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Schreier rewriting beyond the classical setting Dedicated to our teacher Alfred Lvovich Shmelkin on his 70th birthday

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Science China Mathematics 2009年第2期52卷 231-243页

作者： BAHTURIN Yuri OLSHANSKII alexander Department of Mathematics and Statistics Memorial University of Newfoundland St. John'sNL A1C 5S7Canada Department of Algebra Faculty of Mathematics and Mechanics119899 Moscow Russia Department of Mathematics 1326 Stevenson Center Vanderbilt UniversityNashvilleTN 37240 USA

Using actions of free monoids and free associative algebras, we establish some Schreier-type formulas involving ranks of actions and ranks of subactions in free actions or Grassmann-type relations for the ranks of intersections of subactions of free actions. The coset action of the free group is used to establish a generalization of the Schreier formula in the case of subgroups of infinite index. We also study and apply large modules over free associative and free group algebras.

关键词： free algebra group monoid act G-set module

Formal Definition of a User-Adaptive and Length-Optimal Routing Graph for Complex Indoor Environments

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Geo-Spatial Information Science 2011年第2期14卷 119-128页

作者： GOETZ Marcus ZIPF alexander Chair of GIScience Department of GeographyUniversity of Heidelberg

Car routing solutions are omnipresent and solutions for pedestrians also ***,public or commercial buildings are getting bigger and the complexity of their internal structure has ***,the need for indoor routing solutions has *** prototypes are available,but they still lack semantically-enriched modelling (e.g.,access constraints,labels,etc.) and are not suitable for providing user-adaptive length-optimal routing in complex *** approaches consider simple rooms,concave rooms,and corridors,but important characteristics such as distinct areas in huge rooms and solid obstacles inside rooms are not considered at all,although such details can increase navigation *** formally defining a weighted indoor routing graph,it is possible to create a detailed and user-adaptive model for route *** defined graph also contains semantic information such as room labels,door accessibility constraints,***,one-way paths inside buildings are considered,as well as three-dimensional building parts,e.g.,elevators or stairways.A hierarchical structure is also possible with the presented graph model.

关键词： 3D indoor navigation 3D indoor routing city modelling formal definition routing graph buildings

Evolutionary status of T Tauri stars

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Research in Astronomy and Astrophysics 2018年第8期18卷 103-110页

作者： Olga Eretnova alexander Dudorov Physics Department Chelyabinsk State University

The problem of determining the masses and ages of T Tauri star （TTS） using their evolu- tionary status is discussed. We test four pre-main sequence evolutionary models using well determined observational parameters of 12 binary TTSs and two binary red dwarfs. It is shown that the masses derived using the tracks of all models are in good agreement with flhe masses obtained from the obser- vations of TTSs with masses M 〉 0.7 Me （mean error ε,- 10%）. Low-mass stars with M ≤ 0.7 M⊙ have significantly greater mean error; e - 50% for the tracks of Bressan et al. and Chen et al., and e - 30% for the other tracks. The isochrones of all tested evolutionary models diverge for stars with masses M ≤ 0.7 M⊙. The difference increases with the mass decrease and can reach 10% of Kelvin- Helmholtz time for stars with mass M = 0.2 Me. The ages of most of the considered TTSs are smaller than the Kelvin-Helmholtz time. This confirms their evolutionary status of being pre-main sequence stars.

关键词： stars pre-main sequence stars - stars binaries - Hertzsprung-Russell diagram

Typical load profile-supported convolutional neural network for short-term load forecasting in the industrial sector

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Energy and AI 2021年第3期5卷 242-254页

作者： Thilo Walser alexander Sauer Fraunhofer Institute for Manufacturing Engineering and Automation IPA Nobelstraße 1270569 StuttgartGermany Institute for Energy Efficiency in Production EEP University of StuttgartNobelstraße 1270569 StuttgartGermany

This paper investigates how existing forecasting models can be enhanced to accurately forecast the electric load at factory level,enabling industrial companies to shift consumption to times of low energy *** model architecture must outperform state-of-the-art models and be sufficiently robust for use in multiple factories with low effort for specific ***,this work focuses on the processing of high-resolution input data available almost in real time from multiple submeters after the main *** theory of load forecasting and related works are summarized in a first step including the requirements of forecasting models applied at factory *** on existing models,a new hybrid machine-learning model is proposed,combining a decision tree-based typical load profiler with a convolutional neural network that extracts features from multidimensional endogenous inputs with measurements of the preceding two weeks for multi-step-ahead load forecasts updated almost in real ***,a multi-model approach is presented for calculating bottom-up forecasts with submeter data aggregated to a main-meter *** a case study,the forecasting accuracy of the hybrid model is compared to both base models and a seasonal naïve model calculating the load forecasts for three *** results indicate that the proposed typical-load-profile-supported convolutional neural network for all three factories achieves the lowest forecasting ***,it is validated that a reduction in data transfer delay leads to better forecasts,as the forecasting accuracy is higher with near real time data than with a data transfer delay of one ***,a model architecture is proposed for robust forecasting in digitalized factories.

关键词： Electricity Machine learning Load forecasting Hybrid model Industrial energy systems Energy flexibility Submetering Real time data

Immunotherapy in colorectal cancer: Available clinical evidence,challenges and novel approaches

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World Journal of Gastroenterology 2019年第29期25卷 3920-3928页

作者： Joseph Tintelnot alexander Stein Department of Internal Medicine II (Oncology Center) University Medical Center Hamburg-Eppendorf Hamburg 20246 Germany

In contrast to other tumor types, immunotherapy has not yet become a relevant part of the treatment landscape of unselected colorectal cancer. Beside the small subgroup of deficient mismatch repair or microsatellite instable tumors (about 5%) as a surrogate for high mutational burden and subsequently high neoantigen load and immunogenicity, inhibitors of programmed death 1 (PD-1), programmed death ligand 1 (PD-L1) and/or cytotoxic T lymphocyte-associated antigen-4 were not or only modestly effective in metastatic colorectal cancer. Thus, a variety of combination approaches with chemotherapy, targeted therapy, toll-like receptor agonists, local ablation or oncolytic viruses is currently being evaluated in different disease settings. Despite several encouraging single arm data already presented or published, available randomized data are unimpressive. Adding PD-1/PD-L1 inhibitors to fluoropyrimidines and bevacizumab maintenance showed no beneficial impact on delaying progression. In refractory disease, the combination of PD-1/PD-L1 and MEK inhibitor was not different from regorafenib, whereas a PD-1/PD-L1 and cytotoxic T lymphocyteassociated antigen-4 inhibitor combination demonstrated better overall survival compared to supportive care alone. Clinical trials in all disease settings applying different combination approaches are ongoing and may define the role of immunotherapy in colorectal cancer.

关键词： Immunotherapy Combination Colorectal cancer Metastatic Adjuvant

On the Solution Accuracy Downstream of Shocks When Using Godunov-Type *** of Errors in One-Dimensional Problems

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Communications in Computational Physics 2023年第8期34卷 749-786页

作者： alexander V.Rodionov Keldysh Institute of Applied Mathematics Russian Academy of SciencesMoscow125047Russia RFNC–All-Russian Scientific Research Institute of Experimental Physics Sarov607188Russia

The article opens a series of publications devoted to a systematic study of numerical errors behind the shock wave when using high-order Godunov-type schemes,including in combination with the artificial viscosity *** proposed paper describes the numerical methods used in the study,and identifies the main factors affecting the accuracy of the solution for the case of one-dimensional gas dynamic *** physical interpretation of the identified factors is given and their influence on the grid convergence is analyzed.

关键词： Shock-capturing methods Riemann problem WENO reconstruction Runge-Kutta method Hancock-Rodionov method artificial viscosity approach Shu-Osher test problem

Tribological properties of the beetle leg joints

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Friction 2024年第12期12卷 2791-2807页

作者： Konstantin NADEIN alexander KOVALEV Stanislav N.GORB Functional Morphology and Biomechanics Zoological InstituteChristian-Albrechts University of KielAm Botanischen Garten 1-924118 KielGermany

Tribological properties of femoro-tibial leg joints in two beetles,darkling beetle Zophobas morio and Congo rose chafer Pachnoda marginata were *** low friction of 0.004 was revealed by the direct measurements in the *** is assumed that semi-solid lubricant functioning as in technical bearings is one of the leading factors of the friction *** of the surface texture and physical chemical properties(hydrophobicity)on the cuticle friction was *** of the surface texture to the tribological properties of contacting surfaces was examined by the measurement in the tribosystem“contacting surface/glass”.It is supposed that coefficient of friction(COF)decreases with decrease of surface *** the same time,no statistically significant correlation was found between the hydrophobicity of the surface and the value of the friction coefficient.

关键词： biotribology friction articulation contact angle surface texture lubrication

Exact Singularity Subtraction from Boundary Integral Equations in Modeling Vesicles and Red Blood Cells

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Numerical Mathematics(Theory,Methods and Applications) 2014年第4期7卷 413-434页

作者： alexander Farutin Chaouqi Misbah UniversitéGrenoble I/CNRS Laboratoire Interdisciplinaire de Physique/UMR5588Grenoble F-38041France

The study of vesicles,capsules and red blood cells(RBCs)under flow is a field of active research,belonging to the general problematic of fluid/structure ***,we are interested in modeling vesicles,capsules and RBCs using a boundary integral formulation,and focus on exact singularity subtractions of the kernel of the integral equations in *** order to increase the precision of singular and near-singular integration,we propose here a refinement procedure in the vicinity of the pole of the Green-Oseen *** refinement is performed homogeneously everywhere on the source surface in order to reuse the additional quadrature nodes when calculating boundary integrals in multiple target *** also introduce a multi-level look-up algorithm in order to select the additional quadrature nodes in vicinity of the pole of the Green-Oseen *** expected convergence rate of the proposed algorithm is of order δ(1/N^(2))while the computational complexity is of order δ(N^(2) lnN),where N is the number of degrees of freedom used for surface *** numerical tests are presented to demonstrate the convergence and the efficiency of the method.

关键词： Stokes flow fluid structure interaction boundary integral method red blood cells singularity subtraction

OFF-GRID TINy HOUSE SMART RESIDENTIAL ENERGy MANAGEMENT SYSTEM

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Journal of Green Building 2016年第4期11卷 37-53页

作者： David G.alexander Department of Mechanical and Mechatronic Engineering California State UniversityChico

Students at California State University(CSU),Chico designed,built,and tested an off-grid solar powered tiny house and competed in the 2016 Sacramento Municipal Utility District’s(SMUD)Tiny House *** tier research institutions,predominantly undergraduate universities,and community colleges from all over California competed against one another in a variety of performance and aesthetic events in SMUD’s first ever *** of the main goals of the CSU,Chico’s Tiny House was to design and implement an autonomous energy management system to maximize energy capture,use,and efficiency and provide a seamless,comfortable,and uninterrupted indoor living *** system,smart residential energy management system(SREMS),was designed to monitor and sense solar energy collected and stored,indoor heating and cooling loads,occupant cooking and personal water heating needs,and electrical outlets and to determine and allow energy related activities given the amount of stored *** and heat transfer models were developed to predict heating,cooling,and appliance *** models were used to size the solar array,battery storage,and *** was installed in the tiny house and its performance was tested and validated during the week long SMUD Tiny House *** showed close correlation with the predicted energy requirements of the models,and the tiny house maintained net-zero energy use even during overcast and rainy skies throughout the three-day *** CSU,Chico team won best control system and best technology at the statewide *** paper describes the design,installation and testing results of CSU,Chico’s Tiny House SREMS.

关键词： Solar PV energy management tiny house student competition renewable energy sustainability