Hui Wei, Leibing Yan^*

CMES-Computer Modeling in Engineering & Sciences, Vol.137, No.2, pp. 1805-1824, 2023, DOI:10.32604/cmes.2023.028072

Abstract This paper focuses on the secrecy efficiency maximization in intelligent reflecting surface (IRS) assisted unmanned aerial vehicle (UAV) communication. With the popularization of UAV technology, more and more communication scenarios need UAV support. We consider using IRS to improve the secrecy efficiency. Specifically, IRS and UAV trajectories work together to counter potential eavesdroppers, while balancing the secrecy rate and energy consumption. The original problem is difficult to solve due to the coupling of optimization variables. We first introduce secrecy efficiency as an auxiliary variable and propose relaxation optimization problem, and then prove the equivalence between relaxation problem and the original… More >

Adel Hafeezallah¹, Ahlam Al-Dhamari^2,3,*, Syed Abd Rahman Abu-Bakar²

Computer Systems Science and Engineering, Vol.47, No.1, pp. 593-611, 2023, DOI:10.32604/csse.2023.039479

Abstract Visual motion segmentation (VMS) is an important and key part of many intelligent crowd systems. It can be used to figure out the flow behavior through a crowd and to spot unusual life-threatening incidents like crowd stampedes and crashes, which pose a serious risk to public safety and have resulted in numerous fatalities over the past few decades. Trajectory clustering has become one of the most popular methods in VMS. However, complex data, such as a large number of samples and parameters, makes it difficult for trajectory clustering to work well with accurate motion segmentation results. This study introduces a… More >

Kai Yang^*

Computer Systems Science and Engineering, Vol.47, No.1, pp. 317-332, 2023, DOI:10.32604/csse.2023.037266

Abstract With the rapid development of sports, the number of sports images has increased dramatically. Intelligent and automatic processing and analysis of moving images are significant, which can not only facilitate users to quickly search and access moving images but also facilitate staff to store and manage moving image data and contribute to the intellectual development of the sports industry. In this paper, a method of table tennis identification and positioning based on a convolutional neural network is proposed, which solves the problem that the identification and positioning method based on color features and contour features is not adaptable in various… More >

Ruidong Wu¹, Guowei Wang^2,3,4,*, Zhixing Yang¹, Ruiquan Liao^2,3,4, Yang Cheng^2,3,4

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.8, pp. 2053-2066, 2023, DOI:10.32604/fdmp.2023.026301

Abstract An experimental analysis has been conducted to study the process of fluid accumulation for different borehole trajectories. More specifically, five heel angles have been experimentally realized to simulate the borehole trajectory of the sloping section of the formation. The fluid-carrying capacity, pressure drop and fluid discharge volatility have been investigated for these conditions and, accordingly, the relationship between heel angle and wellbore pressure drop fluid-carrying capacity has been determined. The results show that while the reasonable roll angle can increase the pressure loss in the wellbore, it is beneficial to drainage. In terms of pressure loss and liquid-carrying capacity, when… More > Graphic Abstract

Jeong Min Yang^1,2, Hyeon Ji Lee¹, Jae Hyun Kim^1,2,3,*

International Journal of Mental Health Promotion, Vol.25, No.4, pp. 579-594, 2023, DOI:10.32604/ijmhp.2022.027498

Abstract Objectives: This study was to longitudinally investigate the association between occupational change trajectories and mental health in the Korean population aged 45 years and older from the Korean Longitudinal Study of Aging (KLoSA). Methods: After excluding missing values, the data of 6,224 participants from the first to eighth waves of the KLoSA were analyzed using t-test, Analysis of variance (ANOVA), Group-based Trajectory Model (GBTM) from 1–5^th KLoSA and Time-Lagged Generalized estimating equation (GEE) model from 5–8^th KLoSA to analyze the association between occupational change trajectories and mental health in the Korean population aged 45 years and older. Results: An analysis… More >

Xiaohui Cheng¹, Haiqing Si^1,*, Yao Li¹, Peihong Zhang²

CMES-Computer Modeling in Engineering & Sciences, Vol.136, No.2, pp. 1729-1742, 2023, DOI:10.32604/cmes.2023.022694

Abstract To understand the influence of the initial release conditions on the separation characteristics of the store and improve it under high Mach number (Ma = 4) flight conditions, the overset grid method and the Realizable turbulence model coupled with an equation with six degrees of freedom are used to simulate the store released from the internal bay. The motion trajectory and the attitude angle of the store separation under the conditions of different centroid, velocity, height and control measures are given by the calculated result. Through analysis, the position of the centroid will affect the separation of the store, which needs to… More >

Xiang Yu¹, Chonghua Wang², Xiaojing Zheng^3,*, Chaoyu Zeng⁴, Brij B. Gupta^5,6,7

CMC-Computers, Materials & Continua, Vol.75, No.1, pp. 2079-2099, 2023, DOI:10.32604/cmc.2023.034118

Abstract This paper constructs a non-cooperative/cooperative stochastic differential game model to prove that the optimal strategies trajectory of agents in a system with a topological configuration of a Multi-Local-World graph would converge into a certain attractor if the system’s configuration is fixed. Due to the economics and management property, almost all systems are divided into several independent Local-Worlds, and the interaction between agents in the system is more complex. The interaction between agents in the same Local-World is defined as a stochastic differential cooperative game; conversely, the interaction between agents in different Local-Worlds is defined as a stochastic differential non-cooperative game.… More >

Adil Khan^1,*, Jinling Zhang¹, Shabeer Ahmad¹, Saifullah Memon², Babar Hayat¹, Ahsan Rafiq³

CMC-Computers, Materials & Continua, Vol.74, No.3, pp. 4685-4702, 2023, DOI:10.32604/cmc.2023.034892

Abstract The main aim of future mobile networks is to provide secure, reliable, intelligent, and seamless connectivity. It also enables mobile network operators to ensure their customer’s a better quality of service (QoS). Nowadays, Unmanned Aerial Vehicles (UAVs) are a significant part of the mobile network due to their continuously growing use in various applications. For better coverage, cost-effective, and seamless service connectivity and provisioning, UAVs have emerged as the best choice for telco operators. UAVs can be used as flying base stations, edge servers, and relay nodes in mobile networks. On the other side, Multi-access Edge Computing (MEC) technology also… More >

Fadhil Mukhlif^1,*, Ashraf Osman Ibrahim², Norafida Ithnin¹, Roobaea Alroobaea³, Majed Alsafyani³

CMC-Computers, Materials & Continua, Vol.74, No.3, pp. 5589-5606, 2023, DOI:10.32604/cmc.2023.034323

Abstract Due to the fact that network space is becoming more limited, the implementation of ultra-dense networks (UDNs) has the potential to enhance not only network coverage but also network throughput. Unmanned Aerial Vehicle (UAV) communications have recently garnered a lot of attention due to the fact that they are extremely versatile and may be applied to a wide variety of contexts and purposes. A cognitive UAV is proposed as a solution for the Internet of Things ground terminal’s wireless nodes in this article. In the IoT system, the UAV is utilised not only to determine how the resources should be… More >

Yizhi Liu^1,3, Rutian Qing^1,3, Yijiang Zhao^1,3,*, Xuesong Wang^1,3, Zhuhua Liao^1,3, Qinghua Li^1,2, Buqing Cao^1,3

Computer Systems Science and Engineering, Vol.45, No.3, pp. 2505-2519, 2023, DOI:10.32604/csse.2023.021615

Abstract Short-term GPS data based taxi pick-up area recommendation can improve the efficiency and reduce the overheads. But how to alleviate sparsity and further enhance accuracy is still challenging. Addressing at these issues, we propose to fuse spatio-temporal contexts into deep factorization machine (STC_DeepFM) offline for pick-up area recommendation, and within the area to recommend pick-up points online using factorization machine (FM). Firstly, we divide the urban area into several grids with equal size. Spatio-temporal contexts are destilled from pick-up points or points-of-interest (POIs) belonged to the preceding grids. Secondly, the contexts are integrated into deep factorization machine (DeepFM) to mine… More >