148 research outputs found

    Type-2 Fuzzy Hybrid Controller Network for Robotic Systems

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    Dynamic control, including robotic control, faces both the theoretical challenge of obtaining accurate system models and the practical difficulty of defining uncertain system bounds. To facilitate such challenges, this paper proposes a control system consisting of a novel type of fuzzy neural network and a robust compensator controller. The new fuzzy neural network is implemented by integrating a number of key components embedded in a Type-2 fuzzy cerebellar model articulation controller (CMAC) and a brain emotional learning controller (BELC) network, thereby mimicking an ideal sliding mode controller. The system inputs are fed into the neural network through a Type-2 fuzzy inference system (T2FIS), with the results subsequently piped into sensory and emotional channels which jointly produce the final outputs of the network. That is, the proposed network estimates the nonlinear equations representing the ideal sliding mode controllers using a powerful compensator controller with the support of T2FIS and BELC, guaranteeing robust tracking of the dynamics of the controlled systems. The adaptive dynamic tuning laws of the network are developed by exploiting the popular brain emotional learning rule and the Lyapunov function. The proposed system was applied to a robot manipulator and a mobile robot, demonstrating its efficacy and potential; and a comparative study with alternatives indicates a significant improvement by the proposed system in performing the intelligent dynamic control

    Use of human gestures for controlling a mobile robot via adaptive CMAC network and fuzzy logic controller

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    Mobile robots with manipulators have been more and more commonly applied in extreme and hostile environments to assist or even replace human operators for complex tasks. In addition to autonomous abilities, mobile robots need to facilitate the human–robot interaction control mode that enables human users to easily control or collaborate with robots. This paper proposes a system which uses human gestures to control an autonomous mobile robot integrating a manipulator and a video surveillance platform. A human user can control the mobile robot just as one drives an actual vehicle in the vehicle’s driving cab. The proposed system obtains human’s skeleton joints information using a motion sensing input device, which is then recognized and interpreted into a set of control commands. This is implemented, based on the availability of training data set and requirement of in-time performance, by an adaptive cerebellar model articulation controller neural network, a finite state machine, a fuzzy controller and purposely designed gesture recognition and control command generation systems. These algorithms work together implement the steering and velocity control of the mobile robot in real-time. The experimental results demonstrate that the proposed approach is able to conveniently control a mobile robot using virtual driving method, with smooth manoeuvring trajectories in various speeds

    Methylation status of individual CpG sites within Alu elements in the human genome and Alu hypomethylation in gastric carcinomas

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    <p>Abstract</p> <p>Background</p> <p><it>Alu </it>methylation is correlated with the overall level of DNA methylation and recombination activity of the genome. However, the maintenance and methylation status of each CpG site within <it>Alu </it>elements (<it>Alu</it>) and its methylation status have not well characterized. This information is useful for understanding natural status of <it>Alu </it>in the genome and helpful for developing an optimal assay to quantify <it>Alu </it>hypomethylation.</p> <p>Methods</p> <p>Bisulfite clone sequencing was carried out in 14 human gastric samples initially. A <it>Cac</it>8I COBRA-DHPLC assay was developed to detect methylated-<it>Alu </it>proportion in cell lines and 48 paired gastric carcinomas and 55 gastritis samples. DHPLC data were statistically interpreted using SPSS version 16.0.</p> <p>Results</p> <p>From the results of 427 <it>Alu </it>bisulfite clone sequences, we found that only 27.2% of CpG sites within <it>Alu </it>elements were preserved (4.6 of 17 analyzed CpGs, A ~ Q) and that 86.6% of remaining-CpGs were methylated. Deamination was the main reason for low preservation of methylation targets. A high correlation coefficient of methylation was observed between <it>Alu </it>clones and CpG site J (0.963), A (0.950), H (0.946), D (0.945). Comethylation of the sites H and J were used as an indicator of the proportion of methylated-<it>Alu </it>in a <it>Cac</it>8I COBRA-DHPLC assay. Validation studies showed that hypermethylation or hypomethylation of <it>Alu </it>elements in human cell lines could be detected sensitively by the assay after treatment with 5-aza-dC and M.<it>Sss</it>I, respectively. The proportion of methylated-<it>Alu </it>copies in gastric carcinomas (3.01%) was significantly lower than that in the corresponding normal samples (3.19%) and gastritis biopsies (3.23%).</p> <p>Conclusions</p> <p>Most <it>Alu </it>CpG sites are deaminated in the genome. 27% of <it>Alu </it>CpG sites represented in our amplification products. 87% of the remaining CpG sites are methylated. <it>Alu </it>hypomethylation in primary gastric carcinomas could be detected with the <it>Cac</it>8I COBRA-DHPLC assay quantitatively.</p

    Non-sterile fermentation of food waste using thermophilic and alkaliphilic Bacillus licheniformis YNP5-TSU for 2,3-butanediol production

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    Conversion of food waste into 2,3-butanediol (2,3-BDO) via microbial fermentation provides a promising way to reduce waste disposal to landfills and produce sustainable chemicals. However, sterilization of food waste, an energy- and capital-costly process, is generally required before fermentation to avoid any contamination, which reduces the energy net output and economic feasibility of food waste fermentation. In this study, we investigated the non-sterile fermentation of food waste to produce 2,3-BDO using a newly isolated thermophilic and alkaliphilic B. licheniformis YNP5-TSU. Three unitary food waste samples (i.e., pepper, pineapple, cabbage wastes) and one miscellaneous food waste mixture were respectively inoculated with B. licheniformis YNP5-TSU under non-sterile conditions. At 50 °C and an initial pH of 9.0, B. licheniformis YNP5-TSU was able to consume all sugars in food waste and produce 5.2, 5.9, 5.9 and 4.3 g/L of 2,3-BDO within 24 h from pepper, pineapple, cabbage and miscellaneous wastes, respectively, corresponding to a yield of 0.40, 0.38, 0.41 and 0.41 g 2,3-BDO/g sugar. These 2,3-BDO concentrations and yields from the non-sterile fermentations were comparable to those from the traditional sterile fermentations, which produced 4.0–6.8 g/L of 2,3-BDO with yields of 0.31–0.48 g 2,3-BDO/g sugar. Moreover, B. licheniformis was able to ferment various food wastes (pepper, pineapple and miscellaneous wastes) without any external nutrient addition and produce similar 2,3-BDO quantities. The non-sterile fermentation of food waste using novel thermophilic and alkaliphilic B. licheniformis YNP5-TSU provides a robust and energy-efficient approach to convert food waste to high-value chemicals

    Visual-Guided Robotic Object Grasping Using Dual Neural Network Controllers

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    It has been a challenging task for a robotic arm to accurately reach and grasp objects, which has drawn much research attention. This article proposes a robotic hand–eye coordination system by simulating the human behavior pattern to achieve a fast and robust reaching ability. This is achieved by two neural-network-based controllers, including a rough reaching movement controller implemented by a pretrained radial basis function for rough reaching movements, and a correction movement controller built from a specifically designed brain emotional nesting network (BENN) for smooth correction movements. In particular, the proposed BENN is designed with high nonlinear mapping ability, with its adaptive laws derived from the Lyapunov stability theorem; from this, the robust tracking performance and accordingly the stability of the proposed control system are guaranteed by the utilization of the H∞ control approach. The proposed BENN is validated and evaluated by a chaos synchronization simulation, and the overall control system by object grasping tasks through a physical robotic arm in a real-world environment. The experimental results demonstrate the superiority of the proposed control system in reference to those with single neural networks

    Cloning and Expression of Human Norovirus GI.5 and GII.4 P Proteins and Their Binding Characteristics with Histo-Blood Group Antigens-like Substances in Pacific Oysters

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    To clarify the binding characteristics of human norovirus (HuNoV) with histo-blood group antigens (HBGAs)-like substances from Pacific oysters, this study used an Escherichia coli expression system to clone and express HuNoV GI.5 and GII.4 P proteins, and analyzed the binding characteristics of HuNoV P proteins with salivary HBGAs and HBGAs-like substances from Pacific oysters using enzyme-linked immunosorbent assay. The results showed that HuNoV GII.4 exhibited good binding characteristics with blood type A, B, AB, and O salivary HBGAs, while GI.5 HuNoV exhibited weak binding characteristics with blood type B salivary HBGAs but had significant advantage in binding with type O salivary HBGAs. HuNoV GI.5 and GII.4 could be bioaccumulated in the gills, digestive gland, and mantle of Pacific oysters, with the highest bioaccumulation in the digestive gland. Both types of HuNoV were mainly bound to type A and H1 HBGAs-like substances; HuNoV GII.4 had different degrees of binding with type Lea, Leb, Lex, and Ley HBGAs-like substances, while HuNoV GI.5 had weak binding with type Leb HBGAs-like substances but significant advantage in binding with type H1 HBGAs-like substances. In summary, different types of HuNoV have different binding characteristics with HBGAs or HBGAs-like substances. Specifically, HuNoV GII.4 shows broad-spectrum binding characteristics whereas HuNoV GI.5 shows selective binding characteristics

    P16 Methylation as an Early Predictor for Cancer Development From Oral Epithelial Dysplasia: A Double-blind Multicentre Prospective Study

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    AbstractBackgroundSilencing of P16 through methylation and locus deletion is the most frequent early events in carcinogenesis. The aim of this study is to prospectively determine if early P16 methylation is a predictor for oral cancer development.MethodsPatients (n=181) with mild or moderate oral epithelial dysplasia (OED) were recruited into the double blind multicentre cohort. P16 methylation was analyzed using the MethyLight assay. Progression of OEDs was monitored for a minimum 3year follow-up period.FindingsP16 methylation-informative cases (n=152) were enrolled in the prospective multicenter cohorts with an ultimate compliance of 96.7%. OED-derived squamous cell carcinomas were observed in 21 patients (14.3%) during the follow-up (median, 41.0months). The cancer progression rate from the P16 methylation-positive patients was significantly increased when compared to P16 methylation-negative patients [27.1% vs 8.1%; adjusted odds ratio=4.6; P=0.006]. When the P16 methylation-positive criteria were used as a biomarker for early prediction of cancer development from OEDs, sensitivity and specificity of 62% and 76% were obtained, respectively.InterpretationP16 methylation is unequivocally a marker for determining the malignant potential of OED and there is no need for further research regarding this aspect.FundingNational Basic Research Programs of China (2011CB504201 and 2015CB553902), Beijing Science and Technology Commission (Z090507017709016), and Beijing Municipal Administration of Hospital (XM201303) to Dajun Deng. The funding agencies have no role in the actual experimental design, patient recruitment, data collection, analysis, interpretation, or writing of this manuscript

    Prevalence of A2143G mutation of H. pylori-23S rRNA in Chinese subjects with and without clarithromycin use history

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    <p>Abstract</p> <p>Background</p> <p>A2143G mutation of <it>23S rRNA </it>gene of <it>H. pylori </it>results in clarithromycin (CLR) resistance. To investigate the prevalence of the CLR resistance-related A2143G mutation of the <it>H. pylori</it>-specific <it>23S rRNA </it>gene in Chinese subjects with and without CLR use history, 307 subjects received the treatment with amoxicillin and omeprazole (OA) and 310 subjects received a placebo in 1995, and 153 subjects received a triple therapy with OA and CLR (OAC) in 2000. DNA was extracted from fasting gastric juice at the end of the intervention trial in 2003. <it>H. pylori </it>infection was determined by <it>H. pylori</it>-specific <it>23S rRNA </it>PCR, ELISA, and<sup>13</sup>C-urea breath test assays. Mutations of the <it>23S rRNA </it>gene were detected by RFLP assays.</p> <p>Results</p> <p>The presence of <it>23S rRNA </it>due to <it>H. pylori </it>infection in the OA group remained lower than that in the placebo group 7.3 yrs after OA-therapy [51.1% (157/307) vs. 83.9% (260/310), p = 0.0000]. In the OAC group, the <it>23S rRNA </it>detection rate was 26.8% (41/153) three yrs after OAC-treatment. The A2143G mutation rate among the <it>23S rRNA</it>-positive subjects in the OAC group [31.7% (13/41)] was significantly higher than that in the OA group [10.2% (16/157)] and the placebo group [13.8% (36/260)]. The frequency of the AAGGG → CTTCA (2222–2226) and AACC → GAAG (2081–2084) sequence alterations in the OAC group was also significantly higher than those in the OA group and the placebo group.</p> <p>Conclusion</p> <p>Primary prevalence of the A2143G mutation was 10~14% among Chinese population without history of CLR therapy. Administration of CLR to eliminate <it>H. pylori </it>infection increased the prevalence of the A2143G mutation in Chinese subjects (32%) significantly.</p
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