Symmetry-Basel最新文献_第9页

Elastic Wave Mechanics in Damaged Metallic Plates 损伤金属板的弹性波动力学

3区综合性期刊

Symmetry-Basel Pub Date : 2023-10-27 DOI: 10.3390/sym15111989

Samuel Chukwuemeka Olisa, Muhammad A. Khan, Andrew Starr

{"title":"Elastic Wave Mechanics in Damaged Metallic Plates","authors":"Samuel Chukwuemeka Olisa, Muhammad A. Khan, Andrew Starr","doi":"10.3390/sym15111989","DOIUrl":"https://doi.org/10.3390/sym15111989","url":null,"abstract":"Human health monitoring (HHM) is essential for continued daily task execution, as is structural health monitoring (SHM) for structures to ensure the continual performance of their designed tasks with optimal efficiency. The existence of damage in a structure affects its optimal use through stiffness deterioration. Damage of different forms could occur in a structure but have the singular objective of material degradation, leading to its underuse for a task. Guided wave ultrasonics has shown strength in detecting sundry damage in structures, but most of the damage monitored and detected is unfilled with substances. However, some damage could trap and accumulate substances that could hasten material degradation through corrosion activities under favorable conditions, especially in the oil and gas industry. This study used the ultrasonic-guided waves’ pitch–catch inspection technique to identify damage filled with different materials. The assessment was based on the RMSD of the dominant Lamb wave mode’s average maximum amplitude and the response signals’ transmission coefficient (TC). A five-cycle tone burst of excitation signals of different frequencies was created to generate propagating Lamb waves in the structure. The fundamental antisymmetric mode was found to be more sensitive than the fundamental symmetric mode when detecting damage filled with various substances. At 80 kHz, the deviation of the current response signals from the baseline response signals due to different filled substances in the damage was distinct and decreased with increased fluid viscosity. Given that structures in the oil and gas sector are particularly susceptible to substance-induced damage, the outcomes of this study are paramount.","PeriodicalId":48874,"journal":{"name":"Symmetry-Basel","volume":"214 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136316466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Maximum Clique Problem and Integer Programming Models, Their Modifications, Complexity and Implementation 最大团问题与整数规划模型及其修正、复杂性与实现

3区综合性期刊

Symmetry-Basel Pub Date : 2023-10-26 DOI: 10.3390/sym15111979

Milos Seda

{"title":"The Maximum Clique Problem and Integer Programming Models, Their Modifications, Complexity and Implementation","authors":"Milos Seda","doi":"10.3390/sym15111979","DOIUrl":"https://doi.org/10.3390/sym15111979","url":null,"abstract":"The maximum clique problem is a problem that takes many forms in optimization and related graph theory problems, and also has many applications. Because of its NP-completeness (nondeterministic polynomial time), the question arises of its solvability for larger instances. Instead of the traditional approaches based on the use of approximate or stochastic heuristic methods, we focus here on the use of integer programming models in the GAMS (General Algebraic Modelling System) environment, which is based on exact methods and sophisticated deterministic heuristics incorporated in it. We propose modifications of integer models, derive their time complexities and show their direct use in GAMS. GAMS makes it possible to find optimal solutions to the maximum clique problem for instances with hundreds of vertices and thousands of edges within minutes at most. For extremely large instances, good approximations of the optimum are given in a reasonable amount of time. A great advantage of this approach over all the mentioned algorithms is that even if GAMS does not find the best known solution within the chosen time limit, it displays its value at the end of the calculation as a reachable bound.","PeriodicalId":48874,"journal":{"name":"Symmetry-Basel","volume":"12 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134907498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study on the Criteria for Starlikeness in Integral Operators Involving Bessel Functions 涉及贝塞尔函数的积分算子星形判据的研究

3区综合性期刊

Symmetry-Basel Pub Date : 2023-10-26 DOI: 10.3390/sym15111976

Georgia Irina Oros, Gheorghe Oros, Daniela Andrada Bardac-Vlada

{"title":"Study on the Criteria for Starlikeness in Integral Operators Involving Bessel Functions","authors":"Georgia Irina Oros, Gheorghe Oros, Daniela Andrada Bardac-Vlada","doi":"10.3390/sym15111976","DOIUrl":"https://doi.org/10.3390/sym15111976","url":null,"abstract":"The study presented in this paper follows a line of research familiar for Geometric Function Theory, which consists in defining new integral operators and conducting studies for revealing certain geometric properties of those integral operators such as univalence, starlikness, or convexity. The present research focuses on the Bessel function of the first kind and order ν unveiling the conditions for this function to be univalent and further using its univalent form in order to define a new integral operator on the space of holomorphic functions. For particular values of the parameters implicated in the definition of the new integral operator involving the Bessel function of the first kind, the well-known Alexander, Libera, and Bernardi integral operators can be obtained. In the first part of the study, necessary and sufficient conditions are obtained for the Bessel function of the first kind and order ν to be a starlike function or starlike of order α∈[0,1). The renowned prolific method of differential subordination due to Sanford S. Miller and Petru T. Mocanu is employed in the reasoning. In the second part of the study, the outcome of the first part is applied in order to introduce the new integral operator involving the form of the Bessel function of the first kind, which is starlike. Further investigations disclose the necessary and sufficient conditions for this new integral operator to be starlike or starlike of order 12.","PeriodicalId":48874,"journal":{"name":"Symmetry-Basel","volume":"3 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134909244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Regarding the Ideal Convergence of Triple Sequences in Random 2-Normed Spaces 关于随机2赋范空间中三重序列的理想收敛性

3区综合性期刊

Symmetry-Basel Pub Date : 2023-10-26 DOI: 10.3390/sym15111983

Feras Bani-Ahmad, Mohammad H. M. Rashid

引用次数: 0

IoT Vulnerabilities and Attacks: SILEX Malware Case Study 物联网漏洞和攻击:SILEX恶意软件案例研究

3区综合性期刊

Symmetry-Basel Pub Date : 2023-10-26 DOI: 10.3390/sym15111978

Basem Ibrahim Mukhtar, Mahmoud Said Elsayed, Anca D. Jurcut, Marianne A. Azer

{"title":"IoT Vulnerabilities and Attacks: SILEX Malware Case Study","authors":"Basem Ibrahim Mukhtar, Mahmoud Said Elsayed, Anca D. Jurcut, Marianne A. Azer","doi":"10.3390/sym15111978","DOIUrl":"https://doi.org/10.3390/sym15111978","url":null,"abstract":"The Internet of Things (IoT) is rapidly growing and is projected to develop in future years. The IoT connects everything from Closed Circuit Television (CCTV) cameras to medical equipment to smart home appliances to smart automobiles and many more gadgets. Connecting these gadgets is revolutionizing our lives today by offering higher efficiency, better customer service, and more effective goods and services in a variety of industries and sectors. With this anticipated expansion, many challenges arise. Recent research ranked IP cameras as the 2nd highest target for IoT attacks. IoT security exhibits an inherent asymmetry where resource-constrained devices face attackers with greater resources and time, creating an imbalanced power dynamic. In cybersecurity, there is a symmetrical aspect where defenders implement security measures while attackers seek symmetrical weaknesses. The SILEX malware case highlights this asymmetry, demonstrating how IoT devices’ limited security made them susceptible to a relatively simple yet destructive attack. These insights underscore the need for robust, proactive IoT security measures to address the asymmetrical risks posed by adversaries and safeguard IoT ecosystems effectively. In this paper, we present the IoT vulnerabilities, their causes, and how to detect them. We focus on SILEX, one of the famous malware that targets IoT, as a case study and present the lessons learned from this malware.","PeriodicalId":48874,"journal":{"name":"Symmetry-Basel","volume":"18 8","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135013084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Shifting Pattern Biclustering and Boolean Reasoning Symmetry 移动模式双聚类与布尔推理对称

3区综合性期刊

Symmetry-Basel Pub Date : 2023-10-26 DOI: 10.3390/sym15111977

Marcin Michalak, Jesús S. Aguilar-Ruiz

{"title":"Shifting Pattern Biclustering and Boolean Reasoning Symmetry","authors":"Marcin Michalak, Jesús S. Aguilar-Ruiz","doi":"10.3390/sym15111977","DOIUrl":"https://doi.org/10.3390/sym15111977","url":null,"abstract":"There are several goals of the two-dimensional data analysis: one may be interested in searching for groups of similar objects (clustering), another one may be focused on searching for some dependencies between a specified one and other variables (classification, regression, associate rules induction), and finally, some may be interested in serching for well-defined patterns in the data called biclusters. It was already proved that there exists a mathematically proven symmetry between some patterns in the matrix and implicants of data-defined Boolean function. This paper provides the new look for a specific pattern search—the pattern named the δ-shifting pattern. The shifting pattern is interesting, as it accounts for constant fluctuations in data, i.e., it captures situations in which all the values in the pattern move up or down for one dimension, maintaining the range amplitude for all the dimensions. Such a behavior is very common in real data, e.g., in the analysis of gene expression data. In such a domain, a subset of genes might go up or down for a subset of patients or experimental conditions, identifying functionally coherent categories. A δ-shifting pattern meets the necessity of shifting pattern induction together with the bias of the real values acquisition where the original shifts may be disturbed with some outer conditions. Experiments with a real dataset show the potential of our approach at finding biclusters with δ-shifting patterns, providing excellent performance. It was possible to find the 12×9 pattern in the 112×9 input data with MSR=0.00653. The experiments also revealed that δ-shifting patterns are quite difficult to be found by some well-known methods of biclustering, as these are not designed to focus on shifting patterns—results comparable due to MSR had much more variability (in terms of δ) than patterns found with Boolean reasoning.","PeriodicalId":48874,"journal":{"name":"Symmetry-Basel","volume":"3 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136381460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Solitary Wave Propagation of the Generalized Rosenau–Kawahara–RLW Equation in Shallow Water Theory with Surface Tension 浅水理论中具有表面张力的广义Rosenau-Kawahara-RLW方程的孤立波传播

3区综合性期刊

Symmetry-Basel Pub Date : 2023-10-26 DOI: 10.3390/sym15111980

Akeel A. AL-saedi, Omid Nikan, Zakieh Avazzadeh, António M. Lopes

引用次数: 0

More Variations on Shuffle Squares 洗牌方块的更多变化

3区综合性期刊

Symmetry-Basel Pub Date : 2023-10-26 DOI: 10.3390/sym15111982

Jarosław Grytczuk, Bartłomiej Pawlik, Mariusz Pleszczyński

引用次数: 0

Cyberattacks and Security of Cloud Computing: A Complete Guideline 网络攻击与云计算安全:完整指南

3区综合性期刊

Symmetry-Basel Pub Date : 2023-10-26 DOI: 10.3390/sym15111981

Muhammad Dawood, Shanshan Tu, Chuangbai Xiao, Hisham Alasmary, Muhammad Waqas, Sadaqat Ur Rehman

{"title":"Cyberattacks and Security of Cloud Computing: A Complete Guideline","authors":"Muhammad Dawood, Shanshan Tu, Chuangbai Xiao, Hisham Alasmary, Muhammad Waqas, Sadaqat Ur Rehman","doi":"10.3390/sym15111981","DOIUrl":"https://doi.org/10.3390/sym15111981","url":null,"abstract":"Cloud computing is an innovative technique that offers shared resources for stock cache and server management. Cloud computing saves time and monitoring costs for any organization and turns technological solutions for large-scale systems into server-to-service frameworks. However, just like any other technology, cloud computing opens up many forms of security threats and problems. In this work, we focus on discussing different cloud models and cloud services, respectively. Next, we discuss the security trends in the cloud models. Taking these security trends into account, we move to security problems, including data breaches, data confidentiality, data access controllability, authentication, inadequate diligence, phishing, key exposure, auditing, privacy preservability, and cloud-assisted IoT applications. We then propose security attacks and countermeasures specifically for the different cloud models based on the security trends and problems. In the end, we pinpoint some of the futuristic directions and implications relevant to the security of cloud models. The future directions will help researchers in academia and industry work toward cloud computing security.","PeriodicalId":48874,"journal":{"name":"Symmetry-Basel","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134907319","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Secure Trajectory Planning Method for Connected Autonomous Vehicles at Mining Site 矿区联网自动驾驶车辆安全轨迹规划方法

3区综合性期刊

Symmetry-Basel Pub Date : 2023-10-25 DOI: 10.3390/sym15111973

Han Li, Yiming Li, Peng Chen, Guizhen Yu, Yaping Liao

{"title":"A Secure Trajectory Planning Method for Connected Autonomous Vehicles at Mining Site","authors":"Han Li, Yiming Li, Peng Chen, Guizhen Yu, Yaping Liao","doi":"10.3390/sym15111973","DOIUrl":"https://doi.org/10.3390/sym15111973","url":null,"abstract":"Recently, with the assistance of 5G networks and the Internet of Things, specialized applications of autonomous driving to mining sites have been explored, with the goal of realizing the unmanned operation of mining systems and enhancing the safety of the mining industry. After receiving the loading task, the autonomous driving system will generate a feasible trajectory for the mining truck. It requires that the trajectory be generated in advanced within a limited-time high-latency network. In addition, the secure trajectory planning for mining sites involves factors in the complex environment and an unstable network. Thus, a secure trajectory planning method for autonomous trucks at mining sites is proposed. It simplifies the planning by decoupling the planning into front-end path searching and back-end trajectory generation. First, the planner enhances the Hybrid A* search algorithm to find the hauling path within the boundary of the mining site, and then, it post-processes the path with a well-designed symmetric optimization-based method. Then, considering the interaction with other autonomous trucks, a topology-guided search method for secure decision making is proposed, considering the possibility of cybersecurity. The proposed method was validated in real scenarios of the mining environment. The results verify that the planner can generate the secure trajectory under network delay 2.0 s conditions.","PeriodicalId":48874,"journal":{"name":"Symmetry-Basel","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135216520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0