舰艇作战指挥决策模型可信度评估流程分析

舰艇作战指挥决策模型的可信度是一项复杂的系统工程,而评估流程又是这项工程的基础性工作,直接影响到可信度评估的成败。运用了评估学的基本理论对舰艇作战指挥决策模型可信度评估流程进行分析,将可信度评估分为三个阶段,即评估准备阶段、评估实施阶段和评估总结阶段,研究和阐述了这三个阶段的具体工作、要求和标准等,最后,建立了专家评审流程图、可信度评估指标体系以及用于可信度评估指标的数据采集表,分析对比了数据处理方法的优缺点。     

联合作战目标协同模型构建与求解方法?

在对联合作战目标协同研究内容分析的基础上,提出了多任务部队与多作战目标的协同目标分配模型,其融合了目标综合价值、目标打击有效性、目标威胁适配度、目标类型匹配、目标距离匹配等因素。通过对各因素量化并将协同目标分配模型转换为指派问题进行求解,验证了分析方法的可行性。     

The impact of Syrian refugees on the labor market in neighboring countries: empirical evidence from Jordan

This paper analyzes time-sensitive data on a humanitarian crisis in the Middle East. It aims to assess the impact of the steep influx of Syrian refugees into Jordan on the country’s labor market since the onset of the conflict in Syria (March 2011). As of August 2014, nearly three million registered Syrians have sought refuge in neighboring countries (Lebanon, Jordan, Iraq, and Turkey), according to the United Nations High Commissioner for Refugees. Jordan and Lebanon are hosting the majority of them. This paper utilizes data regarding unemployment rates, employment rates, labor force participation, the number of refugees, and economic activity at the level of governorates. The vector autoregressive methodology is used to examine time series data from the most affected governorates in Jordan. The empirical results of Granger causality tests and impulse response functions show that there is no relationship between the influx of Syrian refugees and the Jordanian labor market. Our results are verified through a set of robustness checks.     

几类基本学习认知模型

本文给出了几个类型的学习认知模型,并加以讨论     

攻防对抗中弹道仿真的设计与实现

在攻防对抗仿真试验中,为了验证导弹性能、分析导弹战术指标,需要进行导弹群复杂环境下的弹道仿真试验,这给仿真实现带来了一定的困难。针对这一困难,在详细分析了六自由度下的弹道仿真的复杂情况的基础上,利用分布式计算的原理和标准,探讨了分布式仿真在导弹群复杂环境下弹道仿真中的应用方法及实现途径。     

车辆碰撞检测的仿真

为了提高车辆驾驶仿真的可信性,本文采用物体外部轮廓近似投影法,建立了车辆碰撞检测的一种简化数学模型,并进行了仿真验证。结果表明本模型具有简单和计算快捷的特点,能满足车辆碰撞检测的仿真要求。该模型已得到实际应用。     

Numerical modelling of non-ideal detonation in ANFO explosives applying Wood-Kirkwood theory coupled with EXPLO5 thermochemical code

Ammonium nitrate and fuel oil (ANFO) based explosive is a classic example of non-ideal high explosives. Its detonation is characterized by a strong dependence of detonation parameters on explosive charge diameter, presence and characteristics of confinement, as well as incomplete consumption of explosive at the sonic point.In this work we propose a detonation model based on the Wood-Kirkwood (WK) theory coupled with the thermochemical code EXPLO5 and supplemented with reaction rate models. Our objective is to analyze the validity of the model for highly non-ideal ANFO explosives, with emphasis on effect of reaction rate models.It was found that both single-step and two-step pressure-based models can be calibrated to reproduce experimental detonation velocity-charge radius data of ANFO at radii significantly above the failure radius (i.e. for D/D_id > ∼0.6). Single-step pressure-based model, with the pressure exponent equal to 1.4, proved to be the most accurate, even in the vicinity of the failure radius. The impact of the rate models is most evident on temporal (and spatial) distribution of flow parameters in detonation driving zone, especially when it comes to the conversion and width of detonation driving zone.     

Transverse relaxation characteristic and stress relaxation model considering molecular chains of HTPB coating based on pre-strained thermal aging

In order to accurately describe the transverse relaxation characteristic and stress relaxation modulus of HTPB coating during pre-strain thermal aging process, a one month thermal aging test was carried out at 70 C with pre-strain of 0％, 3％, 6％ and 9％, respectively. The low-field 1H NMR and stress relaxation modulus tests were carried out for HTPB coating at different aging stages. The stress relaxation model considering the molecular chains was proposed according to the changes of crosslinking chain and dangling chain of HTPB coating during pre-strain aging. The results showed that with the increase of aging time, the decay rate of transverse relaxation curve became faster, the transverse relaxation time decreased, the value of combined parameter qMrl increased, the proportion of crosslinking chain decreased, while the proportion of dangling chain increased. Moreover, the stress relaxation modulus increased, the crosslinking network structure of HTPB coating became denser and the degree of cross-linking increased. At the initial aging stage, the pre-strain will destroy the crosslinking network structure of HTPB coating to a certain extent. With the increase of aging time, the effect of pre-strain will gradually weaken and the influence of aging on materials will gradually increase. The correlations between the stress relaxation model considering the molecular chains and the test results were more than 0.9950, which can accurately describe the stress relaxation modulus of HTPB coating during the pre-strain thermal aging process.     

Robust shortest path planning and semicontractive dynamic programming

In this article, we consider shortest path problems in a directed graph where the transitions between nodes are subject to uncertainty. We use a minimax formulation, where the objective is to guarantee that a special destination state is reached with a minimum cost path under the worst possible instance of the uncertainty. Problems of this type arise, among others, in planning and pursuit‐evasion contexts, and in model predictive control. Our analysis makes use of the recently developed theory of abstract semicontractive dynamic programming models. We investigate questions of existence and uniqueness of solution of the optimality equation, existence of optimal paths, and the validity of various algorithms patterned after the classical methods of value and policy iteration, as well as a Dijkstra‐like algorithm for problems with nonnegative arc lengths.© 2016 Wiley Periodicals, Inc. Naval Research Logistics 66:15–37, 2019