• Communications for Statistical Applications and Methods
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• v.30 no.6
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• pp.561-575
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• 2023

Brain network analysis has attracted the interest of neuroscience researchers in studying brain diseases. Magnetoencephalography (MEG) is especially proper for analyzing functional connectivity due to high temporal and spatial resolution. The application of graph theory for functional connectivity analysis has been studied widely, but research on network modeling for MEG still needs more. Temporal exponential random graph model (TERGM) considers temporal dependencies of networks. We performed the brain network analysis, including static/temporal network statistics, on two groups of epilepsy patients who removed the left (LT) or right (RT) part of the brain and healthy controls. We investigate network differences using Multiset canonical correlation analysis (MCCA) and TERGM between epilepsy patients and healthy controls (HC). The brain network of healthy controls had fewer temporal changes than patient groups. As a result of TERGM, on the simulation networks, LT and RT had less stable state than HC in the network connectivity structure. HC had a stable state of the brain network.

• Journal of the Korean Chemical Society
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• v.58 no.5
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• pp.456-462
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• 2014

Binary-doped conducting chiral polyaniline (PAni) was synthesized by electrochemical polymerization of aniline at low-temperature ($0^{\circ}C$) and room-temperature (RT) conditions. (+)-Camphorsulfonic acid (CSA) and hydrochloric acid (HCl) were used as a binary dopant. Formation of the binary-doped PAni rather than a mixture of the corresponding single-doped PAni was confirmed by cyclic voltammogram, FT-IR and circular dichroism spectra. The temperature influenced the electrochemical behavior and doping level, thus determining the crystallinity and morphology of the PAni. However, among other results, morphology of the PAni is found to be most strongly depends on the polymerization temperature. With increased temperature from the initial state to RT, morphology of the PAni changed from fibrous to short-fibrous structure. The sheet resistance of the PAni films on an ITO was measured by using four-point probe dc method.

• Tribology and Lubricants
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• v.36 no.1
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• pp.47-54
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• 2020

In this study, the effects of ultrasonic nanocrystal surface modification (UNSM) treatment at room and high temperatures (RT and HT of 400℃) on friction and wear behavior of Ti-6Al-4V alloy prepared by selective laser melting (SLM) were investigated. The objective of this study is to improve the mechanical properties and frictional behavior of Ti-6Al-4V alloy by UNSM treatment. Dry friction and wear tests were conducted using a ball-on-disk method at RT with a bearing steel as the counter ball. Due to the high HT and UNSM treatment, the surface hardness tended to increase and surface roughness tended to reduce. X-ray diffraction (XRD) analysis showed that nanocrystallization structure and compressive residual stress were formed at the surface layer after UNSM treatment at both RT and HT. After UNSM treatment, it was observed that the wear rate was reduced by about 6% for the specimen treated at RT and a 28% reduction for the specimen treated at HT in comparison with the untreated one. Based on scanning electron microscope (SEM) images showed that the damage caused by fatigue wear occurred in the wear track of the heat-treated specimen, and it is believed to be the cause of the highest wear rate. Mechanical properties and wear resistance of Ti-6Al-4V alloy were improved and prospect of industrial application was confirmed. Further research is still required to improve the characteristics of SLM Ti-6Al-4V alloy to the level of wrought Ti-6Al-4V alloy.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.457-462
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• 2005

Industrial and economical importance of CP(Cellular Phone) is growing rapidly. Combined with IT technology, CP is currently one of the most attractive technologies for all. However, unless we find a breakthrough to the technology, its growth may slow down soon. RT(Robot Technology) is considered one of the most promising next generation technology. Unlike the industrial robot of the past, today's robots require advanced technologies, such as soft computing, human-friendly interface, interaction technique, speech recognition, object recognition, and many others. In this study, we present a new technological concept named RCP(Robotic Cellular Phone), which combines RT & CP, in the vision of opening a new direction to the advance of CP, IT, and RT all together. RCP consists of 3 sub-modules. They are $RCP^{Mobility}$, $RCP^{Interaction}$, and $RCP^{Interaction}$. $RCP^{Mobility}$ is the main focus of this paper. It is an autonomous navigation system that combines RT mobility with CP. Through $RCP^{Mobility}$, we should be able to provide CP with robotic functionalities such as auto-charging and real-world robotic entertainments. Eventually, CP may become a robotic pet to the human being. $RCP^{Mobility}$ consists of various controllers. Two of the main controllers are trajectory controller and self-localization controller. While Trajectory Controller is responsible for the wheel-based navigation of RCP, Self-Localization Controller provides localization information of the moving RCP. With the coordinate information acquired from RFID-based self-localization controller, Trajectory Controller refines RCP's movement to achieve better RCP navigations. In this paper, a prototype system we developed for $RCP^{Mobility}$ is presented. We describe overall structure of the system and provide experimental results of the RCP navigation.

• The Korea Journal of Herbology
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• v.21 no.4
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• pp.115-121
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• 2006

Objectives : For the purpose of developing new anti-HIV agents from natural sources, the extracts of Actinidia arguta were tested for their inhibitory effects on essential enzymes as the reverse transcriptase (RT), protease and ${\alpha}-\;glucosidase$. And we predicted inhibition activity of major compounds of Actinidia arguta using Quantitative Structure Activity Relationships (QSAR). Methods : In this assay the activity of HIV-1 reverse transcriptase is measured as the formation of a strand of copy-DNA (cDNA) using RNA as a template. The activity of HIV-1 protease is measured as the cleavage of an oligopeptide by HIV-1 protease. Results : In the anti-HIV-1 RT using Enzyme Linked Oligonucleotide Sorbent Assay (ELOSA) method, water extracts (100ug/ml) of stem and leaf showed strong activity of 93.9% and 91.9%, respectively. In the HIV-1 protease inhibition assay, aqueous stem extract inhibited the activity of the enzyme to cleave an oligopeptide, resembling one of the cleavage sites in the viral polyprotein which can only be processed by HIV-1 protease with 56.8%. In the ${\alpha}-glucosidase$ inhibition assay, aqueous stem extract showed activity of 73.1%. Conclusion : We found out this result, for these samples it is possible that the inhibition of the viral replication in vitro is due to the inhibition at least one of RT and ${\alpha}-glucosidase$. It would be of great interest to identify the compounds which are responsible for this inhibition, since all therapeutically useful agent up to date are RT, PR and ${\alpha}-glucosidase$ inhibitors.

• The Plant Pathology Journal
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• v.27 no.2
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• pp.148-155
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• 2011

Our previous sequence and phylogenetic analyses of the Korean Rice stripe virus (RSV) suggested possible genetic reassortment of RNA segments, but whether this RNA variation contributed to the recent RSV outbreaks in Korea is yet unclear. To further clarify these RSV-RNA segment variations, we developed a reverse transcription-polymerase reaction/restriction enzyme (RT-PCR/RE) analysis-based method. We identified five REs, including DraI, EcoR1, NdeI/AseI, and SpeI, that could differentiate RSV RNA 1-4 subtypes, respectively. Our RT-PCR/RE results provided a clear pattern of RNA reassortment, i.e., different groups of isolates having their RNA segments derived from two to three different RSV ancestors, such as from Eastern and Southwestern Chinese or Japanese M and T isolates. We also found that the migratory small brown planthopper from Eastern China caught by aerial net traps that possesses RSV-RNA3 genotypes corresponds mainly to Eastern China, with a few for Southwestern China based on RT-PCR/RE, sequence and phylogenetic analyses, indicating that RSV populations in Eastern China may also have strong RNA variation. The development of an RE analysisbased method proved a useful epidemiological tool for rapid genotyping and identification of mixed infections by RSV strain and by different subtype.

• Journal of Microbiology and Biotechnology
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• v.30 no.11
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• pp.1688-1696
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• 2020

Soil physical and chemical characteristics, soil potential denitrification rates (PDR), community composition and nirK-, nirS- and nosZ-encoding denitrifiers were studied by using MiSeq sequencing, quantitative polymerase chain reaction (qPCR), and terminal restriction fragment polymorphism (T-RFLP) technologies base on short-term (5-year) tillage field experiment. The experiment included four tillage treatments: conventional tillage with crop residue incorporation (CT), rotary tillage with crop residue incorporation (RT), no-tillage with crop residue retention (NT), and rotary tillage with crop residue removed as control (RTO). The results indicated that soil organic carbon, total nitrogen and NH₄⁺-N contents were increased with CT, RT and NT treatments. Compared with RTO treatment, the copies number of nirK, nirS and nosZ in paddy soil with CT, RT and NT treatments were significantly increased. The principal coordinate analysis indicated that tillage management and crop residue returning management were the most and the second important factors for the change of denitrifying bacteria community, respectively. Meanwhile, this study indicated that activity and community composition of denitrifiers with CT, RT and NT treatments were increased, compared with RTO treatment. This result showed that nirK, nirS and nosZ-type denitrifiers communities in crop residue applied soil had higher species diversity compared with crop residue removed soil, and denitrifying bacteria community composition were dominated by Gammaproteobacteria, Deltaproteobacteria, and Betaproteobacteria. Therefore, it is a beneficial practice to increase soil PDR level, abundance and community composition of nitrogen-functional soil microorganism by combined application of tillage with crop residue management.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.5
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• pp.480-488
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• 2006

Industrial and economical importance of CP(Cellular Phone) is growing rapidly. Combined with IT technology, CP is one of the most attractive technologies of today. However, unless we find a new breakthrough in the technology, its growth may slow down soon. RT(Robot Technology) is considered one of the most promising next generation technologies. Unlike the industrial robot of the past, today's robots require advanced features, such as soft computing, human-friendly interface, interaction technique, speech recognition object recognition, among many others. In this paper, we present a new technological concept named RCP (Robotic Cellular Phone) which integrates RT and CP in the vision of opening a combined advancement of CP, IT, and RT, RCP consists of 3 sub-modules. They are $RCP^{Mobility}$(RCP Mobility System), $RCP^{Interaction}$, and $RCP^{Integration}$. The main focus of this paper is on $RCP^{Mobility}$ which combines an autonomous navigation system of the RT mobility with CP. Through $RCP^{Mobility}$, we are able to provide CP with robotic functions such as auto-charging and real-world robotic entertainment. Ultimately, CP may become a robotic pet to the human beings. $RCP^{Mobility}$ consists of various controllers. Two of the main controllers are trajectory controller and self-localization controller. While the former is responsible for the wheel-based navigation of RCP, the latter provides localization information of the moving RCP With the coordinates acquired from RFID-based self-localization controller, trajectory controller refines RCP's movement to achieve better navigation. In this paper, a prototype of $RCP^{Mobility}$ is presented. We describe overall structure of the system and provide experimental results on the RCP navigation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.3
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• pp.384-390
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• 2020

The reverberation effect on the sound when producing movies or VR contents is a very important factor in the realism and liveliness. The reverberation time depending the space is recommended in a standard called RT60(Reverberation Time 60 dB). In this paper, we propose a scene recognition technique for automatic reverberation editing. To this end, we devised a classification model that independently trains color images and predicted depth images in the same model. Indoor scene classification is limited only by training color information because of the similarity of internal structure. Deep learning based depth information extraction technology is used to use spatial depth information. Based on RT60, 10 scene classes were constructed and model training and evaluation were conducted. Finally, the proposed SCR + DNet (Scene Classification for Reverb + Depth Net) classifier achieves higher performance than conventional CNN classifiers with 92.4% accuracy.

• Journal of the Korea Computer Industry Society
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• v.3 no.1
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• pp.19-26
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• 2002

This paper propose the queue structure of cell buffering in the output buffer of ATM switch for the traffic with the different QoS. The proposed queue structure can minimize the cell loss ratio of bursty traffic, maximize the queue utilization through the sharing of real-time queue and non-real-time queue. To evaluate the proposed queue structure, we compare the CLP and cell average delay of the proposed queue and fixed queue using the bursty traffic patterns.