GP-SLAM+: real-time 3D lidar SLAM based on improved regionalized Gaussian process map reconstruction

This paper presents a 3D lidar SLAM system based on improved regionalized Gaussian process (GP) map reconstruction to provide both low-drift state estimation and mapping in real-time for robotics applications. We utilize spatial GP regression to model the environment. This tool enables us to recover surfaces including those in sparsely scanned areas and obtain uniform samples with uncertainty. Those properties facilitate robust data association and map updating in our scan-to-map registration scheme, especially when working with sparse range data. Compared with previous GP-SLAM, this work overcomes the prohibitive computational complexity of GP and redesigns the registration strategy to meet the accuracy requirements in 3D scenarios. For large-scale tasks, a two-thread framework is employed to suppress the drift further. Aerial and ground-based experiments demonstrate that our method allows robust odometry and precise mapping in real-time. It also outperforms the state-of-the-art lidar SLAM systems in our tests with light-weight sensors.Comment: Accepted by IROS 202

Multi-damage detection in composite structure

In this paper a pre-stack reverse-time migration concept of signal processing techniques is developed and adapted to guided-wave propagation in composite structure for multi-damage imaging by experimental studies. An anisotropic laminated composite plate with a surface-mounted linear piezoelectric ceramic (PZT) disk array is studied as an example. At first, Mindlin Plate Theory is used to model Lamb waves propagating in laminates. The group velocities of flexural waves are also derived from dispersion relations and validated by experiments. Then reconstruct the response wave fields with reflected data collected by the linear PZT array. Reverse-time migration technique is then performed to back-propagate the reflected energy to the damages using a two-dimensional explicit finite difference algorithm and damages are imaged. Stacking these images together gets the final image of multiple damages. The results show that the pre-stack migration method is hopeful for damage detection in composite structures

Case report: Misdiagnosis of primary mucinous cystadenoma of the testicle by ultrasound

Testicular mucinous cystadenoma is a rare benign testicular tumor with the characteristics of being potentially malignant and showing atypical clinical symptoms; this article reports a case of a primary testicular mucinous cystadenoma misdiagnosed as testicular teratoma by ultrasound. A 69-year-old man was admitted to the hospital because of a 1-year history of left-sided testicular enlargement with scrotal swelling and no obvious abnormalities on laboratory tests. Ultrasound examination revealed solid-mass lesions in the left testicle, suggesting a high probability of teratoma, and contrast-enhanced magnetic resonance imaging (MRI) examination suggested an increased possibility of epidermoid cysts. Contrast-enhanced computed tomography (CT) and contrast-enhanced MRI of the preoperative abdomen and pelvis showed no other primary adenocarcinoma. Doctors performed radical resection of the left testicle. The postoperative pathological diagnosis was mucinous cystadenoma, and calcification as well as partially mildly atypical epithelial cells were discovered. Furthermore, there were no neoplastic lesions in the epididymis or spermatic cord. No metastatic lesions were found after 6 months postoperative follow-up, and the patient’s prognosis remains good

Digital NBC Protection System BIT Optimization Design

BIT technology is an important means of system and equipment fault detection, location and isolation. This paper takes the digital NBC protection system as the research object, and carries out research on the optimization design based on BIT technology. Based on the structural division of the digital NBC protection systems and the analysis of typical failure modes, combined with the weighted cost index function and the selection method of the improved special hierarchically optimized optimal test set, the calculation and comparison of the indices of the actual digitalized NBC protection systems was conducted. Determine the optimal test set, and finally design the BIT circuit for the selected optimal test set

A hybrid framework using a QUBO solver for permutation-based combinatorial optimization

In this paper, we propose a hybrid framework to solve large-scale permutation-based combinatorial problems effectively using a high-performance quadratic unconstrained binary optimization (QUBO) solver. To do so, transformations are required to change a constrained optimization model to an unconstrained model that involves parameter tuning. We propose techniques to overcome the challenges in using a QUBO solver that typically comes with limited numbers of bits. First, to smooth the energy landscape, we reduce the magnitudes of the input without compromising optimality. We propose a machine learning approach to tune the parameters for good performance effectively. To handle possible infeasibility, we introduce a polynomial-time projection algorithm. Finally, to solve large-scale problems, we introduce a divide-and-conquer approach that calls the QUBO solver repeatedly on small sub-problems. We tested our approach on provably hard Euclidean Traveling Salesman (E-TSP) instances and Flow Shop Problem (FSP). Optimality gap that is less than $10\%$ and $11\%$ are obtained respectively compared to the best-known approach.Comment: 23 pages, 10 figure

Global-scale profiling of differential expressed lysine acetylated proteins in colorectal cancer tumors and paired liver metastases

Lysine acetylated modification was indicated to impact colorectal cancer (CRC)'s distant metastasis. However, the global acetylated proteins in CRC and the differential expressed acetylated proteins and acetylated sites between CRC primary and distant metastatic tumor remains unclear. Our aim was to construct a complete atlas of acetylome in CRC and paired liver metastases. Combining high affinity enrichment of acetylated peptides with high sensitive mass spectrometry, we identified 603 acetylation sites from 316 proteins, among which 462 acetylation sites corresponding to 243 proteins were quantified. We further classified them into groups according to cell component, molecular function and biological process and analyzed the metabolic pathways, domain structures and protein interaction networks. Finally, we evaluated the differentially expressed lysine acetylation sites and revealed that 31 acetylated sites of 22 proteins were downregulated in CRC liver metastases compared to that in primary CRC while 40 acetylated sites of 32 proteins were upregulated, of which HIST2H3AK19Ac and H2BLK121Ac were the acetylated histones most changed, while TPM2 K152Ac and ADH1B K331Ac were the acetylated non-histones most altered. These results provide an expanded understanding of acetylome in CRC and its distant metastasis, and might prove applicable in the molecular targeted therapy of metastatic CRC. Biological significance: This study described provides, for the first time, that full-scale profiling of lysine acetylated proteins were identified and quantified in colorectal cancer (CRC) and paired liver metastases. The novelty of the study is that we constructed a complete atlas of acetylome in CRC and paired liver metastases. Moreover, we analyzed these differentially expressed acetylated proteins in cell component, molecular function and biological process. In addition, metabolic pathways, domain structures and protein interaction networks of acetylated proteins were also investigated. Our approaches shows that of the differentially expressed proteins, HIST2H3AK19Ac and H2BLK121Ac were the acetylated histones most changed, while TPM2 K152Ac and ADH1B K331Ac were the acetylated non-histones most altered. Our findings provide an expanded understanding of acetylome in CRC and its distant metastasis, and might prove applicable in the molecular targeted therapy of metastatic CRC. (C) 2016 Elsevier B.V. All rights reserved.Peer reviewe

Preliminary Study on Selling Tickets in Reason for Last Trains on Beijing Rail Transit Network

which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. With the increase of Beijing urban rail transport network, the structure of the road network is becoming more complex, and passengers have more travel options. Together with the complex paths and different timetables, taking the last train is becoming much more difficult and unsuccessful. To avoid losses, we propose feasible suggestions to the last train with reasonable selling tickets system