Trajectory Tracking Control of Parallel Manipulator with Integral Manifold and Observer

In view of the problem that notable flexible displacement will occur for parallel manipulators when operating at high speed, the composite controller based on the integral manifold and high-gain observer is proposed for trajectory tracking and the 3RRR parallel manipulator is taken as the object. Based on the stiffness matrix, the small variable is introduced to decompose the rigid-flexible coupling dynamic model into slow and fast subsystem. For the slow subsystem, the backstepping control is applied for rigid motion tracking. In order to account for the links’ flexible displacement the corrective torque is deduced, and the compensation for the flexible displacement is realized. For the fast subsystem, the sliding mode control is utilized to suppress the vibration. The high-gain observer is designed to avoid the measurement of the curvature rate of flexible links. Also, the stability of the overall system is proven with the Lyapunov stability theorem and the upper bound of the small variable is obtained. At last, the proposed composite controller together with the singular perturbation control and the rigid body model-based backstepping control are simulated, and vibration suppression and tracking performances are compared to validate the proposed control scheme

Genetic heterogeneity of pseudoxanthoma elasticum: the Chinese signature profile of ABCC6 and ENPP1 mutations.

Pseudoxanthoma elasticum (PXE), an autosomal recessive disorder characterized by ectopic mineralization, is caused by mutations in the ABCC6 gene. We examined clinically 29 Chinese PXE patients from unrelated families, so far the largest cohort of Asian PXE patients. In a subset of 22 patients, we sequenced ABCC6 and another candidate gene, ENPP1, and conducted pathogenicity analyses for each variant. We identified a total of 17 distinct mutations in ABCC6, 15 of them being, to our knowledge, previously unreported, including 5 frameshift and 10 missense variants. In addition, a missense mutation in combination with a recurrent nonsense mutation in ENPP1 was discovered in a pediatric PXE case. No cases with p.R1141X or del23-29 mutations, common in Caucasian patient populations, were identified. The 10 missense mutations in ABCC6 were expressed in the mouse liver via hydrodynamic tail-vein injections. One mutant protein showed cytoplasmic accumulation indicating abnormal subcellular trafficking, while the other nine mutants showed correct plasma membrane location. These nine mutations were further investigated for their pathogenicity using a recently developed zebrafish mRNA rescue assay. Minimal rescue of the morpholino-induced phenotype was achieved with eight of the nine mutant human ABCC6 mRNAs tested, implying pathogenicity. This study demonstrates that the Chinese PXE population harbors unique ABCC6 mutations. These genetic data have implications for allele-specific therapy currently being developed for PXE

Randomly Generating the 3D Mesostructure of Soil Rock Mixtures Based on the Full In Situ Digital Image Processed Information

Understanding the occurrence and evolution of geological disasters, such as landslides and debris flows, is facilitated by research on the performance of soil rock mixes (SRM). Recently, more and more researchers have been interested in studying the mesostructure reconstruction process of SRM. The present mesostructure generation approaches, however, have several weaknesses. One of the weaknesses is that they do not consider the impact of particle shape and therefore cannot ensure similarity to the in situ SRMs. In this study, a new mesostructure generation method that randomly generates SRMs based on the full in situ digital image processing (DIP) information is proposed. The generation procedure of the proposed algorithm considers the geometry characteristics of in situ SRMs, including the size distribution, particle shape, and 2D fractal dimension of the cross-section. A parametric study was performed to examine how the rock content and particle shape affected the fractal dimension of the generated SRMs. The results indicate that as the rock content increases in intensity, the fractal dimension also increases. Only when the angular particle content is less than 75% does it affect the fractal dimension. The fractal dimension of the generated mesostructures increases with the increase in the angular particle proportion under the same rock content

Using a 1D FX Predictive Filter for 3D Seismic Data Random Noise Attenuation

Summary For some time now, FXY has been used as a standard algorithm for random noise attenuation on 3D seismic data. Recently, however, users noticed that, when signal/noise ratio is low, FXY is not as successful. In this paper, we will demonstrate that a series of 1D FKxY predictive filters is superior to the 2D FXY filter in the presence of significant random noise

Potential Risk Analysis of Tailings Dam Under Preloading Condition and Its Countermeasures

It is very important for mine production safety to ensure the stability of the tailings dam. Taking a flatland tailings pond as the background, a threedimensional computational model was built based on a tailings dam under mullock heap preloading condition. Considering the current operating water level conditions, a liquid-solid coupling analysis of the model was conducted.The deformation characteristics of the tailings dam were revealed during successive preloading at the front of the dam. The safety factor and the potential slide face of the tailings dam were calculated under different conditions using the strength reduction method. The results show that the tailings dam in its current condition is basically stable, but if the mullock heap continues to be heightened, the tailings dam will become unstable. Therefore, in order to limit the height of the mullock heap, establishing a monitor and early warning mechanism are put forward to ensure mine production safety

Slope Stability Analysis Considering Sliding Effect of Upper Body

Owing to the human engineering activities, the phenomenon that new landslide happen on the upper part of the old sliding body can be found everywhere. This kind of slope consisting of two sliding bodies, which are upper body and lower body, is named as double-sliding-body slope. Its stability is usually analyzed according to two slopes. However, the effect of new landslide movement on the stability of entire slope system is not taken into account. In this paper, sliding effect of upper body is analyzed, and the formula considering sliding effect of upper body is derived based on Sarma method for analysis of entire slope. Theoretical analysis and a case history indicate that the spasmodic motion of upper body has bad effect on the lower body stability; Sliding along the top face of lower body, the effect on the lower body is disadvantageous during starting instant. Nevertheless, the bad effect will disappear and transform as the advantageous effect as descending of the slope gradient and sliding acceleration. For the slope controlling, the sliding effect of upper body should be considered in the stability analysis of double-sliding-body slope, thus it will help us recognizing and mastering or forecasting the evaluative trend of double-siding-body slope. Further reliable scientific basis can be provided in order to make effective controlling measures.特集 : 「資源、新エネルギー、環境、防災研究国際セミナー

Augmented inhibition of angiogenesis by combination of HER2 antibody chA21 and trastuzumab in human ovarian carcinoma xenograft

<p>Abstract</p> <p>Background</p> <p>chA21 is a novel tumor-inhibitory antibody which recognized subdomain I of HER2 extracellular domain with an epitope distinct from other HER2 antibodies. Previously, we demonstrated that chA21 inhibits human ovarian carcinoma cell line SKOV-3 growth <it>in vitro </it>and <it>in vivo </it>study. In this study, we further investigated the anti-angiogenic efficacy combination of chA21 with trastuzumab in SKOV-3 xenograft model.</p> <p>Methods</p> <p>Nude mice were s.c. challenged with SKOV-3 cells and received treatment of chA21 alone, trastuzumab alone or both antibodies together twice a week for 21 days. Tumor volume and microvessel density (MVD) were evaluated. The effect of chA21 plus trastuzumab treament on vascular endothelial growth factor (VEGF) secretion, endothelial cells proliferation and migration, and the status of HER2 downstream pathway AKT/phosphorylated AKT (pAKT) were evaluated <it>in vitro</it>.</p> <p>Results</p> <p><it>In vivo </it>study combination of chA21 with trastuzumab resulted in reduce tumor growth and angiogenesis than each monotherapy. <it>In vitro </it>study, the combination of chA21 with trastuzumab inhibits VEGF secretion, endothelial cells proliferation and migration. Furthermore, the combination treatment inhibits pAKT expression.</p> <p>Conclusion</p> <p>Our findings suggested that the combination of chA21 with trastuzumab can cause augmented inhibition of angiogenesis in SKOV-3 xenograft model. Inhibition of agniogenesis may through suppression of AKT pathway. The therapeutic benefits of combination chA21 with trastuzumab warrant further study in an attempt to make the translation into the clinic.</p