Investigation of system structure and information processing mechanism for cognitive skywave over-the-horizon radar

Based on the cognitive radar concept and the basic connotation of cognitive skywave over-the-horizon radar（SWOTHR）, the system structure and information processingmechanism about cognitive SWOTHR are researched. Amongthem, the hybrid network system architecture which is thedistributed configuration combining with the centralized cognition and its soft/hardware framework with the sense-detectionintegration are proposed, and the information processing framebased on the lens principle and its information processing flowwith receive-transmit joint adaption are designed, which buildand parse the work law for cognition and its self feedback adjustment with the lens focus model and five stages informationprocessing sequence. After that, the system simulation andthe performance analysis and comparison are provided, whichinitially proves the rationality and advantages of the proposedideas. Finally, four important development ideas of futureSWOTHR toward ＂high frequency intelligence information processing system＂ are discussed, which are scene information fusion, dynamic reconfigurable system, hierarchical and modulardesign, and sustainable development. Then the conclusion thatthe cognitive SWOTHR can cause the performance improvement is gotten.

Optimization of Millimeter-Wave RoF System Structure

Based on the seamless integration of broadband optical and wireless access networks,millimeter-wave Radio over Fiber (RoF) technology is considered to be a promising solution for the next generation access networks which will provide high capacity and flexibility with low cost.But due to its large cost to realize,the system architecture needs to be optimized.In the millimeter-wave optical generation part,optical heterodyning method can be introduced to generate a high-frequency millimeter-wave signal using a low-frequency signal source.And the system efficiency can be greatly improved based on injection-locking of a semiconductor laser.In the downlink,the transmission distance can be greatly enhanced using single-sideband modulation.And the single-mode modulation (single-sideband modulation) based on an injection-locked semiconductor laser is a much simpler solution.In the uplink,direct modulation of optical heterodyning signal can be used to realize the down-conversion of uplink millimeter-wave signal,which simplifies the receiver structure at the centre office.In the wavelength division multiplexing millimeter-wave RoF duplex system,the wavelength reuse in both downlink and uplink can save the wavelength resource in the whole system,which improves its efficiency.

Structure Improvement and Optimization of Gantry Milling System for Complex Boring and Milling Machining Center

To enhance the efficiency and machining precision of the TX1600G complex boring and milling machining center,a study was conducted on the structure of its gantry milling system.This study aimed to mitigate the influence of factors such as structural quality,natural frequency,and stiffness.The approach employed for this investigation involved mechanism topology optimization.To initiate this process,a finite element model of the gantry milling system structure was established.Subsequently,an objective function,comprising strain energy and modal eigenvalues,was synthesized.This objective function was optimized through multi-objective topology optimization,taking into account certain mass fraction constraints and considering various factors,including processing technology.The ultimate goal of this optimization was to create a gantry milling structure that exhibited high levels of dynamic and static stiffness,a superior natural frequency,and reduced mass.To validate the effectiveness of these topology optimization results,a comparison was made between the new and previous structures.The findings of this study serve as a valuable reference for optimizing the structure of other components within the machining center.

STRUCTURE PARAMETERS DESIGN AND PERFORMANCE TEST OF FUEL INJECTION SYSTEM

Based on the numerical simulation analysis, structure parameters of the high pressure fuel pump and common rail as well as flow limiter are designed and the GD-1 high pressure common rail fuel injection system is self-developed. Fuel injection characteristics experiment is performed on the GD-1 system. And double-factor variance analysis is applied to investigate the influence of the rail pressure and injection pulse width on the consistency of fuel injection quantity, thus to test whether the design of structure parameters is sound accordingly. The results of experiment and test show that rail pressure and injection pulse width as well as their mutual-effect have no influence on the injection quantity consistency, which proves that the structure parameters design is successful and performance of GD-1 system is sound.

Maintenance Strategy of Multi-Component System Due to Degradation and Shock

The proposed maintenance strategy uses component grades and survival signature to describe and update system structure. A system dynamic stress-strength reliability(SSR) model was established to describe component failure processes because of internal degradation and external shock. Besides, a corrective maintenance rule and two-level preventive maintenance rule made up the proposed maintenance strategy. The former combined sequentially minimal repair and corrective replacement(SMRCR) based on system structure updating. The latter considered group importance measure based on the system dynamic SSR and preventive maintenance cost. Further, a cost model was developed by the proposed strategy, and the optimal decision variables were found by genetic algorithm. Finally, using a case system to illustrate the above strategy improved system and reduced maintenance costs.

Construction and Development of China’s Earthquake Information Release System

Focused on the current situation,monitoring system,technical management regulation,process,system composition,and information publication of the earthquake information release,we summarized the construction and development of China’s earthquake information release system and expected its future.In general,China’s earthquake information release systems is able to publish auto-results with MS≥3.0 from 1 to 3 minutes,M_S≥6.0 in global from 2 to 30 minutes,and formal results with MS≥3.0 in China from 8 to 30 minutes,MS≥6.0 in global from 20 to 60 minutes.These earthquake information is released by various channels such as short message,website,microblog,mobile application,etc.

Design of Intelligent Water-Saving Irrigation System Based on Internet of Things

This paper studies the design of water-saving irrigation system based on Internet of things. The structural model of the water-saving irrigation system was established, and the hardware and software of the control system were designed, with emphasis on the design and coverage calculation of the sensor nodes in the wireless sensor network. The wireless network and control system are tested, including network coverage, network connection, optimal communication distance and accuracy of data transmission. The experimental results show that the data transmitted by the wireless sensor is accurate and reliable, and the software and hardware of the automatic control system can work normally. The system can carry out intelligent irrigation timely and accurately.

Coupling and coordinated evolution characteristics of regional economy-energy-carbon emission multiple systems:A case study of main China's Basin

Comprehensive analysis of the Economy-Energy-Carbon Emission(EECE)system is beneficial for promoting sustainable social development.This study analyzes the system development of major watersheds in China from 2010 to 2019.The research fully considers the system’s internal and external inputs and outputs and proposes an evaluation index system for regional EECE coupling and coordinated development.Then,using the difference in system weight allocation to improve the coupling and coordination model,the study explores the dynamic system’s coupling and coordination.The results show that(1)The development of the system structure is relatively stable,but the overall development status is not ideal;(2)The downstream of China’s main river basins has obvious economic advantages,while the energy system fluctuates greatly.The efficiency of the carbon emission system will decrease in areas with rapid economic development.The coupling and coordination level of the EECE system is better in the Yangtze River Basin than in the Yellow River Basin;(3)From the perspective of dynamic coordinated development,the main river basins have been divided into two states since 2012,but it is relatively stable overall.Regional dynamic coordination is often at a disadvantage in regions with rapid economic and energy development;(4)The coupling coordination degree of the two river basins has significant positive spatial autocorrelation.Most provinces’significant spatial clustering characteristics of the coupling coordination degree are High-High type.Low-Low type provinces are mainly concentrated downstream.The research process has certain reference significance for the collaborative governance of complex regional systems.

Adaptation to a Warming-Drying Trend Through Cropping System Adjustment over Three Decades:A Case Study in the Northern Agro-Pastural Ecotone of China

Long-term field monitoring data and historical crop data are useful to assess the impacts of climate change and to manage cropping systems. The objectives of this study are to understand the cropping system response to a warming-drying trend in the northern agro-pastural ecotone （NAE） of China and to document how farmers can adapt to the warming-drying trend by changing cropping system structure and adjusting planting date. The results indicate that a significant warming-drying trend existed in the NAE from 1980 to 2009, and this trend significantly decreased crop （spring wheat, naked oat, and potato） yields. Furthermore, the yield decreased by 16.2%-28.4% with a 1℃ increase in maximum temperature and decreased by 6.6%-11.8% with a 10% decrease in precipitation. Considering food security, water use efficiency, and water ecological adaptability in the semi-arid NAE, cropping system structure adjustment （e.g., a shift from wheat to potato as the predominant crop） and planting date adaptation （e.g., a delay in crop planting date） can offset the impact of the warming-drying trend in the NAE. Based on the successful offsetting of the impact of the warming-drying trend in the NAE, we conclude that farmers can reduce the negative effects of climate change and minimize the risk of crop failure by adapting their cropping system structure at the farming level.

Key Technology Research for Mobile Police Terminal Fingerprint Collection for Quick Comparison Using Automated Fingerprint Identification System

When the face of the inspected person and the photograph on their identification(ID)card cannot be clearly matched,the individual is undocumented,or the ID is forged,it is often difficult for the on‑site police to respond in time.This study proposes a number of key technologies for collecting fingerprints at mobile terminals for fast comparison using an automated fingerprint ID system(AFIS).These technologies ensure intelligent mobile fingerprint collection and allow the transmission of fingerprint information from the terminal to AFIS,over a wireless public security network for real‑time fingerprint comparison.This study also analyzes the feasibility and effectiveness of the proposed technologies for system design and the applicability of fingerprint ID algorithms.The system achieved good results in a test by the Shanghai Public Security Bureau Criminal Investigation Corps.

A Study on the Cloud Design Resource System Based on Ecology Theory

The cloud design resource system is an organic entity from the ecological system perspective, whose elements have the similar behavioral property of creature individuals, populations, and community. Hence, study on cloud design resource management can refer to the ecology theory. Based on analyzing the structure of cloud design resource system and the features of cloud design resources, the similarity between those are further dis cussed through the ecological system elements and features. An ecological based application framework of cloud design resource management is then presented.

黄土隧道新型组合结构支护效果分析及参数优化研究

黄土隧道在开挖过程中经常发生支护结构破坏或过度变形。依托某黄土隧道,提出一种新型组合结构支护体系(π形拱架),采用理论计算对比了π形拱架与传统工字钢提供的支护反力,结合现场监测和数值模拟分析了不同支护体系下围岩控制效果,优化新型组合结构的构造参数,同时基于正交试验探究了构造参数对围岩支承效果影响显著性大小。结果表明:π形拱架提供的支护反力是型钢钢架的3.14倍,具有强度大、承载力高的优势;建立对比分析模型,较传统支护体系相比,新型支护体系下的拱顶沉降降幅达到53.8%,等效塑性应变减少约64.4%,初期支护最大压应力和拉应力分别减少约35.3%、35.9%;进而建立参数优化模型,通过对围岩竖向位移和塑性区的综合评估,建议拱架壁厚取6 mm,灌浆强度选择C30,翼板长度以200 mm为宜;结合正交试验结果,各因素影响程度由小到大依次为因素B(灌浆强度)<因素A(钢管壁厚)<因素C(翼板长度)。本研究可进一步促进新型拱架在黄土隧道施工支护中的应用。

Effect of structural characteristics on the transport characteristics of solid particles in the thermal storage and release system of circulating fluidized bed

Coal-fired power generation stands as the most economically viable modulating power source in present-day China.It holds the potential to offer prospective solutions to the challenges posed by the rapid expansion of intermittent,unpredictable,and unstable renewable energy sources.Solid particle thermal storage technology emerges as an effective means to enhance the flexibility of coal-fired circulating fluidized bed power units.To attain an optimized structure for the solid particle thermal storage and release system in circulating fluidized bed units,experimental research was conducted on a 0.1 MWth circulating fluidized bed test platform.This study delved into the impact of ash storage bin geometries and the shapes of their feed-discharge valves on the control properties of solid particle transportation.The experimental outcomes reveal that employing inverted m-shaped valve and dual U-shaped valves for feed control,alongside U-shaped valves and N-shaped valves for discharge control,both enable efficient and rapid storage and release of solid particles within the circulating fluidized bed.Under similar air distribution conditions,the inverted m-shaped valve exhibits lower conveying energy consumption than the dual U-shaped valves,while the N-shaped valve excels in control characteristics over the U-shaped valve.Furthermore,the inverted m-shaped valve and the N-shaped valve demonstrate optimal overflow port heights,and the ash storage bin exhibits an optimum height-to-diameter ratio.

Exploration on Armored Equipment Materiel Support Grid Design

The core of grid technology is just to solve the problem of resource share and to eliminate information island and resource island. Thus, it is a perfect approach to apply the grid technology to armored equipment materiel support. Firstly, the military and function demands of armored equipment materiel support grid are analyzed. Besides, according to the function demand, the system structure of armored equipment materiel support grid is designed. Finally, the organizational structure of armored equipment materiel support grid is established in this paper based on actual armored equipment materiel support.