131 research outputs found
Illumination-invariant vegetation detection for a vision sensor-based agricultural applications
In this paper, we propose a novel method, illumination-invariant vegetation detection (IVD), to improve many aspects of agriculture for vision-based autonomous machines or robots. The proposed method derives new color feature functions from simultaneously modeling the spectral properties of the color camera and scene illumination. An experiment in which an image sample dataset was acquired under nature illumination, including various intensities, weather conditions, shadows and reflections, was performed. The results show that the proposed method (IVD) yields the highest performance with the lowest error and standard deviation and is superior to six typical methods. Our method has multiple strengths, including computational simplicity and uniformly high-accuracy image segmentation
Age-of-Information Aware Contents Caching and Distribution for Connected Vehicles
To support rapid and accurate autonomous driving services, road environment
information, which is difficult to obtain through vehicle sensors themselves,
is collected and utilized through communication with surrounding infrastructure
in connected vehicle networks. For this reason, we consider a scenario that
utilizes infrastructure such as road side units (RSUs) and macro base station
(MBS) in situations where caching of road environment information is required.
Due to the rapidly changed road environment, a concept which represents a
freshness of the road content, age of information (AoI), is important. Based on
the AoI value, in the connected vehicle system, it is essential to keep
appropriate content in the RSUs in advance, update it before the content is
expired, and send the content to the vehicles which want to use it. However,
too frequent content transmission for the minimum AoI leads to indiscriminate
use of network resources. Furthermore, a transmission control, that content AoI
and service delay are not properly considered adversely, affects user service.
Therefore, it is important to find an appropriate compromise. For these
reasons, the objective of this paper is about to reduce the system cost used
for content delivery through the proposed system while minimizing the content
AoI presented in MBS, RSUs and UVs. The transmission process, which is able to
be divided into two states, i.e., content caching and service, is approached
using Markov decision process (MDP) and Lyapunov optimization framework,
respectively, which guarantee optimal solutions, as verified via data-intensive
performance evaluation
A Novel Visualization Method for Sleep Spindles Based on Source Localization of High Density EEG
Equivalent dipole source localization is a well-established approach to localizing the electrical activity in electroencephalogram (EEG). So far, source localization has been used primarily in localizing the epileptic source in human epileptic patients. Currently, source localization techniques have been applied to account for localizing epileptic source among the epileptic patients. Here, we present the first application of source localization in the field of sleep spindle in mouse brain. The spatial distribution of cortical potential was obtained by high density EEG and then the anterior and posterior sleep spindles were classified based on the K-mean clustering algorithm. To solve the forward problem, a realistic geometry brain model was produced based on boundary element method (BEM) using mouse MRI. Then, we applied four different source estimation algorithms (minimum norm, eLORETA, sLORETA, and LORETA) to estimate the spatial location of equivalent dipole source of sleep spindles. The estimated sources of anterior and posterior spindles were plotted in a cine-mode that revealed different topographic patterns of spindle propagation. The characterization of sleep spindles may be better be distinguished by our novel visualization method.11Ysciescopuskc
Towards pathogenomics: a web-based resource for pathogenicity islands
Pathogenicity islands (PAIs) are genetic elements whose products are essential to the process of disease development. They have been horizontally (laterally) transferred from other microbes and are important in evolution of pathogenesis. In this study, a comprehensive database and search engines specialized for PAIs were established. The pathogenicity island database (PAIDB) is a comprehensive relational database of all the reported PAIs and potential PAI regions which were predicted by a method that combines feature-based analysis and similarity-based analysis. Also, using the PAI Finder search application, a multi-sequence query can be analyzed onsite for the presence of potential PAIs. As of April 2006, PAIDB contains 112 types of PAIs and 889 GenBank accessions containing either partial or all PAI loci previously reported in the literature, which are present in 497 strains of pathogenic bacteria. The database also offers 310 candidate PAIs predicted from 118 sequenced prokaryotic genomes. With the increasing number of prokaryotic genomes without functional inference and sequenced genetic regions of suspected involvement in diseases, this web-based, user-friendly resource has the potential to be of significant use in pathogenomics. PAIDB is freely accessible at
Comparative analysis of de novo genomes reveals dynamic intra-species divergence of NLRs in pepper
Background
Peppers (Capsicum annuum L.) containing distinct capsaicinoids are the most widely cultivated spices in the world. However, extreme genomic diversity among species represents an obstacle to breeding pepper.
Results
Here, we report de novo genome assemblies of Capsicum annuum Early Calwonder (non-pungent, ECW) and Small Fruit (pungent, SF) along with their annotations. In total, we assembled 2.9 Gb of ECW and SF genome sequences, representing over 91% of the estimated genome sizes. Structural and functional annotation of the two pepper genomes generated about 35,000 protein-coding genes each, of which 93% were assigned putative functions. Comparison between newly and publicly available pepper gene annotations revealed both shared and specific gene content. In addition, a comprehensive analysis of nucleotide-binding and leucine-rich repeat (NLR) genes through whole-genome alignment identified five significant regions of NLR copy number variation (CNV). Detailed comparisons of those regions revealed that these CNVs were generated by intra-specific genomic variations that accelerated diversification of NLRs among peppers.
Conclusions
Our analyses unveil an evolutionary mechanism responsible for generating CNVs of NLRs among pepper accessions, and provide novel genomic resources for functional genomics and molecular breeding of disease resistance in Capsicum species.This study was supported by a grant from the Agricultural Genome Center of the Next Generation BioGreen 21 Program of RDA (Project No. PJ013153) and the National Research Foundation of Korea (NRF) grant funded by the Korean government (No. 2018R1A5A1023599 [SRC]) to D.C., and by the 2020 Research Fund of the University of Seoul to S.K. Theses funding bodies had no role in the study design, data collection, analysis, and preparation of the manuscript
Wood Pellet Driven-Biochar Characterization Produced at Different Targeted Pyrolysis Temperatures
The imperative transition to renewable energy drives the need for innovation. Biomass, particularly wood pellets, has demonstrated poor performance in co-firing scenarios. This study employed pyrolysis to convert wood pellets into biochar with improved fuel quality. The biochar production and characterization were investigated at pyrolysis temperatures of 400°C to 500°C. The findings revealed significant improvements: the observed fixed carbon content increased from 67.2% to 78.8%, and the calorific value increased 1.2 times higher within the pyrolysis temperature increased. On the other hand, as the pyrolysis temperature increased from 400°C to 500°C, biochar yields decreased from 49% to 37%. Thermogravimetric (TG) analysis revealed distinct weight loss during heating, illuminating component volatilization and residue accumulation. Furthermore, Fourier transform infrared (FTIR) spectroscopy elucidated structural changes, demonstrating the evolution of cellulose and hemicellulose into aromatic structures. Ultimately, these insights into biochar characteristics informed the optimization of pyrolysis processes, contributing to the production of superior biochar for renewable energy applications.
Keywords: biochar, biomass, carbon storage, pyrolysis, wood pelle
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