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On the “Onion Husk” Algorithm for Approximate Solution of the Traveling Salesman Problem

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Journal of Applied Mathematics and Physics 2024年第4期12卷 1557-1570页

作者： Mikhail e. Abramyan Nikolai I. Krainiukov Boris f. Melnikov faculty of Computational Mathematics and Cybernetics Shenzhen MSU-BIT University Shenzhen China Department of Algebra and Discrete Mathematics Southern Federal University Rostov-on-Don Russian Federation

The paper describes some implementation aspects of an algorithm for approximate solution of the traveling salesman problem based on the construction of convex closed contours on the initial set of points (“cities”) and their subsequent combination into a closed path (the so-called contour algorithm or “onion husk” algorithm). A number of heuristics related to the dif.e.ent stages of the algorithm are considered, and various variants of the algorithm based on these heuristics are analyzed. Sets of randomly generated points of dif.e.ent sizes (from 4 to 90 and from 500 to 10,000) were used to test the algorithms. The numerical results obtained are compared with the results of two well-known combinatorial optimization algorithms, namely the algorithm based on the branch and bound method and the simulated annealing algorithm. .

关键词： Branch and Bound Method Contour Algorithm “Onion Husk” Algorithm Simulated Annealing Method Traveling Salesman Problem

Artificial ground f.e.zing of underground mines in cold regions using thermosyphons with air insulation

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International Journal of Mining Science and Technology 2024年第5期34卷 643-654页

作者： Ahmad f.Zueter Mohammad Zolfagharroshan Navid Bahrani Agus P.Sasmito Department of Civil and Resource engineering Dalhousie UniversityHalifax B3H4R2Canada Department of Mining engineering McGill UniversityMontreal H3A0E8Canada

Current practice of underground artificial ground f.e.zing(AGf)typically involves huge refrigeration systems of large economic and environmental *** this study,a novel AGf technique is proposed deploying available cold wind in cold *** is achieved by a static heat transfer device called thermosyphon equipped with an air insulation layer.A refrigeration unit can be optionally integrated to meet additional cooling *** introduction of air insulation isolates the thermosyphon from ground zones where f.e.zing is not needed,resulting in:(1)steering the cooling resources(cold wind or refrigeration)towards zones of interest;and(2)minimizing refrigeration *** design is demonstrated using well-validated mathematical models from our previous work based on two-phase enthalpy method of the ground coupled with a thermal resistance network for the *** Canadian mines are considered:the Cigar Lake Mine and the Giant *** results show that our proposed design can speed the f.e.zing time by 30%at the Giant Mine and by two months at the Cigar Lake ***,a cooling load of 2.4 GWh can be saved at the Cigar Lake ***,this study provides mining practitioners with sustainable solutions of underground AGf.

关键词： Artificial ground f.e.zing Underground mining Sustainable mining Thermosyphon Air insulation Cold regions

Digital twin-and extended reality-based telepresence for collaborative robot programming in the 6G perspective

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Digital Communications and Networks 2024年第2期10卷 315-327页

作者： Davide Calandra f.Gabriele Pratticò Alberto Cannavò Claudio Casetti fabrizio Lamberti Politecnico di Torino Department of Control and Computer EngineeringCorso Duca Degli Abruzzi2410129TurinItaly

In the context of Industry 4.0,a paradigm shift from traditional industrial manipulators to Collaborative Robots(CRs)is ongoing,with the latter serving ever more closely humans as auxiliary tools in many production *** this scenario,continuous technological advancements of.e. new opportunities for further innovating robotics and other areas of next-generation *** example,6G could play a prominent role due to its human-centric view of the industrial *** particular,its expected dependability features will pave the way for new applications exploiting highly ef.e.tive Digital Twin(DT)-and eXtended Reality(XR)-based *** this work,a novel application for the above technologies allowing two distant users to collaborate in the programming of a CR is *** approach encompasses demanding data flows(e.g.,point cloud-based streaming of collaborating users and robotic environment),with network latency and bandwidth *** obtained by analyzing this approach from the viewpoint of network requirements in a setup designed to emulate 6G connectivity indicate that the expected performance of forthcoming mobile networks will make it fully feasible in principle.

关键词： 6G Digital twin Telepresence Collaborative robots Industry 4.0 Augmented reality Virtual reality Point cloud streaming

A C-shaped hinge for displacement magnification in MeMS rotational structures

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Microsystems & Nanoengineering 2024年第1期10卷 55-66页

作者： Naga Manikanta Kommanaboina Teferi Sitotaw Yallew Alvise Bagolini Maria f.Pantano Department of Civil Environmental and Mechanical EngineeringUniversity of Trentovia Mesiano 7738123 TrentoItaly fondazione Bruno Kessler(fBK) Microsystems Technology(MST)via S.Croce 7738122 TrentoItaly

The design,analysis,fabrication,and characterization of two distinct MeMS rotational structures are provided;these structures include a classical symmetrical lancet structure and a novel symmetrical C-shaped structure provided with a tilted arm,and both are actuated by thermal *** proposed C-shaped structure implemented a curved beam mechanism to enhance the movement delivered by the thermal *** geometrical parameters of our proposed device were optimized using the design of.e.periment(DOe)***,the analytical modeling based on Castigliano’s second theorem and the simulations based on the finite element method(feM)were used to predict the behavior of the symmetrical C-shaped structure;the results were in good agreement with each *** MeMS-based rotational structures were fabricated on silicon-on-insulator(SOI)wafers using bulk micromachining technology and deep reactive ion etching(DRIe)*** fabricated devices underwent experimental characterization;our results showed that our proposed MeMS rotational structure exhibited a 28%improvement in the delivered displacement compared to the symmetrical lancet ***,the experimental results showed good agreement with those obtained from numerical *** proposed structures have potential applications in a variety of MeMS devices,including accelerometers,gyroscopes,and resonators,due to their ability to maximize displacement and thus enhance sensitivity.

关键词： shaped displacement structures

Connections Between Induction Generator ef.e.t and Open-loop Modal Proximity to Cause Sub-synchronous Oscillations in Series-compensated Power System

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CSee Journal of Power and energy Systems 2024年第3期10卷 963-973页

作者： Wenjuan Du Yang Wang H.f.Wang Tao Zhao Tim Littler College of.e.ectrical engineering Sichuan UniversityChengduChina School of.e.ectrical engineering the Queen’s University of BelfastBelfastUK Ieee

The induction generator ef.e.t(IGe)and the openloop modal proximity(OLMP)are two dif.e.ent reasons why subsynchronous oscillations(SSOs)in a series-compensated power system(SCPS)may *** IGe attributes the growing SSOs to negative resistance,while the OLMP explains the SSO mechanism from the standpoint of modal *** this paper,we investigate the connections between the IGe and the OLMP through equivalent RLC circuit and open-loop modal *** investigation is conducted for two types of seriescompensated power systems where either a synchronous generator or a DfIG is connected at the sending *** investigation reveals the conditions,in which the IGe and the OLMP may jointly cause the growing SSOs,i.e.,both the IGe and the OLMP can explain why the growing SSOs ***,the investigation indicates that the IGe and the OLMP may be totally irrelevant and lead to growing SSOs *** implies that it is possible that in a SCPS,the growing SSOs are only due to the IGe,and the OLMP is non-existent,and vice ***,when the growing SSOs occurs in a SCPS,examination based on both the IGe and the OLMP should be carefully conducted in order to find if the oscillatory instability is due to the IGe,or the OLMP,or both of them.

关键词： Induction generator ef.e.t open-loop modal proximity series compensation sub-synchronous oscillations

Mixing and matching SMXL proteins to fine-tune strigolactone responses

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Molecular Plant 2024年第8期17卷 1167-1169页

作者： Jenna e.Hountalas Shelley Lumba Department of Cell&Systems Biology University of Toronto25 Willcocks StreetTorontoON M5S 3B2Canada Centre for the Analysis of Genome evolution and function University of Toronto25 Willcocks StreetTorontoON M5S 3B2Canada

A common mechanism in plant hormone signaling is hormonedependent degradation of downstream *** the case of strigolactone(SL)signaling,one group of SUPPReSSOR Of MORe AXILLARY BRANCHeS 2(MAX2)1-LIKe(SMXL)proteins undergoes hormone-dependent degradation,while another does not.A recent publication in Molecular Plant by Li et al.(2024)illustrates that mixing and matching a SMXL resistant to SL degradation with a SMXL sensitive to SL degradation finely tunes SL *** phenomenon could ref.e.t a naturally occurring negative transdominance,which is a dominantnegative ef.e.t arising not from a mutant allele of the same gene but rather from a dif.e.ent gene altogether(Veitia,2007).This trans-acting protein attenuates SL-dependent degradation of the SMXL *** findings have exciting implications for how dif.e.ent SMXL combinations could result in a gradient of SL responses.

关键词： complex. matching degradation

Adsorption of yttrium(Y^(3+)) and concentration of rare earth elements from phosphogypsum using chitin and chitin aerogel

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Journal of Rare earths 2024年第4期42卷 775-782页

作者： Glaydson S.dos Reis Diana Pinto Sabrina f.Lütke eder C.Lima Luis f.O.Silva Irineu A.S.De Brum Guilherme L.Dotto Department of forest Biomaterials and Technology Biomass Technology Centre Swedish University of Agricultural SciencesUmeaE13Swedn Universidad De La Costa Calle 58#55-66080002BarranquillaAtlanticoColombia Research Group on Adsorptive and Catalytic Process engineering(eNGePAC) Federal University of Santa MariaAv.Roraima100079705900Santa MariaRSBrazil Institute of Chemistry Federal University of Rio Grande do Sul90040060Porto AlegreBrazil

Chitin powder and chitin-aerogel were prepared from shrimp wastes and used to uptake Y^(3+)from aqueous solutions and concentrate this rare earth element from phosphogypsum(PG).Chitin aerogel displays a specific surface area of 945 m^(2)/g,while chitin powder is 3.6 m^(2)/g,which largely influences its adsorption *** the adsorption in synthetic solutions,the ef.e.t of pH on Y^(3+)removal is strong for chitin powder *** contrast,no big pH influence was detected for chitin *** interactions and chelation can highlight the proposed mechanism of Y^(3+)on chitin adsorbents for the powder and ***,in addition to these interactions,pore filling/pore diffusion is the main mechanism of Y^(3+)removal in the chitin *** aerogel is efficient in concentrating 8 times the Y^(3+)from PG,a very complex *** complex chitin aerogel-Y^(3+)can be a secondary source of rare earth elements for other applications.

关键词： Rare earths Sustainable material Chitin powder Chitin porous aerogel Yttrium adsorption and recovery

Item-Level Analysis of the Revised Occupational Therapy f.e.dwork Performance evaluation Applied in Practice

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Open Journal of Therapy and Rehabilitation 2024年第2期12卷 145-159页

作者： Cynthia L. Sears Brad e. egan Patricia f. Tomsic Craig A. Velozo Graduate College of Health Professions Occupational Therapy Program Hawai&#8217i Pacific University Honolulu HI USA College of Science and Health Occupational Therapy Program DePaul University Chicago IL USA Department of Occupational Therapy Wingate University Wingate NC USA College of Health Professions Department of Rehabilitation Sciences Division of Occupational Therapy Medical University of South Carolina Charleston SC USA

Competency-based assessments for healthcare professionals are critical for safe and ef.e.tive client outcomes. Rehabilitation clinical skill competency assessments must be validated and revised to produce safe and skilled practitioners. The revised American Occupational Therapy Association (AOTA) f.e.dwork Performance evaluation (fWPe) instrument measures occupational therapy student performance to determine readiness for practice. The assessment includes thirty-seven competencies that address both profession specific clinical skills and general professional behavior skills. The objective of this study was to use Rasch methods to explore the use of the revised fWPe in actual f.e.dwork practice and to determine the instrument’s psychometric properties when separating the item components into two distinct subdomains: General Health Professions Competences and Occupational Therapy-Specific Competencies. Internal construct validity and test reliability were analyzed using data from 149 occupational therapy students af.e. completing their initial Level II A f.e.dwork clinical internship. This study examined the item difficulty hierarchy, item fit, person-fit to model, person separation index, person separation reliability coefficient, strata, ceiling and floor ef.e.t, and unidimensionality of the fWPe instrument as a whole and as two separate domains. With the exception of not meeting the criteria for unidimensionality, the full fWPe instrument and the Occupational Therapy-Specific Competencies subdomain showed acceptable item-level psychometrics for reliability and precision. While the General Health Professions Competencies subdomain showed good item-level psychometrics, it was below the criterion for reliability and only separated the sample into two strata. Results support the validity, reliability, and clinical use of the revised fWPe full instrument and the Occupational Therapy-Specific Competencies subdomain to measure entry-level clinical skill competencies in pr

关键词： Rehabilitation Competency-Based Assessments Occupational Therapy Measurement Rasch Analysis

experimental measurements of gamma-photon production and estimation of.e.ectron/positron production on the PeTAL laser facility

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Matter and Radiation at extremes 2024年第5期9卷 32-47页

作者： f.Brun L.Ribotte G.Boutoux X.Davoine P.e.Masson-Laborde Y.Sentoku N.Iwata N.Blanchot D.Batani I.Lantuéjoul L.Lecherbourg B.Rosse C.Rousseaux B.Vauzour D.Raf.e.tin e.D’Humières X.Ribeyre Centre Lasers Intenses et Applications UMR 5107Universitéde Bordeaux-CNRS-CEA33405 TalenceFrance CeA DAMCESTAF-33116 Le BarpFrance CeA DAMDIFF-91297 ArpajonFrance CeA LMCEUniversitéParis-Saclay91680 Bruyères-le-ChâtelFrance Institute of Laser engineering Osaka University2-6 YamadaokaSuitaOsaka 565-0871Japan

This article reports the first measurements of high-energy photons produced with the high-intensity PeTawatt Aquitaine Laser(PeTAL)*** experiments were performed during the commissioning of the *** laser had an energy of about 400 J,an intensity of 8×10^(18)W cm^(−2),and a pulse duration of 660 fs(fWHM).It was shot at a 2 mm-thick solid tungsten *** high-energy photons were produced mainly from the bremsstrahlung process for relativistic electrons accelerated inside a plasma generated on the front side of the *** paper reports measurements of.e.ectrons,protons and *** electrons up to35 MeV with a few-MeV temperature were recorded by a spectrometer,called SeSAMe(SpectreÉlectronS Angulaire MoyenneÉnergie).K-and L-shells were clearly detected by a photon spectrometer called SPeCTIX(Spectromètre PetalàCristal en TransmIssion pour le rayonnnement X).High-energy photons were diagnosed by CRACC-X(Cassette de RAdiographie Centre Chambre-rayonnement X),a bremsstrahlung *** cannon analysis is strongly dependent on the hypothesis adopted for the spectral *** shapes can exhibit similar reproductions of the experimental *** eliminate dependence on the shape hypothesis and to facilitate analysis of the data,simulations of the interaction were *** model the mechanisms involved,a simulation chain including hydrodynamic,particle-in-cell,and Monte Carlo simulations was *** simulations model the preplasma generated at the front of the target by the PeTAL laser prepulse,the acceleration of.e.ectrons inside the plasma,the generation of MeV-range photons from these electrons,and the response of the detector impacted by the energetic photon *** this work enabled reproduction of the experimental *** high-energy photons produced have a large emission angle and an exponential distribution *** addition to the analysis of the photon spectra,positron production was also ***,if high

关键词： process. positron hypothesis