K. Raju^*, M. Chinnadurai

CMC-Computers, Materials & Continua, Vol.69, No.1, pp. 1057-1072, 2021, DOI:10.32604/cmc.2021.016068 - 04 June 2021

Abstract Security is a critical issue in cloud computing (CC) because attackers can fabricate data by creating, copying, or deleting data with no user authorization. Most of the existing techniques make use of password-based authentication for encrypting data. Password-based schemes suffer from several issues and can be easily compromised. This paper presents a new concept of hybrid metaheuristic optimization as an identity-based secure and optimal authentication (HMO-ISOA) scheme for CC environments. The HMO-ISOA technique makes use of iris and fingerprint biometrics. Initially, the HMO-ISOA technique involves a directional local ternary quantized extrema pattern–based feature extraction process… More >

Maatouk Khoukhi^*, Omar Al Khatib

Energy Engineering, Vol.118, No.4, pp. 875-909, 2021, DOI:10.32604/EE.2021.015835 - 31 May 2021

Abstract This paper reviews the principle and application of the thermally activated desiccant cooling systems with their capability to perform efficiently in hot-humid climates. The paper first introduces the continuous increase of thermal comfort required in building and their relation with the consumption of conventional energy sources. The importance of desiccant cooling technology and its applications has been introduced as well. The energy and environmental issues with the conventional energy supply and the demand with the environmental problems and conditions mainly related to indoor air quality have been also discussed in the second chapter of this More >

Heonmoo Kim, Yosoon Choi^*

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.3, pp. 943-964, 2021, DOI:10.32604/cmes.2021.015300 - 24 May 2021

Abstract In underground mine environments where various hazards exist, such as tunnel collapse, toxic gases, the application of autonomous robots can improve the stability of exploration and efficiently perform repetitive exploratory operations. In this study, we developed a small autonomous driving robot for unmanned environmental monitoring in underground mines. The developed autonomous driving robot controls the steering according to the distance to the tunnel wall measured using the light detection and ranging sensor mounted on the robot to estimate its location by simultaneously considering the measured values of the inertial measurement unit and encoder sensors. In… More >

Ahmad Almufarreh, Muhammad Arshad^*, Sameer Hassan Mohammed

Intelligent Automation & Soft Computing, Vol.29, No.1, pp. 73-87, 2021, DOI:10.32604/iasc.2021.017803 - 12 May 2021

Abstract Without the constraints of time and place, e-learning can offer a strong learning environment. The notion of e-learning has taken on a new sense with the advent and popularization of mobile devices and ubiquitous computing, enabling students to have access to several diverse opportunities for communicating with e-learning programs. Around the same time, it has prompted the course’s planners to select the most suitable technology from among the various innovations required for the storing and dissemination of information representation. As a Learning Management System (LMS), the Blackboard system now has a recognized role in the… More >

Jaber Almutairi¹, Mohammad Aldossary^2,*,*

CMC-Computers, Materials & Continua, Vol.68, No.3, pp. 4143-4160, 2021, DOI:10.32604/cmc.2021.018145 - 06 May 2021

Abstract Recently, the number of Internet of Things (IoT) devices connected to the Internet has increased dramatically as well as the data produced by these devices. This would require offloading IoT tasks to release heavy computation and storage to the resource-rich nodes such as Edge Computing and Cloud Computing. However, different service architecture and offloading strategies have a different impact on the service time performance of IoT applications. Therefore, this paper presents an Edge-Cloud system architecture that supports scheduling offloading tasks of IoT applications in order to minimize the enormous amount of transmitting data in the More >

Jaehwan Lee, Sangoh Park^*

CMC-Computers, Materials & Continua, Vol.68, No.3, pp. 4031-4050, 2021, DOI:10.32604/cmc.2021.017872 - 06 May 2021

Abstract Currently, the number of functions to improve user convenience in smartphone applications is increasing. In addition, more mobile applications are being loaded into mobile operating system memory for faster launches, thus increasing the memory requirements for smartphones. The memory used by applications in mobile operating systems is managed using software; allocated memory is freed up by either considering the usage state of the application or terminating the least recently used (LRU) application. As LRU-based memory management schemes do not consider the application launch frequency in a low memory situation, currently used mobile operating systems can… More >

Shiqi Wang¹, Mingfang Jiang^2,*, Jiaohua Qin¹, Hengfu Yang², Zhichen Gao³

CMC-Computers, Materials & Continua, Vol.68, No.3, pp. 2979-2993, 2021, DOI:10.32604/cmc.2021.017094 - 06 May 2021

Abstract In the era of big data, outsourcing massive data to a remote cloud server is a promising approach. Outsourcing storage and computation services can reduce storage costs and computational burdens. However, public cloud storage brings about new privacy and security concerns since the cloud servers can be shared by multiple users. Privacy-preserving feature extraction techniques are an effective solution to this issue. Because the Rotation Invariant Local Binary Pattern (RILBP) has been widely used in various image processing fields, we propose a new privacy-preserving outsourcing computation of RILBP over encrypted images in this paper (called More >

Shinjin Kang¹, Soo Kyun Kim^2,*

CMC-Computers, Materials & Continua, Vol.68, No.3, pp. 3725-3736, 2021, DOI:10.32604/cmc.2021.016828 - 06 May 2021

Abstract In this study, we propose a low-cost system that can detect the space outlier utilization of residents in an indoor environment. We focus on the users’ app usage to analyze unusual behavior, especially in indoor spaces. This is reflected in the behavioral analysis in that the frequency of using smartphones in personal spaces has recently increased. Our system facilitates autonomous data collection from mobile app logs and Google app servers and generates a high-dimensional dataset that can detect outlier behaviors. The density-based spatial clustering of applications with noise (DBSCAN) algorithm was applied for effective singular… More >

Yihuai Liang, Yan Li, Byeong-Seok Shin^*

CMC-Computers, Materials & Continua, Vol.68, No.3, pp. 2825-2842, 2021, DOI:10.32604/cmc.2021.016682 - 06 May 2021

Abstract A centralized trusted execution environment (TEE) has been extensively studied to provide secure and trusted computing. However, a TEE might become a throughput bottleneck if it is used to evaluate data quality when collecting large-scale data in a crowdsourcing system. It may also have security problems compromised by attackers. Here, we propose a scheme, named dTEE, for building a platform for providing distributed trusted computing by leveraging TEEs. The platform is used as an infrastructure of trusted computations for blockchain-based crowdsourcing systems, especially to securely evaluate data quality and manage remuneration: these operations are handled… More >

Songchen Wang, Xinmei Li^*, Cheng Chai, Gen Wang, Caibin Lu

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.3, pp. 653-666, 2021, DOI:10.32604/fdmp.2021.015127 - 29 April 2021

Abstract The interaction of U-shaped rings used for power transmission hardware with a wind-sand field is simulated numerically. A standard turbulence model is used in synergy with an Eulerian-Lagrangian approach. The results show that the wind pressure on the windward side of the U-shaped ring is the highest, a negative pressure zone appears on both sides of the U-shaped ring, while a Kármán Vortex Street is created on its leeward side. There are three possible regimes of motion for the sand grains in the wind field. Sand grains with size below 0.125 mm can follow the More >