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15 pages, 3678 KiB  
Article
Tsallis Entropy-Based Complexity-IPE Casualty Plane: A Novel Method for Complex Time Series Analysis
by Zhe Chen, Changling Wu, Junyi Wang and Hongbing Qiu
Entropy 2024, 26(6), 521; https://doi.org/10.3390/e26060521 - 17 Jun 2024
Viewed by 936
Abstract
Due to its capacity to unveil the dynamic characteristics of time series data, entropy has attracted growing interest. However, traditional entropy feature extraction methods, such as permutation entropy, fall short in concurrently considering both the absolute amplitude information of signals and the temporal [...] Read more.
Due to its capacity to unveil the dynamic characteristics of time series data, entropy has attracted growing interest. However, traditional entropy feature extraction methods, such as permutation entropy, fall short in concurrently considering both the absolute amplitude information of signals and the temporal correlation between sample points. Consequently, this limitation leads to inadequate differentiation among different time series and susceptibility to noise interference. In order to augment the discriminative power and noise robustness of entropy features in time series analysis, this paper introduces a novel method called Tsallis entropy-based complexity-improved permutation entropy casualty plane (TC-IPE-CP). TC-IPE-CP adopts a novel symbolization approach that preserves both absolute amplitude information and inter-point correlations within sequences, thereby enhancing feature separability and noise resilience. Additionally, by incorporating Tsallis entropy and weighting the probability distribution with parameter q, it integrates with statistical complexity to establish a feature plane of complexity and entropy, further enriching signal features. Through the integration of multiscale algorithms, a multiscale Tsallis-improved permutation entropy algorithm is also developed. The simulation results indicate that TC-IPE-CP requires a small amount of data, exhibits strong noise resistance, and possesses high separability for signals. When applied to the analysis of heart rate signals, fault diagnosis, and underwater acoustic signal recognition, experimental findings demonstrate that TC-IPE-CP can accurately differentiate between electrocardiographic signals of elderly and young subjects, achieve precise bearing fault diagnosis, and identify four types of underwater targets. Particularly in underwater acoustic signal recognition experiments, TC-IPE-CP achieves a recognition rate of 96.67%, surpassing the well-known multi-scale dispersion entropy and multi-scale permutation entropy by 7.34% and 19.17%, respectively. This suggests that TC-IPE-CP is highly suitable for the analysis of complex time series. Full article
(This article belongs to the Special Issue Ordinal Pattern-Based Entropies: New Ideas and Challenges)
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<p>The TC-IPE-CP for different lengths of white noise and pink noise judgment results. (<b>a</b>) <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>H</mi> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math>-<math display="inline"><semantics> <mrow> <msub> <mrow> <mi>C</mi> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math> curves with L = 210; (<b>b</b>) <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>H</mi> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math>-<math display="inline"><semantics> <mrow> <msub> <mrow> <mi>C</mi> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math> curves with L = 510; (<b>c</b>) error bar plot of <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>H</mi> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math> with q = 0.1; (<b>d</b>) error bar plot of <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>C</mi> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math> with q = 1.1; (<b>e</b>) error bar plot of <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>H</mi> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math> with q = 1.01; (<b>f</b>) error bar plot of <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>C</mi> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math> with q = 1.01; (<b>g</b>) error bar plot of <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>H</mi> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math> with q = 2.01; and (<b>h</b>) error bar plot of <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>C</mi> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math> with q = 2.01.</p>
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<p>The analysis results of 20 sets of autoregressive time series and white noise on TC-IPE-CP and RC-PE casualty plane. (<b>a</b>) <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>H</mi> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math>-<math display="inline"><semantics> <mrow> <msub> <mrow> <mi>C</mi> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math> curves of TC-IPE-CP; (<b>b</b>) <math display="inline"><semantics> <mrow> <mi>H</mi> </mrow> </semantics></math>-<math display="inline"><semantics> <mrow> <mi>C</mi> </mrow> </semantics></math> curves of RC-PE-CP; (<b>c</b>) q-<math display="inline"><semantics> <mrow> <msub> <mrow> <mi>H</mi> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math> curves of TC-IPE-CP; and (<b>d</b>) q-<math display="inline"><semantics> <mrow> <msub> <mrow> <mi>C</mi> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math> curves of TC-IPE-CP.</p>
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<p>The analysis results of TC-IPE-CP and RC-PE-CP under different signal-to-noise ratio conditions for the Lorenz time series: (<b>a</b>) <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>H</mi> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math>-<math display="inline"><semantics> <mrow> <msub> <mrow> <mi>C</mi> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math> curves of TC-IPE-CP; (<b>b</b>) <math display="inline"><semantics> <mrow> <mi>H</mi> </mrow> </semantics></math>-<math display="inline"><semantics> <mrow> <mi>C</mi> </mrow> </semantics></math> curves of RC-PE-CP; (<b>c</b>) q-<math display="inline"><semantics> <mrow> <msub> <mrow> <mi>H</mi> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math> curves of TC-IPE-CP; and (<b>d</b>) q-<math display="inline"><semantics> <mrow> <msub> <mrow> <mi>C</mi> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math> curves of TC-IPE-CP.</p>
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<p>Boxplots of distinct entropy approaches computed from the RR intervals of healthy young and healthy elderly participants. (<b>a</b>) PE analysis result; (<b>b</b>) DE analysis result; (<b>c</b>) <math display="inline"><semantics> <mrow> <msubsup> <mrow> <mi>q</mi> </mrow> <mrow> <mi>H</mi> </mrow> <mrow> <mo>∗</mo> </mrow> </msubsup> </mrow> </semantics></math> analysis result; and (<b>d</b>) <math display="inline"><semantics> <mrow> <msubsup> <mrow> <mi>q</mi> </mrow> <mrow> <mi>C</mi> </mrow> <mrow> <mo>∗</mo> </mrow> </msubsup> </mrow> </semantics></math> analysis result. The symbol + in this figure represents outlier value.</p>
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<p>Multiscale entropy analysis results of four types of bearing fault signals. (<b>a</b>) PE analysis result; (<b>b</b>) DE analysis result; (<b>c</b>) <math display="inline"><semantics> <mrow> <msubsup> <mrow> <mi>q</mi> </mrow> <mrow> <mi>H</mi> </mrow> <mrow> <mo>∗</mo> </mrow> </msubsup> </mrow> </semantics></math> analysis result; (<b>d</b>) <math display="inline"><semantics> <mrow> <msubsup> <mrow> <mi>q</mi> </mrow> <mrow> <mi>C</mi> </mrow> <mrow> <mo>∗</mo> </mrow> </msubsup> </mrow> </semantics></math> analysis result; (<b>e</b>) <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>H</mi> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math>-<math display="inline"><semantics> <mrow> <msub> <mrow> <mi>C</mi> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math> curves of TC-IPE-CP with scale = 1; and (<b>f</b>) <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>H</mi> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math>-<math display="inline"><semantics> <mrow> <msub> <mrow> <mi>C</mi> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math> curves of TC-IPE-CP with scale = 5. (Note: In this paper, <math display="inline"><semantics> <mrow> <msubsup> <mrow> <mi>q</mi> </mrow> <mrow> <mi>H</mi> </mrow> <mrow> <mo>∗</mo> </mrow> </msubsup> </mrow> </semantics></math> refers to the value of q when the entropy is at its maximum, and <math display="inline"><semantics> <mrow> <msubsup> <mrow> <mi>q</mi> </mrow> <mrow> <mi>C</mi> </mrow> <mrow> <mo>∗</mo> </mrow> </msubsup> </mrow> </semantics></math> refers to the value of q when the complexity is at its maximum. These will not be annotated further in subsequent sections).</p>
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<p>Multiscale entropy analysis results of four types of ship-radiated noise. (<b>a</b>) <math display="inline"><semantics> <mrow> <msubsup> <mrow> <mi>q</mi> </mrow> <mrow> <mi>H</mi> </mrow> <mrow> <mo>∗</mo> </mrow> </msubsup> </mrow> </semantics></math> analysis result; (<b>b</b>) <math display="inline"><semantics> <mrow> <msubsup> <mrow> <mi>q</mi> </mrow> <mrow> <mi>C</mi> </mrow> <mrow> <mo>∗</mo> </mrow> </msubsup> </mrow> </semantics></math> analysis result; (<b>c</b>) PE analysis result; (<b>d</b>) DE analysis result; (<b>e</b>) <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>H</mi> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math>-<math display="inline"><semantics> <mrow> <msub> <mrow> <mi>C</mi> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math> curves of TC-IPE-CP with scale = 1; and (<b>f</b>) <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>H</mi> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math>-<math display="inline"><semantics> <mrow> <msub> <mrow> <mi>C</mi> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math> curves of TC-IPE-CP with scale = 5.</p>
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20 pages, 4590 KiB  
Article
Adaptive Whitening and Feature Gradient Smoothing-Based Anti-Sample Attack Method for Modulated Signals in Frequency-Hopping Communication
by Yanhan Zhu, Yong Li and Zhu Duan
Electronics 2024, 13(9), 1784; https://doi.org/10.3390/electronics13091784 - 5 May 2024
Viewed by 1174
Abstract
In modern warfare, frequency-hopping communication serves as the primary method for battlefield information transmission, with its significance continuously growing. Fighting for the control of electromagnetic power on the battlefield has become an important factor affecting the outcome of war. As communication electronic warfare [...] Read more.
In modern warfare, frequency-hopping communication serves as the primary method for battlefield information transmission, with its significance continuously growing. Fighting for the control of electromagnetic power on the battlefield has become an important factor affecting the outcome of war. As communication electronic warfare evolves, jammers employing deep neural networks (DNNs) to decode frequency-hopping communication parameters for smart jamming pose a significant threat to communicators. This paper proposes a method to generate adversarial samples of frequency-hopping communication signals using adaptive whitening and feature gradient smoothing. This method targets the DNN cognitive link of the jammer, aiming to reduce modulation recognition accuracy and counteract smart interference. First, the frequency-hopping signal is adaptively whitened. Subsequently, rich spatiotemporal features are extracted from the hidden layer after inputting the signal into the deep neural network model for gradient calculation. The signal’s average feature gradient replaces the single-point gradient for iteration, enhancing anti-disturbance capabilities. Simulation results show that, compared with the existing gradient symbol attack algorithm, the attack success rate and migration rate of the adversarial samples generated by this method are greatly improved in both white box and black box scenarios. Full article
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<p>Example of modulated signal adversarial example.</p>
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<p>Modulation recognition process based on DL.</p>
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<p>System model adversarial example attack in communication system.</p>
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<p>Structure of adaptive whitening algorithm.</p>
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<p>Example of non-smoothed lossy surface.</p>
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<p>Anti sample attack based on adaptive whitening and feature gradient smoothing.</p>
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<p>Modulation recognition accuracy of three models without attack.</p>
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<p>Recognition accuracy of three models under white box no-target attack.</p>
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<p>Recognition accuracy of two models under black box non-target attack.</p>
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<p>Black box mobility.</p>
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<p>Relationship between neighborhood boundary and recognition accuracy at 10 dB.</p>
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<p>Relationship between sampling times and recognition accuracy in neighborhood under 10 dB.</p>
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28 pages, 6055 KiB  
Article
Cultural Heritage Recognition through Protection of Historical Value and Urban Regeneration: CSOA Forte Prenestino
by Laura Ricci, Carmela Mariano and Francesca Perrone
Land 2024, 13(4), 453; https://doi.org/10.3390/land13040453 - 2 Apr 2024
Cited by 1 | Viewed by 1480
Abstract
The conformation and dynamics of metropolitanisation act as propulsive elements of territorial transformations. The deficiency of infrastructural equipment, the heterogeneity of urban fabric and the lack of services and public spaces contribute to severing the identity ties between settled communities and territories. In [...] Read more.
The conformation and dynamics of metropolitanisation act as propulsive elements of territorial transformations. The deficiency of infrastructural equipment, the heterogeneity of urban fabric and the lack of services and public spaces contribute to severing the identity ties between settled communities and territories. In light of this, within the more general reflection concerning urban regeneration, we recall the role that cultural heritage plays in the physical and functional organisation of the city, as a reflection of the interaction between community and context. The contribution is contextualized in the research work on the activities related to Thematic Line 4 of the Extended Partnership 5—CHANGES (NRRP). The thematic line activities follow three phases: 1. contextualization; 2. operational phase; 3. experimentation. The research work presented here is part of the ‘operational phase’, to identify strategies and projects for heritage-led regeneration. The article analyses the pilot case of CSOA Forte Prenestino as a starting point for thinking about expanding the research activity to other similar cases. It is a self-managed community centre in Rome (Italy) located in the nineteenth-century Forte, which has become a symbol of collective identity. The case study was identified following three levels of investigation: 1. identification of the municipality, first-level administrative subdivision of the city of Rome (Italy); 2. identification of the main historical, archaeological and architectural emergencies of the municipality; 3. identification of an asset to be analysed as “Heritage by designation” (involvement of experts) and “Heritage by appropriation” (involvement of communities). The research results show the “Recognition Path” of Forte Prenestina: according to what has been ‘designated’ by urban planning instruments, project instruments, legislative instruments and authors of scientific publications and conferences; and on the basis of the bottom-up ‘appropriation’ process of the asset that has allowed its management, assessment of its cultural and social potential and its development. The research results allow us to reflect on heritage-led urban regeneration as a strategy capable of capturing and promoting the links between social integration and cultural–historical identity. Full article
(This article belongs to the Section Urban Contexts and Urban-Rural Interactions)
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<p>Concise outline presenting the theoretical approach adopted to recognize and analyse the role and significance of cultural heritage. The groups of experts and individuals were identified through the contribution of Spennemann [<a href="#B39-land-13-00453" class="html-bibr">39</a>].</p>
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<p>General Regulatory Plan—PRG of the Municipality of Rome 2008. Communication drawings. Scenarios of municipalities. “<span class="html-italic">Legenda dei luoghi</span>” (legend of places): (<b>a</b>) C06—Ex-Municipality VI [<a href="#B50-land-13-00453" class="html-bibr">50</a>]; (<b>b</b>) C07—Ex-Municipality VII [<a href="#B51-land-13-00453" class="html-bibr">51</a>]. The blue star symbolizes Forte Prenestina. It was allocated to “<span class="html-italic">Spazi aperti ed assi</span>” (open spaces and axes).</p>
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<p>General Regulatory Plan—PRG of the Municipality of Rome 2008. Communication drawings. Scenarios of municipalities. “<span class="html-italic">Legenda dei luoghi</span>” (legend of places): (<b>a</b>) C06—Ex-Municipality VI [<a href="#B50-land-13-00453" class="html-bibr">50</a>]; (<b>b</b>) C07—Ex-Municipality VII [<a href="#B51-land-13-00453" class="html-bibr">51</a>]. The blue star symbolizes Forte Prenestina. It was allocated to “<span class="html-italic">Spazi aperti ed assi</span>” (open spaces and axes).</p>
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<p>This is Campo Trincerato (the entrenched field of the city) of Rome [<a href="#B57-land-13-00453" class="html-bibr">57</a>,<a href="#B59-land-13-00453" class="html-bibr">59</a>]. The red stars represent the Forts of Rome. The blue star symbolizes Forte Prenestina.</p>
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<p>This is a revised version of the Forte Prenestina Plan along with its structural components [<a href="#B60-land-13-00453" class="html-bibr">60</a>], specifically focusing on “<span class="html-italic">Pianta delle Murature</span>” (plan of the masonry). TAV III. Rome, Forte Prenestina, military engineering, Rome Territorial Command, Rome Headquarters, Piazza di Roma 1889 [<a href="#B59-land-13-00453" class="html-bibr">59</a>].</p>
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<p>General Regulatory Plan—PRG of the Municipality of Rome 1965. “<span class="html-italic">Zonizzazione</span>” (zoning). Table scale 1:20,000 [<a href="#B65-land-13-00453" class="html-bibr">65</a>]. The blue star symbolizes Forte Prenestina. It was allocated to “<span class="html-italic">Zona N—Parchi pubblici e impianti sportivi</span>” (Zone N—public park and sports facilities).</p>
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<p>Historical Archaeological Map Documenting The Monumental And Landscape Features of The Suburbs And Countryside Around Ancient Rome, published by the Municipality of Rome’s X Department of Antiquities and Fine Arts. Consisting of Sheets 16 S and 25 S. Table scale 1:10,000 [<a href="#B67-land-13-00453" class="html-bibr">67</a>]. The blue star symbolizes Forte Prenestina. It was allocated to “<span class="html-italic">Elementi areali di interesse storico-monumentale</span>” (area elements of historical–monumental interest) as an “<span class="html-italic">Insediamento unitario d’interesse storico-archeologico-tipologico</span>” (unitary settlement of historical–archaeological–typological interest).</p>
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<p>General Regulatory Plan—PRG of the Municipality of Rome 2008. Prescriptive drawing: Systems and Rules. Sheet 18. Table scale 1:10,000 [<a href="#B68-land-13-00453" class="html-bibr">68</a>]. The blue star symbolizes Forte Prenestina. It was allocated to “<span class="html-italic">Sistema dei servizi e delle infrastrutture</span>” (system of services and infrastructures) under the category of “<span class="html-italic">Verde pubblico e servizi pubblici di livello locale</span>” (public green spaces and local public services).</p>
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<p>The photographs depict a selection of activities conducted at CSOA Forte Prenestino: (<b>a</b>) the fort’s main parade ground, from which part of the rampart can also be seen; (<b>b</b>) the cells on the lower levels of CSOA Forte Prenestino during the Crack! Disruptive Comics event [<a href="#B60-land-13-00453" class="html-bibr">60</a>].</p>
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<p>The photographs depict a selection of activities conducted at CSOA Forte Prenestino: (<b>a</b>) the fort’s main parade ground, from which part of the rampart can also be seen; (<b>b</b>) the cells on the lower levels of CSOA Forte Prenestino during the Crack! Disruptive Comics event [<a href="#B60-land-13-00453" class="html-bibr">60</a>].</p>
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7 pages, 4860 KiB  
Proceeding Paper
Research on the Wearable Augmented Reality Seeking System for Rescue-Guidance in Buildings
by Chyi-Gang Kuo, Chi-Wei Lee, Benson P. C. Liu and Chien-Wei Chiu
Eng. Proc. 2023, 55(1), 77; https://doi.org/10.3390/engproc2023055077 - 14 Dec 2023
Cited by 1 | Viewed by 738
Abstract
When a construction disaster occurs, the first-line rescue personnel often enter the disaster site immediately, and every second counts in rescuing the people who need help. However, the rescue personnel may not be familiar with the indoor layouts of different buildings. If the [...] Read more.
When a construction disaster occurs, the first-line rescue personnel often enter the disaster site immediately, and every second counts in rescuing the people who need help. However, the rescue personnel may not be familiar with the indoor layouts of different buildings. If the indoor paths are complicated, or when the fire smoke obstructs the line of sight, the rescue personnel are prone to spatial disorientation, which usually causes the rescue personnel to fall into danger. Therefore, we have developed the “Wearable Augmented reality Seeking System” (WASS) to assist rescue personnel in reading the information provided by the “Building Information Guiding System”. This system allows them to enter an unfamiliar space and reach the target rescue position, retreat to the entrance, or find an alternative escape route. The WASS is based on the HoloLens augmented reality system, which displays 3D digital information such as indoor layouts, one’s current location, spatial images captured by an infrared camera and a depth camera, and 3D virtual guiding symbols or text. The WASS includes two modules: First, the augmented reality gesture interaction module allows one to read the positioning anchor information of the “Building Information Guiding System” (BIGS). The rescue personnel can communicate via gestures, select the task target, and follow the 3D virtual guidance symbols in the air to reach the relay anchor points and finally arrive at the target position. Second, the service support module, including a lighting source and backup power, ensures that the QR code recognition process and long-term operation of the WASS are successful. Full article
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<p>Images captured by thermal imaging cameras used by firefighters [<a href="#B6-engproc-55-00077" class="html-bibr">6</a>]. (From: <a href="https://www.flir.asia/discover/public-safety/no-excuse-for-firefighter-disorientation/" target="_blank">https://www.flir.asia/discover/public-safety/no-excuse-for-firefighter-disorientation/</a> (accessed on 6 November 2022)).</p>
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<p>Hardware components of HoloLens 2 [<a href="#B7-engproc-55-00077" class="html-bibr">7</a>].</p>
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<p>Four views captured by different cameras and sensors equipped on HoloLens launched by the program used for this study. The red-to-white gradient color bar on the screen is the coordinate showing the extent of the HoloLens tilt or rotation detected by the Inertial Measurement Unit (IMU).</p>
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<p>Visible light cameras and IR cameras cannot see objects clearly, but the depth sensor can allow one to see nearby things.</p>
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<p>Helmets used by active-duty firefighters in Taichung City.</p>
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<p>The WASS consists of a fire helmet and HoloLens 2, as well as other accessories.</p>
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<p>Simulation of a firefighter wearing a WASS-based device.</p>
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20 pages, 4054 KiB  
Article
Understanding Map Misinterpretation: Factors Influencing Correct Map Reading and Common Errors
by Csaba Szigeti-Pap, Dávid Kis and Gáspár Albert
ISPRS Int. J. Geo-Inf. 2023, 12(12), 479; https://doi.org/10.3390/ijgi12120479 - 26 Nov 2023
Cited by 2 | Viewed by 2528
Abstract
Misinterpreting maps can have serious consequences, especially in situations requiring quick decisions like using car navigation systems. Studies indicate that a map reader’s experience is crucial for understanding maps, but factors such as age, education, and gender can also influence interpretation. However, understanding [...] Read more.
Misinterpreting maps can have serious consequences, especially in situations requiring quick decisions like using car navigation systems. Studies indicate that a map reader’s experience is crucial for understanding maps, but factors such as age, education, and gender can also influence interpretation. However, understanding only the proportion of correctly interpreted information is not enough. It is essential to investigate the types of mistakes made and their causes. To address this, we conducted a study available in six languages with 511 participants who completed an online questionnaire testing their map reading skills. The questions focused on scale usage, mental rotation, and recognizing map categories (relief, line and point symbols, and geographic names). Gender had significant relation with one skill, qualification with two and age with three. Experience was associated to the highest number of skills, a total of four, confirming previous findings. When making mistakes, participants tended to overestimate distances and struggled with conceptual similarities in symbol recognition. Experienced readers often misplaced reference locations of geographic names. The results of the research could be used in the design of large-scale maps (e.g., car navigation), as they allow to reduce typical map reading errors by careful selection of symbol types and placements. Full article
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<p>The relief map for the test used for questions Q1–3.</p>
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<p>The relief and hydrography map for the test used for question Q4.</p>
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<p>The simplified topographic map for the test used for question Q5, and Q6.</p>
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<p>The last map for the test showing linear and polygonal map symbols and geographic names was used for question Q7, and Q8. Note: the map legend was not included in the test.</p>
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<p>The visual depiction of the study procedure.</p>
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<p>The relative proportion of votes given to incorrect answer options in the case of four-choice questions (the skills tested by the questions are shown on the left). Capital letters indicate the answer variations shown in <a href="#sec2dot1-ijgi-12-00479" class="html-sec">Section 2.1</a>. The answer “I don’t know” was not counted as one of the wrong answers and was therefore not included in the analysis.</p>
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<p>The relative frequency distribution of mistakes grouped by the different levels of erroneous performance.</p>
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17 pages, 5654 KiB  
Article
Usability of Certain Symbols Indicating Automobile Safety Status Based on Youth Assessment
by Uros Manojlovic, Aleksandar Zunjic, Aleksandar Trifunović, Tijana Ivanišević, Darina Duplakova, Jan Duplak and Svetlana Čičević
Appl. Sci. 2023, 13(17), 9749; https://doi.org/10.3390/app13179749 - 29 Aug 2023
Viewed by 1167
Abstract
The research presented in this paper refers to the possibility to understand the information presented by symbols, which indicate safety status and possible troubles regarding automobiles and driving. The testing included sixteen symbols, six of which were ISO-verified and recommended symbols. The study [...] Read more.
The research presented in this paper refers to the possibility to understand the information presented by symbols, which indicate safety status and possible troubles regarding automobiles and driving. The testing included sixteen symbols, six of which were ISO-verified and recommended symbols. The study included 204 youth respondents. The study used a multidisciplinary, ergonomic approach, based on research of the usability of symbols. The basic task of subjects was to recognize the symbols and to rate their confidence on the five-point scale that they gave exact answers. For each symbol, hypotheses about the proportion of correct answers at the population level were tested, applying the inferential statistics technique. The ISO criterion of 67% successful symbol recognition was adopted as the limit value for the justification of the use of symbols. The test results showed that eight out of sixteen symbols did not meet this criterion. The results of this research indicate that it is necessary to take certain measures in order to improve the understanding of the function of symbols on vehicle dashboards. One of the proposed measures consists in the improvement of training courses in driving schools, which from a theoretical but also a practical aspect should include education about symbols on car dashboards, primarily those responsible for informing about the safety status. In addition, a redesign of the symbols that had the lowest recognition rate can be recommended. Full article
26 pages, 30893 KiB  
Article
Knowledge Enhanced Neural Networks for Point Cloud Semantic Segmentation
by Eleonora Grilli, Alessandro Daniele, Maarten Bassier, Fabio Remondino and Luciano Serafini
Remote Sens. 2023, 15(10), 2590; https://doi.org/10.3390/rs15102590 - 16 May 2023
Cited by 13 | Viewed by 2676
Abstract
Deep learning approaches have sparked much interest in the AI community during the last decade, becoming state-of-the-art in domains such as pattern recognition, computer vision, and data analysis. However, these methods are highly demanding in terms of training data, which is often a [...] Read more.
Deep learning approaches have sparked much interest in the AI community during the last decade, becoming state-of-the-art in domains such as pattern recognition, computer vision, and data analysis. However, these methods are highly demanding in terms of training data, which is often a major issue in the geospatial and remote sensing fields. One possible solution to this problem comes from the Neuro-Symbolic Integration field (NeSy), where multiple methods have been defined to incorporate background knowledge into the neural network’s learning pipeline. One such method is KENN (Knowledge Enhanced Neural Networks), which injects logical knowledge into the neural network’s structure through additional final layers. Empirically, KENN showed comparable or better results than other NeSy frameworks in various tasks while being more scalable. Therefore, we propose the usage of KENN for point cloud semantic segmentation tasks, where it has immense potential to resolve issues with small sample sizes and unbalanced classes. While other works enforce the knowledge constraints in post-processing, to the best of our knowledge, no previous methods have injected inject such knowledge into the learning pipeline through the use of a NeSy framework. The experiment results over different datasets demonstrate that the introduction of knowledge rules enhances the performance of the original network and achieves state-of-the-art levels of accuracy, even with subideal training data. Full article
(This article belongs to the Special Issue Semantic Segmentation Algorithms for 3D Point Clouds)
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<p>Promising covariance features as reported in Weinmann et al. [<a href="#B59-remotesensing-15-02590" class="html-bibr">59</a>].</p>
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<p>KENN overview: the neural network (NN) takes the features <math display="inline"><semantics> <mi mathvariant="bold">x</mi> </semantics></math> as inputs and produces an initial output <math display="inline"><semantics> <mi mathvariant="bold">y</mi> </semantics></math>. The KENN layer refines the initial predictions in order to increase knowledge satisfaction.</p>
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<p>Covariance features used to facilitate a unary clause for the identification of poles: (<b>a</b>) Linearity, (<b>b</b>) Verticality.</p>
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<p>Semantic segmentation results for the FBK powerlines dataset. Results achieved using (<b>a</b>) a Point Transformer NN and a set of geometric features (<b>b</b>) and results after the introduction of Over and Near logic rules via KENN.</p>
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<p>Semantic segmentation results for the FBK powerline dataset before (<b>a</b>) and after (<b>b</b>) the introduction of the Near and Close binary rules.</p>
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<p>Predictions of the NN model with zero (initial predictions of a NN), one and two KENN layers. Red points: roof; blue points: powerlines. The KENN layers help in refining the prediction.</p>
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<p>Overview of the Vaihingen training dataset.</p>
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<p>Performance increase for the Vaihingen dataset with the three different configurations.</p>
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<p>Confusion matrix for the Vaihingen dataset, using the Point Transformer NN with features.</p>
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<p>Vaihingen test set: IR G B representation (<b>a</b>) and ground truth (<b>b</b>).</p>
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<p>Prediction results on the Vaihingen test set using: (<b>a</b>) PT, (<b>b</b>) PT plus a selection of features (FEAT), (<b>c</b>) PT plus a selection of features and logic rules (KENN).</p>
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<p>Class distribution for the Hessigheim training dataset.</p>
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<p>F1 score per class for the Hessigheim dataset, before and after the introduction of KENN.</p>
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<p>Visual results for the Hessigheim validation dataset.</p>
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<p>Results achieved for the Hessighein test dataset with and without the use of logic rules. In the close-up views, changes are highlighted in circles for the “chimney” class and in rectangles for the “vehicle” class.</p>
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<p>Confusion matrix and derived metrics for the Hessigheim dataset: results achieved using only some selected features (<b>a</b>); results achieved using selected features and logic rules (<b>b</b>).</p>
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<p>Overview of the S3DIS dataset Area 5 colorized and with assigned labels of all thirtheen classes.</p>
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<p>Performance increase for the S3DIS dataset with the three different configurations.</p>
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<p>Confusion matrix and derived metrics for the S3DIS dataset: (<b>left</b>) Results achieved using a-priori knowledge and (<b>right</b>) results achieved using also a-posteriori knowledge.</p>
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<p>Overview of the remaining missclassifications after applying a-priori knowledge: (<b>left</b>) lack of class consistency and (<b>right</b>) confusion between wall-based classes i.e., windows, doors and bookcases.</p>
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<p>Overview of the effect of the a-posteriori rules on the S3DIS dataset: less stray classification points (<b>top</b>) and better class consistency near wall elements (<b>bottom</b>).</p>
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14 pages, 1303 KiB  
Article
Sample Reduction-Based Pairwise Linear Regression Classification for IoT Monitoring Systems
by Xizhan Gao, Wei Hu, Yu Chu and Sijie Niu
Appl. Sci. 2023, 13(7), 4209; https://doi.org/10.3390/app13074209 - 26 Mar 2023
Viewed by 1365
Abstract
At present, the development of the Internet of Things (IoT) has become a significant symbol of the information age. As an important research branch of it, IoT-based video monitoring systems have achieved rapid developments in recent years. However, the mode of front-end data [...] Read more.
At present, the development of the Internet of Things (IoT) has become a significant symbol of the information age. As an important research branch of it, IoT-based video monitoring systems have achieved rapid developments in recent years. However, the mode of front-end data collection, back-end data storage and analysis adopted by traditional monitoring systems cannot meet the requirements of real-time security. The currently widely used edge computing-based monitoring system can effectively solve the above problems, but it has high requirements for the intelligent algorithms that will be deployed at the edge end (front-end). To meet the requirements, that is, to obtain a lightweight, fast and accurate video face-recognition method, this paper proposes a novel, set-based, video face-recognition framework, called sample reduction-based pairwise linear regression classification (SRbPLRC), which contains divide SRbPLRC (DSRbPLRC), anchor point SRbPLRC (APSRbPLRC), and attention anchor point SRbPLRC (AAPSRbPLRC) methods. Extensive experiments on some popular video face-recognition databases demonstrate that the performance of proposed algorithms is better than that of several state-of-the-art classifiers. Therefore, our proposed methods can effectively meet the real-time and security requirements of IoT monitoring systems. Full article
(This article belongs to the Section Computing and Artificial Intelligence)
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<p>An illustration of the proposed framework. Aiming at obtaining an effective and efficient video face recognition method, a new SRbPLRC framework is proposed, by decreasing the number of images in each video. This framework contains DSRbPLRC, APSRbPLRC, and AAPSRbPLRC methods.</p>
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<p>A diagram of the unrelated S3 and S4 set-constructing strategies. In S3, the sparse representation is used to learn the distances, while in S4, the collaborative representation is used.</p>
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<p>An illustration of the proposed DSRbPLRC and APSRbPLRC algorithms. DSRbPLRC directly divides a large-size video into several small-size sub-videos, and each sub-video is used for classification. Different from DSRbPLRC, APSRbPLRC uses the HDC algorithm to extract anchor points, which will not increase the number of videos.</p>
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<p>The experimental results of DLRC and PLRC methods from two popular databases, with varying numbers of frames.</p>
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<p>The average recognition rates of the DSRbPLRC, APSRbPLRC, and AAPSRbPLRC algorithms, in terms of large-sized videos.</p>
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23 pages, 46299 KiB  
Article
Leveraging Deep Convolutional Neural Network for Point Symbol Recognition in Scanned Topographic Maps
by Wenjun Huang, Qun Sun, Anzhu Yu, Wenyue Guo, Qing Xu, Bowei Wen and Li Xu
ISPRS Int. J. Geo-Inf. 2023, 12(3), 128; https://doi.org/10.3390/ijgi12030128 - 16 Mar 2023
Cited by 5 | Viewed by 2222
Abstract
Point symbols on a scanned topographic map (STM) provide crucial geographic information. However, point symbol recognition entails high complexity and uncertainty owing to the stickiness of map elements and singularity of symbol structures. Therefore, extracting point symbols from STMs is challenging. Currently, point [...] Read more.
Point symbols on a scanned topographic map (STM) provide crucial geographic information. However, point symbol recognition entails high complexity and uncertainty owing to the stickiness of map elements and singularity of symbol structures. Therefore, extracting point symbols from STMs is challenging. Currently, point symbol recognition is performed primarily through pattern recognition methods that have low accuracy and efficiency. To address this problem, we investigated the potential of a deep learning-based method for point symbol recognition and proposed a deep convolutional neural network (DCNN)-based model for this task. We created point symbol datasets from different sources for training and prediction models. Within this framework, atrous spatial pyramid pooling (ASPP) was adopted to handle the recognition difficulty owing to the differences between point symbols and natural objects. To increase the positioning accuracy, the k-means++ clustering method was used to generate anchor boxes that were more suitable for our point symbol datasets. Additionally, to improve the generalization ability of the model, we designed two data augmentation methods to adapt to symbol recognition. Experiments demonstrated that the deep learning method considerably improved the recognition accuracy and efficiency compared with classical algorithms. The introduction of ASPP in the object detection algorithm resulted in higher mean average precision and intersection over union values, indicating a higher recognition accuracy. It is also demonstrated that data augmentation methods can alleviate the cross-domain problem and improve the rotation robustness. This study contributes to the development of algorithms and the evaluation of geographic elements extracted from STMs. Full article
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<p>Examples of point symbols on the 1955 STM of Grand Island. (<b>a</b>,<b>b</b>) are locally enlarged maps with point symbols. Map source: USGS-HTMC.</p>
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<p>Number statistical results for the training set and total set of the scanned map dataset.</p>
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<p>Three annotation samples of the scanned map dataset.</p>
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<p>Statistical results for the entire vectorized map dataset.</p>
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<p>Three annotation samples of the vectorized map dataset.</p>
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<p>Annotation samples of the PASCAL VOC dataset, which is mainly used for natural object detection.</p>
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<p>Overview of the YOLOv4 framework combined with ASPP. The backbone is composed of the feature extraction network CSPDarknet53, the neck is composed of PANet combined with ASPP, and the three heads are used for prediction.</p>
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<p>Illustration of the SPP module structure, redrawn according to [<a href="#B41-ijgi-12-00128" class="html-bibr">41</a>]. Extraction of features using multiple pooling layers at different scales and fusion into a 21-dimensional vector input for the fully connected layer.</p>
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<p>Illustration of the proposed ASPP module structure comprising multiple parallel levels: A 1 × 1 convolution; three 3 × 3 dilated convolutions with dilation rates of 1, 3, 5, respectively; and image pooling.</p>
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<p>Images obtained by applying the data augmentation methods to the original image (<b>a</b>): (<b>b</b>) with a horizontal flip, (<b>c</b>) with vertical flipping, (<b>d</b>) with cropping, (<b>e</b>) ToGray, and (<b>f</b>) by rotating at a small angle.</p>
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<p>Images obtained by applying the Gaussian blur combined with color jitter method to the original image (<b>a</b>): (<b>b</b>) brightness transformation, (<b>c</b>) hue transformation, (<b>d</b>) contrast transformation, (<b>e</b>) saturation transformation, (<b>f</b>) Gaussian blur, and (<b>g</b>) Gaussian blur combined with color jitter.</p>
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<p>Statistical plots of the AP values of the ten point symbols in <a href="#ijgi-12-00128-t001" class="html-table">Table 1</a> identified using different models.</p>
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<p>Results obtained by different models for Map A: (<b>a</b>) faster R-CNN, (<b>b</b>) VGG-SSD, (<b>c</b>) YOLOv3, (<b>d</b>) YOLOv4, and (<b>e</b>) ASPP-YOLOv4.</p>
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<p>Results obtained by different models for Map B: (<b>a</b>) faster R-CNN, (<b>b</b>) VGG-SSD, (<b>c</b>) YOLOv3, (<b>d</b>) YOLOv4, and (<b>e</b>) ASPP-YOLOv4.</p>
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<p>Results obtained by different models for Map C: (<b>a</b>) faster R-CNN, (<b>b</b>) VGG-SSD, (<b>c</b>) YOLOv3, (<b>d</b>) YOLOv4, and (<b>e</b>) ASPP-YOLOv4.</p>
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<p>Comparison of Grad-CAM results obtained with YOLO heads of three YOLOv4-based models. Warmer colors indicate higher interest in the area, whereas cooler colors indicate the opposite; the white arrow points to the object of the study, the point symbol III.</p>
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<p>Results obtained for different input image sizes of Map D: (<b>a</b>) 320 × 320, (<b>b</b>) 512 × 512, and (<b>c</b>) 640 × 640 pixels.</p>
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<p>Results obtained for different input image sizes of Map E: (<b>a</b>) 320 × 320, (<b>b</b>) 512 × 512, and (<b>c</b>) 640 × 640 pixels.</p>
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<p>Symbol detection processing operation for large-scale maps: “first cut, then zoom, detect, and finally stitch”.</p>
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<p>Results obtained by the proposed ASPP-YOLOv4 for Map F of size 1241 × 955 pixels. (<b>a</b>) Original image and (<b>b</b>) the image skewed during scanning. The red circle indicates missed recognition.</p>
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<p>Recognition results of different methods for Map G. (<b>a</b>) Results of Template matching. (<b>b</b>) Results of GHT. (<b>c</b>) Results of the proposed ASPP-YOLOv4. In (<b>a</b>,<b>b</b>), the green box indicates correct recognition, whereas the red circle indicates missed recognition.</p>
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<p>Symbol recognition results of template matching method for different scenes. The green box indicates correct recognition, whereas the red circle indicates missed recognition. (<b>a</b>) Template. (<b>b</b>) Results for different map backgrounds. (<b>c</b>) Results for 0.8 times smaller size. (<b>d</b>) Results for 5° angle rotation.</p>
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<p>Recognition results of the model trained on the vectorized map dataset for the scanned Map H. (<b>a</b>) Recognition results without the Gaussian blur and color jitter data augmentation method. (<b>b</b>) Recognition results with the Gaussian blur and color jitter data augmentation method.</p>
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<p>Statistical plots of different rotation angles on our test set.</p>
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<p>Recognition results for different rotation angles of Map I: (<b>a</b>) original image, (<b>b</b>) rotated by 2.5°, and (<b>c</b>) rotated by 5°.</p>
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21 pages, 5557 KiB  
Article
Machine Recognition of Map Point Symbols Based on YOLOv3 and Automatic Configuration Associated with POI
by Huili Zhang, Xiaowen Zhou, Huan Li, Ge Zhu and Hongwei Li
ISPRS Int. J. Geo-Inf. 2022, 11(11), 540; https://doi.org/10.3390/ijgi11110540 - 28 Oct 2022
Cited by 3 | Viewed by 2048
Abstract
This study is oriented towards machine autonomous mapping and the need to improve the efficiency of map point symbol recognition and configuration. Therefore, an intelligent recognition method for point symbols was developed using the You Only Look Once Version 3 (YOLOv3) algorithm along [...] Read more.
This study is oriented towards machine autonomous mapping and the need to improve the efficiency of map point symbol recognition and configuration. Therefore, an intelligent recognition method for point symbols was developed using the You Only Look Once Version 3 (YOLOv3) algorithm along with the Convolutional Block Attention Module (CBAM). Then, the recognition results of point symbols were associated with the point of interest (POI) to achieve automatic configuration. To quantitatively analyze the recognition effectiveness of this study algorithm and the comparison algorithm for map point symbols, the recall, precision and mean average precision (mAP) were employed as evaluation metrics. The experimental results indicate that the recognition efficiency of point symbols is enhanced compared to the original YOLOv3 algorithm, and that the mAP is increased by 0.55%. Compared to the Single Shot MultiBox Detector (SSD) algorithm and Faster Region-based Convolutional Neural Network (Faster RCNN) algorithm, the precision, recall rate, and mAP all performed well, achieving 97.06%, 99.72% and 99.50%, respectively. On this basis, the recognized point symbols are associated with POI, and the coordinate of point symbols are assigned through keyword matching and enrich their attribute information. This enables automatic configuration of point symbols and achieves a relatively good effect of map configuration. Full article
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<p>YOLOv3 network structure.</p>
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<p>Workflow diagram of CBAM module.</p>
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<p>Map point symbols automatic positioning configuration process.</p>
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<p>Point symbols dataset labeling plot.</p>
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<p>Training results of YOLOv3 and the method proposed in this study:(<b>a</b>) precision comparison chart; (<b>b</b>) recall comparison chart; (<b>c</b>) mAP comparison chart.</p>
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<p>Point Symbols Recognition Results of Four Models on the Target Smaller Map: (<b>a</b>–<b>d</b>) are the recognition results of YOLOv3, the proposed method, Faster RCNN, and SSD on smaller target maps, respectively.</p>
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<p>Point Symbols Recognition Results of Four Models on the Target Bigger Map: (<b>a</b>–<b>d</b>) are the recognition results of YOLOv3, the proposed method, Faster RCNN, and SSD on another style city map and a more prominent target map, respectively.</p>
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<p>The rendering of the point symbols configuration on the Map World image and vector base map: (<b>a</b>) The configuration effect of the Map World image map; (<b>b</b>) The configuration effect of the Map World vector map.</p>
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<p>Attribute Information Query.</p>
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19 pages, 3117 KiB  
Article
DrawnNet: Offline Hand-Drawn Diagram Recognition Based on Keypoint Prediction of Aggregating Geometric Characteristics
by Jiaqi Fang, Zhen Feng and Bo Cai
Entropy 2022, 24(3), 425; https://doi.org/10.3390/e24030425 - 19 Mar 2022
Cited by 9 | Viewed by 7318
Abstract
Offline hand-drawn diagram recognition is concerned with digitizing diagrams sketched on paper or whiteboard to enable further editing. Some existing models can identify the individual objects like arrows and symbols, but they become involved in the dilemma of being unable to understand a [...] Read more.
Offline hand-drawn diagram recognition is concerned with digitizing diagrams sketched on paper or whiteboard to enable further editing. Some existing models can identify the individual objects like arrows and symbols, but they become involved in the dilemma of being unable to understand a diagram’s structure. Such a shortage may be inconvenient to digitalization or reconstruction of a diagram from its hand-drawn version. Other methods can accomplish this goal, but they live on stroke temporary information and time-consuming post-processing, which somehow hinders the practicability of these methods. Recently, Convolutional Neural Networks (CNN) have been proved that they perform the state-of-the-art across many visual tasks. In this paper, we propose DrawnNet, a unified CNN-based keypoint-based detector, for recognizing individual symbols and understanding the structure of offline hand-drawn diagrams. DrawnNet is designed upon CornerNet with extensions of two novel keypoint pooling modules which serve to extract and aggregate geometric characteristics existing in polygonal contours such as rectangle, square, and diamond within hand-drawn diagrams, and an arrow orientation prediction branch which aims to predict which direction an arrow points to through predicting arrow keypoints. We conducted wide experiments on public diagram benchmarks to evaluate our proposed method. Results show that DrawnNet achieves 2.4%, 2.3%, and 1.7% recognition rate improvements compared with the state-of-the-art methods across benchmarks of FC-A, FC-B, and FA, respectively, outperforming existing diagram recognition systems on each metric. Ablation study reveals that our proposed method can effectively enable hand-drawn diagram recognition. Full article
(This article belongs to the Topic Machine and Deep Learning)
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<p>An example of a hand-drawn diagram.</p>
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<p>The architecture of DrawnNet. A backbone with the structure of encode–decode is followed by two keypoint prediction branches (heatmap, embedding, and offset) for top-left and bottom-right corner prediction, respectively, and one arrow orientation prediction branch for keypoints of arrow heads and rear prediction.</p>
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<p>CICP and MICP are leveraged to pool the top-left corner appearing in the same rectangle; (<b>b</b>) obviously demonstrates that MICP fails to capture the top-left corner. By contrast, (<b>a</b>) with CICP is adequate to tackle such situation.</p>
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<p>The architecture of the top-left corner prediction branch with CICP and MICP, and geometric characteristics aggregation.</p>
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<p>Arrow orientation Prediction with SCP to facilitate structure recognition.</p>
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<p>An SCP example with <math display="inline"><semantics> <mrow> <mi>r</mi> <mo>=</mo> <mn>2</mn> </mrow> </semantics></math>, which demonstrates how SCP is leveraged in the arrow orientation branch to capture an arrow pattern.</p>
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<p>Some diagrams’ recognition by DrawnNet from the test split of three benchmarks. Here, arrow heads and rears are marked with red and yellow dots, respectively.</p>
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<p>Some bug samples in a training split of <math display="inline"><semantics> <mrow> <mi>F</mi> <msub> <mi>C</mi> <mi>A</mi> </msub> </mrow> </semantics></math>. (<b>a</b>,<b>b</b>) show arrow heads are mismarked with circles and too small; (<b>c</b>) shows a normal sample.</p>
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18 pages, 9041 KiB  
Article
Usage of Real Time Machine Vision in Rolling Mill
by Jiří David, Pavel Švec, Vít Pasker and Romana Garzinová
Sustainability 2021, 13(7), 3851; https://doi.org/10.3390/su13073851 - 31 Mar 2021
Cited by 14 | Viewed by 3015
Abstract
This article deals with the issue of computer vision on a rolling mill. The main goal of this article is to describe the designed and implemented algorithm for the automatic identification of the character string of billets on the rolling mill. The algorithm [...] Read more.
This article deals with the issue of computer vision on a rolling mill. The main goal of this article is to describe the designed and implemented algorithm for the automatic identification of the character string of billets on the rolling mill. The algorithm allows the conversion of image information from the front of the billet, which enters the rolling process, into a string of characters, which is further used to control the technological process. The purpose of this identification is to prevent the input pieces from being confused because different parameters of the rolling process are set for different pieces. In solving this task, it was necessary to design the optimal technical equipment for image capture, choose the appropriate lighting, search for text and recognize individual symbols, and insert them into the control system. The research methodology is based on the empirical-quantitative principle, the basis of which is the analysis of experimentally obtained data (photographs of billet faces) in real operating conditions leading to their interpretation (transformation into the shape of a digital chain). The first part of the article briefly describes the billet identification system from the point of view of technology and hardware resources. The next parts are devoted to the main parts of the algorithm of automatic identification—optical recognition of strings and recognition of individual characters of the chain using artificial intelligence. The method of optical character recognition using artificial neural networks is the basic algorithm of the system of automatic identification of billets and eliminates ambiguities during their further processing. Successful implementation of the automatic inspection system will increase the share of operation automation and lead to ensuring automatic inspection of steel billets according to the production plan. This issue is related to the trend of digitization of individual technological processes in metallurgy and also to the social sustainability of processes, which means the elimination of human errors in the management of the billet rolling process. Full article
(This article belongs to the Special Issue Green ICT, Artificial Intelligence and Smart Cities)
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<p>Camera mount including an incandescent light source.</p>
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<p>Modification of billet conveyor control.</p>
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<p>A picture of a passing billet and a billet at rest from the Billet Stamping program.</p>
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<p>System function diagram.</p>
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<p>Graphical interface of Billet Stamping program.</p>
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<p>Modification of images of billets from the Billet Stamping program.</p>
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<p>Process of editing the input image.</p>
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<p>The principle of the image resizing process.</p>
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<p>Input images (<b>left</b>—raw input image, <b>right</b>—edited input image).</p>
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<p>Binarized images (<b>left</b>—raw input image, <b>right</b>—edited input image).</p>
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<p>Occurrence of anomalies on axis <span class="html-italic">X</span> (<b>left</b>—raw input image, <b>right</b>—edited input image).</p>
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<p>Occurrence of anomalies on axis <span class="html-italic">Y</span> (<b>left</b>—raw input image, <b>right</b>—edited input image).</p>
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<p>Output images (<b>left</b>—raw input image, <b>right</b>—edited input image).</p>
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<p>Transforming a pattern with a neural network.</p>
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<p>Transforming a pattern.</p>
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<p>The numeric characters on the billet faces.</p>
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<p>The images, which form the basis of the training set.</p>
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<p>STATISTICA software, with visualization of selected neural networks.</p>
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21 pages, 1390 KiB  
Article
(Hyper)Graph Embedding and Classification via Simplicial Complexes
by Alessio Martino, Alessandro Giuliani and Antonello Rizzi
Algorithms 2019, 12(11), 223; https://doi.org/10.3390/a12110223 - 25 Oct 2019
Cited by 26 | Viewed by 5838
Abstract
This paper investigates a novel graph embedding procedure based on simplicial complexes. Inherited from algebraic topology, simplicial complexes are collections of increasing-order simplices (e.g., points, lines, triangles, tetrahedrons) which can be interpreted as possibly meaningful substructures (i.e., information granules) on the top of [...] Read more.
This paper investigates a novel graph embedding procedure based on simplicial complexes. Inherited from algebraic topology, simplicial complexes are collections of increasing-order simplices (e.g., points, lines, triangles, tetrahedrons) which can be interpreted as possibly meaningful substructures (i.e., information granules) on the top of which an embedding space can be built by means of symbolic histograms. In the embedding space, any Euclidean pattern recognition system can be used, possibly equipped with feature selection capabilities in order to select the most informative symbols. The selected symbols can be analysed by field-experts in order to extract further knowledge about the process to be modelled by the learning system, hence the proposed modelling strategy can be considered as a grey-box. The proposed embedding has been tested on thirty benchmark datasets for graph classification and, further, we propose two real-world applications, namely predicting proteins’ enzymatic function and solubility propensity starting from their 3D structure in order to give an example of the knowledge discovery phase which can be carried out starting from the proposed embedding strategy. Full article
(This article belongs to the Section Evolutionary Algorithms and Machine Learning)
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<p>Average accuracy on the test set amongst the dummy classifier, GRALG, WJK and the proposed embedding technique. Results are given in percentage. The colour scale has been normalised row-wise (i.e., for each dataset) from yellow (lower values) towards green (higher values, preferred).</p>
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<p>Resolution distribution within the initial 6685 proteins set. Proteins with no resolution information are not considered.</p>
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<p>Classes distribution within the final 5583 proteins set.</p>
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<p>Solubility distribution within the final 4781 proteins set.</p>
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<p>Average Performance on Test Set for Experiment #2 (<math display="inline"><semantics> <msub> <mo>ℓ</mo> <mn>1</mn> </msub> </semantics></math>-SVM, <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <mn>1</mn> </mrow> </semantics></math>).</p>
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<p>Average Performance on Test Set for Experiment #2 (<math display="inline"><semantics> <msub> <mo>ℓ</mo> <mn>1</mn> </msub> </semantics></math>-SVM, <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <mn>0.5</mn> </mrow> </semantics></math>).</p>
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14 pages, 994 KiB  
Article
Optimized Dimensionality Reduction Methods for Interval-Valued Variables and Their Application to Facial Recognition
by Jorge Arce Garro and Oldemar Rodríguez Rojas
Entropy 2019, 21(10), 1016; https://doi.org/10.3390/e21101016 - 19 Oct 2019
Cited by 2 | Viewed by 3210
Abstract
The center method, which was first proposed in Rev. Stat. Appl. 1997 by Cazes et al. and Stat. Anal. Data Mining 2011 by Douzal-Chouakria et al., extends the well-known Principal Component Analysis (PCA) method to particular types of symbolic objects that are characterized [...] Read more.
The center method, which was first proposed in Rev. Stat. Appl. 1997 by Cazes et al. and Stat. Anal. Data Mining 2011 by Douzal-Chouakria et al., extends the well-known Principal Component Analysis (PCA) method to particular types of symbolic objects that are characterized by multivalued interval-type variables. In contrast to classical data, symbolic data have internal variation. The authors who originally proposed the center method used the center of a hyper-rectangle in R m as a base point to carry out PCA, followed by the projection of all vertices of the hyper-rectangles as supplementary elements. Since these publications, the center point of the hyper-rectangle has typically been assumed to be the best point for the initial PCA. However, in this paper, we show that this is not always the case, if the aim is to maximize the variance of projections or minimize the squared distance between the vertices and their respective projections. Instead, we propose the use of an optimization algorithm that maximizes the variance of the projections (or that minimizes the distances between the squares of the vertices and their respective projections) and finds the optimal point for the initial PCA. The vertices of the hyper-rectangles are, then, projected as supplementary variables to this optimal point, which we call the “Best Point” for projection. For this purpose, we propose four new algorithms and two new theorems. The proposed methods and algorithms are illustrated using a data set comprised of measurements of facial characteristics from a study on facial recognition patterns for use in surveillance. The performance of our approach is compared with that of another procedure in the literature, and the results show that our symbolic analyses provide more accurate information. Our approach can be regarded as an optimization method, as it maximizes the explained variance or minimizes the squared distance between projections and the original points. In addition, the symbolic analyses generate more informative conclusions, compared with the classical analysis in which classical surrogates replace intervals. All the methods proposed in this paper can be executed in the RSDA package developed in R. Full article
(This article belongs to the Special Issue Symbolic Entropy Analysis and Its Applications II)
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<p>Random variables for facial description.</p>
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<p>Principal component analysis (PCA) comparison.</p>
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14 pages, 1857 KiB  
Article
A Combinatorial Solution to Point Symbol Recognition
by Yining Quan, Yuanyuan Shi, Qiguang Miao and Yutao Qi
Sensors 2018, 18(10), 3403; https://doi.org/10.3390/s18103403 - 11 Oct 2018
Cited by 5 | Viewed by 2920
Abstract
Recent work has shown that recognizing point symbols is an essential task in the field of map digitization. For the identification of symbols, it is generally necessary to compare the symbols with a specific criterion and find the most similar one with each [...] Read more.
Recent work has shown that recognizing point symbols is an essential task in the field of map digitization. For the identification of symbols, it is generally necessary to compare the symbols with a specific criterion and find the most similar one with each known symbol one by one. Most of the works can only identify a single symbol, a small number of works are to deal with multiple symbols simultaneously with a low recognition accuracy. Given the two deficiencies, this paper proposes a deep transfer learning architecture, where the task is to learn a symbol classifier with AlexNet. For the insufficient dataset, we develop a method for transfer learning that uses a MNIST dataset to pretrain the model, which makes up for the problem of small training dataset and enhances the generalization of the model. Before the recognition process, preprocessing the point symbols in the map to coarse screening out the areas suspected of point symbols. We show a significant improvement over using point symbol images to keep a high performance in being able to deal with many more categories of symbols simultaneously. Full article
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<p>The point symbols in the topographic maps.</p>
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<p>The figure shows the comparison of map changes after color segmentation, as follows: (<b>a</b>) the original image of the topography map; (<b>b</b>) the sub-layout images of the topography map.</p>
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<p>This figure plays the comparison of map changes after prescreening. They are listed as (<b>a</b>) description of figure after binarization; (<b>b</b>) description of the figure that extracts the black sub-layouts and eliminates the noise.</p>
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<p>(<b>a</b>) the suspected symbols; (<b>b</b>) the connected region (CR).</p>
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<p>The connected region of suspected point symbols.</p>
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<p>The structure of the AlexNet model.</p>
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<p>The error analysis of the different model on Point Symbols.</p>
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<p>The test images for the models.</p>
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<p>The prescreening of point symbols is presented in the figure. They are listed as (<b>a</b>) the original map; (<b>b</b>) the grid pattern; (<b>c</b>) the connected region pattern with prescreening; (<b>d</b>) the connected region pattern.</p>
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<p>The comparison of a three recognition method.</p>
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