Sensors’ optimal dimensionality compression matrix in estimation fusion

When there exists the limitation of communication bandwidth between sensors and a fusion center, one needs to optimally pre-compress sensor outputs–sensor observations or estimates before sensors’ transmission to obtain a constrained optimal estimation at the fusion center in terms of the linear minimum error variance criterion. This paper will give an analytic solution of the optimal linear dimensionality compression matrix for the single sensor case and analyze the existence of the optimal linear dimensionality compression matrix for the multisensor case, as well as how to implement a Gauss–Seidel algorithm to search for an optimal solution to linear dimensionality compression matrix.     

基于网络环境下的图书编目问题及对策

本文结合本馆编目工作实际,总结和分析了编目工作中存在的一些问题,并针对这些问题,提出了相应的改进措施与对策,从而逐步提高编目工作的质量。     

表面活性剂对烷氧基硅烷类混凝土防水剂性能的影响研究

介绍了混凝土表面用有机硅保护剂的研制思路,并根据表面活性剂的亲水亲油平衡值(HLB)及其配合比筛选出了有效的表面活性剂组合,研究了不同表面活性剂组合对烷氧基硅烷类混凝土防水保护剂的稳定性、渗透深度及防水性等性能的影响。     

地下煤制气制取液化天然气和液氢工艺研究

目的脱除地下煤制气中的酸气,将地下煤制气中的CH₄和H₂分离出来并液化。 方法对常见的分离方法进行对比,确定采用低温精馏法对煤制气进行脱酸气、分离CH₄和H₂并液化。根据低温精馏法的原理,设计了一种全新的地下煤制气脱酸气、分离CH₄和H₂并液化的工艺流程,该工艺主要由两个精馏塔、一个两相分离器和三级氦膨胀制冷系统组成。同时利用HYSYS软件对其进行模拟分析,确定最优参数。 结果该工艺可以将地下煤制气中CO₂的摩尔分数脱除到0,H₂S的摩尔分数脱除到3.65×10-14,满足处理要求。同时可以实现CH₄回收率为99.97%,加压液化天然气(PLNG)的摩尔分数为99.97%,H₂的回收率为98.30%,液氢(LH₂)的摩尔分数为99.99%。 结论该工艺可以有效利用地下煤制气制取PLNG和LH₂,且所需能耗较传统工艺能耗降低了11.64％,具有较高的经济效益。      

Globally Optimal Distributed Kalman Fusion With Local Out-of-Sequence-Measurement Updates

In a distributed multisensor fusion systems, observations produced by sensors can arrive at local processors out of sequence. The resulting problem at the central processor/fusion center-how to update current estimate using multiple local out-of-sequence-measurement (OOSM) updates - is a nonstandard distributed estimation problem. In this note, based on the centralized update algorithm with multiple asynchronous (1-step-lag) OOSMs see we firstly deduce the optimal distributed fusion update algorithm with multiple local asynchronous (1-step-lag) OOSM updates, which is proved, under some regularity conditions, to be equivalent to the corresponding optimal centralized update algorithm with all-sensor 1-step-lag OOSMs. Then, we propose an optimal distributed fusion update algorithm with multiple local arbitrary-step-lag OOSM updates.     

Using artificial intelligence technology to fight COVID-19: a review

In late December 2019, a new type of coronavirus was discovered, which was later named severe acute respiratory syndrome coronavirus 2(SARS-CoV-2). Since its discovery, the virus has spread globally, with 2,975,875 deaths as of 15 April 2021, and has had a huge impact on our health systems and economy. How to suppress the continued spread of new coronary pneumonia is the main task of many scientists and researchers. The introduction of artificial intelligence technology has provided a huge contribution to the suppression of the new coronavirus. This article discusses the main application of artificial intelligence technology in the suppression of coronavirus from three major aspects of identification, prediction, and development through a large amount of literature research, and puts forward the current main challenges and possible development directions. The results show that it is an effective measure to combine artificial intelligence technology with a variety of new technologies to predict and identify COVID-19 patients.

     

SJL-2双组分聚硫密封胶的研究及施工工艺

介绍了SJL-2双纽分聚硫密封胶的配方组分及固化机理，分析了聚硫橡胶及各种助剂对密封胶性能的影响．同时介绍了SJL-2双组分聚硫密封胶的施工工艺及应用领域。     

模糊综合评判法优选地下储气库方案设计研究

在天然气供应与消费之间，一直存在着可靠、安全、平稳、连续供气与消费需求量季节、昼夜、小时不均衡性的固有矛盾。随着天然气国际贸易的发展和边远气田的开发,以及输气的平均运距和运时大大增加，使这一矛盾进一步加剧。而地下储气库则能够解决这一矛盾。由于天然气地下储气库建库方案的确定具有多目标性，因此建设天然气地下储气库前期必须对储气库的建库方案进行充分的技术和工程论证。为此，在研究天然气地下储气库建设方案设计部署原则的基础上，确定了8项评价因素：地层注气末压力、地层采气末压力、工作气规模、垫层气比例、工作井数、单井注气能力、单井采气能力和单位注采气成本。采用模糊数学中的综合评判方法，对地下储气库的建库方案进行了综合评判，应用最大隶属度原则确定出方案集中的最优方案。通过计算实例，验证了模糊综合评判法优选地下储气库方案的可行性，得到了某地下储气库的最优建设方案。     

Optimal dimensionality reduction of sensor data in multisensor estimation fusion

When there exists the limitation of communication bandwidth between sensors and a fusion center, one needs to optimally precompress sensor outputs-sensor observations or estimates before the sensors' transmission in order to obtain a constrained optimal estimation at the fusion center in terms of the linear minimum error variance criterion, or when an allowed performance loss constraint exists, one needs to design the minimum dimension of sensor data. This paper will answer the above questions by using the matrix decomposition, pseudo-inverse, and eigenvalue techniques.     

轧管机主机机架的分体设计

由于大规格轧管机主机机架重量重、尺寸大、结构复杂和制造困难等问题,提出了分体机架结构形式,这类机架由整体机架改为分体机架,可以降低制造成本,缩短生产周期。