Umar Zaman¹, Junaid Khan², Eunkyu Lee^1,3, Sajjad Hussain⁴, Awatef Salim Balobaid⁵, Rua Yahya Aburasain⁵, Kyungsup Kim^1,2,*

CMC-Computers, Materials & Continua, Vol.81, No.1, pp. 1789-1808, 2024, DOI:10.32604/cmc.2024.056222 - 15 October 2024

Abstract Maritime transportation, a cornerstone of global trade, faces increasing safety challenges due to growing sea traffic volumes. This study proposes a novel approach to vessel trajectory prediction utilizing Automatic Identification System (AIS) data and advanced deep learning models, including Long Short-Term Memory (LSTM), Gated Recurrent Unit (GRU), Bidirectional LSTM (DBLSTM), Simple Recurrent Neural Network (SimpleRNN), and Kalman Filtering. The research implemented rigorous AIS data preprocessing, encompassing record deduplication, noise elimination, stationary simplification, and removal of insignificant trajectories. Models were trained using key navigational parameters: latitude, longitude, speed, and heading. Spatiotemporal aware processing through trajectory segmentation… More >

Yali Si^1,2, Feng Li^1,*, Shan Zhong^1,2, Chenghang Huo³, Jing Chen⁴, Jinglian Liu^1,2

CMC-Computers, Materials & Continua, Vol.81, No.1, pp. 685-706, 2024, DOI:10.32604/cmc.2024.055141 - 15 October 2024

Abstract Point-of-interest (POI) recommendations in location-based social networks (LBSNs) have developed rapidly by incorporating feature information and deep learning methods. However, most studies have failed to accurately reflect different users’ preferences, in particular, the short-term preferences of inactive users. To better learn user preferences, in this study, we propose a long-short-term-preference-based adaptive successive POI recommendation (LSTP-ASR) method by combining trajectory sequence processing, long short-term preference learning, and spatiotemporal context. First, the check-in trajectory sequences are adaptively divided into recent and historical sequences according to a dynamic time window. Subsequently, an adaptive filling strategy is used to… More >

Jianhua Liu^*, Peng Xie, Jiajia Liu, Xiaoguang Tu

CMES-Computer Modeling in Engineering & Sciences, Vol.141, No.2, pp. 1243-1273, 2024, DOI:10.32604/cmes.2024.054002 - 27 September 2024

Abstract In mobile edge computing, unmanned aerial vehicles (UAVs) equipped with computing servers have emerged as a promising solution due to their exceptional attributes of high mobility, flexibility, rapid deployment, and terrain agnosticism. These attributes enable UAVs to reach designated areas, thereby addressing temporary computing swiftly in scenarios where ground-based servers are overloaded or unavailable. However, the inherent broadcast nature of line-of-sight transmission methods employed by UAVs renders them vulnerable to eavesdropping attacks. Meanwhile, there are often obstacles that affect flight safety in real UAV operation areas, and collisions between UAVs may also occur. To solve… More >

Syed Kamran Haider^1,2, Abbas Ahmed², Noman Mujeeb Khan², Ali Nauman^3,*, Sung Won Kim^3,*

CMC-Computers, Materials & Continua, Vol.80, No.3, pp. 4085-4110, 2024, DOI:10.32604/cmc.2024.052997 - 12 September 2024

Abstract In recent advancements within wireless sensor networks (WSN), the deployment of unmanned aerial vehicles (UAVs) has emerged as a groundbreaking strategy for enhancing routing efficiency and overall network functionality. This research introduces a sophisticated framework, driven by computational intelligence, that merges clustering techniques with UAV mobility to refine routing strategies in WSNs. The proposed approach divides the sensor field into distinct sectors and implements a novel weighting system for the selection of cluster heads (CHs). This system is primarily aimed at reducing energy consumption through meticulously planned routing and path determination. Employing a greedy algorithm More >

Hui Wei, Leibing Yan^*

CMES-Computer Modeling in Engineering & Sciences, Vol.137, No.2, pp. 1805-1824, 2023, DOI:10.32604/cmes.2023.028072 - 26 June 2023

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 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 - 26 May 2023

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… More >

Kai Yang^*

Computer Systems Science and Engineering, Vol.47, No.1, pp. 317-332, 2023, DOI:10.32604/csse.2023.037266 - 26 May 2023

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 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 - 04 April 2023

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… 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 - 01 March 2023

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:… 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 - 06 February 2023

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 More >