Journal of Applied Mathematics and Physics最新文献

{"title":"Deformable Permanent Ferroelectric or Ferromagnetic Media","authors":"Michael Grinfeld, Pavel Grinfeld","doi":"10.4236/jamp.2023.1110202","DOIUrl":"https://doi.org/10.4236/jamp.2023.1110202","url":null,"abstract":"In the framework of continuum mechanics, one of possible consistent definitions of deformable permanent magnets is introduced and explored. Similar model can be used for ferroelectric substances. Based on the suggested definition, we establish the key kinematic relationship for the deformable permanent magnet and suggest the simplest master system, allowing to analyze behavior of such substances.","PeriodicalId":15035,"journal":{"name":"Journal of Applied Mathematics and Physics","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135211854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Investigation of Purely Azimuthal Passive Localization and Position Adjustment in Attempted UAV Formation Flights","authors":"Qi Zhang, Keren Sun, Qiaozhen Zhang","doi":"10.4236/jamp.2023.1110203","DOIUrl":"https://doi.org/10.4236/jamp.2023.1110203","url":null,"abstract":"When a cluster of unmanned aerial vehicles (UAVs) is flying in formation, it is crucial to maintain the formation and not to be interfered by external electromagnetic wave signals. In order to maintain the formation, this paper proposes to use pure azimuth passive positioning to adjust the position of UAVs, i.e., certain UAVs in the formation transmit signals, the rest of the UAVs receive the signals passively, and extract the orientation information from them to adjust the position of the UAVs [1] [2] [3]. In this paper, the position adjustment problem of UAVs in “circular” formation flight under three models is investigated. To address the problem of “how to obtain the position of the receiving UAV when there are two UAVs with known numbers and evenly distributed on the circumference in addition to the UAV transmitting at the known center of the circle, and the rest of the UAVs with slight deviations in their positions are receiving the signals”, two purely mathematical geometric methods, namely, triangular localization method and polar co-ordinate method, are proposed respectively. We have determined the position of the receiving UAV; we have used the exhaustive method and the construction and disproof method to solve the problem of “how many UAVs are needed to transmit signals in order to realize the effective positioning of the UAVs when it is known that a certain UAV with a slight deviation in its position receives the signals emitted by two UAVs at the same time”, and the results show that: in addition to the known signals emitted by two UAVs, it is also necessary to transmit the signals emitted by two UAVs. The results show that in addition to the known two UAVs transmitting signals, two additional UAVs are required to transmit signals for precise po-sitioning. When the position of UAVs has deviation at the initial moment, the ideal approximation method and the target delimitation method are pro-posed, and the target of nine UAVs uniformly distributed on a circle of a spe-cific radius is achieved through several adjustments, after which the ad-vantages and disadvantages of each model are analyzed, and suggestions for improvement are put forward. The purely azimuthal passive localization method and the constructed model approach proposed in this paper can be extended to other fields, such as spacecraft formations in space and battle-ship formations at sea, as well as other formation flight position adjustment problems.","PeriodicalId":15035,"journal":{"name":"Journal of Applied Mathematics and Physics","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135263695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of the Orbitation and Rotation of Celestial Bodies","authors":"Gabriel Barceló","doi":"10.4236/jamp.2023.119179","DOIUrl":"https://doi.org/10.4236/jamp.2023.119179","url":null,"abstract":"We have developed a structure of dynamic knowledge for non-inertial systems, the so-called Theory of Dynamic Interactions (TDI) as a part of non-inertial dynamic knowledge, which incorporates a causal demonstration of phenomena accelerated by rotation, which would complement Classical Mechanics. We believe that the TDI mathematical model that we propose is of great conceptual importance. In addition, we think that it is not only necessary to understand the dynamics of rotating bodies, but also to understand the dynamics of the cosmos, with bodies that orbit and with constantly recurring movements, which make possible systems that have been in dynamic equilibrium for centuries and are not in a process of unlimited expansion. We even believe that this new dynamic theory allows us a better understanding of our universe, and the matter from which it is made.","PeriodicalId":15035,"journal":{"name":"Journal of Applied Mathematics and Physics","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135798356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Constraining Lorentz Invariance Violation Using Short Gamma-Ray Bursts","authors":"Walid Jamil Azzam, Ali Mohamed Hasan","doi":"10.4236/jamp.2023.118139","DOIUrl":"https://doi.org/10.4236/jamp.2023.118139","url":null,"abstract":"Lorentz Invariance is a foundational principle in modern physics, but some recent quantum gravity theories have hinted that it may be violated at extremely high energies. Gamma-ray bursts (GRBs) provide a promising tool for checking and constraining any deviations from Lorentz Invariance due to their huge energies and cosmological distances. Gamma-ray bursts, which are the most intense and powerful explosions in the universe, are traditionally divided into long bursts whose observed duration exceeds 2 s, and short bursts whose observed duration is less than 2 s. In this study, we employ a recent sample of 46 short GRBs to check for any deviation from Lorentz Invariance. We analyze the spectral lag of the bursts in our data sample and check for any redshift dependence in the GRB rest frame, which would indicate a violation of Lorentz Invariance. Our results are consistent, to within 1σ, with no deviation from Lorentz Invariance.","PeriodicalId":15035,"journal":{"name":"Journal of Applied Mathematics and Physics","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135989262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Study on the Duct Acoustic Mode Control of Turbine Interaction Noise with Serrated Configurations","authors":"Kangshen Xiang, Weijie Chen, Jianxin Lian, Weiyang Qiao","doi":"10.4236/jamp.2023.118160","DOIUrl":"https://doi.org/10.4236/jamp.2023.118160","url":null,"abstract":"Turbine noise would be one of the dominant noise sources especially in future UHBR (Ultra High Bypass-Ratio) aeroengine, but its currently far from being studied enough. Acoustic mode is crucial for duct propagation but little study about the relation between serration and mode. Thus, taking axial single-turbine test bench NPU-Turb as object, the effect of Stator with Serrated Trailing-edge (Bionic S) and Rotor with Serrated Leading-edge (Bionic R) on duct acoustic modes of turbine turbulence interac-tion noise were studied in detail using DDES/AA hybrid model validated by acoustic experiment of NPU-Turb. Serval conclusions can be made here. First, for broadband noise, the effect of serrations on duct modes (increased or reduced of PWLmn) with the increasing frequency is more prominent. Second, the changing trend of ?PWLmn is something like Chinese character “人” with circumferential mode m and alternating with radial mode. Such distribution is more obvious at higher frequency. More theoretical and mechanistic research work needs to be carried out in depth in the future.","PeriodicalId":15035,"journal":{"name":"Journal of Applied Mathematics and Physics","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135056484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic Analysis of an Algae-Fish Harvested Model with Allee Effect","authors":"Xiaoyu Song, Hengguo Yu, Min Zhao","doi":"10.4236/jamp.2023.1110195","DOIUrl":"https://doi.org/10.4236/jamp.2023.1110195","url":null,"abstract":"In this paper, an algae-fish harvested model with Allee effect was established to further explore the dynamic evolution mechanism under the influence of key factors. Mathematical theoretical work not only investigated the existence and stability of all possible equilibrium points, but also probed into the occurrence of transcritical and Hopf bifurcation. The numerical simulation works verified the effectiveness of the theoretical derivation results and displayed rich bifurcation dynamical behaviors, which showed that Allee effect and harvest have played a vital role in the dynamic relationship between algae and fish. In summary, it was expected that these research results would be beneficial for promoting the study of bifurcation dynamics in aquatic ecosystems.","PeriodicalId":15035,"journal":{"name":"Journal of Applied Mathematics and Physics","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135157967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Nuclear Clock Correction for Universal Gravitation","authors":"Gianni Donati","doi":"10.4236/jamp.2023.119167","DOIUrl":"https://doi.org/10.4236/jamp.2023.119167","url":null,"abstract":"Science is losing some fixed references shifting from universality to relativity: time and space become space time, the meter is related to the velocity of light and the second is fixed by the ticketing of a Cesium atom. In the case of Gravity, Nature was so friendly to Newton to allow him the writing of the Universal Gravitational Law, that changed the view of the Universe for the last three centuries. However, the way matter generates Gravity was unknown to Newton and the problem is still nowadays ignored by most scientists and remains the ultimate question mark of physics. We paid attention to the ticketing of all existing nuclides and found that the parameters of the neutronproton transformations are so precise, in describing these reactions, that can be considered universal constants. Instead, the emitted neutrino flux Fo is almost constant with a mean value of 6.668E20 neutrino per gram and second over the wide range of all nuclides with some deviation for lighter nuclei. This is the reason why Newton was able to find his Universal Gravitational Law and allows us today to state a relation of this flux with the Gauss constant G on the basis of nuclear properties. Moreover, it explains the mechanism that bodies use for their mutual attraction with a simplification of the three-body problem in celestial bodies computation. We have to remember that Newton model, with a fixed gravitational Gauss constant G, or the equivalent with a fixed neutrino flux Fo, have been used for the determination of the mass of the celestial bodies in motion with the implicit assumption that the gravitational and inertial mass are the same. In this paper we recognize the big difference in composition of the Sun and the gaseous planets compared to the terrestrial ones and show how the relatively small difference of the neutrino flux can change our vision of the Universe.","PeriodicalId":15035,"journal":{"name":"Journal of Applied Mathematics and Physics","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135400253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Comparison of Four Methods of Estimating the Scale Parameter for the Exponential Distribution","authors":"Huda M. Alomari","doi":"10.4236/jamp.2023.1110186","DOIUrl":"https://doi.org/10.4236/jamp.2023.1110186","url":null,"abstract":"In this paper, the estimators of the scale parameter of the exponential distribution obtained by applying four methods, using complete data, are critically examined and compared. These methods are the Maximum Likelihood Estimator (MLE), the Square-Error Loss Function (BSE), the Entropy Loss Function (BEN) and the Composite LINEX Loss Function (BCL). The performance of these four methods was compared based on three criteria: the Mean Square Error (MSE), the Akaike Information Criterion (AIC), and the Bayesian Information Criterion (BIC). Using Monte Carlo simulation based on relevant samples, the comparisons in this study suggest that the Bayesian method is better than the maximum likelihood estimator with respect to the estimation of the parameter that offers the smallest values of MSE, AIC, and BIC. Confidence intervals were then assessed to test the performance of the methods by comparing the 95% CI and average lengths (AL) for all estimation methods, showing that the Bayesian methods still offer the best performance in terms of generating the smallest ALs.","PeriodicalId":15035,"journal":{"name":"Journal of Applied Mathematics and Physics","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135009950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimal Treatment Strategy for Infectious Diseases with Two Treatment Stages","authors":"Fushui Wang, Cuicui Jiang","doi":"10.4236/jamp.2023.1110185","DOIUrl":"https://doi.org/10.4236/jamp.2023.1110185","url":null,"abstract":"In this paper, a disease transmission model with two treatment stages is proposed and analyzed. The results indicate that the basic reproduction number is a critical threshold for the prevalence of the disease. If the basic reproduction number is less than one, the disease free equilibrium is globally asymptotically stable. Otherwise, the endemic equilibrium is globally asymptotically stable. Therefore, besides the basic reproduction number, a new marker for characterizing the seriousness of the disease, named as dynamical final infective size, is proposed, which differs from traditional final size because the proposed model includes the natural birth and death. Finally, optimization strategies for limited medical resources are obtained from the perspectives of basic reproduction number and dynamical final infective size, and the real-world disease management scenarios are given based on these finding.","PeriodicalId":15035,"journal":{"name":"Journal of Applied Mathematics and Physics","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135009952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heat Characteristics and Viscous Flow in a Moving Isothermal Cylindrical Duct with Nanoparticles","authors":"Emmanuel O. Sangotayo, Kasali A. Adedeji, Joel Ovo Ogidiga","doi":"10.4236/jamp.2023.118151","DOIUrl":"https://doi.org/10.4236/jamp.2023.118151","url":null,"abstract":"Extrusion, melt spinning, glass fiber production, food processing, and mechanical molding rely on heat transmission. Isothermal techniques have been employed in highly structured equipment and living cell temperature regulators. The flow and heat properties of CuO nanofluids flowing through a moving cylindrical isothermal conduit were examined, in the presence of nanoparticles and viscous dissipation. Two-dimensional flows of an incompressible Newtonian fluid via a cylindrical conduit with uniform surface velocity and temperature were utilized. The flow’s partial differential equations were transformed to a non-dimensional form and numerically solved using a finite difference scheme built in the C++ program. The effect of nanoparticle size (0.0 to 0.6) and viscous dissipation (0, 20, 40) on heat behavior and fluid movement are examined and profiles are used to present the numerical findings. The findings revealed that decreasing the variable nanoparticle parameter increased fluid velocity, stream function, and circulation while decreasing fluid temperature. The temperature of the fluid rises in direct proportion, as the viscous dissipation factor improves. This study improves understanding of the viscous flow and heat behavior of boundary layer problems when a nanofluid is used as the heat transfer working fluid in various engineering isothermal processes such as boiling and condensation.","PeriodicalId":15035,"journal":{"name":"Journal of Applied Mathematics and Physics","volume":"242 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136256641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}