13,442 research outputs found
Autonomous Ship Collision Avoidance in Restricted Waterways Considering Maritime Navigation Rules
No full textThis article addresses autonomous collision avoidance in restricted waterways in compliance with maritime navigation rules. Since waterways may have diverse shapes, it is not straightforward to design a generic approach that can be applied to all types of waterways. In this article, we propose a shape-invariant coordinate system and a systematic collision avoidance procedure that complies with maritime navigation rules. The waterway space is defined using the coordinates in the along-track and cross-track directions to efficiently represent various types of waterway shapes. An automatic collision avoidance algorithm is designed and applied to the transformed coordinate system, which additionally takes into account the compliance with maritime traffic rules in restricted waterways. The performance of the proposed approach is evaluated in diverse types of waterways by performing Monte Carlo simulations, and the simulation results are presented and discussed.
Urban localization based on aerial imagery by correcting projection distortion
No full textThis study proposes a vehicle localization method that fuses aerial maps and LiDAR measurements in urban canyon environments. The building outlines from an aerial image can be used as appropriate features for matching with the LiDAR data for localization. However, distortions caused by scaled orthographic projection of aerial maps are commonly observed in the images of metropolitan areas, which may significantly degrade the matching and resulting localization performance. In this study, a novel method for correcting such distortions is proposed and used for the vehicle localization by matching the corrected map and LiDAR measurements. Instance and semantic segmentation algorithms were used to distinguish individual buildings and generate corrected outlines of the buildings. A particle filter is applied to determine the pose of the vehicle based on the mutual information between the map and LiDAR measurements. The performance of the proposed algorithm was verified using a dataset obtained in urban areas.
Spin-forbidden transitions in the vicinity of the 2 (1)Pi(u)<- X(1)Sigma(+)(g) band system of Rb(2)
No full textWe have investigated the Rb(2) 475 nm system by resonance enhanced two-photon ionization spectroscopy in a pulsed molecular beam. Strong extra bands accompanying the 2 (1)Pi(u) nu' = 5 - 8 <- X (1)Sigma(+)(g) nu '' = 0 bands were newly observed. Rotational analysis of the main and extra bands reveals that the 2 (1)Pi(u) nu' = 5 - 8 levels are significantly perturbed, mainly by the 3 (3)Sigma(+)(u)(1(u)) state and also by the 2 (3)Pi(u)(1(u)) state. For the major perturber, 3 (3)Sigma(+)(u)(1(u)), the intensity borrowing has been found to be facilitated by the 2 (3)Pi(+)(u)(1(u)) potential energy curve crossing near 21100 cm(-1). For the vibronic-band intensities of the 2 (3)Pi(u)(1(u)) nu' <- X (1)Sigma(+)(g) nu '' = 0 transitions observed in this spectral region, intensity borrowing was most effective when the 2 (3)Pi(u)(1(u)) levels were close to the 3 (3)Sigma(+)(u)(1(u)) levels. A deperturbation fit for the perturbing bands has provided the 2 (1)Pi(u)-3 (3)Sigma(+)(u)(1(u)) coupling constants
Supplemental Material - Feasibility of a Low-Power, Low-Resolution Laser-Induced Breakdown Spectroscopy Instrument for Analysis of Nickel Alloys: Quantification of the Major Alloying Elements and Classification
No full textSupplemental Material for Feasibility of a Low-Power, Low-Resolution Laser-Induced Breakdown Spectroscopy Instrument for Analysis of Nickel Alloys: Quantification of the Major Alloying Elements and Classification by Hanbum Choi, Hyang Kim, Song-Hee Han, Sunhye Kim, Sehoon Jung, Sang-Ho Nam and Yonghoon Lee in Applied Spectroscopy</p
Clathrin-coated Pits are Shredded Organelles Presorting Receptors in the Plasma Membrane
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Photodissociation and Laser Spectroscopy of alkali metal dimers in a very cold molecular beam
No full textIdentification of lead small molecule inhibitors of glycogen synthase kinase-3 beta using a fragment-linking strategy
No full textGlycogen synthase kinase-3 beta (GSK3β) kinase serves as a promising therapeutic target for the treatment of various human diseases, such as diabetes, obesity, and Alzheimer's disease. In this study, we report lead GSK3β inhibitors identified using a fragment-linking strategy. Through the systematic exploration, a six-atom chain unit bearing the rigid double bond was found to be a suitable linker connecting two fragments, which enables favorable contacts with backbone groups of residues in the pockets. As a consequence, potent GSK3β inhibitor 9i was found with IC50 values of 19 nM. The binding mode analysis indicates that the activities of the inhibitors appear to be achieved by the establishment of multiple hydrogen bonds and hydrophobic interactions in the ATP-binding site of GSK3β. The good biochemical potencies and structural uniqueness of the inhibitors support consideration in the further study to optimize the biological activity. © 2016 Elsevier Ltd.1441sciescopu
Assessing and mapping cultural ecosystem services of an urban forest based on narratives from blog posts
No full textAlthough extensive research has been conducted to quantify and map the cultural values of nature and wildlife, there are still many challenges that need to be solved. We propose an approach using blog posts that provide rich narratives and knowledge about place values for assessing cultural ecosystem services (CESs). In this study, blog posts on an urban forest in Korea (Bukhansan) were classified according to different CESs defined by the MA (Millennium Ecosystem Assessment, 2005) through content analysis, while place keywords were quantified and mapped. Consequently, five types of CESs were derived from Bukhansan, whose individual characteristics such as sense of place and aesthetic values in the MA were further subdivided. This relates to the indirect use values that were not sufficiently considered in the existing CES assessment. Indirect use values were found in type 4 and type 5, which accounted for 20% of the CESs in Bukhansan. This is particularly relevant to the location characteristics of Bukhansan, which is adjacent to the city, and its value as an urban forest. Furthermore, semantic relationships of words vectorized by CES type and the occurrence information of place keywords allow for abundant interpretations of people's perceptions and activities. Generally, CESs in mountainous areas, where the scope of activities is limited to traversing nature trails, have similar spatial patterns and physical indicators. However, CESs continue to change with socio-cultural flows, and in this respect, semantic-oriented analysis is more effective in capturing these temporal, spatial, and programmatic features and changes. In conclusion, the use of blog posts for evaluating cultural services can be a compromising alternative to reducing the gap between the quantitative evaluations and the qualitative understanding of the ultimate beneficiaries of the service.Y
Author Correction: Evaluation of skin cancer resection guide using hyper‑realistic in‑vitro phantom fabricated by 3D printing
No full textThe original version of this Article contained an error in the spelling of the author Taehun Kim which was incorrectly given as Teahun Kim. The original Article has been corrected
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