173 results match your criteria: "School of Information and Communications[Affiliation]"
Chemphyschem
December 2015
Department of Physics, Yogi Vemana University, Kadapa-, 516 003, India.
Er(3+) -Yb(3+) co-doped Lu3 Ga5 O12 nanogarnets were prepared and characterized; their structural and luminescence properties were determined as a function of the Yb(3+) concentration. The morphology of the nanogarnets was studied by HRTEM. Under 488 nm excitation, the nanogarnets emit green, red, and near-infrared light.
View Article and Find Full Text PDFJ Neural Eng
December 2015
School of Information and Communications, Gwangju Institute of Science and Technology, Gwangju 500-701, Korea.
Objective: A brain-computer interface (BCI) usually requires a time-consuming training phase during which data are collected and used to generate a classifier. Because brain signals vary dynamically over time (and even over sessions), this training phase may be necessary each time the BCI system is used, which is impractical. However, the variability in background noise, which is less dependent on a control signal, may dominate the dynamics of brain signals.
View Article and Find Full Text PDFComput Biol Med
November 2015
School of Information and Communications, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea. Electronic address:
One of the main problems related to electroencephalogram (EEG) based brain-computer interface (BCI) systems is the non-stationarity of the underlying EEG signals. This results in the deterioration of the classification performance during experimental sessions. Therefore, adaptive classification techniques are required for EEG based BCI applications.
View Article and Find Full Text PDFSci Rep
August 2015
1] School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea [2] Research Institute for Solar and Sustainable Energies, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea.
Recently, growing interest in implantable bionics and biochemical sensors spurred the research for developing non-conventional electronics with excellent device characteristics at low operation voltages and prolonged device stability under physiological conditions. Herein, we report high-performance aqueous electrolyte-gated thin-film transistors using a sol-gel amorphous metal oxide semiconductor and aqueous electrolyte dielectrics based on small ionic salts. The proper selection of channel material (i.
View Article and Find Full Text PDFBrain Stimul
June 2016
Department of Medical System Engineering, Gwangju Institute of Science and Technology, Gwangju, South Korea; School of Mechatronics, Gwangju Institute of Science and Technology, Gwangju, South Korea. Electronic address:
Background: Although computational studies of electrical brain stimulation (EBS) have received attention as a cost-effective tool, few studies have validated the technique, particularly in invasive cortical stimulation.
Objective: In order to validate such studies, we used EBS to compare electric potential distributions generated by both numerical simulations and empirical measurements in three phantom head models (one-/three-layered spherical heads and MRI-based head).
Methods: We constructed spherical phantom heads that consisted of one or three layers, and an anatomical, MRI-based phantom that consisted of three layers and represented the brain or brain/skull/scalp in order to perform both numerical simulations using the finite element method (FEM) and experimental measurements.
Bioinformatics
October 2015
Department of Bio and Brain Engineering, KAIST, Yuseong-Gu, Daejeon 305-701, Korea.
Motivation: Finding somatic mutations from massively parallel sequencing data is becoming a standard process in genome-based biomedical studies. There are a number of robust methods developed for detecting somatic single nucleotide variations However, detection of somatic copy number alteration has been substantially less explored and remains vulnerable to frequently raised sampling issues: low frequency in cell population and absence of the matched control samples.
Results: We developed a novel computational method SoloDel that accurately classifies low-frequent somatic deletions from germline ones with or without matched control samples.
PLoS One
April 2016
School of Information and Communications, Gwangju Institute of Science and Technology, Gwangju, South Korea.
Subdural cortical stimulation (SuCS) is an appealing method in the treatment of neurological disorders, and computational modeling studies of SuCS have been applied to determine the optimal design for electrotherapy. To achieve a better understanding of computational modeling on the stimulation effects of SuCS, the influence of anisotropic white matter conductivity on the activation of cortical neurons was investigated in a realistic head model. In this paper, we constructed pyramidal neuronal models (layers 3 and 5) that showed primary excitation of the corticospinal tract, and an anatomically realistic head model reflecting complex brain geometry.
View Article and Find Full Text PDFSci Rep
May 2015
Department of Mechatronics, Gwangju Institute of Science and Technology, Gwangju, Korea 500-712.
Memristive synapses, the most promising passive devices for synaptic interconnections in artificial neural networks, are the driving force behind recent research on hardware neural networks. Despite significant efforts to utilize memristive synapses, progress to date has only shown the possibility of building a neural network system that can classify simple image patterns. In this article, we report a high-density cross-point memristive synapse array with improved synaptic characteristics.
View Article and Find Full Text PDFBMC Urol
February 2015
School of Information and Communications, Gwangju Institute of Science and Technology, Gwangju, 500-712, Korea.
Background: In this paper, we observed a discrepancy of penile hemodynamics dependent on location by using near infrared spectroscopy (NIRS) sensor, and showcase NIRS as a potentially suitable sensor in supplementing the diagnosis and treatment of erectile dysfunction.
Methods: To observe the effect that location has on penile hemodynamics, the NIRS sensor was placed on the top and the side of genital organ, and oxy- (HbO), deoxy-(RHb), and total (HbT) hemoglobin concentration changes were acquired. Our results from 6 healthy subjects show that hemodynamic changes vary depending on where the probe was placed.
Bioinformatics
August 2015
School of Information and Communications, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea.
Motivation: The generation of a large volume of cancer genomes has allowed us to identify disease-related alterations more accurately, which is expected to enhance our understanding regarding the mechanism of cancer development. With genomic alterations detected, one challenge is to pinpoint cancer-driver genes that cause functional abnormalities.
Results: Here, we propose a method for uncovering the dominant effects of cancer-driver genes (DEOD) based on a partial covariance selection approach.
Phys Rev Lett
January 2015
Department of Physics, University of Florida, Gainesville, Florida 32611, USA.
We experimentally explore the use of a novel device where lateral electric fields can be applied to break the translational symmetry within the isotropic plane and hence change the selection rules to allow normally forbidden transverse acoustic (TA) phonon generations. The ultrafast screening of the lateral electric field by the photocarriers relieves shear strain in the structure and switches on the propagating TA waves. The amplitude and on-state time of the TA mode can be modulated by the external field strength and size of the laterally biased region.
View Article and Find Full Text PDFJ Neurosci Methods
March 2015
School of Information and Communications, Gwangju Institute of Science and Technology, Gwangju 500-712, South Korea. Electronic address:
Brain-computer interface (BCI) technology has attracted significant attention over recent decades, and has made remarkable progress. However, BCI still faces a critical hurdle, in that performance varies greatly across and even within subjects, an obstacle that degrades the reliability of BCI systems. Understanding the causes of these problems is important if we are to create more stable systems.
View Article and Find Full Text PDFPLoS Comput Biol
January 2015
School of Information and Communications, Gwangju Institute of Science and Technology, Gwangju, South Korea.
MicroRNAs (miRNAs) play key roles in the initiation and progression of various cancers by regulating genes. Regulatory interactions between genes and miRNAs are complex, as multiple miRNAs can regulate multiple genes. In addtion, these interactions vary from patient to patient and even among patients with the same cancer type, as cancer development is a heterogeneous process.
View Article and Find Full Text PDFNanoscale Res Lett
December 2014
School of Information and Communications, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 500-712, Republic of Korea ; Advanced Photonics Research Institute, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 500-712, Republic of Korea.
Unlabelled: We report the observation of room temperature photoluminescence (PL) emission from GaAs/GaInAs core-multiple-quantum-well (MQW) shell nanowires (NWs) surrounded by AlGaAs grown by molecular beam epitaxy (MBE) using a self-catalyzed technique. PL spectra of the sample show two PL peaks, originating from the GaAs core NWs and the GaInAs MQW shells. The PL peak from the shell structure red-shifts with increasing well width, and the peak position can be tuned by adjusting the width of the MQW shell.
View Article and Find Full Text PDFJ Neural Eng
December 2014
School of Information and Communications, Gwangju Institute of Science and Technology, Gwangju, 500-712, Korea.
Objective: We propose a new hybrid brain-computer interface (BCI) system that integrates two different EEG tasks: tactile selective attention (TSA) using a vibro-tactile stimulator on the left/right finger and motor imagery (MI) of left/right hand movement. Event-related desynchronization (ERD) from the MI task and steady-state somatosensory evoked potential (SSSEP) from the TSA task are retrieved and combined into two hybrid senses.
Approach: One hybrid approach is to measure two tasks simultaneously; the features of each task are combined for testing.
PLoS One
December 2015
School of Information and Communications, Gwangju Institute of Science and Technology, Gwangju, South Korea.
Subdural cortical stimulation (SuCS) is a method used to inject electrical current through electrodes beneath the dura mater, and is known to be useful in treating brain disorders. However, precisely how SuCS must be applied to yield the most effective results has rarely been investigated. For this purpose, we developed a three-dimensional computational model that represents an anatomically realistic brain model including an upper chest.
View Article and Find Full Text PDFJ Biomed Opt
September 2014
Gwangju Institute of Science and Technology, School of Information and Communications, 261 Cheomdan-gwagiro, Buk-gu, Gwangju 500-712, Republic of Korea.
In breast-conserving surgery, an optical wire is a useful surgical guiding tool to optically locate small lesions within the breast tissue. However, the use of a long silica glass fiber as the optical wire can be burdensome to patients because of its stiffness and nonbiocompatibility. We investigate the use of a biocompatible fiber for light localization in tissue.
View Article and Find Full Text PDFPLoS One
May 2015
School of Information and Communications, Gwangju Institute of Science and Technology, Gwangju, South Korea.
Sub-networks can expose complex patterns in an entire bio-molecular network by extracting interactions that depend on temporal or condition-specific contexts. When genes interact with each other during cellular processes, they may form differential co-expression patterns with other genes across different cell states. The identification of condition-specific sub-networks is of great importance in investigating how a living cell adapts to environmental changes.
View Article and Find Full Text PDFSensors (Basel)
August 2014
School of Information and Communications, Gwangju Institute of Science and Technology, Gwangju 500712, Korea.
In recent years, research on Brain-Computer Interface (BCI) technology for healthy users has attracted considerable interest, and BCI games are especially popular. This study reviews the current status of, and describes future directions, in the field of BCI games. To this end, we conducted a literature search and found that BCI control paradigms using electroencephalographic signals (motor imagery, P300, steady state visual evoked potential and passive approach reading mental state) have been the primary focus of research.
View Article and Find Full Text PDFNucleic Acids Res
July 2014
Department of Computer Science, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
In order to identify genes that are involved in oncogenesis and to understand how such genes affect cancers, abnormal gene expressions in cancers are actively studied. For an efficient access to the results of such studies that are reported in biomedical literature, the relevant information is accumulated via text-mining tools and made available through the Web. However, current Web tools are not yet tailored enough to allow queries that specify how a cancer changes along with the change in gene expression level, which is an important piece of information to understand an involved gene's role in cancer progression or regression.
View Article and Find Full Text PDFJ Biomed Opt
May 2014
University of California Irvine, Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road East, Irvine, California 92612gUniversity of California Irvine Medical Center, Department of Pulmonary and Critical Care, 333 West City Boulevard, Suite.
A major need exists for methods to assess organ oxidative metabolic states in vivo. By contrasting the responses to cyanide (CN) poisoning versus hemorrhage in animal models, we demonstrate that diffuse optical spectroscopy (DOS) can detect cytochrome c oxidase (CcO) redox states. Intermittent decreases in inspired O2 from 100% to 21% were applied before, during, and after CN poisoning, hemorrhage, and resuscitation in rabbits.
View Article and Find Full Text PDFNanoscale Res Lett
February 2014
School of Information and Communications, Gwangju Institute of Science and Technology, 1 Oryong-dong, Buk-gu, Gwangju, 500-712, Republic of Korea.
We report the fabrication of broadband antireflective silicon (Si) nanostructures fabricated using spin-coated silver (Ag) nanoparticles as an etch mask followed by inductively coupled plasma (ICP) etching process. This fabrication technique is a simple, fast, cost-effective, and high-throughput method, making it highly suitable for mass production. Prior to the fabrication of Si nanostructures, theoretical investigations were carried out using a rigorous coupled-wave analysis method in order to determine the effects of variations in the geometrical features of Si nanostructures to obtain antireflection over a broad wavelength range.
View Article and Find Full Text PDFFront Hum Neurosci
December 2013
School of Information and Communications, Gwangju Institute of Science and Technology Gwangju, South Korea ; Wadsworth Center, New York State Health Department, Albany NY, USA.
While brain computer interface (BCI) can be employed with patients and healthy subjects, there are problems that must be resolved before BCI can be useful to the public. In the most popular motor imagery (MI) BCI system, a significant number of target users (called "BCI-Illiterates") cannot modulate their neuronal signals sufficiently to use the BCI system. This causes performance variability among subjects and even among sessions within a subject.
View Article and Find Full Text PDFPLoS One
December 2014
School of Information and Communications, Gwangju Institute of Science and Technology, Gwangju, South Korea.
In most brain computer interface (BCI) systems, some target users have significant difficulty in using BCI systems. Such target users are called 'BCI-illiterate'. This phenomenon has been poorly investigated, and a clear understanding of the BCI-illiteracy mechanism or a solution to this problem has not been reported to date.
View Article and Find Full Text PDFPLoS One
September 2014
School of Information and Communications, Gwangju Institute of Science and Technology, Gwangju, South Korea.
Computational methods for predicting drug-target interactions have become important in drug research because they can help to reduce the time, cost, and failure rates for developing new drugs. Recently, with the accumulation of drug-related data sets related to drug side effects and pharmacological data, it has became possible to predict potential drug-target interactions. In this study, we focus on drug-drug interactions (DDI), their adverse effects ([Formula: see text]) and pharmacological information ([Formula: see text]), and investigate the relationship among chemical structures, side effects, and DDIs from several data sources.
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