• Journal of information and communication convergence engineering
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• v.17 no.3
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• pp.205-212
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• 2019

Motion tracking and localization devices are an important building block of motion tracking systems in a virtual reality (VR) environment. This study is about improving the accuracy of motion and location for enhancing user immersion in experience type VR environment to position tracking technique. In this study, we propose and test a design of such a device. The module data test of the attitude and heading reference system shows that the implementation with the MPU-9250 sensor is successful and adequate to be used with short operation time. We consider various sensor hardware dependencies of VR, and compare various correction methods and filtering methods to lower the motion to photon (MTP) time that user movement is fully reflected on the display using sensor devices. The Kalman filter is used to combine the accelerometer with the gyroscope in the sensing unit.

• Korean Journal of Cognitive Science
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• v.33 no.2
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• pp.109-133
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• 2022

Episodic memory consists of a core event and the associated contexts. Although the role of the hippocampus and its neighboring regions in contextual representations during encoding has become increasingly evident, it remains unclear how these regions handle various context-specific information other than spatio-temporal contexts. Using high-resolution functional MRI, we explored the patterns of the medial temporal lobe (MTL) and cortical regions' involvement during the encoding of various types of contextual information (i.e., journalism principle 5W1H): "Who did it?," "Why did it happen?," "What happened?," "When did it happen?," "Where did it happen?," and "How did it happen?" Participants answered six different contextual questions while looking at simple experimental events consisting of two faces with one object on the screen. The MTL was divided to sub-regions by hierarchical clustering from resting-state data. General linear model analyses revealed a stronger activation of MTL sub-regions, the prefrontal lobe (PFC), and the inferior parietal lobule (IPL) during social (Who), behavioral (How), and intentional (Why) contextual processing when compared with spatio-temporal (Where/When) contextual processing. To further investigate the functional networks involved in contextual encoding dissociation, a multivariate pattern analysis was conducted with features selected as the task-based connectivity links between the hippocampal subfields and PFC/IPL. Each social, behavioral, and intentional contextual processing was individually and successfully classified from spatio-temporal contextual processing, respectively. Thus, specific contexts in episodic memory, namely social, behavior, and intention, involve distinct functional connectivity patterns that are distinct from those for spatio-temporal contextual memory.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.3
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• pp.697-707
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• 2015

This paper covered the design and implementation of the demodulation receiver in the ADS-B 1090ES system, which is one of the CNS/ATM's surveillance systems. This researched demodulation performed at the level required by RTCA DO-268B and EUROCAE ED-129. The single signal process method, which applies a baseline multi-sample technique among multi-amplitude sample demodulations, was suggested to improve the quality of the receiver signal, the dynamic range and so on. The suggested multi-signal level tuning method has enhanced the single-signal process method, reducing the unstable reception ratio by the transmit output level difference and manufacturing receiver hardware. The result was that the receiver suggested by the method had 0~87dBm in dynamic range and -90dBm in MTL. This shows a better performance by -3dBm less than the international standard in ADS-B 1090ES ground receiver equipment. The systems which use a similar modulation method, will be considered to be widely applied.

• Journal of Korean Foot and Ankle Society
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• v.14 no.1
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• pp.25-30
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• 2010

Purpose: The purpose of this study was to evaluate the clinical and radiological outcomes of the S.E.R.I. (simple, effective, rapid, inexpensive) operation for the bunionette deformity. Materials and Methods: Between March 2005 and February 2009, 22 patients (26 feet) who had been treated for the bunionette deformity with minimally invasive osteotomy were reviewed retrospectively. Clinically, Visual Analogue Scale (VAS), American Orthopaedic Foot and Ankle Society (AOFAS) score, shoes selectivity, disappearance of callus and patient's satisfaction level by Coughlin scoring system were evaluated. Radiologically, the bunionette was classified as four types according to the Fallat classification. The 4-5$^{th}$ intermetatarsal angle (4-5$^{th}$ IMA), the 5$^{th}$ metatarsophalangeal angle (5$^{th}$ MPA) and the length of 5th metatarsal bone (5$^{th}$ MTL) were analyzed at preoperatively and at final follow up visit. Results: VAS improved from $6.8{\pm}1.8$ points to $2.2{\pm}1.8$ points (p<0.05). AOFAS score improved from $54.0{\pm}14.2$ points to $90.0{\pm}4.8$ points (p<0.05). There was no change in shoes selectivity. 9 feet (34.6%) were satisfied with excellent results, 16 feet (61.5%) with good results and 1 foot (3.9%) with fair results. The average 4-5$^{th}$ IMA was corrected from $10.1{\pm}2.3^{\circ}$ to $4.4{\pm}1.7^{\circ}$ (p<0.05). The average 5$^{th}$ MPA was corrected from $11.5{\pm}8.6^{\circ}$ to $-0.1{\pm}4.1^{\circ}$ (p<0.05). The average 5$^{th}$ MTL was changed from $66.1{\pm}4.3$ millimeters to $64.1{\pm}4.4$ millimeters (p=0.069). There was no malunion, nonunion or delayed union and other perioperative complications. Conclusion: S.E.R.I. operation is less invasive and easy technique. This procedure is recommendable for the treatment of the bunionette deformity.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.12B
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• pp.1565-1573
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• 2011

In this paper, we present a MIMO-OFDM broadband power line communication (BPLC) for Smart Grid and its associated applications and analyze its performance over the 3-phase 4-wire power line channels. For practical BPLC system simulation, we adopt the statistical power line fading channel model instead of the existing deterministic fading channel models (Zimmermann model, MTL model, and so on). In this paper, we implement $2{\times}2$ and $3{\times}3$ MIMO schemes using 3-phase 4-wire power lines. We investigate the capacity loss and BER performance of the proposed MIMO system by considering the effect of cross-talk between antenna paths. We choose space-frequency coding in order to reduce frequency interference between subcarriers and employ maximum ratio combining (MRC) that achieves both multiple antenna path diversity gain and multiple fading path diversity gain. We evaluate the proposed system performance through computer simulation in terms of the impulse noise index and the capacity loss ratio and compare the different signal combining schemes including MRC, equal gain combing (EGC), and selection combining (SC).

• Laboraroty Animal Research
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• v.34 no.4
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• pp.223-231
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• 2018

Regulation of gastrointestinal hormones have been reported in animal models for constipation undergoing laxative therapy when administered herbal products. We undertook to investigate whether the laxative activity of gallotannin-enriched extracts isolated from Galla Rhois (GEGR) affects the regulation of gastrointestinal hormones, by examining the concentration of four hormones and the activation of their receptors in the loperamide (Lop)-induced constipation model. Stool parameters, including number, weight and water content, were significantly recovered in the Lop+GEGR treated group, relative to the Lop+ vehicle treated group; however, food intake and water consumption were maintained at a constant level. Also, a similar recovery was detected for thickness of mucosa, muscle and flat luminal surface in the Lop+GEGR treated group. Furthermore, concentration of the four gastrointestinal hormones evaluated, namely, cholecystokinin (CCK), gastrin (GAS), somatostatin (SS) and motilin (MTL), were lower in the Lop+vehicle treated group than the No treated group, but were remarkably enhanced in the Lop+GEGR treated group. Moreover, the downstream signaling pathway of MTL and SS receptors were recovered after GEGR administration. Results of the present study therefore indicate that the laxative effects of GEGR treatment may be tightly related with the regulation of gastrointestinal hormones in the Lopinduced constipation model.

• Advances in Traditional Medicine
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• v.5 no.4
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• pp.283-293
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• 2005

Our previous study showed that a novel synthetic shikonin derivative, 6-(1-hydroxyimino-4-methylpentyl)5,8-dimethyoxy 1,4-naphthoquinone S-52 (DMNQ S-52) induced apoptosis. In the present study, we investigated its anti-metastatic activities as compared with shikonin because DMNQ S-52 was synthesized for overcoming weak points of shikonin such as high toxicity, low solubility and deleterious effects. DMNQ S-52 showed the weaker cytotoxicity $(IC_{50};\;12.3{\pm}1.6\;{\mu}M)$ against Lewis lung carcinoma (LLC) cells than that of shikonin $(IC_{50};\;4.2{\pm}1.1\;{\mu}M)$. DMNQ S-52, at non-toxic concentrations $(less\;than\;10\;{\mu}M)$, significantly inhibited the invasion and migration of LLC cells. DMNQ S-52 also significantly inhibited the production of MMP-9, MTl-MMP and uPAR. Moreover, daily i.p. administration of DMNQ S-52 at dose of 5 mg/kg in mice resulted in a potent inhibition of the primary tumor size of LLC in the lung as well as the metastasis of lymph nodes. These findings suggest that the DMNQ S-52 has therapeutic potential to inhibit metastasis via inhibition of MMP family and uPA/plasminogen system.

• Environmental Analysis Health and Toxicology
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• v.23 no.1
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• pp.11-16
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• 2008

카드뮴은 환경과 인체 위해도에 큰 영향을 미치는 중요한 환경오염물질로 잘 알려져 있다. 본 연구에서는 토양선충인 Caenorhabditis elegans에 카드뮴을 12시간과 48시간으로 나누어 처리하여 시간에 따른 장, 단기적 독성영향을 알아보고자 하였다. 이때 생리학적 수준으로 성장 및 생식을 조사하고, 분자수준에서 스트레스 관련 유전자들의 시간에 따른 발현 정도를 관찰하였다. 생식에서는 단기노출(12시간) 시 그 영향이 대조군에 비해 크게 나타났으며, mtl-2의 스트레스 관련 유전자가 증가하였다 장기 노출(48시간) 시에는 cyp35a2, ape-1, sod-1, ctl-2 유전자가 대조군에 비해 약 $2{\sim}4$배 가량의 발현 증가 결과를 조사할 수 있었다. 본 연구결과들을 통해 스트레스 관련 유전자의 발현을 조사하는 것이 중요하고 민감한 생체지표가 된다는 것과 토양선충 C. elegans는 환경중 오염물질에 대한 장기, 단기적 영향을 평가하기 위한 좋은 생물학적 모델이 된다는 것을 알 수 있었다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.5
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• pp.719-726
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• 1999

Multiconductor transmission line(MTL) equations are solved by FDTD method to examine the coupling between incident electromagnetic fields and multiconductor transmission lines. The measurement of induced voltages on UTP Category 5 and STP Category 5 cables which are used as LAN cables is carried out using a TEM cell where uniform and strong TEM fields can be established. The comparison between measured and simulated results shows good agreement. It is also found that grounding of shield foil at both terminations and small grounding resistance give good shielding effects for STP Category 5.

• Mycobiology
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• v.50 no.2
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• pp.132-141
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• 2022

Amylomyces rouxii is commonly found as amylolytic fungi in tapai fermentation. However, its diversity is rarely reported despite being often used for food production in Southeast Asia. This research aims to analyze the genetic diversity and the distribution pattern of A. rouxii from Ragi tapai in Java Island, Indonesia. We isolated the fungus from samples obtained from Ragi tapai producing centers in Bandung, Sumedang, Muntilan, Blora, Yogyakarta, and Bondowoso. The obtained isolates were molecularly identified based on the ribosomal regions ITS1/ITS2 and D1/D2, then analyzed for phylogenetic tree reconstruction, genetic distance, genetic variation, and haplotype networking. Six isolates showed specific morphological traits of A. rouxii. However, phylogenetic tree reconstruction on the ribosomal genes showed that the isolates were grouped into two different clades related to two species. Clade A included BDG, SMD, and MTL isolates related to A. rouxii, whereas clade B included YOG, BLR, and BDS isolates related to Mucor indicus. The genetic distances between clades for ITS1/ITS2 and D1/D2 were 0.6145 and 0.1556, respectively. In conclusion, we confirmed the genetic diversity of molds from Ragi tapai in Java Island and showed that the isolates are not only related to A. rouxii as reported before.