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Keywords = data center energy efficiency improvement

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27 pages, 11681 KiB  
Article
HyperGAN: A Hyperspectral Image Fusion Approach Based on Generative Adversarial Networks
by Jing Wang, Xu Zhu, Linhai Jing, Yunwei Tang, Hui Li, Zhengqing Xiao and Haifeng Ding
Remote Sens. 2024, 16(23), 4389; https://doi.org/10.3390/rs16234389 - 24 Nov 2024
Viewed by 457
Abstract
The objective of hyperspectral pansharpening is to fuse low-resolution hyperspectral images (LR-HSI) with corresponding panchromatic (PAN) images to generate high-resolution hyperspectral images (HR-HSI). Despite advancements in hyperspectral (HS) pansharpening using deep learning, the rich spectral details and large data volume of HS images [...] Read more.
The objective of hyperspectral pansharpening is to fuse low-resolution hyperspectral images (LR-HSI) with corresponding panchromatic (PAN) images to generate high-resolution hyperspectral images (HR-HSI). Despite advancements in hyperspectral (HS) pansharpening using deep learning, the rich spectral details and large data volume of HS images place higher demands on models for effective spectral extraction and processing. In this paper, we present HyperGAN, a hyperspectral image fusion approach based on Generative Adversarial Networks. Unlike previous methods that deepen the network to capture spectral information, HyperGAN widens the structure with a Wide Block for multi-scale learning, effectively capturing global and local details from upsampled HSI and PAN images. While LR-HSI provides rich spectral data, PAN images offer spatial information. We introduce the Efficient Spatial and Channel Attention Module (ESCA) to integrate these features and add an energy-based discriminator to enhance model performance by learning directly from the Ground Truth (GT), improving fused image quality. We validated our method on various scenes, including the Pavia Center, Eastern Tianshan, and Chikusei. Results show that HyperGAN outperforms state-of-the-art methods in visual and quantitative evaluations. Full article
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<p>The flowchart of HyperGAN. G denotes the generator and D denotes the discriminator. The upsampled LR-HSI is resized to the same resolution as the PAN image. CA denotes channel attention and SA denotes spatial attention. C stands for contact, N represents the number of spectral bands, <math display="inline"><semantics> <mrow> <mi mathvariant="normal">“</mi> <mo>+</mo> <mi mathvariant="normal">”</mi> </mrow> </semantics></math> denotes addition, <math display="inline"><semantics> <mrow> <mi mathvariant="normal">“</mi> <mo>×</mo> <mi mathvariant="normal">”</mi> </mrow> </semantics></math> and denotes multiplication.</p>
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<p>The architecture of generator. <math display="inline"><semantics> <mrow> <mi mathvariant="normal">“</mi> <mo>↑</mo> <mi mathvariant="normal">”</mi> </mrow> </semantics></math> represents upsampling.</p>
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<p>The detailed structure of the Resblock (<b>a</b>) and the Wide Block (<b>b</b>). ESCA includes channel attention (<b>c</b>) and spatial attention (<b>d</b>). LeakyReLU represents an activation function, N represents the number of spectral bands, GAP represents Global Average Pooling, Norm represents batchnorm.</p>
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<p>The architecture of discriminator. “SPLIT” represents the separation of the fused image after convolution from the GT, and <math display="inline"><semantics> <mrow> <mi mathvariant="normal">“</mi> <mo>−</mo> <mi mathvariant="normal">”</mi> </mrow> </semantics></math> represents subtraction.</p>
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<p>Comparison of all methods on the Pavia Center dataset with a fusion ratio of 1:6.</p>
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<p>Comparison of all methods on the Eastern Tianshan dataset with a fusion ratio of 1:6.</p>
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<p>Comparison of all methods on the Chikusei dataset with a fusion ratio of 1:6.</p>
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<p>Visualization of the Pavia Center dataset: (<b>a</b>) statistical feature analysis, (<b>b</b>) PCA scatter plot after dimensionality reduction.</p>
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<p>Visualization of the Eastern Tianshan dataset: (<b>a</b>) statistical feature analysis, (<b>b</b>) PCA scatter plot after dimensionality reduction.</p>
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<p>Visualization of the Chikusei dataset: (<b>a</b>) statistical feature analysis, (<b>b</b>) PCA scatter plot after dimensionality reduction.</p>
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<p>Comparison of all methods on the Pavia Center dataset with a fusion ratio of 1:12.</p>
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<p>Comparison of all methods on the Eastern Tianshan dataset with a fusion ratio of 1:12.</p>
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<p>Comparison of all methods on the Chikusei dataset with a fusion ratio of 1:12.</p>
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<p>Comparison of different Gaussian kernel effects in data processing on the Pavia Center dataset.</p>
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<p>Comparison of different Gaussian kernel effects in data processing on the Eastern Tianshan dataset.</p>
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<p>Comparison of different Gaussian kernel effects in data processing on the Chikusei dataset.</p>
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18 pages, 610 KiB  
Article
A Discrete Brain Storm Optimization Algorithm for Hybrid Flowshop Scheduling Problems with Batch Production at Last Stage in the Steelmaking-Refining-Continuous Casting Process
by Kunkun Peng, Chunjiang Zhang, Weiming Shen, Xinfu Pang, Yanlan Mei and Xudong Deng
Sensors 2024, 24(22), 7137; https://doi.org/10.3390/s24227137 - 6 Nov 2024
Viewed by 758
Abstract
The iron and steel industry is energy-intensive due to the large volume of steel produced and its high-temperature and high-weight characteristics, sensors such as high-temperature application sensors can be utilized to collect production data and support the process control and optimization. Steelmaking-refining-continuous casting [...] Read more.
The iron and steel industry is energy-intensive due to the large volume of steel produced and its high-temperature and high-weight characteristics, sensors such as high-temperature application sensors can be utilized to collect production data and support the process control and optimization. Steelmaking-refining-continuous casting (SRCC) is a bottleneck in the iron and steel production process. SRCC scheduling problems are worldwide problems and NP-hard. The problems are not only important for iron and steel enterprises to enhance production efficiency, but also play a significant role in saving energy and reducing resource consumption. SRCC scheduling problems can be modeled as hybrid flowshop scheduling problems with batch production at the last stage. In this paper, a Discrete Brain Storm Optimization (DBSO) algorithm is proposed to handle SRCC scheduling problems. In the proposed DBSO, population initialization and cluster center replacement are specially designed to enhance the intensification abilities. Moreover, a perturbation operator is devised to enhance its diversification abilities. Furthermore, a new individual generation operator is devised to improve the intensification and diversification abilities simultaneously. Experimental results have demonstrated that the proposed DBSO is an efficient method for solving SRCC scheduling problems. Full article
(This article belongs to the Special Issue Internet of Things, Big Data and Smart Systems II)
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<p>Illustration of a simple SRCC process [<a href="#B15-sensors-24-07137" class="html-bibr">15</a>,<a href="#B18-sensors-24-07137" class="html-bibr">18</a>].</p>
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<p>The flowchart of the proposed DBSO.</p>
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<p>The Gantt chart of the best schedule obtained by DBSO.</p>
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17 pages, 2607 KiB  
Article
Energy Consumption Trends and Determinants in Polish Hospitals: Implications for Energy Efficiency Strategies
by Małgorzata Cygańska and Magdalena Kludacz-Alessandri
Sustainability 2024, 16(21), 9153; https://doi.org/10.3390/su16219153 - 22 Oct 2024
Viewed by 739
Abstract
In the construction sector, hospitals are the buildings with the highest energy consumption. Due to the high demand for energy, hospitals’ energy efficiency is becoming very important. This study aims to examine the trends and factors that determine energy consumption in Polish hospitals [...] Read more.
In the construction sector, hospitals are the buildings with the highest energy consumption. Due to the high demand for energy, hospitals’ energy efficiency is becoming very important. This study aims to examine the trends and factors that determine energy consumption in Polish hospitals from 2010 to 2019, highlighting the impact of hospital size and medical activities on energy efficiency. The analysis was carried out using data from 3061 hospital reports obtained from the e-Health Center, a state budgetary unit established by the Minister of Health. To measure and compare the efficiency of energy usage in hospitals, we developed eight energy usage efficiency indexes based on hospital size and medical activity. The size of the hospitals was described by the number of beds, operation rooms, doctors, nurses, and fixed assets value. Hospital activity was measured by the number of person-days, patients, and operations. Statistical analysis was carried out using StatSoft Statistica software version 13.3. The results show that larger hospitals are more energy efficient across various measures of energy use than smaller hospitals. The findings revealed also several important relationships between energy usage and factors connected with size and hospital activity, such as the number of beds, patients and person-days, medical staff, operations, and fixed asset values, underscoring the necessity for customizing energy efficiency strategies. This research contributes empirical insights that can guide policymakers and hospital administrators in their endeavors to improve energy efficiency and promote sustainability within healthcare facilities. Full article
(This article belongs to the Special Issue Energy Economy and Sustainable Energy)
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<p>Energy consumption in 2010–2019 by hospitals: (<b>a</b>) in total; (<b>b</b>) by size.</p>
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<p>The number of person-days (<b>a</b>) and patients (<b>b</b>) in hospitals by size in 2010–2019.</p>
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<p>The number of operations (<b>a</b>) and operating rooms (<b>b</b>) in hospitals by size in 2010–2019.</p>
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<p>The number of doctors (<b>a</b>) and nurses (<b>b</b>) in hospitals by size in 2010–2019.</p>
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<p>The number of beds (<b>a</b>) and fixed assets value (<b>b</b>) in hospitals by size in 2010–2019.</p>
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<p>Energy consumption per person-day in 2010–2019: (<b>a</b>) total; (<b>b</b>) by number of beds.</p>
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<p>Energy consumption per patient by hospitals in 2010–2019: (<b>a</b>) hospitals total; (<b>b</b>) by number of beds.</p>
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<p>Energy consumption per number of beds by hospitals in 2010–2019: (<b>a</b>) hospitals total; (<b>b</b>) by hospital size.</p>
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<p>Energy consumption per operating room by hospitals in 2010–2019: (<b>a</b>) hospitals total; (<b>b</b>) by number of beds.</p>
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<p>Energy consumption per doctor by hospitals in 2010–2019: (<b>a</b>) hospitals total; (<b>b</b>) by number of beds.</p>
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<p>Energy consumption per nurse by hospitals in 2010–2019: (<b>a</b>) hospitals total; (<b>b</b>) by number of beds.</p>
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<p>Energy consumption per fixed asset value by hospitals in 2010–2019: (<b>a</b>) hospitals total; (<b>b</b>) by number of beds.</p>
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40 pages, 3325 KiB  
Article
Cybersecurity in a Scalable Smart City Framework Using Blockchain and Federated Learning for Internet of Things (IoT)
by Seyed Salar Sefati, Razvan Craciunescu, Bahman Arasteh, Simona Halunga, Octavian Fratu and Irina Tal
Smart Cities 2024, 7(5), 2802-2841; https://doi.org/10.3390/smartcities7050109 - 1 Oct 2024
Viewed by 2287
Abstract
Smart cities increasingly rely on the Internet of Things (IoT) to enhance infrastructure and public services. However, many existing IoT frameworks face challenges related to security, privacy, scalability, efficiency, and low latency. This paper introduces the Blockchain and Federated Learning for IoT (BFLIoT) [...] Read more.
Smart cities increasingly rely on the Internet of Things (IoT) to enhance infrastructure and public services. However, many existing IoT frameworks face challenges related to security, privacy, scalability, efficiency, and low latency. This paper introduces the Blockchain and Federated Learning for IoT (BFLIoT) framework as a solution to these issues. In the proposed method, the framework first collects real-time data, such as traffic flow and environmental conditions, then normalizes, encrypts, and securely stores it on a blockchain to ensure tamper-proof data management. In the second phase, the Data Authorization Center (DAC) uses advanced cryptographic techniques to manage secure data access and control through key generation. Additionally, edge computing devices process data locally, reducing the load on central servers, while federated learning enables distributed model training, ensuring data privacy. This approach provides a scalable, secure, efficient, and low-latency solution for IoT applications in smart cities. A comprehensive security proof demonstrates BFLIoT’s resilience against advanced cyber threats, while performance simulations validate its effectiveness, showing significant improvements in throughput, reliability, energy efficiency, and reduced delay for smart city applications. Full article
(This article belongs to the Special Issue The Convergence of 5G and IoT in a Smart City Context)
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<p>Conceptual framework for secure and scalable IoT integration in smart city infrastructure.</p>
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<p>ProVerif verification process.</p>
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<p>Comparative Analysis of Computational Overhead in Cryptographic Operations across BFLIoT Scenarios.</p>
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<p>Reliability in differnet number of sensors.</p>
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<p>Energy consumption of different security methods as a function of the number of sensors.</p>
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<p>Latency in different numbers of nodes.</p>
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<p>Model accuracy in different epochs.</p>
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<p>Model loss in different epochs.</p>
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15 pages, 13605 KiB  
Article
Dynamic Performance and Power Optimization with Heterogeneous Processing-in-Memory for AI Applications on Edge Devices
by Sangmin Jeon, Kangju Lee, Kyeongwon Lee and Woojoo Lee
Micromachines 2024, 15(10), 1222; https://doi.org/10.3390/mi15101222 - 30 Sep 2024
Viewed by 1684
Abstract
The rapid advancement of artificial intelligence (AI) technology, combined with the widespread proliferation of Internet of Things (IoT) devices, has significantly expanded the scope of AI applications, from data centers to edge devices. Running AI applications on edge devices requires a careful balance [...] Read more.
The rapid advancement of artificial intelligence (AI) technology, combined with the widespread proliferation of Internet of Things (IoT) devices, has significantly expanded the scope of AI applications, from data centers to edge devices. Running AI applications on edge devices requires a careful balance between data processing performance and energy efficiency. This challenge becomes even more critical when the computational load of applications dynamically changes over time, making it difficult to maintain optimal performance and energy efficiency simultaneously. To address these challenges, we propose a novel processing-in-memory (PIM) technology that dynamically optimizes performance and power consumption in response to real-time workload variations in AI applications. Our proposed solution consists of a new PIM architecture and an operational algorithm designed to maximize its effectiveness. The PIM architecture follows a well-established structure known for effectively handling data-centric tasks in AI applications. However, unlike conventional designs, it features a heterogeneous configuration of high-performance PIM (HP-PIM) modules and low-power PIM (LP-PIM) modules. This enables the system to dynamically adjust data processing based on varying computational load, optimizing energy efficiency according to the application’s workload demands. In addition, we present a data placement optimization algorithm to fully leverage the potential of the heterogeneous PIM architecture. This algorithm predicts changes in application workloads and optimally allocates data to the HP-PIM and LP-PIM modules, improving energy efficiency. To validate and evaluate the proposed technology, we implemented the PIM architecture and developed an embedded processor that integrates this architecture. We performed FPGA prototyping of the processor, and functional verification was successfully completed. Experimental results from running applications with varying workload demands on the prototype PIM processor demonstrate that the proposed technology achieves up to 29.54% energy savings. Full article
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<p>Proposed heterogeneous PIM architecture.</p>
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<p>Weight allocation scheme for convolution layers in the proposed heterogeneous PIM architecture.</p>
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<p>Weight allocation scheme for fully connected layers in the proposed PIM architecture.</p>
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<p>Relationship between time parameters in the proposed weight placement strategy.</p>
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<p>Prediction of inference occurrence level using the SES method.</p>
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<p>Architecture of the prototyped processor with the proposed heterogeneous PIM.</p>
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<p>A demonstration of running a testbench on the FPGA prototype of the processor equipped with the heterogeneous PIM.</p>
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<p>Measured results of data placement from the testbench application. The input pattern for each case is described at the top of the plot. The blue line indicates the number of tasks, while the green line shows <math display="inline"><semantics> <mrow> <mi>L</mi> <mi>e</mi> <mi>v</mi> <mi>e</mi> <mi>l</mi> <mo>_</mo> <mi>r</mi> <mi>e</mi> <mi>a</mi> <mi>l</mi> </mrow> </semantics></math>. The red line represents <math display="inline"><semantics> <mrow> <mi>L</mi> <mi>e</mi> <mi>v</mi> <mi>e</mi> <mi>l</mi> <mo>_</mo> <mi>p</mi> <mi>r</mi> <mi>e</mi> <mi>d</mi> </mrow> </semantics></math>.</p>
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14 pages, 4118 KiB  
Article
Towards Sustainability and Energy Efficiency Using Data Analytics for HPC Data Center
by Andrea Chinnici, Eyvaz Ahmadzada, Ah-Lian Kor, Davide De Chiara, Adrián Domínguez-Díaz, Luis de Marcos Ortega and Marta Chinnici
Electronics 2024, 13(17), 3542; https://doi.org/10.3390/electronics13173542 - 6 Sep 2024
Viewed by 973
Abstract
High-performance computing (HPC) in data centers increases energy use and operational costs. Therefore, it is necessary to efficiently manage resources for the sustainability of and reduction in the carbon footprint. This research analyzes and optimizes ENEA HPC data centers, particularly the CRESCO6 cluster. [...] Read more.
High-performance computing (HPC) in data centers increases energy use and operational costs. Therefore, it is necessary to efficiently manage resources for the sustainability of and reduction in the carbon footprint. This research analyzes and optimizes ENEA HPC data centers, particularly the CRESCO6 cluster. The study starts by gathering and cleaning extensive datasets consisting of job schedules, environmental conditions, cooling systems, and sensors. Descriptive statistics accompanied with visualizations provide deep insight into collated data. Inferential statistics are then used to investigate relationships between various operational variables. Finally, machine learning models predict the average hot-aisle temperature based on cooling parameters, which can be used to determine optimal cooling settings. Furthermore, idle periods for computing nodes are analyzed to estimate wasted energy, as well as for evaluating the effect that idle node shutdown will have on the thermal characteristics of the data center under consideration. It closes with a discussion on how statistical and machine learning techniques can improve operations in a data center by focusing on important variables that determine consumption patterns. Full article
(This article belongs to the Special Issue High-Performance Software Systems)
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<p>Daily job counts.</p>
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<p>Job status distribution.</p>
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<p>Temperature and humidity trends Over time.</p>
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<p>Average CPU temperature and node temperature differences over time.</p>
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<p>Correlation matrix Between environment and cooling parameters.</p>
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<p>Actual vs. predicted average hot-Aisle temperature based on cooling parameters.</p>
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<p>Actual vs. predicted fan speed values under ideal conditions.</p>
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<p>Actual vs. predicted (ideal) average hot-Aisle temperature.</p>
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<p>Actual vs. predicted average hot-Aisle temperature based on sensor parameters.</p>
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<p>Actual vs. predicted average Hot-Aisle temperature on updated data.</p>
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18 pages, 1648 KiB  
Article
Parameters Identification for Lithium-Ion Battery Models Using the Levenberg–Marquardt Algorithm
by Ashraf Alshawabkeh, Mustafa Matar and Fayha Almutairy
World Electr. Veh. J. 2024, 15(9), 406; https://doi.org/10.3390/wevj15090406 - 5 Sep 2024
Viewed by 1749
Abstract
The increasing adoption of batteries in a variety of applications has highlighted the necessity of accurate parameter identification and effective modeling, especially for lithium-ion batteries, which are preferred due to their high power and energy densities. This paper proposes a comprehensive framework using [...] Read more.
The increasing adoption of batteries in a variety of applications has highlighted the necessity of accurate parameter identification and effective modeling, especially for lithium-ion batteries, which are preferred due to their high power and energy densities. This paper proposes a comprehensive framework using the Levenberg–Marquardt algorithm (LMA) for validating and identifying lithium-ion battery model parameters to improve the accuracy of state of charge (SOC) estimations, using only discharging measurements in the N-order Thevenin equivalent circuit model, thereby increasing computational efficiency. The framework encompasses two key stages: model parameter identification and model verification. This framework is validated using experimental measurements on the INR 18650-20R battery, produced by Samsung SDI Co., Ltd. (Suwon, Republic of Korea), conducted by the Center for Advanced Life Cycle Engineering (CALCE) battery group at the University of Maryland. The proposed framework demonstrates robustness and accuracy. The results indicate that optimization using only the discharging data suffices for accurate parameter estimation. In addition, it demonstrates excellent agreement with the experimental measurements. The research underscores the effectiveness of the proposed framework in enhancing SOC estimation accuracy, thus contributing significantly to the reliable performance and longevity of lithium-ion batteries in practical applications. Full article
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<p>ECM of the Li-ion battery model that consists of N pairs of resistors and capacitors connected in parallel, using Thevenin’s method.</p>
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<p>The proposed framework for battery model verification and parameter identification.</p>
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<p>Experimental discharging current.</p>
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<p>Experimental charging current.</p>
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<p>Experimental setup for battery tests.</p>
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<p>A cylindrical INR 18650-20R cell utilized in this study.</p>
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<p>The simulation and experimental comparison results of the <math display="inline"><semantics> <msub> <mi>V</mi> <mi>t</mi> </msub> </semantics></math> described by the first-order RC equivalent circuit model during the discharge phase.</p>
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<p>The simulation and experimental comparison results of the <math display="inline"><semantics> <msub> <mi>V</mi> <mi>t</mi> </msub> </semantics></math> described by the second-order RC equivalent circuit model during the discharge phase.</p>
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<p>The simulation and experimental comparison results of the <math display="inline"><semantics> <msub> <mi>V</mi> <mi>t</mi> </msub> </semantics></math> described by the third-order RC equivalent circuit model during the discharge phase.</p>
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<p>Terminal voltage prediction for the first-order model during the pulse charging validation experiment.</p>
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<p>Terminal voltage prediction for the second-order model during the pulse charging validation experiment.</p>
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<p>Terminal voltage prediction for the third-order model during the pulse charging validation experiment.</p>
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19 pages, 8469 KiB  
Article
Experimental and Numerical Investigation of Airflow Organization in Modular Data Centres Utilizing Floor Grid Air Supply
by Jingping Zhao, Jianlin Wu and Mengying Li
Buildings 2024, 14(9), 2750; https://doi.org/10.3390/buildings14092750 - 2 Sep 2024
Viewed by 787
Abstract
Under the background of “dual carbon” development goals, the rapid expansion of internet data centers driven by advancements in 5G technology has led to increased energy consumption and elevated heat densities within the server rooms in these facilities. In this study, the modular [...] Read more.
Under the background of “dual carbon” development goals, the rapid expansion of internet data centers driven by advancements in 5G technology has led to increased energy consumption and elevated heat densities within the server rooms in these facilities. In this study, the modular data center is taken as the research object for the purpose of figuring out a way to improve the thermal environment of the computer room, reduce power consumption, and ensure the safe and stable running of servers. To this end, this study established an airflow organization model for the modular data center and verified this model through experimental methods. Computational Fluid Dynamics (CFD) simulations were employed to investigate the effects of raised floor height, floor opening rate, and cold/hot air channel closure on airflow organization. Furthermore, the efficiency of airflow organization was evaluated using entransy loss metrics. The results show that optimal airflow conditions are achieved when the height of the raised floor is 600–800 mm, the opening rate is 40%, and the combined opening is 40%. Additionally, the closure of either the cold channel or both the cold and hot channels significantly improves airflow performance. Specifically, cold channel closure is recommended for new data centers with underfloor air supply systems, while combined cold and hot channel closure is suitable for data centers with high power density and extended air supply distances. Full article
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<p>Single-module data centers.</p>
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<p>Single-module data centers.</p>
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<p>Schematic diagram of the airflow organization in the data centers.</p>
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<p>The schematic diagram of a single cabinet.</p>
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<p>Layout of test room air return test points.</p>
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<p>Grid independence verification.</p>
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<p>Pressure distribution beneath the raised floor.</p>
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<p>Pressure distribution beneath the raised floor.</p>
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<p>Velocity distribution beneath the raised floor.</p>
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<p>Variation in temperature of raised flooring at various elevations.</p>
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<p>Static pressure distribution under raised floor.</p>
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<p>Combined openings of floor air supply grilles.</p>
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<p>Speed distribution on the top of the cabinet.</p>
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<p>Speed distribution on the top of the cabinet.</p>
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<p>Vertical temperature distribution within the cabinet.</p>
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<p>Diagram illustrating cold/hot channel closure.</p>
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<p>Temperature distribution within the enclosed cabinet’s cold and hot channels.</p>
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<p>Airflow organization in the server room.</p>
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<p>Energy loss due to entrapment at varying raised floor heights.</p>
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<p>Entransy loss under different floor grid opening rates.</p>
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<p>Entransy loss under closed cold/hot channel.</p>
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41 pages, 11807 KiB  
Review
Optimization Control Strategies and Evaluation Metrics of Cooling Systems in Data Centers: A Review
by Qiankun Chang, Yuanfeng Huang, Kaiyan Liu, Xin Xu, Yaohua Zhao and Song Pan
Sustainability 2024, 16(16), 7222; https://doi.org/10.3390/su16167222 - 22 Aug 2024
Cited by 2 | Viewed by 4027
Abstract
In the age of digitalization and big data, cooling systems in data centers are vital for maintaining equipment efficiency and environmental sustainability. Although many studies have focused on the classification and optimization of data center cooling systems, systematic reviews using bibliometric methods are [...] Read more.
In the age of digitalization and big data, cooling systems in data centers are vital for maintaining equipment efficiency and environmental sustainability. Although many studies have focused on the classification and optimization of data center cooling systems, systematic reviews using bibliometric methods are relatively scarce. This review uses bibliometric analysis to explore the classifications, control optimizations, and energy metrics of data center cooling systems, aiming to address research gaps. Using CiteSpace and databases like Scopus, Web of Science, and IEEE, this study maps the field’s historical development and current trends. The findings indicate that, firstly, the classification of cooling systems, optimization strategies, and energy efficiency metrics are the current focal points. Secondly, this review assesses the applicability of air-cooled and liquid-cooled systems in different operational environments, providing practical guidance for selection. Then, for air cooling systems, the review demonstrates that optimizing the design of static pressure chamber baffles has significantly improved airflow uniformity. Finally, the article advocates for expanding the use of artificial intelligence and machine learning to automate data collection and energy efficiency analysis, it also calls for the global standardization of energy efficiency metrics. This study offers new perspectives on the design, operational optimization, and performance evaluation of data center cooling systems. Full article
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<p>Paper search flowchart.</p>
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<p>Proportion of selected studies in search databases.</p>
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<p>Publication year trends.</p>
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<p>Keyword co-occurrence graph from Scopus.</p>
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<p>Keyword co-occurrence graph from Scopus.</p>
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<p>Keyword co-occurrence graph from Web of Science.</p>
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<p>Temporal clustering of keywords in Scopus.</p>
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<p>Journal publication year bubble chart.</p>
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<p>High-publishing countries graph.</p>
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<p>Country co-occurrence map.</p>
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<p>Issuing authority co-occurrence map.</p>
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<p>Co-citation network of Scopus papers.</p>
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<p>Keyword burstness graph.</p>
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<p>Components of data center energy consumption.</p>
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<p>Basic mechanism of liquid cooling technology.</p>
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<p>Basic mechanism of air cooling technology.</p>
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<p>Schematic diagrams of different microchannel structures.</p>
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20 pages, 9760 KiB  
Review
Application and Challenge of High-Speed Pumps with Low-Temperature Thermosensitive Fluids
by Beile Zhang, Ben Niu, Ze Zhang, Shuangtao Chen, Rong Xue and Yu Hou
Energies 2024, 17(15), 3732; https://doi.org/10.3390/en17153732 - 29 Jul 2024
Viewed by 1204
Abstract
The rapid development of industrial and information technology is driving the demand to improve the applicability and hydraulic performance of centrifugal pumps in various applications. Enhancing the rotational speed of pumps can simultaneously increase the head and reduce the impeller diameter, thereby reducing [...] Read more.
The rapid development of industrial and information technology is driving the demand to improve the applicability and hydraulic performance of centrifugal pumps in various applications. Enhancing the rotational speed of pumps can simultaneously increase the head and reduce the impeller diameter, thereby reducing the pump size and weight and also improving pump efficiency. This paper reviews the current application status of high-speed pumps using low-temperature thermosensitive fluids, which have been applied in fields such as novel energy-saving cooling technologies, aerospace, chemical industries, and cryogenic engineering. Due to operational constraints and thermal effects, there are inherent challenges that still need to be addressed for high-speed pumps. Based on numerical simulation and experimental research for different working fluids, the results regarding cavitation within the inducer have been categorized and summarized. Improvements to cavitation models, the mechanism of unsteady cavity shedding, vortex generation and cavitation suppression, and the impact of cavitation on pump performance were examined. Subsequently, the thermal properties and cavitation thermal effects of low-temperature thermosensitive fluids were analyzed. In response to the application requirements of pump-driven two-phase cooling systems in data centers, a high-speed refrigerant pump employing hydrodynamic bearings has been proposed. Experimental results indicate that the prototype achieves a head of 56.5 m and an efficiency of 36.1% at design conditions (n = 7000 rpm, Q = 1.5 m3/h). The prototype features a variable frequency motor, allowing for a wider operational range, and has successfully passed both on/off and continuous operation tests. These findings provide valuable insights for improving the performance of high-speed refrigerant pumps in relevant applications. Full article
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<p>Typical applications of centrifugal pumps with low-temperature thermosensitive fluids.</p>
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<p>Centrifugal pump with liquid xenon [<a href="#B20-energies-17-03732" class="html-bibr">20</a>].</p>
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<p>Schematic diagram of LNG submersible pump [<a href="#B26-energies-17-03732" class="html-bibr">26</a>].</p>
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<p>Liquid rocket engine turbopump with inducer [<a href="#B40-energies-17-03732" class="html-bibr">40</a>].</p>
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<p>Pump-driven two-phase cooling loop using high-speed R134a refrigerant pump.</p>
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<p>Axial vorticity distribution and cavity evolution of tip leakage vortex in inducer [<a href="#B49-energies-17-03732" class="html-bibr">49</a>].</p>
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<p>Effect of the inducer on the hydraulic and cavitation performance of the LH<sub>2</sub> pump: (<b>a</b>) frequency–head curve, (<b>b</b>) flow rate–head curve, (<b>c</b>) flow rate–efficiency curve, and (<b>d</b>) NPSH–head curve [<a href="#B34-energies-17-03732" class="html-bibr">34</a>].</p>
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<p>Suppression of backflow cavitation in the inducer by gutter at the inlet casing [<a href="#B57-energies-17-03732" class="html-bibr">57</a>]. The distribution of the axial velocity component is plotted on the plane, which includes the rotation axis by a gray-scale contour map. The brightest area represents the backflow region. Red lines and the colored inducer indicate the vortex cores and pressure, respectively.</p>
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<p>Cavity shedding of LN<sub>2</sub> cavitation under different thermal cavitation modes. Within the gray-shaded cavities, the curves with blue and red arrows represent the direction of cavity rotation. The green straight line with arrows represents the movement of the detached cavity. The numbers indicate the cavity shedding process [<a href="#B69-energies-17-03732" class="html-bibr">69</a>].</p>
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<p>Tip vortex and backflow vortex cavitation occurring on the inducer with thermosensitive fluid LN<sub>2</sub> vs. room-temperature water. The arrows indicate the locations where tip vortex and backflow vortex occur [<a href="#B48-energies-17-03732" class="html-bibr">48</a>].</p>
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<p>The cavity evolution of LN<sub>2</sub> cavitation, considering thermal effects [<a href="#B81-energies-17-03732" class="html-bibr">81</a>].</p>
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<p>The impact of the thermal effect on the hydraulic performance of pump [<a href="#B84-energies-17-03732" class="html-bibr">84</a>].</p>
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<p>The impact of temperature on the R114 refrigerant cavitation [<a href="#B18-energies-17-03732" class="html-bibr">18</a>].</p>
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<p>Major components of two-stage centrifugal refrigerant pump. The arrows indicate the direction of fluid flow.</p>
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<p>Experimentally obtained external characteristic curve of the prototype.</p>
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<p>The theoretical and experimental values of the BEP at different rotational speeds.</p>
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21 pages, 2767 KiB  
Article
A Multidimensional Health Indicator Based on Autoregressive Power Spectral Density for Machine Condition Monitoring
by Roberto Diversi and Nicolò Speciale
Sensors 2024, 24(15), 4782; https://doi.org/10.3390/s24154782 - 23 Jul 2024
Viewed by 694
Abstract
Condition monitoring (CM) is the basis of prognostics and health management (PHM), which is gaining more and more importance in the industrial world. CM, which refers to the tracking of industrial equipment’s state of health during operations, plays, in fact, a significant role [...] Read more.
Condition monitoring (CM) is the basis of prognostics and health management (PHM), which is gaining more and more importance in the industrial world. CM, which refers to the tracking of industrial equipment’s state of health during operations, plays, in fact, a significant role in the reliability, safety, and efficiency of industrial operations. This paper proposes a data-driven CM approach based on the autoregressive (AR) modeling of the acquired sensor data and their analysis within frequency subbands. The number and size of the bands are determined with negligible human intervention, analyzing only the time–frequency representation of the signal of interest under normal system operating conditions. In particular, the approach exploits the synchrosqueezing transform to improve the signal energy distribution in the time–frequency plane, defining a multidimensional health indicator built on the basis of the AR power spectral density and the symmetric Itakura–Saito spectral distance. The described health indicator proved capable of detecting changes in the signal spectrum due to the occurrence of faults. After the initial definition of the bands and the calculation of the characteristics of the nominal AR spectrum, the procedure requires no further intervention and can be used for online condition monitoring and fault diagnosis. Since it is based on the comparison of spectra under different operating conditions, its applicability depends neither on the nature of the acquired signal nor on a specific system to be monitored. As an example, the effectiveness of the proposed method was favorably tested using real data available in the Case Western Reserve University (CWRU) Bearing Data Center, a widely known and used benchmark. Full article
(This article belongs to the Special Issue Fault Diagnosis and Prognosis in Rotating Machines)
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<p>Bands definition and computation of the nominal AR spectrum through healthy data.</p>
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<p>Online monitoring procedure.</p>
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<p>Time–frequency analysis of acceleration signal in the absence of failure and at a maximum speed of 1797 rpm (Healthy0): (<b>a</b>) Spectrogram (<b>b</b>) magnitude of Fourier Synchrosqueezed Transform, (<b>c</b>) Fourier power spectrum, (<b>d</b>) integral over time of local instantaneous squeezed frequencies in the TF plane. Vertical red lines identify the boundaries of the bands obtained by the procedure.</p>
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<p>Time–frequency analysis of acceleration signal in the absence of failure and at a speed of 1750 rpm (Healthy2): (<b>a</b>) Spectrogram (<b>b</b>) magnitude of Fourier Synchrosqueezed Transform, (<b>c</b>) Fourier power spectrum, (<b>d</b>) integral over time of local instantaneous squeezed frequencies in the TF plane. Vertical red lines identify the boundaries of the bands obtained by the procedure.</p>
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<p>CWRU bearing test rig: (1) electric motor, (2) torque transducer/encoder, (3) dynamometer. Accelerometers are located at the housing of both drive end (4) and fan end (5) bearings.</p>
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<p>CWRU DE vibration signals sampled at 48 kHz (motor load 0 hp): (<b>a</b>) healthy, (<b>b</b>) ball fault (0.007 inches), (<b>c</b>) ball fault (0.014 inches), (<b>d</b>) ball fault (0.021 inches).</p>
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<p>Estimation of the AR order <span class="html-italic">p</span>: (<b>a</b>) FPE criterion (<b>b</b>) MDL criterion. The red star shows the values of FPE and MDL associated with the order <math display="inline"><semantics> <mrow> <mi>p</mi> <mo>=</mo> <mn>54</mn> </mrow> </semantics></math>, which is double the number of peaks <math display="inline"><semantics> <msub> <mi>N</mi> <mi>p</mi> </msub> </semantics></math> estimated through the FSST procedure.</p>
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<p>Evolution of the SISSD indicator in the four different conditions associated with the set of signals <math display="inline"><semantics> <mrow> <mo>{</mo> <mn>1</mn> <mo>,</mo> <mn>2</mn> <mo>,</mo> <mn>3</mn> <mo>,</mo> <mn>4</mn> <mo>}</mo> </mrow> </semantics></math> as a function of the signal frames: (1) healthy, (2) BF (<math display="inline"><semantics> <mrow> <mn>0.007</mn> </mrow> </semantics></math> in), (3) BF (<math display="inline"><semantics> <mrow> <mn>0.014</mn> </mrow> </semantics></math> in), (4) BF (<math display="inline"><semantics> <mrow> <mn>0.021</mn> </mrow> </semantics></math> in).</p>
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<p>Evolution of the MSISSD indicator in the four different conditions associated with the set of signals <math display="inline"><semantics> <mrow> <mo>{</mo> <mn>1</mn> <mo>,</mo> <mn>2</mn> <mo>,</mo> <mn>3</mn> <mo>,</mo> <mn>4</mn> <mo>}</mo> </mrow> </semantics></math> for all the defined frequency bands as a function of the signal frames. Subfigures (<b>a</b>–<b>f</b>) refer to the subbands 1–6 defined in <a href="#sensors-24-04782-t002" class="html-table">Table 2</a>. The picture associated with Band <span class="html-italic">i</span> reports the evolution of the <span class="html-italic">i</span>-th entry of the MSISSD indicator. For every picture, the four conditions are (1) healthy, (2) BF (<math display="inline"><semantics> <mrow> <mn>0.007</mn> </mrow> </semantics></math> in), (3) BF (<math display="inline"><semantics> <mrow> <mn>0.014</mn> </mrow> </semantics></math> in), (4) BF (<math display="inline"><semantics> <mrow> <mn>0.021</mn> </mrow> </semantics></math> in).</p>
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<p>Evolution of the SISSD indicator in the four different conditions associated with the set of signals <math display="inline"><semantics> <mrow> <mo>{</mo> <mn>1</mn> <mo>,</mo> <mn>5</mn> <mo>,</mo> <mn>6</mn> <mo>,</mo> <mn>7</mn> <mo>}</mo> </mrow> </semantics></math> as a function of the signal frames: (1) healthy, (2) IRF (<math display="inline"><semantics> <mrow> <mn>0.007</mn> </mrow> </semantics></math> in), (3) IRF (<math display="inline"><semantics> <mrow> <mn>0.014</mn> </mrow> </semantics></math> in), (4) IRF (<math display="inline"><semantics> <mrow> <mn>0.021</mn> </mrow> </semantics></math> in).</p>
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<p>Evolution of the MSISSD indicator in the four different conditions associated with the set of signals <math display="inline"><semantics> <mrow> <mo>{</mo> <mn>1</mn> <mo>,</mo> <mn>5</mn> <mo>,</mo> <mn>6</mn> <mo>,</mo> <mn>7</mn> <mo>}</mo> </mrow> </semantics></math> for all the defined frequency bands as a function of the signal frames. Subfigures (<b>a</b>–<b>f</b>) refer to the subbands 1–6 defined in <a href="#sensors-24-04782-t002" class="html-table">Table 2</a>. The picture associated with Band <span class="html-italic">i</span> reports the evolution of the <span class="html-italic">i</span>-th entry of the MSISSD indicator. For every picture, the four conditions are (1) healthy, (2) IRF (<math display="inline"><semantics> <mrow> <mn>0.007</mn> </mrow> </semantics></math> in), (3) IRF (<math display="inline"><semantics> <mrow> <mn>0.014</mn> </mrow> </semantics></math> in), (4) IRF (<math display="inline"><semantics> <mrow> <mn>0.021</mn> </mrow> </semantics></math> in).</p>
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<p>Evolution of the SISSD indicator in the three different conditions associated with the set of signals <math display="inline"><semantics> <mrow> <mo>{</mo> <mn>1</mn> <mo>,</mo> <mn>11</mn> <mo>,</mo> <mn>12</mn> <mo>}</mo> </mrow> </semantics></math> as a function of the signal frames: (1) healthy, (2) ORF orthogonal (<math display="inline"><semantics> <mrow> <mn>0.007</mn> </mrow> </semantics></math> in), (4) ORF orthogonal (<math display="inline"><semantics> <mrow> <mn>0.021</mn> </mrow> </semantics></math> in).</p>
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<p>Evolution of the MSISSD indicator in the four different conditions associated with the set of signals <math display="inline"><semantics> <mrow> <mo>{</mo> <mn>1</mn> <mo>,</mo> <mn>11</mn> <mo>,</mo> <mn>12</mn> <mo>}</mo> </mrow> </semantics></math> for all the defined frequency bands as a function of the signal frames. Subfigures (<b>a</b>–<b>f</b>) refer to the subbands 1–6 defined in <a href="#sensors-24-04782-t002" class="html-table">Table 2</a>. The picture associated with Band <span class="html-italic">i</span> reports the evolution of the <span class="html-italic">i</span>-th entry of the MSISSD indicator. For every picture, the four conditions are (1) healthy, (2) ORF orthogonal (<math display="inline"><semantics> <mrow> <mn>0.007</mn> </mrow> </semantics></math> in), (4) ORF orthogonal (<math display="inline"><semantics> <mrow> <mn>0.021</mn> </mrow> </semantics></math> in).</p>
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<p>Confusion matrices associated with two classification experiments: (<b>a</b>) 0 hp load, <math display="inline"><semantics> <mrow> <mn>50</mn> <mo>%</mo> </mrow> </semantics></math> training ratio, worst case (accuracy <math display="inline"><semantics> <mrow> <mn>98.41</mn> <mo>%</mo> </mrow> </semantics></math>), (<b>b</b>) 1 hp load, <math display="inline"><semantics> <mrow> <mn>50</mn> <mo>%</mo> </mrow> </semantics></math> training ratio, accuracy <math display="inline"><semantics> <mrow> <mn>100</mn> <mo>%</mo> </mrow> </semantics></math>.</p>
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14 pages, 358 KiB  
Article
VMP-ER: An Efficient Virtual Machine Placement Algorithm for Energy and Resources Optimization in Cloud Data Center
by Hasanein D. Rjeib and Gabor Kecskemeti
Algorithms 2024, 17(7), 295; https://doi.org/10.3390/a17070295 - 5 Jul 2024
Viewed by 1059
Abstract
Cloud service providers deliver computing services on demand using the Infrastructure as a Service (IaaS) model. In a cloud data center, several virtual machines (VMs) can be hosted on a single physical machine (PM) with the help of virtualization. The virtual machine placement [...] Read more.
Cloud service providers deliver computing services on demand using the Infrastructure as a Service (IaaS) model. In a cloud data center, several virtual machines (VMs) can be hosted on a single physical machine (PM) with the help of virtualization. The virtual machine placement (VMP) involves assigning VMs across various physical machines, which is a crucial process impacting energy draw and resource usage in the cloud data center. Nonetheless, finding an effective settlement is challenging owing to factors like hardware heterogeneity and the scalability of cloud data centers. This paper proposes an efficient algorithm named VMP-ER aimed at optimizing power consumption and reducing resource wastage. Our algorithm achieves this by decreasing the number of running physical machines, and it gives priority to energy-efficient servers. Additionally, it improves resource utilization across physical machines, thus minimizing wastage and ensuring balanced resource allocation. Full article
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<p>An example of improved VM placement.</p>
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<p>The number of PMs required to host the given number of VMs.</p>
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<p>Energy consumption for given number of VMs.</p>
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<p>Average resource wastage for given number of VMs.</p>
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30 pages, 3089 KiB  
Review
Industrial Metaverse: A Comprehensive Review, Environmental Impact, and Challenges
by Sindiso Mpenyu Nleya and Mthulisi Velempini
Appl. Sci. 2024, 14(13), 5736; https://doi.org/10.3390/app14135736 - 1 Jul 2024
Cited by 5 | Viewed by 2409
Abstract
The Industrial Metaverse paradigm can be broadly described as a virtual environment that integrates various technologies such as augmented reality and mixed reality to enhance business operations and processes. It aims to streamline workflows, reduce error rates, improve efficiency, and provide a more [...] Read more.
The Industrial Metaverse paradigm can be broadly described as a virtual environment that integrates various technologies such as augmented reality and mixed reality to enhance business operations and processes. It aims to streamline workflows, reduce error rates, improve efficiency, and provide a more engaging experience for employees. The promise of the Industrial Metaverse to drive sustainability and resource efficiency is compelling. Using advanced technologies such as the Industrial Metaverse is vital in an endeavor to have a competitive edge in a rapidly evolving business environment. However, the environmental impact of the technologies underpinning the Industrial Metaverse, like data centers and network infrastructure, should not be overlooked. The ecological footprint of these technologies must be considered in the sustainability equation. Researchers have warned that, by 2025, without sustainable artificial intelligence (AI) practices, AI will consume more energy than the human workforce, significantly offsetting zero carbon gains. As the Metaverse persists in evolving and gaining momentum, it will be necessary for companies to prioritize sustainability and explore new ways to balance technological advancements with environmental stewardship. However, recent studies have conjectured that the Metaverse holds the potential to reduce carbon emissions, as digital replacements for physical goods become more prevalent and physical activities like mobility and construction are reduced. Moreover, the specific extent to which this substitution can alleviate environmental concerns remains an open issue, presenting a knowledge gap in understanding the real-world impact of digital replacements. Thus, the objective of this paper is to provide a comprehensive review of the Industrial Metaverse, as well as explore the environmental impact of the Industrial Metaverse. The integrative literature review design and methodological approach involved multiple sources from the Web of Science and databases such as the ACM library, IEEE Library, and Google Scholar, which were analyzed to provide a comprehensive understanding of the developments in the Industrial Metaverse. Firstly, by considering the Industrial Metaverse’s architecture, we elucidate the Industrial Metaverse concept and the associated enabling technologies. Secondly, we performed an exploration through a discussion of the prevalent use cases and the deployment of the emerging Industrial Metaverse. Thirdly, we explored the impact of the Industrial Metaverse on the environment. Lastly, we address novel security and privacy risks, as well as upcoming research challenges, keeping in mind that the Industrial Metaverse is based on a strong data fabric. The results point to the Industrial Metaverse as having both positive and negative environmental effects in terms of energy consumption, e-waste, and pollution. Research, however, indicates that most Industrial Metaverse applications have a positive environmental impact and subsequently trend toward sustainability. Finally, for sustainability in the Industrial Metaverse, enterprises may consider utilizing renewable energy sources and cloud services. Furthermore, we examined the effects of products on the environment, as well as in the creation of a circular economy. Full article
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<p>Organization of the structure of this paper.</p>
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<p>Research design.</p>
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<p>IM’s architecture [<a href="#B15-applsci-14-05736" class="html-bibr">15</a>].</p>
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<p>IM’s driving technologies.</p>
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<p>Liters per beverage.</p>
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<p>CO<sub>2</sub> emission levels [<a href="#B75-applsci-14-05736" class="html-bibr">75</a>].</p>
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<p>Renault energy intensity [<a href="#B74-applsci-14-05736" class="html-bibr">74</a>].</p>
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<p>Analysis of energy components [<a href="#B77-applsci-14-05736" class="html-bibr">77</a>].</p>
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<p>Global data centers [<a href="#B92-applsci-14-05736" class="html-bibr">92</a>].</p>
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<p>Global PUE.</p>
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18 pages, 1359 KiB  
Article
Distance- and Angle-Based Hybrid Localization Integrated in the IEEE 802.15.4 TSCH Communication Protocol
by Grega Morano, Aleš Simončič, Teodora Kocevska, Tomaž Javornik and Andrej Hrovat
Sensors 2024, 24(12), 3925; https://doi.org/10.3390/s24123925 - 17 Jun 2024
Viewed by 768
Abstract
Accurate localization of devices within Internet of Things (IoT) networks is driven by the emergence of novel applications that require context awareness to improve operational efficiency, resource management, automation, and safety in industry and smart cities. With the Integrated Localization and Communication (ILAC) [...] Read more.
Accurate localization of devices within Internet of Things (IoT) networks is driven by the emergence of novel applications that require context awareness to improve operational efficiency, resource management, automation, and safety in industry and smart cities. With the Integrated Localization and Communication (ILAC) functionality, IoT devices can simultaneously exchange data and determine their position in space, resulting in maximized resource utilization with reduced deployment and operational costs. Localization capability in challenging scenarios, including harsh environments with complex geometry and obstacles, can be provided with robust, reliable, and energy-efficient communication protocols able to combat impairments caused by interference and multipath, such as the IEEE 802.15.4 Time-Slotted Channel Hopping (TSCH) protocol. This paper presents an enhancement of the TSCH protocol that integrates localization functionality along with communication, improving the protocol’s operational capabilities and setting a baseline for monitoring, automation, and interaction within IoT setups in physical environments. A novel approach is proposed to incorporate a hybrid localization by integrating Direction of Arrival (DoA) estimation and Multi-Carrier Phase Difference (MCPD) ranging methods for providing DoA and distance estimates with each transmitted packet. With the proposed enhancement, a single node can determine the location of its neighboring nodes without significantly affecting the reliability of communication and the efficiency of the network. The feasibility and effectiveness of the proposed approach are validated in a real scenario in an office building using low-cost proprietary devices, and the software incorporating the solution is provided. The experimental evaluation results show that a node positioned in the center of the room successfully estimates both the DoA and the distance to each neighboring node. The proposed hybrid localization algorithm demonstrates an accuracy of a few tens of centimeters in a two-dimensional space. Full article
(This article belongs to the Special Issue Integrated Localization and Communication: Advances and Challenges)
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<p>Topology of the destination-oriented directed acyclic graph (DODAG) network with the proposed method of hybrid localization, where a single node referred to as the root/parent node can determine the location of its child nodes.</p>
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<p>Integration of a phase measurement process into the Time Slotted Channel Hopping (TSCH) timeslot.</p>
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<p>(<b>a</b>) Experiment setup. (<b>b</b>) Micro-controller equipped with AT86RF215 radio and RF switch. (<b>c</b>) Uniform circular antenna array with eight elements.</p>
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<p>Cumulative Distribution Function (CDF) for estimated location errors. (<b>a</b>) Comparison of CDF with a single measurement with 5 and 16 successive measurements. (<b>b</b>) CDF for each node’s location with 5 successive measurements.</p>
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<p>Actual (circles) and estimated (crosses) locations of devices in an office room based on five successive measurements as a final result.</p>
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20 pages, 501 KiB  
Article
Efficient Resource Management in Cloud Environments: A Modified Feeding Birds Algorithm for VM Consolidation
by Deafallah Alsadie and Musleh Alsulami
Mathematics 2024, 12(12), 1845; https://doi.org/10.3390/math12121845 - 13 Jun 2024
Cited by 1 | Viewed by 693
Abstract
Cloud data centers play a vital role in modern computing infrastructure, offering scalable resources for diverse applications. However, managing costs and resources efficiently in these centers has become a crucial concern due to the exponential growth of cloud computing. User applications exhibit complex [...] Read more.
Cloud data centers play a vital role in modern computing infrastructure, offering scalable resources for diverse applications. However, managing costs and resources efficiently in these centers has become a crucial concern due to the exponential growth of cloud computing. User applications exhibit complex behavior, leading to fluctuations in system performance and increased power usage. To tackle these obstacles, we introduce the Modified Feeding Birds Algorithm (ModAFBA) as an innovative solution for virtual machine (VM) consolidation in cloud environments. The primary objective is to enhance resource management and operational efficiency in cloud data centers. ModAFBA incorporates adaptive position update rules and strategies specifically designed to minimize VM migrations, addressing the unique challenges of VM consolidation. The experimental findings demonstrated substantial improvements in key performance metrics. Specifically, the ModAFBA method exhibited significant enhancements in energy usage, SLA compliance, and the number of VM migrations compared to benchmark algorithms such as TOPSIS, SVMP, and PVMP methods. Notably, the ModAFBA method achieved reductions in energy usage of 49.16%, 55.76%, and 65.13% compared to the TOPSIS, SVMP, and PVMP methods, respectively. Moreover, the ModAFBA method resulted in decreases of around 83.80%, 22.65%, and 89.82% in the quantity of VM migrations in contrast to the aforementioned benchmark techniques. The results demonstrate that ModAFBA outperforms these benchmarks by significantly reducing energy consumption, operational costs, and SLA violations. These findings highlight the effectiveness of ModAFBA in optimizing VM placement and consolidation, offering a robust and scalable approach to improving the performance and sustainability of cloud data centers. Full article
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<p>Cloud computing model architecture.</p>
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<p>Comparison of energy usage by ModAFBA method against TOPSIS, SVMP, and PVMP methods.</p>
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<p>Comparison of SLAV_TPM by ModAFBA method against TOPSIS, SVMP, and PVMP methods.</p>
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<p>Comparison of migration count by ModAFBA method against TOPSIS, SVMP, and PVMP methods.</p>
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<p>Comparison of SLA_EC by ModAFBA method against TOPSIS, SVMP, and PVMP methods.</p>
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<p>Comparison of SLA_EC_M by ModAFBA method against TOPSIS, SVMP, and PVMP methods.</p>
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