313 research outputs found
Exact Point Cloud Downsampling for Fast and Accurate Global Trajectory Optimization
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
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
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
Imitation-regularized Optimal Transport on Networks: Provable Robustness and Application to Logistics Planning
Network systems form the foundation of modern society, playing a critical
role in various applications. However, these systems are at significant risk of
being adversely affected by unforeseen circumstances, such as disasters.
Considering this, there is a pressing need for research to enhance the
robustness of network systems. Recently, in reinforcement learning, the
relationship between acquiring robustness and regularizing entropy has been
identified. Additionally, imitation learning is used within this framework to
reflect experts' behavior. However, there are no comprehensive studies on the
use of a similar imitation framework for optimal transport on networks.
Therefore, in this study, imitation-regularized optimal transport (I-OT) on
networks was investigated. It encodes prior knowledge on the network by
imitating a given prior distribution. The I-OT solution demonstrated robustness
in terms of the cost defined on the network. Moreover, we applied the I-OT to a
logistics planning problem using real data. We also examined the imitation and
apriori risk information scenarios to demonstrate the usefulness and
implications of the proposed method
Laparoscopic total colectomy with lymph node dissection for familial adenomatous polyposis with multiple colorectal cancers
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
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.
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
- …