Journal of Physics Communications最新文献_第7页

Self-focusing, compression and collapse of ultrashort weakly-relativistic Laguerre–Gaussian lasers in near-critical plasma 超短弱相对论拉盖尔-高斯激光在近临界等离子体中的自聚焦、压缩和坍缩

IF 1.2

Journal of Physics Communications Pub Date : 2023-02-24 DOI: 10.1088/2399-6528/acbf05

T. Wilson, Z. Sheng, P. McKenna, B. Hidding

引用次数: 0

Interactions of deposited Ca with TiSe2 and TiTe2 surfaces 沉积Ca与TiSe2和TiTe2表面的相互作用

IF 1.2

Journal of Physics Communications Pub Date : 2023-02-15 DOI: 10.1088/2399-6528/acbc65

H. Starnberg

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Compression and information entropy of binary strings from the collision history of three hard balls 三个硬球碰撞历史中二进制字符串的压缩和信息熵

IF 1.2

Journal of Physics Communications Pub Date : 2023-02-14 DOI: 10.1088/2399-6528/acd2a3

Matej Vedak, G. Ackland

{"title":"Compression and information entropy of binary strings from the collision history of three hard balls","authors":"Matej Vedak, G. Ackland","doi":"10.1088/2399-6528/acd2a3","DOIUrl":"https://doi.org/10.1088/2399-6528/acd2a3","url":null,"abstract":"We investigate how to measure and define the entropy of a simple chaotic system, three hard spheres on a ring. A novel approach is presented, which does not assume the ergodic hypothesis. It consists of transforming the particles’ collision history into a sequence of binary digits. We then investigate three approaches which should demonstrate the non-randomness of these collision-generated strings compared with random number generator created strings: Shannon entropy, diehard randomness tests and compression percentage. We show that the Shannon information entropy is unable to distinguish random from deterministic strings. The Diehard test performs better, but for certain mass-ratios the collision-generated strings are misidentified as random with high confidence. The zlib and bz2 compression algorithms are efficient at detecting non-randomness and low information content, with compression efficiencies that tend to 100% in the limit of infinite strings. Thus ‘compression algorithm entropy’ is non-extensive for this chaotic system, in marked contrast to the extensive entropy determined from phase-space integrals by assuming ergodicity.","PeriodicalId":47089,"journal":{"name":"Journal of Physics Communications","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48712194","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}

引用次数: 0

Surgical outcome of a patient with Bertolotti's syndrome in whom the established Castellvi classification system failed: illustrative case. 已建立的Castellvi分类系统失败的Bertolotti综合征患者的手术结果:说明性病例

Journal of Physics Communications Pub Date : 2023-02-13 DOI: 10.3171/CASE22450

Richard J Chung, Camryn Harvie, John O'Donnell, Sarah Jenkins, Arthur L Jenkins

{"title":"Surgical outcome of a patient with Bertolotti's syndrome in whom the established Castellvi classification system failed: illustrative case.","authors":"Richard J Chung, Camryn Harvie, John O'Donnell, Sarah Jenkins, Arthur L Jenkins","doi":"10.3171/CASE22450","DOIUrl":"10.3171/CASE22450","url":null,"abstract":"Background: Bertolotti's syndrome is a condition of the lower back and/or L5 distribution leg pain caused by a lumbosacral transitional vertebra (LSTV). Diagnosing the LSTV as the cause of the symptoms and condition is essential for accurate management of this syndrome. Castellvi's classification system is widely accepted for LSTV anatomy, but it measures only one aspect of transitional anatomy and was intended primarily to identify target-level disk herniations.Observations: In this case, the Castellvi classification system failed to identify the patient (with 2 years of back and L5 pain) as having an LSTV, even though he displayed LSTV-like anatomy because both L5 transverse process heights measured less than 19 mm. He attained brief but significant relief from bilateral injections into the L5-S1 transverse/ala region and underwent a minimally invasive bilateral decompression of L5-S1 with almost complete relief of his symptoms maintained more than 6 months postoperatively.Lessons: Given that the patient gained significant relief from treatment of transitional anatomy that failed to be identified using Castellvi's classification system, this case suggests that transverse process height may not be adequate or even the most clinically relevant indicator in identifying LSTV anatomy, which is a precursor to the diagnosis of Bertolotti's syndrome.","PeriodicalId":47089,"journal":{"name":"Journal of Physics Communications","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10550603/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83210511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Streamer and leader characterization in HFO1234ze(E) gas, in a divergent electric field 发散电场条件下HFO1234ze(E)气体中拖缆和引线的表征

IF 1.2

Journal of Physics Communications Pub Date : 2023-02-09 DOI: 10.1088/2399-6528/acbae3

S. Soulié, N. Bonifaci, O. Lesaint, F. Gentils

引用次数: 0

The Dirac impenetrable barrier in the limit point of the Klein energy zone 克莱因能区极限点的狄拉克不可穿透障壁

IF 1.2

Journal of Physics Communications Pub Date : 2023-02-03 DOI: 10.1088/2399-6528/acb8ff

S. De Vincenzo

{"title":"The Dirac impenetrable barrier in the limit point of the Klein energy zone","authors":"S. De Vincenzo","doi":"10.1088/2399-6528/acb8ff","DOIUrl":"https://doi.org/10.1088/2399-6528/acb8ff","url":null,"abstract":"We reanalyze the problem of a 1D Dirac single particle colliding with the electrostatic potential step of height V 0 with a positive incoming energy that tends to the limit point of the so-called Klein energy zone, i.e. E → V 0 − mc 2, for a given V 0. In such a case, the particle is actually colliding with an impenetrable barrier. In fact, V 0 → E + mc 2, for a given relativistic energy E( < V 0), is the maximum value that the height of the step can reach and that ensures the perfect impenetrability of the barrier. Nevertheless, we note that, unlike the nonrelativistic case, the entire eigensolution does not completely vanish, either at the barrier or in the region under the step, but its upper component does satisfy the Dirichlet boundary condition at the barrier. More importantly, by calculating the mean value of the force exerted by the impenetrable wall on the particle in this eigenstate and taking its nonrelativistic limit, we recover the required result. We use two different approaches to obtain the latter two results. In one of these approaches, the corresponding force on the particle is a type of boundary quantum force. Throughout the article, various issues related to the Klein energy zone, the transmitted solutions to this problem, and impenetrable barriers related to boundary conditions are also discussed. In particular, if the negative-energy transmitted solution is used, the lower component of the scattering solution satisfies the Dirichlet boundary condition at the barrier, but the mean value of the external force when V 0 → E + mc 2 does not seem to be compatible with the existence of the impenetrable barrier.","PeriodicalId":47089,"journal":{"name":"Journal of Physics Communications","volume":"7 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"61174272","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}

引用次数: 0

Reinforcing critical links for robust network logistics: A centrality measure for substitutability 加强健全网络物流的关键环节:可替代性的中心性措施

IF 1.2

Journal of Physics Communications Pub Date : 2023-01-31 DOI: 10.1088/2399-6528/acb7c9

Takahiro Ezaki, Naoto Imura, K. Nishinari

{"title":"Reinforcing critical links for robust network logistics: A centrality measure for substitutability","authors":"Takahiro Ezaki, Naoto Imura, K. Nishinari","doi":"10.1088/2399-6528/acb7c9","DOIUrl":"https://doi.org/10.1088/2399-6528/acb7c9","url":null,"abstract":"Logistics networks are becoming more complex and interconnected. Guaranteeing the performance of the entire system when a part of the network is disrupted (e.g. due to excessive demands and extreme weather conditions) is one of the important issues. However, how much transportation resources should be allocated to which part of the network while maintaining efficiency is an open question. In this paper, we propose a novel metric, the substitutability centrality, which quantifies how much each transport link in the network contributes to the robustness of the system against disruptions. This metric is compelling in the following aspects: (1) it is intuitively interpretable; (2) it does not require simulation or optimization calculations; and (3) it takes into account changes in transportation routes of delivery due to disruptions. Furthermore, as a proof of concept, we demonstrate a simple case study, in which capacity allocation based on the proposed metric can maintain high performance of the system against various types of disruptions. We also found that this approach might not be effective for further increasing the robustness of networks that have many bypass routes.","PeriodicalId":47089,"journal":{"name":"Journal of Physics Communications","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48887178","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}

引用次数: 0

Random error propagation on electron beam dynamics for a 50 MeV S-band linac 50 MeV s波段直线加速器电子束动力学中的随机误差传播

IF 1.2

Journal of Physics Communications Pub Date : 2023-01-17 DOI: 10.1088/2399-6528/acb415

H. Purwar, E. Goutierre, H. Guler, M. Rossetti Conti, S. Chancé, A. Gonnin, H. Monard, A. Bacci, M. Sebag, J. Cohen, C. Bruni

引用次数: 0

Non-linear correlation analysis in financial markets using hierarchical clustering 基于层次聚类的金融市场非线性相关分析

IF 1.2

Journal of Physics Communications Pub Date : 2023-01-12 DOI: 10.1088/2399-6528/acd618

J. E. Salgado-Hern'andez, Manan Vyas

引用次数: 0

Modeling of optical wave propagation through turbulent atmosphere using fractional approach for FSO wireless communication FSO无线通信中光波在湍流大气中传播的分形建模

IF 1.2

Journal of Physics Communications Pub Date : 2023-01-10 DOI: 10.1088/2399-6528/acb1ef

A. Khan, M. Zubair, U. Younis

{"title":"Modeling of optical wave propagation through turbulent atmosphere using fractional approach for FSO wireless communication","authors":"A. Khan, M. Zubair, U. Younis","doi":"10.1088/2399-6528/acb1ef","DOIUrl":"https://doi.org/10.1088/2399-6528/acb1ef","url":null,"abstract":"Free space optical (FSO) wireless communication has emerged as a viable alternative to the existing fiber optics and radio frequency (RF) communications due to its ability to operate in unlicensed spectrum, offering huge data handling capacities and being cost effective with easy deployment. The underlying communication mechanism in the FSO link is based upon the laser beam propagation model. The propagating free space optical beam undergoes signal degradation due to refraction and diffraction caused by atmospheric turbulence measured by refractive index structure parameter (C n 2). In this work, a novel, robust analytical model for propagating Gaussian-beam through atmospheric turbulence is presented, by solving the space-fractional paraxial wave equation. We report analytical expressions for the intensity and long-term beam spreading of a Gaussian beam in terms of space-fractional parameter D, for the range 2 < D ≤ 3. This range of parameter D, defines the effective number of euclidean space corresponding to atmospheric turbulence levels faced by the propagating Gaussian beam in the FSO link. The results of the proposed fractional model and the existing models agreed well, therefore the D-dimensional parameter can be used to effectively express the value of refractive index structure parameter (C n 2). The classical values of C n 2 ranges form 10−13 to 10−16 for strong to weak fluctuations respectively. However, in fractional-dimension scale, these fluctuations can be express as D = 2.668 (strong fluctuations) to D = 2.999 (weak fluctuations). The ideal case of free space beam propagation can be expressed as D = 3, with no turbulence. Moreover, we have studied the fractional-dimension model performance for varying wavelengths. Further, based upon a practical example, we proposed a self-sustainable FSO link architecture to efficiently minimize the effect of weak and strong fluctuations on the propagating optical beam, based upon the D-dimension fractional parameter, hence ensuring reliability of FSO link.","PeriodicalId":47089,"journal":{"name":"Journal of Physics Communications","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46407158","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}

引用次数: 0