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Track-Pattern-Based Characteristics of Extratropical Transitioning Tropical Cyclones in the Western North Pacific

Advances in Atmospheric Sciences 2024年第6期41卷 1251-1263页

作者： Hong HUANG Dan WU Yuan WANG Zhen WANG Yu LIU College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410000China No.31631 army of pla Huizhou 516000China School of Atmospheric Sciences and Key Laboratory of Mesoscale Severe Weather/Ministry of Education Nanjing 210023China no.93721 army of pla Shuozhou 038300China

Based on the Regional Specialized Meteorological Center(RSMC)Tokyo-Typhoon Center best-track data and the NCEP-NCAR reanalysis dataset,extratropical transitioning(ET)tropical cyclones(ETCs)over the western North Pacific(WNP)during 1951–2021 are classified into six clusters using the fuzzy c-means clustering method(FCM)according to their track *** characteristics of the six hard-clustered ETCs with the highest membership coefficient are *** tropical cyclones(TCs)that were assigned to clusters C2,C5,and C6 made landfall over eastern Asian countries,which severely threatened these *** landfalling TCs,93.2%completed their ET after landfall,whereas 39.8%of ETCs completed their transition within one *** frequency of ETCs over the WNP has decreased in the past four decades,wherein cluster C5 demonstrated a significant decrease on both interannual and interdecadal timescales with the expansion and intensification of the western Pacific subtropical high(WPSH).This large-scale circulation pattern is favorable for C2 and causes it to become the dominant track pattern,owning to it containing the largest number of intensifying ETCs among the six clusters,a number that has increased insignificantly over the past four *** surface roughness variation and three-dimensional background circulation led to C5 containing the maximum number of landfalling TCs and a minimum number of intensifying *** results will facilitate a better understanding of the spatiotemporal distributions of ET events and associated environment background fields,which will benefit the effective monitoring of these events over the WNP.

关键词： Western North Pacific tropical cyclone extratropical transition fuzzy c-means clustering method

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An extended state observer with adjustable bandwidth for measurement noise

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Journal of Systems Engineering and Electronics 2024年第1期35卷 233-241页

作者： ZHANG Shihua QI Xiaohui YANG Sen Shijiazhuang Campus Army Engineering University of PLAShijiazhuang 050053China

In this paper,a bandwidth-adjustable extended state observer(ABESO)is proposed for the systems with measurement *** is known that increasing the bandwidth of the observer improves the tracking speed but tolerates noise,which conflicts with observation ***,we introduce a bandwidth scaling factor such that ABESO is formulated to a 2-degree-of-freedom *** observer gain is determined and the bandwidth scaling factor adjusts the bandwidth according to the tracking *** the tracking error decreases,the bandwidth decreases to suppress the noise,otherwise the bandwidth does not *** is proven that the error dynamics are bounded and converge in finite *** relationship between the upper bound of the estimation error and the scaling factor is *** the scaling factor is less than 1,the ABESO has higher estimation accuracy than the linear extended state observer(LESO).Simulations of an uncertain nonlinear system with compound disturbances show that the proposed ABESO can successfully estimate the total disturbance in noisy *** mean error of total disturbance of ABESO is 15.28% lower than that of LESO.

关键词： extended state observer(ESO) boundedness and convergence adjustable bandwidth measurement noise

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Secure resource allocation against colluding eavesdropping in a user-centric cell-free massive multiple-input multiple-output system

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Frontiers of Information Technology & Electronic Engineering 2024年第4期25卷 500-512页

作者： Na LI Yuanyuan GAO Kui XU Xiaochen XIA Huazhi HU Yang LI Yueyue ZHANG College of Communication Engineering Army Engineering University of PLANanjing 210007China

We investigate the resource allocation problem of a cell-free massive multiple-input multiple-output system under the condition of colluding eavesdropping by multiple passive *** address the problem of limited pilot resources,a scheme is proposed to allocate the pilot with the minimum pollution to users based on access point selection and optimize the pilot transmission power to improve the accuracy of channel *** at the secure transmission problem under a colluding eavesdropping environment by multiple passive eavesdroppers,based on the local partial zero-forcing precoding scheme,a transmission power optimization scheme is formulated to maximize the system’s minimum security spectral *** results show that the proposed scheme can effectively reduce channel estimation error and improve system security.

关键词： Cell-free Colluding eavesdropping Limited pilot resources Access point selection Security rate

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Resource allocation for D2D-assisted haptic communications

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Digital Communications and Networks 2024年第1期10卷 63-74页

作者： Yan Wu Chao Yue Yang Yang Liang Ao College of Telecommunication Engineering Army Engineering University of PLANanjing210000China

Haptic communications is recognized as a promising enabler of extensive services by enabling real-time haptic control and feedback in remote environments,e.g.,teleoperation and autonomous *** the strict transmission requirements on reliability and latency,Device-to-Device(D2D)communications is introduced to assist haptic *** particular,the teleoperators with poor channel quality are assisted by auxiliaries,and each auxiliary and its corresponding teleoperator constitute a D2D ***,the haptic interaction and the scarcity of radio resources pose severe challenges to the resource allocation,especially facing the sporadic packet ***,the contentionbased access scheme is applied to achieve low-latency transmission,where the resource scheduling latency is omitted and users can directly access available *** this context,we derive the reliability index of D2D pairs under the contention-based access scheme,i.e.,closed-loop packet error ***,the reliability performance is guaranteed by bidirectional power control,which aims to minimize the sum packet error probability of all D2D *** game theory is introduced to solve the problem with low ***,a distributed power control algorithm based on synchronous log-linear learning is proposed to converge to the optimal Nash *** results demonstrate the superiority of the proposed learning algorithm.

关键词： Haptic communications D2D Power control Contention-based access Potential game

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A Practical Approach for Missing Wireless Sensor Networks Data Recovery

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China Communications 2024年第5期21卷 202-217页

作者： Song Xiaoxiang Guo Yan Li Ning Ren Bing The College of Communications Engineering Army Engineering University of PLANanjing 210007China The 63891 Unit of pla Luoyang 471000China

In wireless sensor networks(WSNs),the performance of related applications is highly dependent on the quality of data ***,missing data is almost inevitable in the process of data acquisition and *** methods often rely on prior information such as low-rank characteristics or spatiotemporal correlation when recovering missing WSNs ***,in realistic application scenarios,it is very difficult to obtain these prior information from incomplete data ***,we aim to recover the missing WSNs data effectively while getting rid of the perplexity of prior *** designing the corresponding measurement matrix that can capture the position of missing data and sparse representation matrix,a compressive sensing(CS)based missing data recovery model is ***,we design a comparison standard to select the best sparse representation basis and introduce average cross-correlation to examine the rationality of the established ***,an improved fast matching pursuit algorithm is proposed to solve the *** results show that the proposed method can effectively recover the missing WSNs data.

关键词： average cross correlation matching pursuit missing data wireless sensor networks

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Mechanical properties and energy evolution of Beishan shallow-layer granite under different unloading paths

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Journal of Mountain Science 2024年第5期21卷 1728-1744页

作者： WANG Chuanle LI Erbing ZHANG Dengke HAN Yang LU Hui HE Kang DU Guangyin School of Transportation Southeast UniversityNanjing 211189China College of Defense Engineering Army Engineering University of PLANanjing 210007China Nanjing Urban Construction Management Group Co. Ltd.Nanjing 210006China College of Field Engineering Army Engineering University of PLANanjing 210007China

Rock has mechanical characteristics and a fracture damage mechanism that are closely related to its loading history and loading path. The mechanical properties, fracture damage features, acoustic emission(AE) characteristics, and strain energy evolution of the Beishan shallow-layer granite used in triaxial unloading tests were investigated in this study. Three groups of triaxial tests, namely, conventional triaxial compression test(Group Ⅰ), maintaining deviatoric stress synchronously unloading confining pressure test(Group Ⅱ), and loading axial pressure synchronously unloading confining pressure test(Group Ⅲ), were carried out for the cylindrical granite specimens. AE monitoring device was utilized in these tests to determine the degree to which the AE waves and AE events reflected the degree of rock damage. In addition, the crack stress thresholds of the specimens were determined by volumetric strain method and AE parameter method, and strain energy evolution of the rock was explored in different damage stages. The results show that the shallow-layer granite experiences brittle failure during the triaxial loading test and unloading test, and the rock has a greater damage degree during the unloading test. The crack stress thresholds of these samples vary greatly between tests, but the threshold ratios of all samples are similar in the same crack damage stage. The Mogi-Coulomb strength criterion can better describe the unloading failure strength of the rock. The evolution of the AE parameter characteristics and strain energy differs between the specimens used in different stress path tests. The dissipative strain energy is the largest in Group Ⅱ and the smallest in Group Ⅰ.

关键词： Beishan granite Unloading test Mechanical properties Damage mechanism Acoustic emission Strain energy

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Translocation of a fish spike from the pharynx to the thyroid gland:A case report

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World Journal of Clinical Cases 2024年第7期12卷 1365-1370页

作者： Deng Li Wan-Ting Zeng Jian-Guo Jiang Ji-Chuan Chen Department of Otolaryngology Head and Neck Surgery Army Medical Center of PLAChongqing 400042China

BACKGROUND A fish spike stuck in the throat is a common ear,nose,and throat(ENT)***,it is very rare for a fish spike to reach the thyroid tissue through the throat,which is very dangerous and can lead to pharyngeal fistula,cervical abscess,mediastinal abscess,and thyroid *** and timely management can help reduce complications,especially in elderly *** SUMMARY In the case presented here,the causative factor was dentures,but improper management aggravated the *** the case presented here,an elderly woman with a history of accidentally swallowing fish bones for 20 d had a sensation of foreign bodies in her ***,computed tomography(CT)of the neck showed that the left side of the thyroid gland had a dense shadow in the form of a *** If a fishbone foreign body is not visible during endoscopic examination but the patient has significant symptoms,the surgeon should be aware that the fishbone may be lodged in the *** avoid a misdiagnosis,ultrasound,CT,and other tests can be used to clarify the diagnosis.T The first step in treating a fish bone in the thyroid gland is to determine the position of the foreign body and the extent of the infection,and to develop a personalized surgical plan for its *** the same time,scientific information should be made available to the general public so that people know that if a fish bone is accidentally lodged,they should not force it to be swallowed or be spit out by inducing vomiting,which are incorrect methods and may aggravate the condition or even cause it to migrate outside the cavity,leading to serious complications,as in this reported case.

关键词： Fish spike Thyroid Pharynx Foreign body migration Case report

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Non-dimensional analysis on blast wave propagation in foam concrete:Minimum thickness to avoid stress enhancement

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Defence Technology（防务技术） 2024年第6期36卷 30-46页

作者： Ya Yang Xiangzhen Kong Qin Fang State Key Laboratory of Disaster Prevention&Mitigation of Explosion&Impact Army Engineering University of PLANanjing 210007JiangsuChina

Foam concrete is a prospective material in defense engineering to protect structures due to its high energy absorption capability resulted from the long plateau ***,stress enhancement rather than stress mitigation may happen when foam concrete is used as sacrificial claddings placed in the path of an incoming blast *** investigate this interesting phenomenon,a one-dimensional difference model for blast wave propagation in foam concrete is firstly proposed and numerically solved by improving the second-order Godunov *** difference model and numerical algorithm are validated against experimental results including both the stress mitigation and the stress *** difference model is then used to numerically analyze the blast wave propagation and deformation of material in which the effects of blast loads,stress-strain relation and length of foam concrete are *** particular,the concept of minimum thickness of foam concrete to avoid stress enhancement is ***,non-dimensional analysis on the minimum thickness is conducted and an empirical formula is proposed by curve-fitting the numerical data,which can provide a reference for the application of foam concrete in defense engineering.

关键词： Foam concrete Blast wave propagation Non-dimensional analysis Stress enhancement

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Jamming Assisted Covert Wireless Communication in Multi-Channel Systems

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China Communications 2024年第9期 211-224页

作者： Che Bohan Sha Nan Yang Weiwei Lu Xingbo Gao Chang army Engineering University of pla Beijing University of Posts and Telecommunications

This paper investigates the jammerassisted multi-channel covert wireless communication(CWC) by exploiting the randomness of sub-channel selection to confuse the *** particular,we propose two sub-channel selection transmission schemes,named random sub-channel selection(RSS) scheme and maximum sub-channel selection(MSS) scheme,to enhance communication *** each proposed scheme,we first derive closed-form expressions of the transmission outage probability(TOP),the average effective rate,and the minimum average detection error probability(DEP).Then,the average effective covert rate(ECR) is maximized by jointly optimizing the transmit power at the transmitter and the number of *** results show that there is an optimal value of the number of sub-channels that maximizes the average *** also find that to achieve the maximum average ECR,a larger number of subchannels are needed facing a stricter covertness constraint.

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Fluorographene with Narrow Lateral Size and Thickness Distributions Prepared for Enhancing Lubrication Performance of Bentonite Grease

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Journal of Wuhan University of Technology(Materials Science) 2024年第5期39卷 1294-1302页

作者： XIANG Shuo LU Peng ZHANG Qinhui XIAO Bowen YANG Xin* ZHANG Peili MA Pengfei HE Yan LI Xuebin army Logistics Academy of pla Chongqing 401311China Naval Aeronautical University Yantai 2640003China Unit 32568 Shaoguan 512131China

Fluorographene(FG)with narrow lateral size and thickness distributions was prepared by a liquid-phase exfoliation method,based on liquid cascade *** Rtec MFT-5000 tribo-meter was used to investigate the lubricating performance of bentonite grease enhanced by the as-prepared *** results showed that the coefficient of friction and the wear volume of bentonite grease with 0.3 wt%FG were decreased by 20.4%and 44.9%,respectively,as compared to those of the base *** main reason is that FG can promote the formation of the tribo-chemical reaction film consisting of complex carbon oxide,Fe_(2)O_(3)and FeF_(3)on the friction surface,which can remarkably improve the performance of friction reduction and prevent the appearance of severe wear.

关键词： fluorographene liquid-phase exfoliation bentonite grease lubrication performance

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