Estimating the Lateral Motion States of an Underwater Robot by Propeller Wake Sensing Using an Artificial Lateral Line

An artificial lateral line (ALL) is a bioinspired flow sensing system of an underwater robot that consists of distributed flow sensors. The ALL has achieved great success in sensing the motion states of bioinspired underwater robots, e.g., robotic fish, that are driven by body undulation and/or tail flapping. However, the ALL has not been systematically tested and studied in the sensing of underwater robots driven by rotating propellers due to the highly dynamic and complex flow field therein. This paper makes a bold hypothesis that the distributed flow measurements sampled from the propeller wake flow, although infeasible to represent the entire flow dynamics, provides sufficient information for estimating the lateral motion states of the leader underwater robot. An experimental testbed is constructed to investigate the feasibility of such a state estimator which comprises a cylindrical ALL sensory system, a rotating leader propeller, and a water tank with a planar sliding guide. Specifically, a hybrid network that consists of a one-dimensional convolution network (1DCNN) and a bidirectional long short-term memory network (BiLSTM) is designed to extract the spatiotemporal features of the time series of distributed pressure measurements. A multi-output deep learning network is adopted to estimate the lateral motion states of the leader propeller. In addition, the state estimator is optimized using the whale optimization algorithm (WOA) considering the comprehensive estimation performance. Extensive experiments are conducted the results of which validate the proposed data-driven algorithm in estimating the motion states of the leader underwater robot by propeller wake sensing.Comment: 10 pages, 8 figure

Three-Dimensional Passive Source Localisation using the Flank Array of an Autonomous Underwater Vehicle in Shallow Water

Researchers have become interested in autonomous underwater vehicles equipped with various kinds of sonar systems that can perform many of underwater tasks, which is encouraged by the potential benefits of cost reduction and flexible deployment. This paper proposes an approach to three-dimensional passive source localisation with the flank array of an autonomous underwater vehicle in shallow water. The approach is developed based on matched-field processing for the likelihood of passive source localisation in the shallow water environment. Inter-position processing is also used for the improved localisation performance and the enhanced stability of the estimation process against the lack of spatial gain due to the small physical size of the flank array. The proposed approach is presented and validated through simulation and experimental data. The results illustrate the localisation performance at different signal-to-noise ratios and demonstrate the build up over time of the positional parameters of the estimated source as the autonomous underwater vehicle cruises at a low speed along a straight line at a constant depth.Defence Science Journal, 2013, 63(3), pp.323-330, DOI:http://dx.doi.org/10.14429/dsj.63.301

Identification of natural killer cell associated subtyping and gene signature to predict prognosis and drug sensitivity of lung adenocarcinoma

Introduction: This research explored the immune characteristics of natural killer (NK) cells in lung adenocarcinoma (LUAD) and their predictive role on patient survival and immunotherapy response.Material and methods: Molecular subtyping of LUAD samples was performed by evaluating NK cell-associated pathways and genes in The Cancer Genome Atlas (TCGA) dataset using consistent clustering. 12 programmed cell death (PCD) patterns were acquired from previous study. Riskscore prognostic models were constructed using Least absolute shrinkage and selection operator (Lasso) and Cox regression. The model stability was validated in Gene Expression Omnibus database (GEO).Results: We classified LUAD into three different molecular subgroups based on NK cell-related genes, with the worst prognosis in C1 patients and the optimal in C3. Homologous Recombination Defects, purity and ploidy, TMB, LOH, Aneuploidy Score, were the most high-expressed in C1 and the least expressed in C3. ImmuneScore was the highest in C3 type, suggesting greater immune infiltration in C3 subtype. C1 subtypes had higher TIDE scores, indicating that C1 subtypes may benefit less from immunotherapy. Generally, C3 subtype presented highest PCD patterns scores. With four genes, ANLN, FAM83A, RHOV and PARP15, we constructed a LUAD risk prediction model with significant differences in immune cell composition, cell cycle related pathways between the two risk groups. Samples in C1 and high group were more sensitive to chemotherapy drug. The score of PCD were differences in high- and low-groups. Finally, we combined Riskscore and clinical features to improve the performance of the prediction model, and the calibration curve and decision curve verified that the great robustness of the model.Conclusion: We identified three stable molecular subtypes of LUAD and constructed a prognostic model based on NK cell-related genes, maybe have a greater potential for application in predicting immunotherapy response and patient prognosis

Germanium-lead perovskite light-emitting diodes.

Reducing environmental impact is a key challenge for perovskite optoelectronics, as most high-performance devices are based on potentially toxic lead-halide perovskites. For photovoltaic solar cells, tin-lead (Sn-Pb) perovskite materials provide a promising solution for reducing toxicity. However, Sn-Pb perovskites typically exhibit low luminescence efficiencies, and are not ideal for light-emitting applications. Here we demonstrate highly luminescent germanium-lead (Ge-Pb) perovskite films with photoluminescence quantum efficiencies (PLQEs) of up to ~71%, showing a considerable relative improvement of ~34% over similarly prepared Ge-free, Pb-based perovskite films. In our initial demonstration of Ge-Pb perovskite LEDs, we achieve external quantum efficiencies (EQEs) of up to ~13.1% at high brightness (~1900 cd m-2), a step forward for reduced-toxicity perovskite LEDs. Our findings offer a new solution for developing eco-friendly light-emitting technologies based on perovskite semiconductors

The Role of Long Non-Coding RNAs in Epithelial-Mesenchymal Transition-Related Signaling Pathways in Prostate Cancer

Prostate cancer (PCa) is one of the most common male malignancies with frequent remote invasion and metastasis, leading to high mortality. Epithelial-mesenchymal transition (EMT) is a fundamental process in embryonic development and plays a key role in tumor proliferation, invasion and metastasis. Numerous long non-coding RNAs (lncRNAs) could regulate the occurrence and development of EMT through various complex molecular mechanisms involving multiple signaling pathways in PCa. Given the importance of EMT and lncRNAs in the progression of tumor metastasis, we recapitulate the research progress of EMT-related signaling pathways regulated by lncRNAs in PCa, including AR signaling, STAT3 signaling, Wnt/β-catenin signaling, PTEN/PI3K/AKT signaling, TGF-β/Smad and NF-κB signaling pathways. Furthermore, we summarize four modes of how lncRNAs participate in the EMT process of PCa via regulating relevant signaling pathways

Some observations on the effects of EGR, oxygen concentration, and engine speed on the homogeneous charge combustion of n-heptane

Paper presented at the 2004 SAE Fuels and Lubricants Meeting and Exhibition, June 2004, Toulouse, France. Retrieved 3/16/2006 from http://www.mem.drexel.edu/cnf/.NOx and soot emissions remain critical issues in diesel engines. One method to address these problems is to achieve homogeneous combustion at lower peak temperatures – the goal of research on controlled autoignition. In this paper n-heptane is used to represent a large hydrocarbon fuel and some of the effects of internal and external EGR, oxygen concentration, and engine speed on its combustion have been examined through simulation and experiment. Simulations were conducted using our existing skeletal chemical kinetic model, which combines the chemistry of the low, intermediate, and high temperature regimes. Experiments were carried out in a single cylinder, four-stroke, air cooled engine and a single cylinder, two stroke, water cooled engine. In the four-stroke engine experiments the effects of EGR were examined using heated N2 addition as a surrogate for external EGR and engine modifications to increase internal EGR. Two-stage ignition was observed in both the simulations and experiments. The modeling results indicate that the ignition times were sensitive to EGR through both thermal and chemical effects. High levels of EGR completely suppressed autoignition. The most apparent effect of oxygen concentration is a shortening of the time between the first stage and second stage ignition. The modeling shows that EGR or extra air are key factors in eliminating knock during mid-load conditions. For higher load operation knock is serious and the only way to avoid it is to control reaction timing through the use of spark ignition. The experimental and modeling results from the two-stroke engine show that autoignition can be avoided by increasing the engine speed. This appears to result from shortened reaction time at lower temperatures thereby reducing the extent of the low and intermediate temperature chemical reactivity. The two-stroke engine experiments indicate that high levels of internal EGR (obtained by increasing the engine back pressure) can enable spark ignition at lean/dilute conditions. Based on the similarity between two-stoke and four-stroke engines, spark ignition may be possible at higher load conditions using internal EGR (simultaneously keeping peak temperature lower) for four-stroke engines

Evaluating the importation of yellow fever cases into China in 2016 and strategies used to prevent and control the spread of the disease

During the yellow fever epidemic in Angola in 2016, cases of yellow fever were reported in China for the first time. The 11 cases, all Chinese nationals returning from Angola, were identified in March and April 2016, one to two weeks after the peak of the Angolan epidemic. One patient died; the other 10 cases recovered after treatment. This paper reviews the epidemiological characteristics of the 11 yellow fever cases imported into China. It examines case detection and disease control and surveillance, and presents recommendations for further action to prevent additional importation of yellow fever into China

An emerging recombinant human enterovirus 71 responsible for the 2008 outbreak of Hand Foot and Mouth Disease in Fuyang city of China

Hand, foot and mouth disease (HFMD), a common contagious disease that usually affects children, is normally mild but can have life-threatening manifestations. It can be caused by enteroviruses, particularly Coxsackieviruses and human enterovirus 71 (HEV71) with highly variable clinical manifestations. In the spring of 2008, a large, unprecedented HFMD outbreak in Fuyang city of Anhui province in the central part of southeastern China resulted in a high aggregation of fatal cases. In this study, epidemiologic and clinical investigations, laboratory testing, and genetic analyses were performed to identify the causal pathogen of the outbreak. Of the 6,049 cases reported between 1 March and 9 May of 2008, 3023 (50%) were hospitalized, 353 (5.8%) were severe and 22 (0.36%) were fatal. HEV71 was confirmed as the etiological pathogen of the outbreak. Phylogenetic analyses of entire VP1 capsid protein sequence of 45 Fuyang HEV71 isolates showed that they belong to C4a cluster of the C4 subgenotype. In addition, genetic recombinations were found in the 3D region (RNA-dependent RNA polymerase, a major component of the viral replication complex of the genome) between the Fuyang HEV71 strain and Coxsackievirus A16 (CV-A16), resulting in a recombination virus. In conclusion, an emerging recombinant HEV71 was responsible for the HFMD outbreak in Fuyang City of China, 2008

Activation and Suppression of Non-Basal Slip and Extension Twinning in Magnesium and Magnesium Alloys

Magnesium (Mg) and its alloys are promising lightweight and high specific strength structural materials, especially for transportation and aerospace applications. However, pure Mg and many Mg alloys exhibit low room-temperature ductility and formability, which is due to the low-symmetry hexagonal close-packed crystal structure and high plastic anisotropy. Therefore, a comprehensive understanding of the fundamental deformation behavior in Mg and its alloys is critical to further improve the mechanical performance of Mg. In this dissertation, advanced characterization techniques (scanning electron microscopy, transmission electron microscopy, etc.) were used to study the activation and suppression of non-basal slips (non-basal and ) and extension twinning in deformed pure Mg and Mg alloys. In the first part, the effect of Schmid factor was examined on the activation and suppression of dislocation and extension twinning. Textured Mg-3Al-1Zn (AZ31) alloy was selected as the model material. Regarding dislocations, statistical analyses on the normal-direction compressed AZ31 revealed that the activation and suppression of dislocations in individual grains are primarily dictated by the overall texture rather than the crystallographic orientation of each grain. (Global texture prevails!) Regarding extension twinning, statistical analyses on the deformed Mg under multiply deformation conditions (normal-direction compression and tension, rolling-direction compression and tension, and 45 degree compressions) revealed extension twinning generally obeys the Schmid law for individual grains rather than the global stress state that favors extension twinning or not. (Schmid factor of individual grain prevails!) In the second part, the effect of non-rare earth (RE) alloying was investigated on the activation and suppression of dislocation and extension twinning. Moreover, the operation of specific deformation mode on the sample ductility was discussed. Non-RE Mg (pure Mg and AZ31) with similar initial microstructures (i.e., grain size and texture) were chosen. To uncover the fundamental mechanisms for the much-improved ductility in AZ31, statistical analyses on the pure Mg and AZ31 after rolling-direction tension at different strain levels were performed. The observations revealed a significant disparity of non-basal dislocation activities between the pure Mg and AZ31. For the pure Mg, dislocations were activated since the early stage of plastic deformation. For AZ31, dislocations were largely absent at all strain levels, even in the strain-to-failure samples. The promotion of the non-basal dislocation activities and the suppression of dislocations in AZ31 are expected to offer more sustainable hardening, which could elucidate the absence of apparent shear banding and much-improved ductility in AZ31 compared to pure Mg. In the third part, the effect of RE alloying was investigated on the activation and suppression of dislocation and extension twinning, and the influence on sample ductility was discussed. The microstructure of a newly developed Mg RE alloy (Mg–2Zn-0.3Ca-0.2Ce-0.1Mn) alloy with an exceptionally high tensile ductility was characterized. Compared with the pure Mg and AZ31 alloy microstructure at the same deformation condition in the second part, our results revealed that the high ductility of the ZXEM2000 could be attributed to four key factors: weaker texture, finer grain size, reduced twinning, and increased cross-slip frequency of dislocations. Taken together, this dissertation explores the roles of Schmid factor and alloying on the operation of non-basal slip and extension twinning in Mg and Mg alloy. Both above deformation mechanisms have a significant impact on the ductility of Mg and Mg alloys. The fundamental mechanisms uncovered in this work are anticipated to help guide the future Mg alloy design, especially in the area of simultaneously achieving high strengthen, high ductility, and improved formability

Distributed optimal dispatch of virtual power plant via limited communication

In this letter, a distributed optimal dispatch method based on the distributed primal-dual sub-gradient algorithm is proposed. By coordinating individual decision-making of distributed energy resources (DERs) in the virtual power plant (VPP) via limited communication, the profit of VPP can be maximized. It can be proven that the proposed distributed algorithm has similar performance to the centralized dispatch