307 research outputs found

    Exact Point Cloud Downsampling for Fast and Accurate Global Trajectory Optimization

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    This paper presents a point cloud downsampling algorithm for fast and accurate trajectory optimization based on global registration error minimization. The proposed algorithm selects a weighted subset of residuals of the input point cloud such that the subset yields exactly the same quadratic point cloud registration error function as that of the original point cloud at the evaluation point. This method accurately approximates the original registration error function with only a small subset of input points (29 residuals at a minimum). Experimental results using the KITTI dataset demonstrate that the proposed algorithm significantly reduces processing time (by 87\%) and memory consumption (by 99\%) for global registration error minimization while retaining accuracy.Comment: IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS2023

    Single-Shot Global Localization via Graph-Theoretic Correspondence Matching

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    This paper describes a method of global localization based on graph-theoretic association of instances between a query and the prior map. The proposed framework employs correspondence matching based on the maximum clique problem (MCP). The framework is potentially applicable to other map and/or query modalities thanks to the graph-based abstraction of the problem, while many of existing global localization methods rely on a query and the dataset in the same modality. We implement it with a semantically labeled 3D point cloud map, and a semantic segmentation image as a query. Leveraging the graph-theoretic framework, the proposed method realizes global localization exploiting only the map and the query. The method shows promising results on multiple large-scale simulated maps of urban scenes

    BRAKING FORCES DURING BICYCLE PEDALING: AN EXAMINATION OF THE FULL CRANK ROTATION

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    Pedalling skills are evaluated using angular impluse of negative crank torque (INCT) that occurs in pulling phase (180-360° of crank rotation that 0° is top dead center. INCT has the effect of inhibit crank rotation (“braking force“). The aim of study was to obtain findings to reduce INCT for improving cyclists\u27 pedalling skills. We examined the relationship between INCT and kinetic pedalling data through the full crank rotation. Fifteen male cyclists performed constant pedalling at 80%Vo2max and 90rpm. Kinetic and kinematic pedalling data were measured by the pedal-shaped force platform (KISTLER) and by a 3D motion capture system (VICON). A negative correlation was indicated 80-250° of crank rotation between horizontal pedal force (Fh) and INCT (pNCT occurring in pulling phase was affected by amount of Fh in pushing phase

    Laparoscopic total colectomy with lymph node dissection for familial adenomatous polyposis with multiple colorectal cancers

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     A 49-year-old Japanese man visited our hospital with chief complaints of difficulty with and bleeding during defecation. After a detailed examination, he was diagnosed with familial adenomatous polyposis (FAP) with multiple (five) colorectal cancers. The tumors were located in the right-sided, left-sided, and sigmoid colon, and the lower rectum. Regional lymph node involvement was observed, but no metastasis to other organs was detected. We, therefore, performed a laparoscopic total colectomy with superior mesenteric artery (SMA) and inferior mesenteric artery (IMA) lymph node dissection. We were able to perform minimally invasive and cosmetically acceptable surgery using laparoscopy instead of highly-invasive open abdominal surgery. Our search of the literature revealed no reported cases of laparoscopic total colectomy with lymph node dissection for FAP with multiple colorectal cancers, making the present case the first to be reported in the literature

    Probabilistic Prediction Method of Erosion Volume and Deposition Area from Rainfall Observation Data

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    We propose a methodology to estimate the spatial distribution of the probability of sediment deposition due to debris flow from rainfall data by combining the probability prediction of erosion volume based on an ordinal logistic regression and a sediment transport simulation. By using the Receiver Operating Characteristic (ROC) curve and Area Under Curve (AUC) we have selected the best combination of shortand long-term rainfall indices used as explanatory variables in the ordinal logistic model. The results showed that the regression model using 60-minute and 48-hour rainfall indices performed well and that the regression model using three events improved the predictability of local disasters in 2014. Furthermore, we performed Monte Carlo debris-flow simulations using rainfall data from 2014 using the model. We confirmed that the spatial distribution of disaster probability is consistent with the actual damage

    Design and synthesis of amidine-type peptide bond isosteres: application of nitrile oxide derivatives as active ester equivalents in peptide and peptidomimetics synthesis.

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    Amidine-type peptide bond isosteres were designed based on the substitution of the peptide bond carbonyl (C=O) group with an imino (C=NH) group. The positively-charged property of the isosteric part resembles a reduced amide-type peptidomimetic. The peptidyl amidine units were synthesized by the reduction of a key amidoxime (N-hydroxyamidine) precursor, which was prepared from nitrile oxide components as an aminoacyl or peptidyl equivalent. This nitrile oxide-mediated C-N bond formation was also used for peptide macrocyclization, in which the amidoxime group was converted to peptide bonds under mild acidic conditions. Syntheses of the cyclic RGD peptide and a peptidomimetic using both approaches, and their inhibitory activity against integrin-mediated cell attachment, are presented

    Bilateral Orbital Inflammation as a Manifestation of Paraneoplastic Syndrome

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    Paraneoplastic neurologic syndromes (PNS) constitute a rare group of disorders whose optimal treatment is yet to be established. We report a patient with bilateral orbital inflammation associated with PNS, who responded well to surgical resection of the primary tumor. An 83-year-old woman was referred to our department for treatment of a progressive reduction in visual acuity and palpebral swelling in both eyes for the past 2 months. She was scheduled to undergo thoracic surgery for lung cancer. The best-corrected visual acuity (BCVA) in the right and left eye had worsened from 0.3 to 0.5 one month before she was referred to our department to 0.03 and 0.07, respectively. A slit-lamp examination revealed edema in both eyelids. Goldmann perimetry revealed several paracentral scotomas with constriction of the peripheral visual fields of both eyes, along with central absolute scotomas in V-4e isopter in the right eye. Magnetic resonance imaging revealed swelling of the bilateral extraocular muscles, which compressed the bilateral optic nerves at the orbital apex. Seven days after the resection of the lung cancer, the BCVA improved to 0.07 and 0.15 in the right and left eyes, respectively, without concomitant immunotherapy. Intravenous methylprednisolone (500 mg/day) was administered for 3 days to treat the residual orbital inflammation. Fourteen days after surgery, the BCVA further improved to 0.4 and 0.5 in the right and left eyes, respectively. Swelling of the bilateral extraocular muscles and the visual field abnormalities improved dramatically. Early diagnosis is crucial for the management of PNS
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