Hasil untuk "Semantics"

Thomas Dufaud, Jorge Linares, Devan Sohier

We discuss the design, the analysis and the parallel implementation of a dynamic programming approach for the computation of the density of state in the simulation of spin-crossover nanoparticles. The motivation is the computation of a Hamiltonian, which is usually approximated using Monte Carlo techniques. However, physicists need better control of the accuracy of this approximation. An exact counting algorithm allows this error to be controlled, and also measures the impact on accuracy for the entire simulation. We propose an exact parallel counting algorithm and its two-level parallel implementation to tackle nanoscale problems on HPC architecture. We discuss its scalability and feasibility for <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>2</mn><mi>D</mi></mrow></semantics></math></inline-formula> grids of <i>n</i> molecules. The new algorithm enables the exact computation for a three-variable density of state at nanoscale, which is seen as intractable. A comparison between the expectation of the model and implementation is proposed. The parallel complexity achieved is <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>O</mi><mo stretchy="false">(</mo><msup><mi>n</mi><mstyle scriptlevel="0" displaystyle="true"><mfrac><mn>5</mn><mn>2</mn></mfrac></mstyle></msup><msup><mn>2</mn><msqrt><mi>n</mi></msqrt></msup><mo stretchy="false">)</mo></mrow></semantics></math></inline-formula> and the results allow the prediction of never-before-seen phenomena.

Aviv Padawer-Blatt, Zhiwei Shao, Renier T. Hough et al.

We employ the <span style="font-variant: small-caps;">simba-c</span> cosmological simulation to study the impact of its upgraded chemical enrichment model (Chem5) on the distribution of metals in the intragroup medium (IGrM). We investigate the projected X-ray emission-weighted abundance profiles of key elements over two decades in halo mass (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mn>10</mn><mn>13</mn></msup><mo>≤</mo><msub><mi>M</mi><mn>500</mn></msub><mo>/</mo><msub><mi mathvariant="normal">M</mi><mo>⊙</mo></msub><mo>≤</mo><msup><mn>10</mn><mn>15</mn></msup></mrow></semantics></math></inline-formula>). Typically, <span style="font-variant: small-caps;">simba-c</span> generates lower-amplitude abundance profiles than <span style="font-variant: small-caps;">simba</span> with flatter cores, in better agreement with observations. For low-mass groups, both simulations over-enrich the IGrM with Si, S, Ca, and Fe compared to observations, a trend likely related to inadequate modeling of metal dispersal and mixing. We analyze the 3D mass-weighted abundance profiles, concluding that the lower <span style="font-variant: small-caps;">simba-c</span> IGrM abundances are primarily a consequence of fewer metals in the IGrM, driven by reduced metal yields in Chem5, and the removal of the instantaneous recycling of metals approximation employed by <span style="font-variant: small-caps;">simba</span>. Additionally, an increased IGrM mass in low-mass <span style="font-variant: small-caps;">simba-c</span> groups is likely triggered by changes to the AGN and stellar feedback models. Our study suggests that a more realistic chemical enrichment model broadly improves agreement with observations, but physically motivated sub-grid models for other key processes, like AGN and stellar feedback and turbulent diffusion, are required to realistically reproduce observed group environments.

Yuyao Zhang, Hongliang Guan, Fuzhou Duan

Water pipeline leak detection in a fast and accurate way is of much importance for water utility companies and the general public. At present, the rapid development of remote sensing and computer technologies makes it possible to detect water pipeline leaks on a large scale efficiently and timely. The leakage will cause an increase in the water content and dielectric constant of the soil around the pipeline, so it is feasible to determine the leakage site by measuring the subsurface soil relative dielectric constant (SSRDC). In this paper, we combine the SAOCOM-1A L-band synthetic-aperture radar (SAR) and the ground-penetrating radar (GPR) data to develop regression models that predict the SSRDC values. The model features are selected with the Boruta wrapper algorithm based on the SAOCOM-1A images after pre-processing, and the SSRDC values at sampling locations within the research area are calculated with the reflected wave method based on the GPR data. We evaluate multiple linear regression (MLR), random forest (RF), and multi-layer perceptron neural network (MLPNN) models for their ability to predict the SSRDC values using the selected features. The experimental results show that the MLPNN model (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>R</mi><mn>2</mn></msup></semantics></math></inline-formula> = 0.705, RMSE = 1.936, MAE = 1.664) can better estimate the SSRDC values. Further, in the main urban area of Tianjin, China, which has a large water pipeline system, the SSDRC values of the area are obtained with the best model, and the locations where the predicted SSDRC values exceeded a certain threshold were considered potential leak locations. The empirical results indicate an encouraging potential of the proposed method to locate the pipeline leaks. This will provide a new avenue for the monitoring and treatment of water pipeline leaks.

N.B. Shumakova, Y.P. Kosheleva, N.V. Kozyreva

<p>The concept of "Classroom climate" has a broad semantics. It covers the quality of interaction not only between students and teachers, but also with classmates at the managerial, social, emotional and academic levels. It is shown that students' subjective perception of the classroom climate carries their behavior, psychological well-being and success in teaching students, as well as their personal characteristics, the development of abilities and giftedness. The use of an evidence-based approach in education improves the quality of psychological tools used in different regions of the Russian Federation and other countries. The article reflects the standardization of the questionnaire "Climate in the classroom" in the Republic of Belarus. The study sample consisted of 425 school students from different regions of the Republic of Belarus (Minsk, Rogachev and Zhlobin) aged 10-18 years (54,35% female). The average age was 15&plusmn;1 years (median=15 years). Using confirmatory factor analysis, the six-factor structure of the questionnaire was statistically validated, and its structure demonstrated satisfactory alignment with the empirical data. The Cronbach's alpha coefficient confirms the internal consistency of the scales, with their mutual correlations being at a moderate level. The magnitude and direction of the relationships are consistent with the expected outcomes. The convergent and differential validity of the questionnaire scales has been tested on the scales of the Multidimensional Life Satisfaction Scale (SHUJI) and academic performance. The questionnaire is recommended to school psychologists and teachers for psychological and pedagogical support of students from different age groups to create a favorable school environment.</p>

Miroslav D. Maksimović, Milan Lj. Zlatanović

We study the quarter-symmetric metric <i>A</i>-connection on a cosymplectic manifold. Observing linearly independent curvature tensors with respect to the quarter-symmetric metric <i>A</i>-connection, we construct the Weyl projective curvature tensor on a cosymplectic manifold. In this way, we obtain new conditions for the manifold to be projectively flat. At the end of the paper, we define <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>η</mi></semantics></math></inline-formula>-Einstein cosymplectic manifolds of the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>θ</mi></semantics></math></inline-formula>-th kind and prove that they coincide with the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>η</mi></semantics></math></inline-formula>-Einstein cosymplectic manifold.

Mohan Krishna Banda, Sreedhar Madichetty, Shanthi Kumar Nandavaram Banda

Growth in renewable energy systems, direct current (DC) microgrids, and the adoption of electric vehicles (EVs) will substantially increase the demand for bi-directional converters. Precise control mechanisms are essential to ensure optimal performance and better efficiency of these converters. This paper proposes a deep neural network (DNN)-based controller designed to precisely control bi-directional converters for vehicle-to-vehicle (V2V) and vehicle-to-grid (V2G) applications. This control technique allows the converter to quickly attain new reference values, enhancing performance and efficiency by significantly reducing the overshoot duration. To train the DNN controller, large synthetic data are used by performing simulations for various sets of conditions, and the results are validated with a hardware setup. The real-time performance of the DNN controller is compared with a conventional proportional–integral (PI)-based controller through simulated results using MATLAB Simulink (version 2023a) and with a real-time setup. The converter attains a new reference of about 975 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">μ</mi></semantics></math></inline-formula>s with the proposed control technique. In contrast, the PI controller takes about 220 ms, which shows that the proposed control technique is far better than the PI controller.

Aihua Wu, Songyu Ding

Research on few-shot action recognition has received widespread attention recently. However, there are some blind spots in the current research: (1) The prevailing practice in many models is to assign uniform weights to all samples; nevertheless, such an approach may yield detrimental consequences for the model in the presence of high-noise samples. (2) Samples with similar features but different classes make it difficult for the model to be distinguished. (3) Skeleton data harbors rich temporal features, but most encoders face challenges in effectively extracting them. In response to these challenges, this study introduces a reconstructed prototype network (RC-PN) based on a prototype network framework and a novel spatiotemporal encoder. The RC-PN comprises two enhanced modules: Sample coefficient reconstruction (SCR) and a reconstruction loss function (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>L</mi></mrow><mrow><mi>R</mi><mi>C</mi></mrow></msub></mrow></semantics></math></inline-formula>). SCR leverages cosine similarity between samples to reassign sample weights, thereby generating prototypes robust to noise interference and more adept at conveying conceptual essence. Simultaneously, the introduction of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi>L</mi></mrow><mrow><mi>R</mi><mi>C</mi></mrow></msub></mrow></semantics></math></inline-formula> enhances the feature similarity among samples of the same class while increasing feature distinctiveness between different classes. In the encoder aspect, this study introduces a novel spatiotemporal convolutional encoder called CDC-TAGCN. The temporal convolution operator is redefined in CDC-TAGCN. The vanilla temporal convolution operator can only capture the surface-level characteristics of action samples. Drawing inspiration from differential convolution (CDC), this research enhances TCN to CDC-TGCN. CDC-TGCN allows for the fusion of discrepant features from action samples into the features extracted by the vanilla convolutional operator. Extensive feasibility and ablation experiments are performed on the skeleton action dataset NTU-RGB + D 120 and Kinetics and compared with recent research.

Santosh V. Lohakare, Francisco Tello-Ortiz, S. K. Tripathy et al.

In this paper, we studied the bouncing behavior of the cosmological models formulated in the background of the Hubble function in the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>F</mi><mo>(</mo><mi>R</mi><mo>,</mo><mi mathvariant="script">G</mi><mo>)</mo></mrow></semantics></math></inline-formula> theory of gravity, where <i>R</i> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="script">G</mi></semantics></math></inline-formula>, respectively, denote the Ricci scalar and Gauss–Bonnet invariant. The actions of the bouncing cosmology are studied with a consideration of the different viable models that can resolve the difficulty of singularity in standard Big Bang cosmology. Both models show bouncing behavior and satisfy the bouncing cosmological properties. Models based on dynamical, deceleration, and energy conditions indicate the accelerating behavior at the late evolution time. The phantom at the bounce epoch is analogous to quintessence behavior. Finally, we formulate the perturbed evolution equations and investigate the stability of the two bouncing solutions.

L. V. Nikiforova, N. N. Rozanova

The questions of classification of political metaphors are considered. This classification is necessary for the analysis of the data of sociological survey, which was conducted by the team of Smolensk University in 2022 in regions of Russia. The study of the reputational image of power (respondents' answers to the questions: “How would you draw the reputational image of Russian / regional power?”) problematizes the principles of classification. The relevance of the study in working out the diagnosis of the reputational image of power. The novelty of the study is that the analysis was conducted on the basis of folk metaphorization, rather than professional political discourse, which researchers of political metaphorology and political semantics usually deal with. The empirical material for the problematization of the classification was the results of the sociological survey 2021, which included similar questions. The classification of power metaphors on the basis of major philosophical categories and structural relationships (space/time; living/artificial; human/nature/society) is presented, as such principle allows capturing the real diversity and multidimensionality of figurative likenesses proposed by respondents. The results of the study of folk metaphorization adjust the existing classifications of power metaphors, do not fully coincide with the known classifications of metaphorical models of power, also adjust the ideas about the popularity of typical metaphorical models.

Binlin Zhang, Rafia Majeed, Mehboob Alam

In this paper, we focus on the study of the implicit <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="double-struck">FDE</mi></semantics></math></inline-formula> involving Stieltjes integral boundary conditions. We first exploit some sufficient conditions to guarantee the existence and uniqueness of solutions for the above problems based on the Banach contraction principle and Schaefer’s fixed point theorem. Then, we present different kinds of stability such as <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="script">UHS</mi></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="script">GUHS</mi></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="script">UHRS</mi></semantics></math></inline-formula>, and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="script">GUHRS</mi></semantics></math></inline-formula> by employing the classical techniques. In the end, the main results are demonstrated by two examples.

Lee J. Yamin, Jessica R. Cauchard

Novel applications for human-drone interaction demand new design approaches, such as social drones that need to be perceived as likable by users. However, given the complexity of the likability perception process, gathering such design information from the interaction context is intricate. This work leverages deep learning-based techniques to generate novel likable drone images. We collected a drone image database (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>N</mi><mo>=</mo><mn>360</mn></mrow></semantics></math></inline-formula>) applicable for design research and assessed the drone’s likability ratings in a user study (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>N</mi><mo>=</mo><mn>379</mn></mrow></semantics></math></inline-formula>). We employed two clustering methodologies: 1. likability-based, which resulted in non-likable, neutral, and likable drone clusters; and 2. feature-based (VGG, PCA), which resulted in drone clusters characterized by visual similarity; both clustered using the K-means algorithm. A characterization process identified three drone features: colorfulness, animal-like representation, and emotional expressions through facial features, which affect drone likability, going beyond prior research. We used the likable drone cluster (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>N</mi><mo>=</mo><mn>122</mn></mrow></semantics></math></inline-formula>) for generating new images using StyleGAN2-ADA and addressed the dataset size limitation using specific configurations and transfer learning. Our results were mitigated due to the dataset size; thus, we illustrate the feasibility of our approach by generating new images using the original database. Our findings demonstrate the effectiveness of Generative Adversarial Networks (GANs) exploitation for drone design, and to the best of our knowledge, this work is the first to suggest GANs for such application.

Michal Staš

In the paper, the crossing number of the join product <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi>G</mi><mo>*</mo></msup><mo>+</mo><msub><mi>D</mi><mi>n</mi></msub></mrow></semantics></math></inline-formula> for the disconnected graph <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>G</mi><mo>*</mo></msup></semantics></math></inline-formula> consisting of two components isomorphic to <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>K</mi><mn>2</mn></msub></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>K</mi><mn>3</mn></msub></semantics></math></inline-formula> is given, where <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>D</mi><mi>n</mi></msub></semantics></math></inline-formula> consists of <i>n</i> isolated vertices. Presented proofs are completed with the help of the graph of configurations that is a graphical representation of minimum numbers of crossings between two different subgraphs whose edges do not cross the edges of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>G</mi><mo>*</mo></msup></semantics></math></inline-formula>. For the first time, multiple symmetry between configurations are presented as parity properties. We also determine crossing numbers of join products of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>G</mi><mo>*</mo></msup></semantics></math></inline-formula> with paths <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>P</mi><mi>n</mi></msub></semantics></math></inline-formula> and cycles <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>C</mi><mi>n</mi></msub></semantics></math></inline-formula> on <i>n</i> vertices by adding new edges joining vertices of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>D</mi><mi>n</mi></msub></semantics></math></inline-formula>.

Davron Aslonqulovich Juraev, Ali Shokri, Daniela Marian

In this paper, the Carleman matrix is constructed, and based on it we found explicitly a regularized solution of the Cauchy problem for the matrix factorization of the Helmholtz equation in a multidimensional unbounded domain in <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mrow><mi mathvariant="double-struck">R</mi></mrow><mi>m</mi></msup><mspace width="4pt"></mspace><mo>,</mo><mrow><mo>(</mo><mi>m</mi><mo>=</mo><mn>2</mn><mi>k</mi><mo>,</mo><mspace width="0.166667em"></mspace><mi>k</mi><mo>≥</mo><mn>2</mn><mo>)</mo></mrow></mrow></semantics></math></inline-formula>. The corresponding theorems on the stability of the solution of problems are proved.

Muhammed Rasheed Irshad, Radhakumari Maya, Francesco Buono et al.

Tsallis introduced a non-logarithmic generalization of Shannon entropy, namely Tsallis entropy, which is non-extensive. Sati and Gupta proposed cumulative residual information based on this non-extensive entropy measure, namely cumulative residual Tsallis entropy (CRTE), and its dynamic version, namely dynamic cumulative residual Tsallis entropy (DCRTE). In the present paper, we propose non-parametric kernel type estimators for CRTE and DCRTE where the considered observations exhibit an <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>ρ</mi></semantics></math></inline-formula>-mixing dependence condition. Asymptotic properties of the estimators were established under suitable regularity conditions. A numerical evaluation of the proposed estimator is exhibited and a Monte Carlo simulation study was carried out.

Yanou Ramon, R.A. Farrokhnia, Sandra C. Matz et al.

Every step we take in the digital world leaves behind a record of our behavior; a digital footprint. Research has suggested that algorithms can translate these digital footprints into accurate estimates of psychological characteristics, including personality traits, mental health or intelligence. The mechanisms by which AI generates these insights, however, often remain opaque. In this paper, we show how Explainable AI (XAI) can help domain experts and data subjects validate, question, and improve models that classify psychological traits from digital footprints. We elaborate on two popular XAI methods (rule extraction and counterfactual explanations) in the context of Big Five personality predictions (traits and facets) from financial transactions data (<i>N</i> = <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>6408</mn></mrow></semantics></math></inline-formula>). First, we demonstrate how global rule extraction sheds light on the spending patterns identified by the model as most predictive for personality, and discuss how these rules can be used to explain, validate, and improve the model. Second, we implement local rule extraction to show that individuals are assigned to personality classes because of their unique financial behavior, and there exists a positive link between the model’s prediction confidence and the number of features that contributed to the prediction. Our experiments highlight the importance of both global and local XAI methods. By better understanding how predictive models work in general as well as how they derive an outcome for a particular person, XAI promotes accountability in a world in which AI impacts the lives of billions of people around the world.

Zhen-Hang Yang, Jing-Feng Tian, Ya-Ru Zhu

Let <inline-formula> <math display="inline"> <semantics> <mrow> <msub> <mi>I</mi> <mi>v</mi> </msub> <mfenced open="(" close=")"> <mi>x</mi> </mfenced> </mrow> </semantics> </math> </inline-formula> be he modified Bessel function of the first kind of order <i>v</i>. We prove the double inequality <inline-formula> <math display="inline"> <semantics> <mrow> <msqrt> <mrow> <mfrac> <mrow> <mo form="prefix">sinh</mo> <mi>t</mi> </mrow> <mi>t</mi> </mfrac> <msup> <mo form="prefix">cosh</mo> <mrow> <mn>1</mn> <mo>/</mo> <mi>q</mi> </mrow> </msup> <mfenced separators="" open="(" close=")"> <mi>q</mi> <mi>t</mi> </mfenced> </mrow> </msqrt> <mo><</mo> <msub> <mi>I</mi> <mn>0</mn> </msub> <mfenced open="(" close=")"> <mi>t</mi> </mfenced> <mo><</mo> <msqrt> <mrow> <mfrac> <mrow> <mo form="prefix">sinh</mo> <mi>t</mi> </mrow> <mi>t</mi> </mfrac> <msup> <mo form="prefix">cosh</mo> <mrow> <mn>1</mn> <mo>/</mo> <mi>p</mi> </mrow> </msup> <mfenced separators="" open="(" close=")"> <mi>p</mi> <mi>t</mi> </mfenced> </mrow> </msqrt> </mrow> </semantics> </math> </inline-formula> holds for <inline-formula> <math display="inline"> <semantics> <mrow> <mi>t</mi> <mo>></mo> <mn>0</mn> </mrow> </semantics> </math> </inline-formula> if and only if <inline-formula> <math display="inline"> <semantics> <mrow> <mi>p</mi> <mo>≥</mo> <mn>2</mn> <mo>/</mo> <mn>3</mn> </mrow> </semantics> </math> </inline-formula> and <inline-formula> <math display="inline"> <semantics> <mrow> <mi>q</mi> <mo>≤</mo> <mfenced separators="" open="(" close=")"> <mo form="prefix">ln</mo> <mn>2</mn> </mfenced> <mo>/</mo> <mo form="prefix">ln</mo> <mi>π</mi> </mrow> </semantics> </math> </inline-formula>. The corresponding inequalities for means improve already known results.

Nur Nabilah Fauziyah, Roikhatul Nur Ilmi

This study was conducted to analyze several words which have denotative and connotative meaning and find the relation of those words with the context of a love relationship in real life. In analyzing the denotative and connotative meaning of four words that were already chosen, this study uses Palmer’s theory of denotation and connotation as a theoretical basis. The data was collected from the text of the short story “A Child of the Rain”, which is categorized as a ghost story. Particularly, this study focuses on analyzing four specific words namely invisible, glad, expert, and coldness. This study uses descriptive qualitative as the design of this study. Therefore, after analyzing the meaning of words, this study found that (1) the words invisible, glad, expert, and coldness have denotative and connotative meaning, (2) connotative meaning of these words have a relation with the context of love relationship in real life, (3) these words can portray someone’s feeling in a specific situation like in love relationship. These findings can be utilized by second-language learners in the process of understanding the denotative and connotative meaning of the English language.

Liang Lu, Carlos Redondo, Pascual Campoy

Aerial robots are widely used in search and rescue applications because of their small size and high maneuvering. However, designing an autonomous exploration algorithm is still a challenging and open task, because of the limited payload and computing resources on board UAVs. This paper presents an autonomous exploration algorithm for the aerial robots that shows several improvements for being used in the search and rescue tasks. First of all, an RGB-D sensor is used to receive information from the environment and the OctoMap divides the environment into obstacles, free and unknown spaces. Then, a clustering algorithm is used to filter the frontiers extracted from the OctoMap, and an information gain based cost function is applied to choose the optimal frontier. At last, the feasible path is given by A* path planner and a safe corridor generation algorithm. The proposed algorithm has been tested and compared with baseline algorithms in three different environments with the map resolutions of <inline-formula><math display="inline"><semantics><mrow><mn>0.2</mn></mrow></semantics></math></inline-formula> m, and <inline-formula><math display="inline"><semantics><mrow><mn>0.3</mn></mrow></semantics></math></inline-formula> m. The experimental results show that the proposed algorithm has a shorter exploration path and can save more exploration time when compared with the state of the art. The algorithm has also been validated in the real flight experiments.

金權鎬

Kohei Honda, N. Yoshida