Ankit Kumar, Balram Dubey^*

CMES-Computer Modeling in Engineering & Sciences, Vol.126, No.2, pp. 505-547, 2021, DOI:10.32604/cmes.2021.013206

Abstract In this paper, the impact of additional food and two discrete delays on the dynamics of a prey-predator model is investigated. The interaction between prey and predator is considered as Holling Type-II functional response. The additional food is provided to the predator to reduce its dependency on the prey. One delay is the gestation delay in predator while the other delay is the delay in supplying the additional food to predators. The positivity, boundedness and persistence of the solutions of the system are studied to show the system as biologically well-behaved. The existence of steady states, their local and global… More >

Rihem Farkh^1,2,*, Khaled A. Aljaloud¹, Moufida Ksouri², Faouzi Bouani²

Computer Systems Science and Engineering, Vol.36, No.2, pp. 307-321, 2021, DOI:10.32604/csse.2021.014334

Abstract Proportional-Integral-Derivative control system has been widely used in industrial applications. For uncertain and unstable systems, tuning controller parameters to satisfy the process requirements is very challenging. In general, the whole system’s performance strongly depends on the controller’s efficiency and hence the tuning process plays a key role in the system’s response. This paper presents a robust optimal Proportional-Integral-Derivative controller design methodology for the control of unstable delay system with parametric uncertainty using a combination of Kharitonov theorem and genetic algorithm optimization based approaches. In this study, the Generalized Kharitonov Theorem (GKT) for quasi-polynomials is employed for the purpose of designing… More >

Fan Zhang^1,2, Fenlin Liu^1,2,*, Rui Xu^3,4, Xiangyang Luo^1,2, Shichang Ding⁵, Hechan Tian^1,2

CMC-Computers, Materials & Continua, Vol.66, No.3, pp. 3345-3361, 2021, DOI:10.32604/cmc.2021.014526

Abstract Existing IP geolocation algorithms based on delay similarity often rely on the principle that geographically adjacent IPs have similar delays. However, this principle is often invalid in real Internet environment, which leads to unreliable geolocation results. To improve the accuracy and reliability of locating IP in real Internet, a street-level IP geolocation algorithm based on landmarks clustering is proposed. Firstly, we use the probes to measure the known landmarks to obtain their delay vectors, and cluster landmarks using them. Secondly, the landmarks are clustered again by their latitude and longitude, and the intersection of these two clustering results is taken… More >

Khairol Amali bin Ahmad¹, Mohammad Nazmul Hasan², Md. Sharif Hossen^2,*, Khaleel Ahmad³

CMC-Computers, Materials & Continua, Vol.66, No.3, pp. 3075-3087, 2021, DOI:10.32604/cmc.2021.014436

Abstract Pocket Switched Networks (PSN) represent a particular remittent network for direct communication between the handheld mobile devices. Compared to traditional networks, there is no stable topology structure for PSN where the nodes observe the mobility model of human society. It is a kind of Delay Tolerant Networks (DTNs) that gives a description to circulate information among the network nodes by the way of taking the benefit of transferring nodes from one area to another. Considering its inception, there are several schemes for message routing in the infrastructure-less environment in which human mobility is only the best manner to exchange information.… More >

Ahmed Y. Hamed¹, Monagi H. Alkinani², M. R. Hassan^3,*

Intelligent Automation & Soft Computing, Vol.26, No.6, pp. 1201-1216, 2020, DOI:10.32604/iasc.2020.012663

Abstract Many applications require to send information from a source node to multiple destinations nodes. To support these applications, the paper presents a multi-objective based genetic algorithm, which is used in the construction of the multicast tree for data transmission in a computer network. The proposed algorithm simultaneously optimizes total weights (cost, delay, and hop) of the multicast tree. Experimental results prove that the proposed algorithm outperforms a recently published Multi-objective Multicast Algorithm specially designed for solving the multicast routing problem. Also, the proposed approach has been applied to ten-node and twenty-node network to illustrate its efficiency. In addition, the execution… More >

Zejian Zhang¹, Dawei Wang^2,*, Peng Li¹, Xiao-Zhi Gao³

Intelligent Automation & Soft Computing, Vol.26, No.5, pp. 905-915, 2020, DOI:10.32604/iasc.2020.010123

Abstract In this paper, the stabilization problem of an observer-based T-S fuzzy time-delay system under imperfect premise matching is studied, in which the T-S fuzzy observer model with time-delay and the fuzzy controller do not share the same membership functions. The objective is to design a state observer and unmatching fuzzy controller such that the closed-loop system with time-delay is asymptotically stable. A sufficient condition for the stabilization via observerbased state feedback under imperfect premise matching is presented, and an observer-based state feedback controller under imperfect premise is also constructed. The proposed control scheme is well capable of enhancing the design… More >

Fadhila Mansour^1,2,*, Abdelhak Lakehal^2,3, Lahcène Nezzal^2,3

Oncologie, Vol.22, No.3, pp. 117-128, 2020, DOI:10.32604/oncologie.2020.014979

Abstract The objective of this study was to quantify the delays in access to diagnosis and treatment of women with breast cancer who are managed at the anticancer center of Batna, Algeria. This was a descriptive retrospective study conducted during the period August 2015 to February 2016. In order to trace the history of the journey from the first signs of cancer to the first treatments, a questionnaire was filled in from the medical files and completed by an interview with the patients. A total of 267 patients were included in the study. The median time to management was 4.5 months.… More >

Senyun Liu^1,2, Qinglin Liu^1,2, Xian Yi^1,2,*, Yizhou Shen^4,*, Long Guo^1,2, Wenqing Hou⁴, Haifeng Chen³, Zhen Wang⁴

Journal of Renewable Materials, Vol.8, No.12, pp. 1617-1631, 2020, DOI:10.32604/jrm.2020.014158

Abstract The aim of this study is to explore the heterogeneous ice nucleation behavior based on controllable micro-cubic array structure surfaces from the statistic perspective. To this end, we firstly constructed a group of micro-cubic array structures on silicon substrates by a selective plasma etching technique. After grafting low-free-energy substance, the as-constructed micro-cubic array structure surfaces exhibited higher non-wettability with the water contact angle being up to 150°. On this basis, 500 cycles of freezing and melting processes were accurately recorded to analyze the instantaneous ice nucleation behavior according to the statistical results of freezing temperature. As a consequence, the statistical… More >

Qixue Guan^*, Yueqiu Jiang

Intelligent Automation & Soft Computing, Vol.26, No.4, pp. 773-781, 2020, DOI:10.32604/iasc.2020.010112

Abstract It is known that congestion in the reverse direction happens in advance of the congestion in the forward direction due to the significant bandwidth asymmetry in the two directions of the space networks, especially in the satellite networks, which enables the TCP Vegas to enter the phase of the congestion avoidance blindly and reduce the throughput of the forward direction. To solve this problem, a congestion control model, TCP Vegas-DDA, which maintains the frequency of the acknowledgments in the reverse direction is proposed. The model sets the interval time between acknowledgments dynamically based on the variation of the queuing delay… More >

Y. A. Amer¹, A. T. El-Sayed², M. N. Abd El-Salam^3,*

Sound & Vibration, Vol.54, No.3, pp. 149-161, 2020, DOI:10.32604/sv.2020.08469

Abstract In this paper, we used time delay feedback to minimize the vibrations of a hybrid Rayleigh–van der Pol–Duffing oscillator. This system is a one-degree-offreedom containing the cubic and fifth nonlinear terms and an external force. We applied the multiple scales method to get the solution from first approximation. Graphically and numerically, we studied the system before and after adding time delay feedback at the primary resonance case (Ω ≌ ω). We used MATLAB program to simulate the efficacy of different parameters and the time delay on the main system. More >