1,661 research outputs found

    Static Balancing Control of Humanoid Robot based on Accelerometer

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    [[abstract]]A static balancing control method is proposed and implemented on a humanoid robot so that the robot can stand and balance on a plane. A small-size humanoid robot named TWNHR-IV with 26 degree-of-freedom (DOF) is implemented. A 3-axis accelerometer is installed on TWNHR-IV to obtain the x-axis, y-axis, and z-axis accelerations of TWNHR-IV. Based on the obtained information from the 3-axis accelerometer, a system structure with two two-input-and-one-output fuzzy systems is proposed. The acceleration and the accelerationpsilas variation of the x-axis obtained by the 3-axis accelerometer are considered to be the inputs of forward-and-backward fuzzy system. The acceleration and the accelerationpsilas variation of the y-axis are considered to be the inputs of right-and-left fuzzy system. Some practical tests are presented to illustrate the proposed method can let the humanoid robot stand and balance on a plane.[[conferencetype]]國際[[conferencelocation]]Tokyo, Japa

    Experimental investigation on shock wave diffraction over sharp and curved splitters

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    Shock wave diffraction occurs when a normal travelling wave passes through a sudden area expansion. Turbulent, compressible, and vortical are the characterising adjectives that describe the flow features, which are slowly smeared out due to the dissipative nature of turbulence. The study of this phenomenon provides insight into several flow structures such as shear layer formation, vortex development, and vortex/shock interaction whose applications include noise control, propulsion or wing aerodynamics. A large amount of research has been carried out in the analysis of shock wave diffraction mainly around sharp wedges, but only few studies have considered rounded corners. This project has the aim to examine and compare the flow features which develop around three different geometries, ramp, symmetric and rounded, with experimental incident shock Mach numbers of 1.31 and 1.59, and Reynolds numbers of 1.08×106 and 1.68×106. Schlieren photography is used to obtain qualitative information about the evolution of the flow field. The results show that ramp and symmetrical wedges with a tip angle of 172° behave in the same manner, which exhibit clear dissimilarities with a curved corner. The flow field evolves more rapidly for a higher incoming Mach number which is also responsible for the development of stronger structures

    Strength Degradation of Glass Fiber Reinforced Polymer Bars Subjected to Reversed Cyclic Load

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    Glass fiber reinforced polymer (GFRP) due to its corrosion resistance is gaining popularity in the civil engineering community, as an alternative material to steel reinforcement. GFRP reinforced bar (rebar) has a high tensile strength with moderate elastic modulus and is elastic up to failure. However, it should not be treated in the same way as steel rebar because the interfacial bond behavior of GFRP bars to concrete is expected to vary from that of conventional steel bars, since various parameters that influence bond performance are different. This paper presents the results of an experimental and analytical studies on the bond strength of glass fiber reinforced polymer bars subjected to monotonic or reversed cyclic loads. The experimental program consisted of 30 test specimens. The test results indicated that the interfacial strength of the GFRP bars was quite different to that of the steel bars. In addition, the strength degradation of GFRP bars subjected to reversed cyclic load was more severe than that of the GFRP bars subjected to a monotonic load.Полимеры, армированные стекловолокном, имеют повышенную коррозионную стойкость, по-этому используются в строительстве в качестве альтернативы стальной арматуре. Арматурный стержень, армированный стекловолокном, обладает высоким пределом прочности при растяжении, средним модулем упругости и упругим поведением вплоть до разрушения. При расчете данного стержня необходимо использовать нетрадиционный подход, поскольку предполагается, что связь на границе раздела между арматурным стержнем, армированным стекловолокном, и бетоном отличается от таковой для традиционных стальных стержней, так как параметры, оказывающие влияние на прочностную характеристику, имеют разные значения. Представлены результаты экспериментальных и аналитических исследований по оценке прочности связи полимерных стержней, армированных стекловолокном, при монотонной или циклической переменной нагрузке. Для экспериментальных исследований использовали 30 образцов. Установлено, что значения прочности при сдвиге по поверхности раздела для полимерных стержней, армированных стекловолокном, отличаются от таковых для стальных стержней. Процесс разупрочнения полимерных стержней, армированных стекловолокном, при циклической переменной нагрузке более жесткий, чем при монотонной нагрузке.Полімери, армовані скловолокном, мають підвищену корозійну стійкість, тому використовуються на будівництві як альтернатива стальній арматурі. Арматурний стрижень, армований скловолокном, має високу границю міцності при розтязі, середній модуль пружності і пружну поведінку майже до руйнування. Для розрахунку даного стрижня необхідно використовувати нетрадиційний підхід, оскільки припускається, що зв’язок на границі поділу між арматурним стрижнем, армованим скловолокном, і бетоном відрізняється від такого для традиційних стальних стрижнів, оскільки параметри, що мають вплив на міцнісну характеристику, мають різні значення. Представлено результати експериментальних і аналітичних досліджень щодо оцінки міцності зв’язку полімерних стрижнів, армованих скловолокном, за монотонного або циклічного змінного навантаження. Для експериментальних випробувань використовували 30 зразків. Установлено, що значення міцності при зсуві по поверхні поділу для полімерних стрижнів, армованих скловолокном, відрізняються від таких для стальних. Процес знеміцнення полімерних стрижнів, армованих скловолокном, під час циклічного змінного навантаження більш жорсткий, аніж за монотонного навантаження

    Cryptococcal Meningoencephalitis Presenting as Cerebell itis - A case report -

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    , , We herein report an elderly patient with cryptococcosis in the nervous system who presented with cerebellar dysfunction and showed cerebellar parenchymal lesion with adjacent focal meningeal enhancement on the brain CT and the serial brain MRls. The cerebellar lesion suggests cryptococcal inflammatory reaction or a cerebellar infarction from the arteritis of a branch of the left superior cerebellar artery. This clinical and neuroimaging finding of cerebellitis has not been reported in cryptococcosis. We think cryptococcosis would be included in the differential diagnosis of cerebellitis

    Search for Small Trans-Neptunian Objects by the TAOS Project

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    The Taiwan-America Occultation Survey (TAOS) aims to determine the number of small icy bodies in the outer reach of the Solar System by means of stellar occultation. An array of 4 robotic small (D=0.5 m), wide-field (f/1.9) telescopes have been installed at Lulin Observatory in Taiwan to simultaneously monitor some thousand of stars for such rare occultation events. Because a typical occultation event by a TNO a few km across will last for only a fraction of a second, fast photometry is necessary. A special CCD readout scheme has been devised to allow for stellar photometry taken a few times per second. Effective analysis pipelines have been developed to process stellar light curves and to correlate any possible flux changes among all telescopes. A few billion photometric measurements have been collected since the routine survey began in early 2005. Our preliminary result of a very low detection rate suggests a deficit of small TNOs down to a few km size, consistent with the extrapolation of some recent studies of larger (30--100 km) TNOs.Comment: 4 pages, 3 figures, IAU Symposium 23

    Measurement of the Cross Sections and Analyzing Powers for Transitions in 58-Ni Using 200 MeV Proton Scattering

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    This research was sponsored by the National Science Foundation Grant NSF PHY-931478

    Distribution and inter-regional relationship of amyloid-beta plaque deposition in a 5xFAD mouse model of Alzheimer’s disease

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    Alzheimer’s disease (AD) is the most common form of dementia. Although previous studies have selectively investigated the localization of amyloid-beta (Aβ) deposition in certain brain regions, a comprehensive characterization of the rostro-caudal distribution of Aβ plaques in the brain and their inter-regional correlation remain unexplored. Our results demonstrated remarkable working and spatial memory deficits in 9-month-old 5xFAD mice compared to wildtype mice. High Aβ plaque load was detected in the somatosensory cortex, piriform cortex, thalamus, and dorsal/ventral hippocampus; moderate levels of Aβ plaques were observed in the motor cortex, orbital cortex, visual cortex, and retrosplenial dysgranular cortex; and low levels of Aβ plaques were located in the amygdala, and the cerebellum; but no Aβ plaques were found in the hypothalamus, raphe nuclei, vestibular nucleus, and cuneate nucleus. Interestingly, the deposition of Aβ plaques was positively associated with brain inter-regions including the prefrontal cortex, somatosensory cortex, medial amygdala, thalamus, and the hippocampus. In conclusion, this study provides a comprehensive morphological profile of Aβ deposition in the brain and its inter-regional correlation. This suggests an association between Aβ plaque deposition and specific brain regions in AD pathogenesis

    A reduction of unilateral ureteral obstruction-induced renal fibrosis by a therapy combining valsartan with aliskiren

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    Wu WP, Chang CH, Chiu YT, Ku CL, Wen MC, Shu KH, Wu MJ. A reduction of unilateral ureteral obstruction-induced renal fibrosis by a therapy combining valsartan with aliskiren. Am J Physiol Renal Physiol 299: F929-F941, 2010. First published August 4, 2010; doi:10.1152/ajprenal.00192.2010.-The protective effect of combination therapy with valsartan and aliskiren against renal fibrosis remains to be defined. This study was undertaken to examine the protective effects of the combination of valsartan and aliskiren against renal fibrosis induced by unilateral ureteral obstruction (UUO). Combination therapy with valsartan (15 mg . kg(-1) . day(-1)) and aliskiren (10 mg . kg(-1) . day(-1)), valsartan monotherapy (30 mg . kg(-1) . day(-1)), and aliskiren monotherapy (20 mg . kg(-1) . day(-1)) all significantly ameliorated the increase in blood urea nitrogen and the degree of hydronephrosis determined by the increase in weight and length of the obstructed kidney. The dose titration study and blood pressure measurement confirmed that the combination therapy provided a greater benefit independent of the vasodilatory effect. There were no significant changes in serum levels of creatinine, sodium, and potassium in UUO rats and any treatment groups. Combination therapy also attenuated UUO-related increases in the scores of tubular dilatation, interstitial volume, interstitial collagen deposition, alpha-smooth muscle actin, the activation of ERK 1/2, the infiltration of monocytes/macrophages, the mRNA expression of snail-1, and transforming growth factor-beta 1 to a greater extent compared with aliskiren or valsartan used alone. The mRNA expression of renin and the (pro) renin receptor significantly increased after UUO. Combination therapy and monotherapy of valsartan and aliskiren had a comparable enhancing effect on the mRNA expression of renin, whereas all these treatments did not affect the expression of the (pro) renin receptor. In conclusion, a direct renin inhibitor in conjunction with an angiotensin II receptor blocker exerts increased renal protection against renal fibrosis and inflammation during obstruction over either agent alone
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