LiDAR Enhanced Structure-from-Motion

Although Structure-from-Motion (SfM) as a maturing technique has been widely used in many applications, state-of-the-art SfM algorithms are still not robust enough in certain situations. For example, images for inspection purposes are often taken in close distance to obtain detailed textures, which will result in less overlap between images and thus decrease the accuracy of estimated motion. In this paper, we propose a LiDAR-enhanced SfM pipeline that jointly processes data from a rotating LiDAR and a stereo camera pair to estimate sensor motions. We show that incorporating LiDAR helps to effectively reject falsely matched images and significantly improve the model consistency in large-scale environments. Experiments are conducted in different environments to test the performance of the proposed pipeline and comparison results with the state-of-the-art SfM algorithms are reported.Comment: 6 pages plus reference. Work has been submitted to ICRA 202

Lobaplatin-based prophylactic hyperthermic intraperitoneal chemotherapy for T4 gastric cancer patients: A retrospective clinical study

ObjectiveTo explore the clinical efficacy of lobaplatin-based prophylactic hyperthermic intraperitoneal chemotherapy (HIPEC) for patients with T4 gastric cancer after surgery and to evaluate its impact on survival.Materials and methodsData on patients with T4 gastric cancer who underwent radical gastric resection between March 2016 and August 2017 were collected from the National Cancer Center and Huangxing Cancer Hospital. Enrolled patients were divided into two groups according to receiving or not receiving HIPEC.ResultsA total of 106 patients were included in this study; among them, 51 patients underwent radical gastric resection plus prophylactic HIPEC, and 55 patients underwent radical gastric resection only. The baseline characteristics were well balanced between the two groups. The postoperative platelet counts in the HIPEC group were significantly lower than those in the non-HIPEC group (P < 0.05); however, we did not observe any occurrences of serious bleeding in the HIPEC group. There were no significant differences in the postoperative complication rates between the two groups (P > 0.05). The postoperative (1 month) CEA, CA19-9, and CA72-4 levels in the HIPEC group were significantly decreased in the HIPEC group (P < 0.05). At a median follow-up of 59.3 months, 3 (5.5%) patients in the HIPEC group experienced peritoneal recurrence, and 10 (18.2%) patients in the non-HIPEC group experienced peritoneal recurrence (P < 0.05). Both groups had comparable 5-year overall survival (OS) rates (41.1% HIPEC group vs. 34.5% non-HIPEC group, P = 0.118). The 5-year disease-free survival was significantly higher in the HIPEC group than in the non-HIPEC group (28.6% versus 39.7%, p = 0.046).ConclusionsLobaplatin-based prophylactic HIPEC is feasible and safe for patients with T4 gastric cancer and does not increase postoperative adverse effects. The use of HIPEC showed a significant decrease in the incidence of local recurrence rates and blood tumor marker levels. The 5-year disease-free survival was significantly higher in the HIPEC group; however, the 5-year OS benefit was not found in T4 stage patients

Overdue invoice forecasting and data mining

Thesis: S.M. in Transportation, Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2016.Cataloged from PDF version of thesis.Includes bibliographical references (pages 64-67).The account receivable is one of the main challenges in the business operation. With poor management of invoice to cash collection process, the over due invoice may pile up, and the increasing amount of unpaid invoice may lead to cash flow problems. In this thesis, I addressed the proactive approach to improving account receivable management using predictive modeling. To complete the task, I built supervised learning models to identity the delayed invoices in advance and made recommendations on improving performance of order to cash collection process. The main procedures of the research work are data cleaning and processing, statistical analysis, building machine learning models and evaluating model performance. The analytical and modeling of the study are based on the real-world invoice data from a Fortune 500 company. The thesis also discussed approaches of dealing with imbalanced data, which includes sampling techniques, performance measurements and ensemble algorithms. The invoice data used in this thesis is imbalanced, because on-time invoice and delayed invoice classes are not approximately equally represented. The cost sensitivity learning techniques demonstrates favorable improvement on classification results. The results of the thesis reveal that the supervised machine learning models can predict the potential late payment of invoice with high accuracy.by Weikun Hu.S.M. in Transportatio

Intervention using a novel biodegradable hollow stent containing polylactic acid-polyprolactone-polyethylene glycol complexes against lacrimal duct obstruction disease.

Lacrimal duct obstruction disease (LDOD) is a common ophthalmologic disease. Stent implantation surgery is one of the most effective therapies. In this study, we intended to find out the satisfactory biodegradable stents containing poly-L-lactic acid-polycaprolactone-polyethylene glycol (PLLA- PCL- PEG) complexes for therapeutic application in LDOD. Stents made of PLLA- PCL- PEG complexes in various ratios, were prepared and used in vitro to determine stents with appropriate mechanical properties and shorter range of bio-degradation for study in vivo. Thirty-two rabbits were randomized into eight groups of four eyes each in advance for test in vivo. The selected stents were implanted into the left lacrimal ducts of 16 rabbits and silica gel stents as the control for the other 16 rabbits. At four points in time (1, 4, 10 and 16 weeks after the implantation), weight loss rate (WLR) of the stents was measured and analysed. To access the change of lacrimal duct, fluorescein excretion test, lacrimal duct endoscopy and histopathological testing were conducted. The stent containing PLLA: PCL6: 4+ 15%PEG was selected for study in vivo. Analysis of weight loss rate (WLR), fluorescein excretion test, lacrimal duct endoscopy and histopathological testing indicated that the selected stent was biodegradable and caused minimal stimulation and earlier tissue restoration in the lacrimal epithelium compared with the silica gel stent used as the control. The study results suggest that the PLLA: PCL6: 4+ 15% PEG stent is a satisfactory biodegradable stent as a promising alternative for therapeutic application in LDOD, which showed tissue compatibility, biodegradation and adequate mechanical intensity

Modeling Chronic Dacryocystitis in Rabbits by Nasolacrimal Duct Obstruction with Self-Curing Resin

We established a chronic dacryocystitis model by injecting of 0.05, 0.1, and 0.15 ml self-curing resin via the lacrimal punctum in rabbits. Animals were randomized into four groups (n=11 animals/group). The control group received 0.15 ml normal saline. Within three months postinjection, epiphora and eye discharge were observed. At the 90th day postlacrimal passage irrigation, CT dacryocystography was performed to find changes in the lacrimal image, and hematoxylin and eosin staining was made to identify pathological changes of the lacrimal sac. Three months postinjection, the rabbits in control group and those who received 0.05 and 0.1 ml self-curing resin failed to develop chronic dacryocystitis. However, 8/11 (72.7%) rabbits those received 0.15 ml self-curing resin were symptomatic and showed complete reflux in lacrimal passage irrigation, indicating the obstruction of the nasolacrimal duct. CT dacryocystography showed that the obstruction was present only in the animals with chronic dacryocystitis. Pathological examinations of chronic dacryocystitis also revealed significantly inflammatory changes, such as mucus epithelium thickening, irregular papillary proliferation, and submucosal fibrous deposition. Local injection of 0.15 ml self-curing resin can induce permanent obstruction of the nasolacrimal duct in rabbits and establish a model of chronic dacryocystitis

Management of γ-Alumina with High-Efficient {111} External Surfaces for HDS Reactions

A series of γ-alumina samples with different exposure ratio of {111} facet were synthesized by an efficient hydrothermal method via adjusting the pH value of the gel precursor. The nanorod alumina supported catalyst with the highest exposure of {111} facet exhibited the best hydrodesulfurization (HDS) activities of both thiophene and dibenzothiophene (DBT). Characterization of the sulfided NiMo/Al2O3 catalyst with preferential exposure of {111} facet showed that the MoS2 nano slabs were inclined to distribute in the direction along the edges of alumina nanocrystal in reduced stacking layers. The selective exposure of {111} facet played a decisive role in obtaining alumina-supported HDS catalysts with improved intrinsic activity. This work helps to better understand the relationship between catalytic properties and varied support surfaces, which demonstrate a proper design of the catalyst support morphology on the facet-level