39,849 research outputs found
Chinese Cataloging Rules and International Cataloguing Principles: a Report of Similarities and Differences
No full textThis paper is to compare International Cataloguing Principles and Chinese Cataloging Rules, and analyze their differences. It is jointly written by Prof. Songlin Wang (uniform titles and GMD), Ms. Qinfang Xie (personal names and serials), Mr. Shaoping Wang (corporate bodies and multi-part structures) and Dr. Ben Gu (descriptive cataloging and personal names). Through such cooperation, we are trying to reflect the actual situation in China and considering a national coordination in the near future
A Study of the Classical Landscape at the Wang River Villa of Wang Wei
No full textThe landscape of Wang Wei's Wang River Villa is examined by reviewing the essays and papers written about the poetical collaboration, the “Wang River Collection.” The purpose of this paper is to clarify the meaning of villa architecture in China. The author expects that this research will contribute to a mutual understanding between cultures. The villa was a Utopia for Wang. On the other hand, he was a pious Buddhist and Buddhistic concepts are reflected in the landscape. I consider the features of the classical landscape of Xie Lingyun and "Chu Ci," as written in “The Collection,” a reflection of the Buddhistic concept. When considering what the classics meant to Wang Wei, it is apparent that his villa is a representation of the classical landscape. It is not an imitation of the classical landscape, but a unique and original creation of art by Wang.departmental bulletin pape
Simulation analysis of cable-driven rolling joint for humanoid robot via Adams
No full textThis study introduces a novel anthropomorphic cable-driven rolling joint structure that can achieve bidirectional motion using a single motor. A specific cable system configuration is designed, and an experimental platform is constructed. To ensure the safety of the cable-driven rolling joint and facilitate the exploration of cable tension dynamics, Adams software is employed for modeling and simulation of the joint. The simulation results are validated against experimental data obtained from the physical platform. By comparing the motion effects of two winch drive simulation methods—the winch function and the large disk winding method—while varying the joint angle over time, consistent behavior is observed. Additionally, the tension changes in the upper and lower cable systems are analyzed as the joint angle varies. Despite minor deviations caused by cable deformation and pulley friction at extreme joint positions, the Adams simulations align well with the experimental observations. Notably, the simulation accurately captures the trend of cable tension relative to joint angle, demonstrating Adams' efficacy as a powerful tool for analyzing and optimizing cable-actuated rolling joints
Digital twin modeling and performance analysis of dissimilar redundant actuation system
No full textLAUREA MAGISTRALEIl Dissimilar Redundant Actuation System (DRAS) è un sistema di attuazione comunemente usato degli aeroplani moderni. Riceve le istruzioni dal computer di controllo del volo ed emette la forza e lo spostamento per guidare il timone dell'aeroplano e realizza l'assetto di volo dell'aeroplano o il controllo della traiettoria. Le sue prestazioni e affidabilità influiscono direttamente sulla sicurezza dell'aeromobile, quindi è di grande importanza studiarlo. L'utilizzo della tecnologia digital twin per modellare e simulare il DRAS può abbreviare notevolmente il ciclo di progettazione e sviluppo e ridurre i costi. Pertanto, è molto significativo studiare l'applicazione della tecnologia digital twin in tale contesto.
In questa tesi, si considera come oggetto di ricerca un tipico sistema DRAS e se ne analizza il modello geometrico, il modello elettrico, il modello del campo di flusso e il modello termico, al fine di sviluppare un modello multifisico e condurre ricerche basate sulla tecnologia digital twin, includendo principalmente quanto segue :
(1) Per l'attuatore elettro-idrostatico, si studia il modello di accoppiamento del controllo motore, elettrico e termico; si studia la parte pompa-cilindro dell'attuatore elettro-idrostatico e se ne stabilisce il campo di flusso e il campo termico. Si stabilisce un modello multifisico dell'attuatore elettro-idrostatico si effettuano simulazioni di verifica.
(2) Per quanto riguarda l'attuatore idraulico, vengono studiati il campo di flusso e il modello termico. Per il DRAS, viene adottata la modalità di funzionamento attivo/attivo e viene stabilito il modello multifisico basato sulla modalità di uscita completa della forza meccanica.
(3) Vengono proposti un ambiente di modellazione digital twin del sistema di attuazione e un modello corrispondente. Sebbene lo stato tecnico completo sia noto, i parametri vengono aggiornati dinamicamente in base all'algoritmo di discesa del gradiente, in modo che l'output del modello possa seguire l'output effettivo.
(4) Facendo uso della modalità 3D in Unity, si esegue una dimostrazione dinamica tridimensionale dei dati di simulazione nello spazio digitale.
L'attività di ricerca riportata in questa tesi è stata svolta sotto la supervisione della Professoressa Shaoping Wang presso l’Università Beihang nell'ambito del doppio Ms.c. corso di laurea in Ingegneria Elettrica tra l’Università Beihang e il Politecnico di Milano.The dissimilar redundant actuation system is a commonly used actuation system in modern airplanes. It receives instructions from the flight control computer and outputs force and displacement to drive the airplane rudder, and realizes airplane trajectory control. Its performance and reliability directly affect the safety of the aircraft, so it is of great significance to study it. Using digital twin technology to model and simulate the dissimilar redundant actuation system can greatly shorten the design and development cycle and reduce the cost. Therefore, it is very meaningful to study the application of digital twin technology in the dissimilar redundant actuation system.
In this thesis, we take a typical dissimilar redundant actuation system as the research object, analyze its geometric model, electrical model, flow field model and thermal model, establish its multiphysics model, and conduct research based on digital twin technology, mainly including the following:
(1) For the electro-hydrostatic actuator, we study the coupling model of motor control, electrical and thermal; we study the pump-cylinder part of the electro-hydrostatic actuator, and establish its flow field and thermal field. A multiphysics model of the actuator is established and its performance is verified by simulations.
(2) Regarding the hydraulic actuator, the flow field and thermal model are studied. For the dissimilar redundant actuation system, the active/active operation mode is adopted, and the multiphysics model is established based on the comprehensive output mode of mechanical force.
(3) A digital twin modeling framework of the actuation system and a corresponding model are proposed. While the full technical state is known, the parameters are dynamically updated based on the gradient descent algorithm, so that the model output can follow the actual output.
(4) Based on the 3D mode in Unity, perform a three-dimensional dynamic demonstration of the simulation data in the digital space.
The research activity reported in this thesis has been carried out under the supervision of Professor Shaoping Wang at Beihang University within the framework of the double Ms.c. degree programme in Electrical Engineering between Beihang University and Politecnico di Milano
First person – Yihua Wang
No full textFirst Person is a series of interviews with the first authors of a selection of papers published in Journal of Cell Science, helping early-career researchers promote themselves alongside their papers. Yihua Wang is the first author on ‘Nuclear entry and export of FIH are mediated by HIF1α and exportin1, respectively’, published in Journal of Cell Science. Yihua is a Lecturer in Biological Sciences at the University of Southampton, studying cell signalling in lung fibrosis and cancer, drug target validation and gene function analysis
Research on terrain perception for exoskeleton robot
No full textLAUREA MAGISTRALELa percezione di scene di campo complesse è una funzione importante per i robot di esoscheletro per eseguire operazioni sul campo. Al momento, la maggior parte delle applicazioni di robot di esoscheletro sta completando funzioni specifiche in priori o scene semplici. È difficile completare le applicazioni di interazione umana-computer in scene complesse sconosciute, poiché una ragione importante è la mancanza di capacità generale di percezione del terreno autonomo. Come migliorare questa capacità in modo da espandere l'applicazione di interazione umana-computer di esoscheletro, è una direzione di ricerca.
Questo documento studia il robot di esoscheletro dell'arto inferiore che lavora in scene di campo complesse. È difficile per gli utenti giudicare se determinate scene sono sicure e attraversabili solo attraverso l'esperienza umana. Se dotati di telecamere binoculari che sono facilmente montate su dispositivi mobili, le informazioni quantitative del terreno possono essere ottenute da algoritmi di visione artificiale. Sulla base di questo, questo studio svolge principalmente il seguente lavoro.
Per l'acquisizione delle informazioni di profondità, la mappa della disparità viene stimata prima in base alle immagini binoculari, quindi viene stabilita la nuvola di punti 3D del modello del terreno anteriore. Considerando l'effetto di abbinamento e l'efficienza del tempo, viene utilizzato e migliorato l'algoritmo di abbinamento semi-globale. Nella fase di calcolo dei costi, il coefficiente di penalità è impostato in base alle informazioni sulla trama e vengono esplorati il percorso di aggregazione dei costi ottimale e lo spazio di ricerca della disparità. Nella fase di correzione della disparità, la disparità viene colmata e diversi metodi di filtraggio. Il metodo migliorato esegue un migliore effetto di abbinamento. Quindi, vari metodi vengono utilizzati per ottimizzare il modello del terreno.
Per la percezione del terreno in avanti, il problema della percezione è definito come determinazione della traversabilità e stimare i parametri geometrici. Per l'identificazione della regione attraversabile, viene proposto un metodo basato su algoritmo di coltivazione della regione migliorato e vincoli geometrici. Per l'identificazione di ostacoli, viene proposto un metodo basato sul clustering di cloud point e sull'algoritmo della scatola di delimitazione.
Al fine di verificare l'efficacia e l'universalità dei metodi proposti, l'esperimento di percezione del terreno viene condotto per raccogliere dati e fare esperimento in vari scenari. I risultati della percezione visiva forniscono agli utenti la base per le successive decisioni soggettive e calcoli dei parametri del controller, forniscono quindi soluzioni per l'interazione da uomo-computer.
L'attività di ricerca riportata in questa tesi è stata svolta sotto la supervisione della Professoressa Shaoping Wang presso l’Università Beihang nell'ambito del programma di doppia laurea magistrale in Ingegneria Elettrica tra l’Università Beihang e il Politecnico di Milano.The perception of complex field scenes is an important function for exoskeleton robots to perform field operations. At present, most of the exoskeleton robots applications are completing specific functions in priori or simple scenes. It is difficult to complete human-computer interaction applications in unknown complex scenes, since one important reason is the lack of general autonomous terrain perception ability. How to improve this ability so as to expand the human-computer interaction application of exoskeleton, is a research direction.
This thesis studies on the individual lower limb exoskeleton robot working in complex field scenes. It is difficult for users to judge whether certain scenes are safe and traversable only through human experience. If equipped with binocular cameras that are easily mounted on mobile devices, quantitative terrain information can be obtained by computer vision algorithms. Based on this, this study mainly does the following work.
For the depth information acquisition, the disparity map is estimated first based on binocular images, and then the 3D point cloud of the front terrain model is established. Considering the matching effect and time efficiency, the Semi-global Matching algorithm is used and improved. In cost calculation stage, the penalty coefficient is set based on texture information, and the optimal cost aggregation path and disparity search space are explored. In disparity correction stage, the disparity is filled and several filtering methods. Improved method performs better matching effect. Then, various methods are used to optimize the terrain model.
For the forward terrain perception, the perception problem is defined as determining the traversability and estimating geometric parameters. For the traversable region identification, a method based on improved region growing algorithm and geometric constraints is proposed. For the identification of obstacles, a method based on point cloud clustering and bounding box algorithm is proposed.
In order to verify the effectiveness and universality of the proposed methods, the terrain perception experiment is carried out to collect data and do experiment in various scenarios. Visual perception results provide users with the basis for subsequent subjective decisions and controller parameters calculation, thus provide solutions for human-computer interaction.
The research activity reported in this thesis has been carried out under the supervision of Professor Shaoping Wang at Beihang University within the framework of the double Ms.c. degree programme in Electrical Engineering between Beihang University and Politecnico di Milano
Digital twin-based health service framework and its application in permanent magnet synchronous motors
No full textDesign and Dynamic Analysis of a Bio-Inspired Rolling Joint Manipulator Based on Pulley-Cable System
No full textCable-driven joints have gained widespread use in various applications, yet the inherent limitations in cable stiffness and strength pose challenges in ensuring joint stability and operational safety. Enhancing joint stiffness and predicting cable tension changes during motion are essential to mitigate the risk of cable breakage. This article presents the design of a novel bio-inspired rolling joint manipulator, featuring a single-motor-driven pulley transmission system with symmetrical tension amplification. A novel cable winding drive mechanism with integrated tension detection is proposed. The tension distribution across the pulley system is analyzed via the classic Euler equation. A comprehensive system model is established, spanning from the motor-driven winch, through the guide pulleys, to the load-bearing tension amplification pulley. By incorporating the derived tension distribution into the kinematic and dynamic equations of the joint, the model accurately predicts how cable tension evolves during joint movement. The theoretical formulations and tension distribution are validated through both software simulations and prototype experiments, demonstrating high consistency. The results confirm that the dynamic model proposed in this article is more accurate and comprehensive, considering friction and tension transmission
sj-xls-1-tih-10.1177_07482337221081206 – Supplemental Material for 2,2′,4,4′-Tetrabromodiphenyl ether disrupts spermatogenesis in mice by interfering with the ER-Nrf1-Tfam-mitochondria pathway
No full textSupplemental Material, sj-xls-1-tih-10.1177_07482337221081206 for 2,2′,4,4′-Tetrabromodiphenyl ether disrupts spermatogenesis in mice by interfering with the ER-Nrf1-Tfam-mitochondria pathway by Shaoping Huang, Jiangyan Xia, Xinxin Zhang, Tao Zhou, Jing Wang, Tong Liu, Siyi Xu, and Geyu Liang in Toxicology and Industrial Health</p
Locheutis pingxiangensis Wang & Tao 2021, sp. nov.
No full textLocheutis pingxiangensis Wang, sp. nov. (Figs 4, 9) urn:lsid:zoobank.org:act: 2E76B763-62D5-4B80-A10A-7CC0298DD0C2 Type material. CHINA, Guangxi: Holotype ♂, Shaoping Forest Farm, Pingxiang, 190 m, 26.VII.2012, leg. BB Hu et al., slide No. TZL19689. Paratypes: 2♂, Shaoping Forest Farm, Pingxiang, 280 m, 15–19.IV.2012, leg. XF Yang, slide No. TZL19693; 1♂, Shaoping Forest Farm, Fingxiang, 280 m, 14.IV.2013, leg. XF Yang, Slide No. TZL19694. Diagnosis. The new species can be distinguished from its congeners by the costal part of the valva with an apical spine directed ventrad, the saccular part of the valva with a spine beyond basal 2/3 on the dorsal margin, the vase-shaped juxta and the aedeagus with a cluster of fine spines distally. Description. Adult (Fig. 4). Wingspan 17.0– 17.5 mm. Head shining fuscous, with purplish shine laterally. Antenna with scape blackish brown, with a longitudinal streak along midline dorsally, with yellow scales on ventral surface; flagellum yellow, ringed with brown on dorsal surface. Labial palpus with second palpomere blackish brown, tinged with yellow on inner surface; third palpomere black basally, yellow mixed with black scales distally. Thorax yellowish brown; tegula pale purple basally, pale yellow distally. Forewing yellow, mixed with brown scales, denser between fold and dorsum basally as well as between subterminal fascia and terminal margin; costal margin black basally, forming a large basal patch; discal, discocellular and plical spots blackish brown, discal spot smallest, discocellular spot transversely narrow, sub-rectangular; tornal spot represent by scattered blackish brown scales; subterminal fascia yellowish brown, from distal 1/4 of costal margin sinuate to tornus; terminal dots blackish brown, extending from preapex along termen to tornus; fringe brownish yellow basally, yellow distally. Hindwing and fringe yellowish brown. Fore- and midlegs dark brown on dorsal surface, yellow on ventral surface; hindleg with femur whitish yellow on ventral surface, blackish brown on dorsal surface, tibia yellow on dorsal surface, blackish brown on ventral surface, tarsus dark brown on outer surface except yellow at apex of each tarsomere, yellow mixed with brown on inner surface; spurs yellow on dorsal surface, dark brown on ventral surface. Male genitalia (Fig. 9): Tegumen arched, lateral part broad. Gnathos widely banded, slightly produced posteromedially. Costal part of valva wide at base, gradually narrowed to apex, curved before apex; apex rounded, with a spine-shaped process directed ventrad almost at a right angle; costal margin with a narrow sclerotized flap basally; saccular part of valva with basal half uniformly narrow, widened from middle to beyond basal 2/3, thereafter triangularly narrowed to pointed apex; dorsal margin with a spine beyond basal 2/3, finely serrate from this spine to apex; ventral margin smooth. Juxta weakly sclerotized, vase-like; anterior margin sclerotized, with a notch in middle; median portion broadened, roundly arched outward laterally; distal 2/5 digitate. Aedeagus straight, slightly shorter than saccular part of valva, with a cluster of fine spines distally (Fig. 9a); cornuti consisting of a bundle of easily shed long spines. Female unknown. Distribution: China (Guangxi). Etymology. The specific epithet is derived from the type locality of the species (Pingxiang).Published as part of Wang, Shuxia & Tao, Zhulin, 2021, The genus Locheutis Meyrick (Lepidoptera: Oecophoridae) from the Palaearctic and Oriental regions, with descriptions of four new species, pp. 561-570 in Zootaxa 4952 (3) on page 566, DOI: 10.11646/zootaxa.4952.3.8, http://zenodo.org/record/469068
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