Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
71
result(s) for
"AOA network"
Sort by:
Multi-objective optimization of discrete time-cost tradeoff problem in project networks using non-dominated sorting genetic algorithm
2016
The time-cost tradeoff problem is one of the most important and applicable problems in project scheduling area. There are many factors that force the mangers to crash the time. This factor could be early utilization, early commissioning and operation, improving the project cash flow, avoiding unfavorable weather conditions, compensating the delays, and so on. Since there is a need to allocate extra resources to short the finishing time of project and the project managers are intended to spend the lowest possible amount of money and achieve the maximum crashing time, as a result, both direct and indirect costs will be influenced in the project, and here, we are facing into the time value of money. It means that when we crash the starting activities in a project, the extra investment will be tied in until the end date of the project; however, when we crash the final activities, the extra investment will be tied in for a much shorter period. This study is presenting a two-objective mathematical model for balancing compressing the project time with activities delay to prepare a suitable tool for decision makers caught in available facilities and due to the time of projects. Also drawing the scheduling problem to real world conditions by considering nonlinear objective function and the time value of money are considered. The presented problem was solved using NSGA-II, and the effect of time compressing reports on the non-dominant set.
Journal Article
Precise Indoor Positioning Using UWB: A Review of Methods, Algorithms and Implementations
by
Mazhar, Fazeelat
,
Sällberg, Benny
,
Khan, Muhammad Gufran
in
Algorithms
,
Communications Engineering
,
Computer Communication Networks
2017
The demand and growth of indoor positioning has increased rapidly in the past few years for a diverse range of applications. Various innovative techniques and technologies have been introduced but precise and reliable indoor positioning still remains a challenging task due to dependence on a large number of factors and limitations of the technologies. Positioning technologies based on radio frequency (RF) have many advantages over the technologies utilizing ultrasonic, optical and infrared devices. Both narrowband and wideband RF systems have been implemented for short range indoor positioning/real-time locating systems. Ultra wideband (UWB) technology has emerged as a viable candidate for precise indoor positioning due its unique characteristics. This article presents a comparison of UWB and narrowband RF technologies in terms of modulation, throughput, transmission time, energy efficiency, multipath resolving capability and interference. Secondly, methods for measurement of the positioning parameters are discussed based on a generalized measurement model and, in addition, widely used position estimation algorithms are surveyed. Finally, the article provides practical UWB positioning systems and state-of-the-art implementations. We believe that the review presented in this article provides a structured overview and comparison of the positioning methods, algorithms and implementations in the field of precise UWB indoor positioning, and will be helpful for practitioners as well as for researchers to keep abreast of the recent developments in the field.
Journal Article
On Target Localization Using Combined RSS and AoA Measurements
by
Beko, Marko
,
Dinis, Rui
,
Tomic, Slavisa
in
angle of arrival (AoA)
,
hybrid measurements
,
Localization
2018
This work revises existing solutions for a problem of target localization in wireless sensor networks (WSNs), utilizing integrated measurements, namely received signal strength (RSS) and angle of arrival (AoA). The problem of RSS/AoA-based target localization became very popular in the research community recently, owing to its great applicability potential and relatively low implementation cost. Therefore, here, a comprehensive study of the state-of-the-art (SoA) solutions and their detailed analysis is presented. The beginning of this work starts by considering the SoA approaches based on convex relaxation techniques (more computationally complex in general), and it goes through other (less computationally complex) approaches, as well, such as the ones based on the generalized trust region sub-problems framework and linear least squares. Furthermore, a detailed analysis of the computational complexity of each solution is reviewed. Furthermore, an extensive set of simulation results is presented. Finally, the main conclusions are summarized, and a set of future aspects and trends that might be interesting for future research in this area is identified.
Journal Article
Hybrid RSS/AOA Localization using Approximated Weighted Least Square in Wireless Sensor Networks
by
Chung, WonZoo
,
Kang, SeYoung
,
Kim, TaeHyun
in
angle of arrival (AOA)
,
Chemical technology
,
received signal strength (rss)
2020
We present a target localization method using an approximated error covariance matrix based weighted least squares (WLS) solution, which integrates received signal strength (RSS) and angle of arrival (AOA) data for wireless sensor networks. We approximated linear WLS errors via second-order Taylor approximation, and further approximated the error covariance matrix using a least-squares solution and the variance in measurement noise over the sensor nodes. The algorithm does not require any prior knowledge of the true target position or noise variance. Simulations validated the superior performance of our new method.
Journal Article
A Bluetooth Indoor Positioning System Based on Deep Learning with RSSI and AoA
2025
Traditional received signal strength indicator (RSSI)-based and angle of arrival (AoA)-based positioning methods are highly susceptible to multipath effects, signal attenuation, and noise interference in complex indoor environments, which significantly degrade positioning accuracy. To mitigate the impact of the above deterioration, we propose a deep learning-based Bluetooth indoor positioning system, which employs a Kalman filter (KF) to reduce the angular error in AoA measurements and utilizes a median filter (MF) and moving average filter (MAF) to mitigate fluctuations in RSSI-based distance measurements. In the deep learning network architecture, we propose a convolutional neural network (CNN)–multi-head attention (MHA) model. During the training process, the backpropagation (BP) algorithm is used to compute the gradient of the loss function and update the parameters of the entire network, gradually optimizing the model’s performance. Experimental results demonstrate that our proposed indoor positioning method achieves an average error of 0.29 m, which represents a significant improvement compared to traditional RSSI and AoA methods. Additionally, it displays superior positioning accuracy when contrasted with numerous emerging indoor positioning methodologies.
Journal Article
A Novel Evolutionary Arithmetic Optimization Algorithm for Multilevel Thresholding Segmentation of COVID-19 CT Images
by
Abualigah, Laith
,
Gandomi, Amir H.
,
Diabat, Ali
in
Algorithms
,
Arithmetic
,
Computed tomography
2021
One of the most crucial aspects of image segmentation is multilevel thresholding. However, multilevel thresholding becomes increasingly more computationally complex as the number of thresholds grows. In order to address this defect, this paper proposes a new multilevel thresholding approach based on the Evolutionary Arithmetic Optimization Algorithm (AOA). The arithmetic operators in science were the inspiration for AOA. DAOA is the proposed approach, which employs the Differential Evolution technique to enhance the AOA local research. The proposed algorithm is applied to the multilevel thresholding problem, using Kapur’s measure between class variance functions. The suggested DAOA is used to evaluate images, using eight standard test images from two different groups: nature and CT COVID-19 images. Peak signal-to-noise ratio (PSNR) and structural similarity index test (SSIM) are standard evaluation measures used to determine the accuracy of segmented images. The proposed DAOA method’s efficiency is evaluated and compared to other multilevel thresholding methods. The findings are presented with a number of different threshold values (i.e., 2, 3, 4, 5, and 6). According to the experimental results, the proposed DAOA process is better and produces higher-quality solutions than other comparative approaches. Moreover, it achieved better-segmented images, PSNR, and SSIM values. In addition, the proposed DAOA is ranked the first method in all test cases.
Journal Article
A positioning method based on map and single base station towards 6G networks
by
Wang, Youqing
,
Zheng, Zhengqi
,
Zhao, Kun
in
6G mobile communication
,
Algorithms
,
Communication networks
2024
Positioning based on wireless communication networks has great application potential. In this paper, we propose a positioning method for the 5G-Advanced (5GA) or 6G network. Firstly, we establish the communication link and generate the map-based hybrid channel model based on 3GPP standards and open-source maps, where each multipath channel is expanded into a cluster that contains 20 rays. Then, we improve the Orthogonal-Matching-Pursuit (OMP) algorithm, which can estimate Angle-Of-Arrival (AOA) through only one OFDM symbol and does not require the signal to have a very narrow bandwidth, a high Signal-to-Noise-Ratio (SNR) or multiple snapshots like the classical OMP algorithm. Finally, we propose a positioning algorithm, which locates the target through the estimated AOA and the open-source map. The proposed method can locate the target with a single Base Station and has the advantages of lower delay, lower cost, and higher accuracy. The simulation results show that the positioning error of the proposed algorithm is submeter in 63% of the cases and less than 2.2 m in 80% of the cases.
Journal Article
An efficient multimodal sentiment analysis in social media using hybrid optimal multi-scale residual attention network
by
Marudhamuthu, Krishnamurthy
,
Murugesan, Kanipriya
,
Subbaiah, Bairavel
in
Age of acquisition
,
Algorithms
,
Analysis
2024
Sentiment analysis is a key component of many social media analysis projects. Additionally, prior research has concentrated on a single modality in particular, such as text descriptions for visual information. In contrast to standard image databases, social images frequently connect to one another, making sentiment analysis challenging. The majority of methods now in use consider different images individually, rendering them useless for interrelated images. We proposed a hybrid Arithmetic Optimization Algorithm- Hunger Games Search (AOA-HGS)-optimized Ensemble Multi-scale Residual Attention Network (EMRA-Net) technique in this paper to explore the modal correlations including texts, audio, social links, and video for more effective multimodal sentiment analysis. The hybrid AOA-HGS technique learns complementary and comprehensive features. The EMRA-Net uses two segments, including Ensemble Attention CNN (EA-CNN) and Three-scale Residual Attention Convolutional Neural Network (TRA-CNN), to analyze the multimodal sentiments. The loss of spatial domain image texture features can be reduced by adding the Wavelet transform to TRA-CNN. The feature-level fusion technique known as EA-CNN is used to combine visual, audio, and textual information. The proposed method performs significantly better than the existing multimodel sentimental analysis techniques of HALCB, HDF, and MMLatch when evaluated using the Multimodal Emotion Lines Dataset (MELD) and EmoryNLP datasets. Also, even though the size of the training set varies, the proposed method outperformed other techniques in terms of recall, accuracy, F score, and precision and takes less time to compute in both datasets.
Journal Article
From Fingerprinting to Advanced Machine Learning: A Systematic Review of Wi-Fi and BLE-Based Indoor Positioning Systems
by
Miralles, Ignacio
,
Martín-Frechina, Sara
,
Torres-Sospedra, Joaquín
in
Accuracy
,
Algorithms
,
Analysis
2025
The Indoor Positioning System (IPS) is used to locate devices and people in smart environments. In recent years, position determination methods have evolved from simple Received Signal Strength Indicator (RSSI) measurements to more advanced approaches such as Channel State Information (CSI), Round Trip Time (RTT), and Angle of Arrival (AoA), increasingly combined with Machine Learning (ML). This article presents a systematic review of the literature on ML-based IPS using IEEE 802.11 Wireless LAN (Wi-Fi) and Bluetooth Low Energy (BLE), including studies published between 2020 and 2024 under the Preferred Reporting Items for Systematic Reviews and Meta-Analyse (PRISMA) methodology. This study examines the techniques used to collect measurements and the ML models used, and discusses the growing use of Deep Learning (DL) approaches. This review identifies some challenges that remain for the implementation of these systems, such as environmental variability, device heterogeneity, and the need for calibration. Future research should expand ML applications to RTT and AoA, explore hybrid multimetric systems, and design lightweight, adaptive DL models. Advances in wireless standards and emerging technologies are also expected to further enhance accuracy and scalability in next-generation IPS.
Journal Article
The potential of plant-derived triterpenoids as biological nitrification inhibitors
by
Papadopoulou, Evangelia S.
,
Zhang, Kunyang
,
Papadopoulou, Kalliope K.
in
Acids
,
Agriculture
,
Ammonia
2026
Biological nitrification inhibitors (BNIs) present an environmentally friendly approach to reduce nitrogen losses and enhance nitrogen use efficiency, with plant-derived triterpenoids emerging as promising candidates. We evaluated 18 triterpenoids as BNIs using
in vitro
assays with soil ammonia-oxidizing bacteria (AOB) (
Nitrosospira multiformis
,
Nitrosomonas ureae
) and archaea (AOA) (
Nitrososphaera viennensis
,
Nitrosotalea sinensis
) at high and low concentrations. A Graph Neural Network framework was applied to predict nitrification inhibition (NI) and identify structural features, including key functional groups, linked to inhibitory patterns. Triterpenoids were more active on AOA, demonstrating higher efficacy than sakuranetin (a known BNI), but did not inhibit AOB. Six triterpenoids showed inhibitory activity on AOA (29–100%), with 3-O-acetyl-11-keto-beta boswellic acid and 11-keto-beta boswellic acid as the most potent inhibitors (ammonia oxidation inhibition > 94%), followed by echinocystic acid (> 87%), ursolic acid (> 74%), asiatic acid (> 65%), and echinocystic acid-3-O-glucoside (29–94%).
In silico
analyses predicted accurately the activity of model inhibitors such as DMPP, MHPP, and ethoxyquin on AOB and AOA, respectively, and the limited activity of triterpenoids on AOB, but did not predict their strong inhibitory effects on AOA, underscoring the need for expanded datasets for model refinement. The selective activity of some triterpenoids on AOA is hypothesized to involve interference with 3-hydroxy-3-methylglutaryl-CoA reductase, a key enzyme in archaeal membrane biosynthesis, although this requires experimental validation. Still, strain-specific responses suggest the involvement of additional mechanisms. This study provides the first experimental evidence for the potential of plant-derived triterpenoids as BNIs, supporting their relevance for sustainable agriculture.
Graphical Abstract
Key points
•
Triterpenoids strongly inhibited AOA but had no effect on AOB nitrification activity.
•
Six ursane/oleanane-type triterpenoids showed strong AOA inhibition beyond known BNIs.
•
Inhibition patterns suggest triterpenoid structure relates to AOA selectivity.
Journal Article