Analytical Solution and Simplified Formula for Added Mass of Horizontal and Vertical Motions of Truncated Cylinders Under Earthquake Action

This paper investigates the hydrodynamic characteristics of floating truncated cylinders undergoing horizontal and vertical motions due to earthquake excitations in the finite water depth.The governing equation of the hydrodynamic pressure acting on the cylinder is derived based on the radiation theory with the inviscid and incompressible assumptions.The governing equation is solved by using the method of separating variables and analytical solutions are obtained by assigning reasonable boundary conditions.The analytical result is validated by a numerical model using the exact artificial boundary simulation of the infinite water.The main variation and distribution characteristics of the hydrodynamic pressure acting on the side and bottom of the cylinder are analyzed for different combinations of wide-height and immersion ratios.The added mass coefficient of the cylinder is calculated by integrating the hydrodynamic pressure and simplified formulas are proposed for engineering applications.The calculation results show that the simplified formulas are in good agreement with the analytical solutions.

基于DEMATEL-ISM的水利工程EPC项目价值增值机理研究

采用设计-采购-施工(engineering-procurement-construction,EPC)总承包模式的水利工程项目日益增多,研究其价值增值机理有利于总承包方做好项目的价值管理。从水利工程EPC项目的价值链分析入手,基于文献和专家访谈得到23个价值增值影响因素。采用问卷调查方式得到各因素间的影响程度评分,用决策实验和评估实验(decision-making trial and evaluation laboratory,DEMATEL)法计算了各因素的中心度和原因度,结合解释结构模型(interpretative structural modeling,ISM)对数据进行分析,将价值增值因素划分为6类,构建了水利工程EPC项目价值增值的递阶模型,探究和揭示了项目价值增值的路径和机理。研究结果对水利工程EPC总承包方制订管理策略有一定启示作用。

COSPAS-SARSAT系统第二代示位标信号的软件无线电设计实现

遇险示位标是全球卫星搜救系统(COSPAS-SARSAT)的一个重要组成部分。目前遇险示位标大多是第一代窄带示位标,采用固定的调制变频架构,存在集成度低、功能单一、升级需要更换硬件电路等问题。针对这些问题,文中设计了一种基于ZYNQ7000+AD9361软件定义无线电集成架构的第二代遇险信标示位标信号产生电路,其优点是信息内容、信号格式、发射参数可软件灵活定义。文中首先根据COSPAS-SARSAT系统第二代遇险示位标信号的格式规范,设计了扩频、滤波、调制等信号处理流程,仿真验证了信号特性;然后,用ZYNQ7000+AD9361软件定义无线电架构完成了PL和PS设计,实现了符合第二代COSPAS-SARSAT示位标规范的发射信号;最后进行了测试,结果表明该设计方法符合设计要求,有效可行。该设计具有分立器件少、集成度很高、高度可编程性、可灵活实现示位标的在线维护升级和信号转换等优点。

NEAT1、miR-27a-3p在阿尔茨海默病患者血清和脑脊液中的表达关系

目的:探究长链非编码RNA核富含丰富的转录本1(long chain non-coding RNA nuclear-enriched abundant transcript 1, LncRNA NEAT1)、miR-27a-3p在阿尔茨海默病(Alzheimer disease, AD)患者血清和脑脊液中的表达关系及意义。方法:选择2019年10月至2021年9月天津市第五中心医院神经内科收治的AD患者66例作为病例组,根据临床痴呆评定量表(clinical dementia rating, CDR)评分分为轻度组(≤1分,n=41)与中重度组(>1分,n=25);另取同期门诊其他就诊患者血清和脑脊液标本66例志愿者作为对照组。收集所有受试者的一般资料并评估认知程度,采用实时荧光定量PCR检测血清和脑脊液miR-27a-3p、NEAT1表达水平,酶联免疫吸附试验检测脑脊液β-淀粉样前体蛋白裂解酶1(β-site amyloid precursor protein cleaving enzyme 1,BACE1)、β淀粉样蛋白(amyloid β,Aβ)40和Aβ42水平,采用Spearman法分析血清miR-27a-3p、NEAT1水平与简易精神状态检测量表的相关性,采用Pearson法分析血清miR-27a-3p、NEAT1水平与Aβ沉积平均标准摄取值比率(standardized uptake value ratio, SUVR)及脑脊液miR-27a-3p、NEAT1、BACE1、Aβ42、Aβ40水平的相关性。结果:MMSE评分[21 (17,25),9(7,11)vs. 27 (21,34)]、MoCA评分[17 (12,21),10 (7,13)vs. 27 (21,31)]、血清miR-27a-3p水平(0.55±0.13,0.46±0.06 vs. 0.97±0.22)、脑脊液miR-27a-3p(0.48±0.10,0.35±0.10 vs. 1.03±0.31)、Aβ42水平[(303.55±36.77) ng/L,(231.45±34.14) ng/L vs.(499.99±53.63) ng/L]及Aβ42/Aβ40比值(0.030±0.008, 0.022±0.007 vs. 0.048±0.010)轻度组、中重度组AD患者均低于对照组(P均<0.05),且中重度组AD患者较轻度组低(P均<0.05);血清NEAT1水平(2.31±0.64,3.13±0.76 vs. 1.05±0.20)、SUVR(1.50±0.29,1.76±0.52 vs. 0.74±0.15)及脑脊液NEAT1(3.51±1.24,4.30±1.65 vs. 1.01±0.23)、BACE1水平[(55.78±5.98)μg/L,(72.32±16.08)μg/L vs.(21.39±3.73)μg/L]轻度组、中重度组AD患者均高于对照组(P均<0.05),且中重度组AD患者较轻度组高(P均<0.05)。AD患者血清NEAT1水平与SUVR及脑脊液NEAT1、BACE1呈正相关(r=0.350,0.606,0.341,P<0.05),与MMSE评分、MoCA评分呈负相关(r=-0.473,-0.482,P均<0.05);血清miR-27a-3p水平与脑脊液miR-27a-3p水平、MMSE评分、MoCA评分呈正相关(r=0.695,0.424,0.412,P<0.05),与SUVR及脑脊液BACE1水平呈负相关(r=-0.521、-0.447,P均<0.05)。结论:NEAT1、miR-27a-3p在AD患者血清及脑脊液中表达趋势具有一致性,NEAT1水平均升高,miR-27a-3p水平均降低,二者水平呈负相关,与AD患者脑中Aβ沉积程度有关,并参与AD的病情进展。

An inverse analysis of fluid flow through granular media using differentiable lattice Boltzmann method

This study presents a method for the inverse analysis of fluid flow problems.The focus is put on accurately determining boundary conditions and characterizing the physical properties of granular media,such as permeability,and fluid components,like viscosity.The primary aim is to deduce either constant pressure head or pressure profiles,given the known velocity field at a steady-state flow through a conduit containing obstacles,including walls,spheres,and grains.The lattice Boltzmann method(LBM)combined with automatic differentiation(AD)(AD-LBM)is employed,with the help of the GPU-capable Taichi programming language.A lightweight tape is used to generate gradients for the entire LBM simulation,enabling end-to-end backpropagation.Our AD-LBM approach accurately estimates the boundary conditions for complex flow paths in porous media,leading to observed steady-state velocity fields and deriving macro-scale permeability and fluid viscosity.The method demonstrates significant advantages in terms of prediction accuracy and computational efficiency,making it a powerful tool for solving inverse fluid flow problems in various applications.

Emerging Novel Therapeutic Approaches for the Treatment of Alzheimer’s Disease

Alzheimer’s disease (AD) is caused by synaptic failure and the excessive accumulation of misfolded proteins especially Aβ and tau, and associated with memory loss and cognitive impairment. Treatment of AD mainly consists of symptomatic therapy and disease-modifying therapy (DMT). Several monotherapies including small molecules or antibodies have been evaluated through multiple clinical trials, but a very few have been approved by the USFDA to intervene the disease’s pathogenesis. Past research has shown multifactorial nature of AD, therefore, multi-target drugs were proposed to target different pathways at the same time, however, currently no rationally designed multi-target directed ligand (MTDL) has been clinically approved. Different combinations and bispecific antibodies are also under development. Novel approaches like stem cell-based therapies, microRNAs, peptides, ADCs and vaccines cast a new hope for AD treatment, however, a number of questions remained to be answered prior to their safe and effective clinical translation. This review explores the small molecules, MTDL, and antibodies (monospecific and bispecific) for the treatment of AD. Finally, future perspectives (stem cell therapy, PROTAC approaches, microRNAs, ADC, peptides and vaccines) are also discussed with regard to their clinical applications and feasibility.

Assessment of Satisfaction in the Reception and Emergency Department of a Health Center

Introduction The main objective of any healthcare establishment must be to ensure the quality of patient care and customer satisfaction. It is necessary to regularly assess patient satisfaction. The aim of this study was to assess the level of satisfaction of customers aged over 18 years attending the emergency department of the health center. Methodology This was a descriptive and analytical cross-sectional study of patients aged 18 years and over, who attended the Samu Municipal emergency department between 02 and 30 May 2023. The satisfaction index was determined using the adapted 2009 SAPHORA-MCO questionnaire and the Likert satisfaction scale. Results A total of 400 patients were surveyed. The average age was 35 years, with a standard deviation of 14.7. Of those surveyed, 51% were women, 87% were educated, 50% lived in Grand Yoff and 59.5% were unemployed. Satisfaction levels linked to perception of the cost of care (72%), waiting time (64.3%), information given to patients (69.1%) and pain management (74 .5%) are fair. On the other hand, the levels of satisfaction linked to administrative procedures (82.5%), staff attitudes towards patients (84%), staff availability (86.4%), patient privacy (89.2%), general atmosphere (87.2%), staff competence (87.3%), and the effectiveness of care (89.4%) were satisfactory. The average waiting time was 38 minutes. However, 32% of patients waited less than 30 minutes and 92% less than an hour. The satisfaction index linked to administration and reception was 72.9% and 79.85%, respectively. The satisfaction index linked to the administration and technical quality of care is equal to 85.8% and 83.7%, respectively. The overall satisfaction index is equal to 80.6%;the level of satisfaction of users of the health structure is satisfactory. Conclusion Patient satisfaction is an essential part of quality care. Patient satisfaction must be based on effective communication from the healthcare team and the creation of a patient-caregiver relationship.

Caching Strategies in NDN Based Wireless Ad Hoc Network:A Survey

Wireless Ad Hoc Networks consist of devices that are wirelessly connected.Mobile Ad Hoc Networks(MANETs),Internet of Things(IoT),and Vehicular Ad Hoc Networks(VANETs)are the main domains of wireless ad hoc network.Internet is used in wireless ad hoc network.Internet is based on Transmission Control Protocol(TCP)/Internet Protocol(IP)network where clients and servers interact with each other with the help of IP in a pre-defined environment.Internet fetches data from a fixed location.Data redundancy,mobility,and location dependency are the main issues of the IP network paradigm.All these factors result in poor performance of wireless ad hoc networks.The main disadvantage of IP is that,it does not provide in-network caching.Therefore,there is a need to move towards a new network that overcomes these limitations.Named Data Network(NDN)is a network that overcomes these limitations.NDN is a project of Information-centric Network(ICN).NDN provides in-network caching which helps in fast response to user queries.Implementing NDN in wireless ad hoc network provides many benefits such as caching,mobility,scalability,security,and privacy.By considering the certainty,in this survey paper,we present a comprehensive survey on Caching Strategies in NDN-based Wireless AdHocNetwork.Various cachingmechanism-based results are also described.In the last,we also shed light on the challenges and future directions of this promising field to provide a clear understanding of what caching-related problems exist in NDN-based wireless ad hoc networks.

Recess-free enhancement-mode AlGaN/GaN RF HEMTs on Si substrate

Enhancement-mode(E-mode)GaN-on-Si radio-frequency(RF)high-electron-mobility transistors(HEMTs)were fabri-cated on an ultrathin-barrier(UTB)AlGaN(<6 nm)/GaN heterostructure featuring a naturally depleted 2-D electron gas(2DEG)channel.The fabricated E-mode HEMTs exhibit a relatively high threshold voltage(VTH)of+1.1 V with good uniformity.A maxi-mum current/power gain cut-off frequency(fT/fMAX)of 31.3/99.6 GHz with a power added efficiency(PAE)of 52.47%and an out-put power density(Pout)of 1.0 W/mm at 3.5 GHz were achieved on the fabricated E-mode HEMTs with 1-μm gate and Au-free ohmic contact.

Secure and Reliable Routing in the Internet of Vehicles Network:AODV-RL with BHA Attack Defense

Wireless technology is transforming the future of transportation through the development of the Internet of Vehicles(IoV).However,intricate security challenges are intertwinedwith technological progress:Vehicular ad hoc Networks(VANETs),a core component of IoV,face security issues,particularly the Black Hole Attack(BHA).This malicious attack disrupts the seamless flow of data and threatens the network’s overall reliability;also,BHA strategically disrupts communication pathways by dropping data packets from legitimate nodes altogether.Recognizing the importance of this challenge,we have introduced a new solution called ad hoc On-Demand Distance Vector-Reputation-based mechanism Local Outlier Factor(AODV-RL).The significance of AODVRL lies in its unique approach:it verifies and confirms the trustworthiness of network components,providing robust protection against BHA.An additional safety layer is established by implementing the Local Outlier Factor(LOF),which detects and addresses abnormal network behaviors.Rigorous testing of our solution has revealed its remarkable ability to enhance communication in VANETs.Specifically,Our experimental results achieve message delivery ratios of up to 94.25%andminimal packet loss ratios of just 0.297%.Based on our experimental results,the proposedmechanismsignificantly improves VANET communication reliability and security.These results promise a more secure and dependable future for IoV,capable of transforming transportation safety and efficiency.

Growth and Interactions of Multi-Source Perturbations in Convection-Allowing Ensemble Forecasts

This study investigated the growth of forecast errors stemming from initial conditions(ICs),lateral boundary conditions(LBCs),and model(MO)perturbations,as well as their interactions,by conducting seven 36 h convectionallowing ensemble forecast(CAEF)experiments.Two cases,one with strong-forcing(SF)and the other with weak-forcing(WF),occurred over the Yangtze-Huai River basin(YHRB)in East China,were selected to examine the sources of uncertainties associated with perturbation growth under varying forcing backgrounds and the influence of these backgrounds on growth.The perturbations exhibited distinct characteristics in terms of temporal evolution,spatial propagation,and vertical distribution under different forcing backgrounds,indicating a dependence between perturbation growth and forcing background.A comparison of the perturbation growth in different precipitation areas revealed that IC and LBC perturbations were significantly influenced by the location of precipitation in the SF case,while MO perturbations were more responsive to convection triggering and dominated in the WF case.The vertical distribution of perturbations showed that the sources of uncertainties and the performance of perturbations varied between SF and WF cases,with LBC perturbations displaying notable case dependence.Furthermore,the interactions between perturbations were considered by exploring the added values of different source perturbations.For the SF case,the added values of IC,LBC,and MO perturbations were reflected in different forecast periods and different source uncertainties,suggesting that the combination of multi-source perturbations can yield positive interactions.In the WF case,MO perturbations provided a more accurate estimation of uncertainties downstream of the Dabie Mountain and need to be prioritized in the research on perturbation development.

Message Verification Protocol Based on Bilinear Pairings and Elliptic Curves for Enhanced Security in Vehicular Ad Hoc Networks

Vehicular ad hoc networks(VANETs)provide intelligent navigation and efficient route management,resulting in time savings and cost reductions in the transportation sector.However,the exchange of beacons and messages over public channels among vehicles and roadside units renders these networks vulnerable to numerous attacks and privacy violations.To address these challenges,several privacy and security preservation protocols based on blockchain and public key cryptography have been proposed recently.However,most of these schemes are limited by a long execution time and massive communication costs,which make them inefficient for on-board units(OBUs).Additionally,some of them are still susceptible to many attacks.As such,this study presents a novel protocol based on the fusion of elliptic curve cryptography(ECC)and bilinear pairing(BP)operations.The formal security analysis is accomplished using the Burrows–Abadi–Needham(BAN)logic,demonstrating that our scheme is verifiably secure.The proposed scheme’s informal security assessment also shows that it provides salient security features,such as non-repudiation,anonymity,and unlinkability.Moreover,the scheme is shown to be resilient against attacks,such as packet replays,forgeries,message falsifications,and impersonations.From the performance perspective,this protocol yields a 37.88%reduction in communication overheads and a 44.44%improvement in the supported security features.Therefore,the proposed scheme can be deployed in VANETs to provide robust security at low overheads.

A Review on the Recent Trends of Image Steganography for VANET Applications

Image steganography is a technique of concealing confidential information within an image without dramatically changing its outside look.Whereas vehicular ad hoc networks(VANETs),which enable vehicles to communicate with one another and with roadside infrastructure to enhance safety and traffic flow provide a range of value-added services,as they are an essential component of modern smart transportation systems.VANETs steganography has been suggested by many authors for secure,reliable message transfer between terminal/hope to terminal/hope and also to secure it from attack for privacy protection.This paper aims to determine whether using steganography is possible to improve data security and secrecy in VANET applications and to analyze effective steganography techniques for incorporating data into images while minimizing visual quality loss.According to simulations in literature and real-world studies,Image steganography proved to be an effectivemethod for secure communication on VANETs,even in difficult network conditions.In this research,we also explore a variety of steganography approaches for vehicular ad-hoc network transportation systems like vector embedding,statistics,spatial domain(SD),transform domain(TD),distortion,masking,and filtering.This study possibly shall help researchers to improve vehicle networks’ability to communicate securely and lay the door for innovative steganography methods.

Trust-based Intelligent Scheme for Mitigating Black Hole Attacks in IoT

Internet of Things(IoT)networks are characterized by a multitude of wireless,interconnected devices that can dynamically join or exit the network without centralized administration or fixed infrastructure for routing.While multipath routing in IoT networks can improve data transmission reliability and load balancing by establishing multiple paths between source and destination nodes,these networks are susceptible to security threats due to their wireless nature.Traditional security solutions developed for conventional networks are often ill-suited to the unique challenges posed by IoT environments.In response to these challenges,this paper proposes the integration of the Ad hoc On-demand Multipath Distance Vector(AOMDV)routing protocol with a trust model to enhance network performance.Key findings from this research demonstrate the successful fusion of AOMDV with a trust model,resulting in tangible improvements in network performance.The assessment of trustworthiness bolsters both security and routing capabilities in IoT networks.The trust model plays a crucial role in mitigating black hole attacks in IoT networks by evaluating the trustworthiness of nodes and helping in the identification and avoidance of malicious nodes that may act as black holes.Simulation results validate the efficacy of the proposed trust-based routing mechanism in achieving its objectives.Trust plays a pivotal role in decision-making and in the creation of secure distribution systems.By assessing the trustworthiness of nodes,both network security and routing efficiency can be enhanced.The effectiveness of the proposed trust-based routing mechanism is scrutinized through simulations,offering insights into its potential advantages in terms of improved network security and routing performance in the context of the IoT.

面向大规模飞行自组网的NBATMAN-ADV路由协议

飞行自组网是当前研究的热点,当无人机节点规模较大时,大量的路由开销可能会导致网络瘫痪,因此路由协议的设计具有挑战性。针对大规模无人机场景,首先提出利用统一连通支配集算法构建虚拟骨干网,目的是减少路由洪泛的节点数;其次在骨干节点上部署和运行NBATMAN-ADV路由协议,利用物理层数据的接收信号强度指标和信噪比评价链路质量,在减少路由开销的同时,能够快速感知链路的变化情况。仿真结果表明,较传统的先验式路由协议如优化链路状态路由和目的节点序列距离矢量,该路由协议在数据包交付率、端到端时延和吞吐量上均有明显的提升。在通信模块上的实验结果表明,该路由协议在多跳时延方面有较好的性能。

丹参酮提取物调控JAK2/STAT3通路对AD大鼠炎症反应、学习记忆能力及海马神经元凋亡的影响

分析丹参酮提取物(Tan E)调控Janus激酶2/信号转导和转录激活因子3(JAK2/STAT3)通路对阿尔茨海默病(AD)大鼠炎症反应、学习记忆能力及海马神经元凋亡的影响。方法 选择30只健康SD大鼠,分为正常对照组、AD组、Tan E低剂量组、高剂量组及JAK2/STAT3通路激活剂(DUSP19)组。比较各组大鼠炎症反应、学习记忆能力及海马神经元凋亡情况,比较各组大鼠海马脑组织中JAK2/STAT3通路蛋白表达情况。结果 AD组白细胞介素-1β(IL-1β)、肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)水平相较于正常对照组明显升高(P<0.05);Tan E低、高剂量组IL-6、TNF-α、IL-1β水平相较于AD组明显下降;高剂量组IL-6、TNF-α、IL-1β水平相较于低剂量组明显下降(P<0.05)。AD组穿越平台次数相较于正常对照组明显降低(P<0.05);Tan E低、高剂量组穿越平台次数相较于AD组升高,且高剂量组学习记忆能力相较于低剂量组升高(P<0.05)。AD组神经元细胞凋亡率相较于正常对照组明显升高,神经元细胞数目明显下降;an E低、高剂量组神经元细胞凋亡率相较于AD组明显下降,神经元细胞数目明显增加(P<0.05)。AD组JAK2、STAT3表达相较于正常对照组明显升高(P<0.05);Tan E低、高剂量组JAK2、STAT3表达相较于AD组明显降低(P<0.05);DUSP19组JAK2、STAT3表达相较于Tan E剂量组明显升高(P<0.05)。结论 Tan E可有效提高AD大鼠模型学习记忆能力,改善脑组织炎症性反应并抑制其海马区神经元凋亡,具有一定的神经元保护作用。

基于CNN-LSTM-attention模型航迹预测研究

以航迹预测方法作为切入点,重庆-广州航路航空器记录的ADS-B数据作为研究内容,提出了一种融合注意力机制的长时序航迹预测方法(CNN-LSTM-attention)。研究运用一维卷积神经网络对航迹数据多维特征进行提取,并将经纬度、高度、速度、航向等的多维特征向量构造成时序形式作为LSTM网络输入,通过赋予LSTM网络隐含层的权重占比并区别不同时序点隐藏层信息对未来航迹预测的影响程度来达到优化预测模型的作用。构建好的CNN-LSTM-attention模型采用Adam优化算法进行训练,LSTM和CNN-LSTM作为实验对比模型,将决定系数R^(2)作为模型评价标准来衡量航迹预测模型的准确性。实验结果表明加入注意力机制的神经网络预测模型CNN+LSTM+attention(卷积神经网络-长短期记忆网络-注意力机制)的方法相较于其他两种,其预测精确性更高。

Variation of Added Mass and Its Application to the Calculation of Amplitude Response for A Circular Cylinder

In the present study, analyzed are the variation of added mass for a circular cylinder in the lock-in （synchronization） range of vortex-induced vibration （VIV） and the relationship between added mass and natural frequency. A theoretical minimum value of the added mass coefficient for a circular cylinder at lock-in is given. Developed are semi-empirical formulas for the added mass of a circular cylinder at lock-in as a function of flow speed and mass ratio. A comparison between experiments and numerical simulations shows that the semi-empirical formulas describing the variation of the added mass for a cireular cylinder at lock-in are better than the ideal added mass. In addition, computation models such as the wake oscillator model using the present formulas can predict the amplitude response of a circular cylinder at lock-in more accurately than those using the ideal added mass.

Added Resistance Acting on Hull of a Non Ballast Water Ship

In this paper, added resistances acting on a hull of non ballast water ship(NBS) in high waves is discussed. The non ballast water ships were developed at the laboratory of the authors at Osaka Prefecture University, Japan. In the present paper, the performances of three kinds of bow shapes developed for the NBS were theoretically and experimentally investigated to find the best one in high waves. In previous papers, an optimum bow shape for the NBS was developed in calm water and in moderated waves. For a 2 m model for experiments and computations, the wave height is 0.02 m. This means that the wave height is 15% of the draft of the ship in full load conditions. In this paper, added resistances in high waves up to 0.07 m for a 2 m model or 53% of the full load draft are investigated. In such high waves linear wave theories which have been used in the design stage of a ship for a long time may not work well anymore, and experiments are the only effective tool to predict the added resistance in high waves. With the computations for waves, the ship is in a fully captured condition because shorter waves, λ/Lpp<0.6, are assumed.

Numerical analysis of added mass and damping of floating production,storage and offloading system

An integral equation approach is utilized to in- vestigate the added mass and damping of floating produc- tion, storage and offloading system （FPSO system）. Finite water depth Green function and higher-order boundary ele- ment method are used to solve integral equation. Numeri- cal results about added mass and damping are presented for odd and even mode motions of FPSO. The results show ro- bust convergence in high frequency range and can be used in wave load analysis for FPSO designing and operation.