square Error (MSE) of the proposed algorithm could attain the CRLB with moderate Gaussian measurement noise.     

One-dimensional numerical investigation on multi-cylinder gasoline engine fueled by micro-emulsions,CNG, and hydrogen in dual fuel mode

This research work is the novel state-of-the-art technology performed on multi-cylinder SI engine fueled compressed natural gas, emulsified fuel, and hydrogen as dual fuel. This work predicts the overall features of performance, combustion, and exhaust emissions of individual fuels based on AVL Boost simulation technology. Three types of alternative fuels have been compared and analyzed. The results show that hydrogen produces 20% more brake power than CNG and 25% more power than micro-emulsion fuel at 1500 r/min, which further increases the brake power of hydrogen, CNG, and micro-emulsions in the range of 25%, 20%, and 15% at higher engine speeds of 2500–4000 r/min, respectively. In addition, the brake-specific fuel consumption is the lowest for 100% hydrogen, followed by CNG 100% and then micro-emulsions at 1500 r/min. At 2500–5000 r/min, there is a significant drop in brake-specific fuel consumption due to a lean mixture at higher engine speeds. The CO, HC, and NO_x emissions significantly improve for hydrogen, CNG, and micro-emulsion fuel. Hydrogen fuel shows zero CO and HC emissions and is the main objective of this research to produce 0% carbon-based emissions with a slight increase in NO_x emissions, and CNG shows 30% lower CO emissions than micro-emulsions and 21.5% less hydrocarbon emissions than micro-emulsion fuel at stoichiometric air/fuel ratio.     

Collaborative image compression and classification with multi-task learning for visual Internet of Things

Widespread deployment of the Internet of Things(Io T) has changed the way that network services are developed, deployed, and operated. Most onboard advanced Io T devices are equipped with visual sensors that form the so-called visual Io T. Typically, the sender would compress images, and then through the communication network, the receiver would decode images, and then analyze the images for applications. However, image compression and semantic inference are generally conducted separately, and t...     

SAR performance-based fault diagnosis for electro-hydraulic control system: A novel FDI framework for closed-loop system

Model-based fault diagnosis serves as an efficient and powerful technique in addressing fault detection and isolation (FDI) issues for control systems. However, the standard methods and their modifications still encounter some difficulties in algorithm design and application for complex higher-order systems. To avoid these difficulties, a novel fault diagnosis framework based on multiple performance indicators of closed-loop control system is proposed. Under this framework, a so-called performance residual vector is constructed to measure the differences between the real system and the nominal model in terms of system stability, accuracy, and rapidity (SAR) respectively. The criteria for quantification, normalization of the SAR residuals and the explicit mappings between the thresholds and the required performance are given. FDI can be easily achieved simultaneously by monitoring the normalized residual vector length and direction in the SAR performance residual space. A case study on electro-hydraulic servo control system of turbofan engine is adopted to demonstrate the effectiveness of the proposed method.     

带连续爆震加力燃烧室的涡轮发动机循环及推进性能研究

为进一步提升现有涡轮喷气发动机推进性能,可以采用连续爆震加力燃烧室,针对此,本文首先建立考虑了三种耦合热力过程的连续爆震燃烧室热力过程分析模型,通过与传统涡轮发动机性能分析模型相耦合,分析了带连续爆震加力燃烧的涡轮发动机推进性能及加力燃烧室部件特性。结果表明,由于连续爆震燃烧室具有自增压特性,当将其替代传统加力燃烧室可以显著提升加力时涡轮发动机性能;但另一方面,作为加力燃烧室,由于涡轮后气流温度过高,导致连续爆震加力燃烧室增压比的降低,通过对发动机循环参数的选择可以得到改善;同时,连续爆震加力燃烧室部件特性还受到燃烧室进气损失、反应物填充速度及反应物提前燃烧比例影响。     

ADS数据的处理和显示

基于航空卫星通信的飞行监视,即自动相关监视（ADS）,是航空卫星移动业务（AMSS）通信应用新领域,是建立在航空卫星通信基础上的一种新的飞行监视技术。该文介绍了基本ADS报告信息电文的组成及各部分的含义,着重阐述将所收到的ADS数据进行处理,并以直观易懂的表格及图象形式显示出来,便于确切地知道飞机的四维位置（纬度、经度、高度和时间）。     

现代对策论研究

对策论是研究斗争局势中冲突问题的数学理论,笔者长期以来在此领域进行了大量的研究探讨,本文概要介绍了主要工作。     

小功率单轴燃气轮机及其功热并供装置变工况典型解析特性

采用动力机械变工况特性解析分析方法［１,２］,分析总结了使用离心式压气机的小功率单轴恒速燃气轮机稳态变工况的典型特性及一些定量规律。所得燃气轮机装置典型效率曲线及统计公式得到了实际数据的验证。计算了该种燃气轮机功热并供装置用饱和蒸汽供热时的典型情况及其他一些变工况性能,如大气温度的影响等     

INTEGRATED GPS/INS OF PSEUDO-RANGE DELTA-RANGE SEMI-PHYSICAL SIMULATION'S RESEARCH

In order to further study the performance of tightly integrated navigation system of GPS/INS, a semi-physical simulation of tightly coupled system has been done based on the data gathered from the experiment of integrated system of GPS and INS. The closed-loop Kalman Filter and U-D discompose algorithm have been used. The simulation results associated to four integrated models of pseudo-range, delta-range, pseudo-range and delta-range alternation, and pseudo-range and delta-range synthesis have been provided, and the actual effects of variously integrated models have been analyzed. The results show that the pseudo-range and delta-range synthesis coupled model is the most effective to improve the coupled system performance and the individual delta-range coupled model had better be avoided in application.     

一个DIS实时通讯网络的设计与实现

以一个ＤＩＳ（分布交互仿真）实时网络的设计和开发过程为背景,研究了ＤＩＳ实时网络开发中的几个问题。在进行实时ＤＩＳ网络规划时,采用了多点传送的通讯服务方式,保证每个仿真应用只发送变化的信息,只处理与自身相关的信息。指出了进行数据的实时传输格式定义时应注意的几个问题,这些数据定义必须支持多种不同的操作系统和平台。最后给出了开发ＤＩＳ实时通讯软件的方法,包括通讯协议和应用编程接口的选择。