• Transactions on Electrical and Electronic Materials
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• v.11 no.3
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• pp.93-105
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• 2010

Complementary metal-oxide-semiconductor (CMOS) technology scaling has been a main key for continuous progress in silicon-based semiconductor industry over the past three decades. However, as the technology scaling enters nanometer regime, CMOS devices are facing many serious problems such as increased leakage currents, difficulty on increase of on-current, large parameter variations, low reliability and yield, increase in manufacturing cost, and etc. To sustain the historical improvements, various innovations in CMOS materials and device structures have been researched and introduced. In parallel with those researches, various new nanoelectronic devices, so called "Beyond CMOS Devices," are actively being investigated and researched to supplement or possibly replace ultimately scaled conventional CMOS devices. While those nanoelectronic devices offer ultra-high density system integration, they are still in a premature stage having many critical issues such as high variations and deteriorated reliability. The practical realization of those promising technologies requires extensive researches from device to system architecture level. In this paper, the current researches and challenges on nanoelectronics are reviewed and critical tasks are summarized from device level to circuit design/CAD domain to better prepare for the forthcoming technologies.

• Transactions on Electrical and Electronic Materials
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• v.16 no.3
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• pp.156-161
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• 2015

In this paper, we present simulation results obtained using SILVACO TCAD tools for a 3-D silicon on insulator (SOI) n-FinFET structure with a gate length of 8 nm at 300K. The effects of variations of the device’s key electrical parameters, such as threshold voltage, subthreshold slope, transconductance, drain induced barrier lowering, oncurrent, leakage current and on/off current ratio are presented and analyzed. We will also describe some simulation results related to the influence of the gate work function variations on the considered structure. These variations have a direct impact on the electrical device characteristics. The results show that the threshold voltage decreases when we reduce the gate metal work function Φ_m. As a consequence, the behavior of the leakage current improves with increased Φ_m. Therefore, the short channel effects in real 3-D FinFET structures can reasonably be controlled and improved by proper adjustment of the gate metal work function.

• Journal of Ginseng Research
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• v.35 no.2
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• pp.219-225
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• 2011

Korean red ginseng (KRG) is a valuable and important traditional medicine in East Asian countries and is currently used extensively for botanical products in the world. KRG has both stimulatory and inhibitory effects on the central nervous system (CNS) suggesting its complicated action mechanisms. The substantia gelatinosa (SG) neurons of the trigeminal subnucleus caudalis (Vc) are involved in orofacial nociceptive processing. Some studies reported that KRG has antinociceptive effects, but there are few reports of the functional studies of KRG on the SG neurons of the Vc. In this study, a whole cell patch clamp study was performed to examine the action mechanism of a KRG extract on the SG neurons of the Vc from juvenile mice. KRG induced short-lived and repeatable inward currents on all the SG neurons tested in the high chloride pipette solution. The KRG-induced inward currents were concentration dependent and were maintained in the presence of tetrodotoxin, a voltage gated $Na^+$ channel blocker. The KRG-induced inward currents were suppressed by 6-cyano-7-nitroquinoxaline-2,3-dione, a non-N-methyl-D-aspartate (NMDA) glutamate receptor antagonist and/or picrotoxin, a gamma-aminobutyric acid $(GABA)_A$ receptor antagonist. However, the inward currents were not suppressed by d,l-2-amino-5-phosphonopentanoic acid, an NMDA receptor antagonist. These results show that KRG has excitatory effects on the SG neurons of the Vc via the activation of non-NMDA glutamate receptor as well as an inhibitory effect by activation of the $GABA_A$ receptor, indicating the KRG has both stimulatory and inhibitory effects on the CNS. In addition, KRG may be a potential target for modulating orofacial pain processing.

• Biomolecules & Therapeutics
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• v.14 no.4
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• pp.253-258
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• 2006

LDD175(4-choloro-7-trifluoromethyl-10H-benzo[4,5]furo[3,2-b]indole-l-carboxylic acid) is one of benzofuroindole derivatives that act as a potent $BK_{Ca}$ channel openers. In the process of testing LDD175 as a new drug candidate, an acute toxicity study was carried out in mice. The mice were administered LDD175 intraperitoneally at dose of 0.2, 1, 10, 50, 100, 200, 400, 800mg/kg and orally at dose of 10, 100, 400, 800mg/kg body weight. After administering LDD175, the vital organs such as the liver, kidney and spleen were carefully observed for any significant pathological features or differences from the norm over a l4-day period. LDD175 did not induce any short-term toxicity at doses less than 100mg/kg. A $LD_{50}$ of LDD175 was 2493mg/kg in male mice and 4908mg/kg in female mice. Weight reduction was observed at a dose of 800mg/kg in male, and 400 and 800mg/kg in female. The kidney weight decreased in females after an intraperitoneal injection of LDD175 high dose(>400mg/kg, i.p.), and the spleen weight increased in the male(800mg/kg, i.p.) and female(400mg/kg, i.p.) mice. Inspite of the change in organ weights, there were neither histopathological changes nor any gross morphological abnormalities detected in any organ. LDD175 did not produce significant changes in the general behavior at doses of <200mg/kg, but decreased locomotor activity was observed at an intraperitoneal dose of 400mg/kg. Its effects on the locomotor activity and activity on the rotarod were tested and compared with the effects of diazepam 5mg/kg. The decrement in the locomotor activity and the activity on the rotarod induced by LDD175 was less serious than it by diazepam.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.683-685
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• 2012

This paper have presented the analysis of the change for threshold voltage and drain induced barrier lowering among short channel effects occurred in subthreshold region for double gate(DG) MOSFET with two gates to be next-generation devices, based on scaling theory. To obtain the analytical solution of Poisson's equation, Gaussian function been used as carrier distribution to analyze closely for experimental results, and the threshold characteristics have been analyzed for device parameters such as channel thickness and doping concentration and projected range and standard projected deviation of Gaussian function. Since this potential model has been verified in the previous papers, we have used this model to analyze the threshold chatacteristics. As a result to apply scaling theory, we know the threshold voltage and drain induced barrier lowering is changed, and the deviation rate is changed for device parameters for DGMOSFET.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.1
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• pp.145-150
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• 2013

This paper has presented the analysis for threshold voltage and drain induced barrier lowering among short channel effects occurred in subthreshold region for double gate(DG) MOSFET as next-generation devices, based on scaling theory. To obtain the analytical solution of Poisson's equation, Gaussian function has been used as carrier distribution to analyze closely for experimental results, and the threshold characteristics have been analyzed for device parameters such as channel thickness and doping concentration and projected range and standard projected deviation of Gaussian function. Since this potential model has been verified in the previous papers, we have used this model to analyze the threshold characteristics. As a result to apply scaling theory, we know the threshold voltage and drain induced barrier lowering are changed, and the deviation rate is changed for device parameters for DGMOSFET.

• Journal of Yeungnam Medical Science
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• v.39 no.4
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• pp.294-299
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• 2022

Background: Medical therapy is the standard treatment for uncomplicated acute type B aortic dissection (ATBAD), but there is little evidence of the need for intensive care unit (ICU) management. Therefore, we aimed to investigate the effects of ICU treatment on uncomplicated ATBAD. Methods: We retrospectively studied patients with uncomplicated ATBAD who were medically treated between January 2010 and July 2020. Patients were divided into short-term ICU stay (SIS) and long-term ICU stay (LIS) groups, according to a 48-hour cutoff of ICU stay duration. The incidence of pneumonia and delirium, rate of aortic events, hospital mortality, and survival rate were compared. Results: Fifty-five patients were treated for uncomplicated ATBAD (n=29 for SIS and n=26 for LIS). The incidence of pneumonia (3.6% vs. 7.7%) and delirium (14.3% vs. 34.6%) was higher in the LIS group than in the SIS group, but the differences were not statistically significant. The survival rates at 1, 3, and 5 years were not different between the two groups (SIS: 96.4%, 92.2%, and 75.5% vs. LIS: 96.2%, 88.0%, and 54.2%, respectively; p=0.102). Multivariate Cox regression analysis for aortic events showed that using a calcium channel blocker lowered the risk of aortic events. Conclusion: Long-term ICU treatment is unlikely to be necessary for the treatment of uncomplicated ATBAD. Active use of antihypertensive agents, such as calcium channel blockers, may be needed during the follow-up period.

• Journal of The Geomorphological Association of Korea
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• v.26 no.1
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• pp.15-26
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• 2019

In this study, we investigated the grain size, lithological type, and shape of coarse bed materials in the upper and middle reaches of Gongneungcheon River. For this purpose, 11 sampling points were selected along the river. For 100 samples of the coarse bed materials at each point, three axes (long, intermediate, and short) of samples were measured, and their lithological types were also identified. By measuring grain size, the sphericity and flatness of samples were calculated. Finally, every particle was classified into four shape categories: sphere, disc, blade and rod. We found that the grain size in incised meandering reach is the largest. This is mainly due to the supply of coarse materials from steep valley sides along the meandering channel. According to the lithological analysis, all samples were identified as granite, gneiss and schist, and quartz. The proportion of granite decreased, whereas the proportion of gneiss and schist increased downstream. These patterns indicate that the bedrock distribution within the study area accounts for the downstream lithological variation of coarse bed materials. With regard to the grain shape, sphericity gradually decreased while flatness gradually increased downstream. In the case of the shape classification, unlike the general downstream pattern of grain shape, the proportion of the sphere type decreased and the proportion of the blade type increased downstream. Such a reversal change in the downstream direction turns out to be determined by the lithology (such as foliation, bedding and the pattern of weathering) of coarse bed materials.

• Journal of Korean Society of Disaster and Security
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• v.16 no.4
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• pp.33-43
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• 2023

The impact of prolonged rainfall, such as during the monsoon season or intense concentrated rainfall over a short period, can lead to mountainous disasters such as landslides and debris flows. These events, such as landslides and debris flows, cause both human and material damage, prompting the implementation of various measures and research to prevent them. In the context of researching debris flow disasters, numerical models for debris flows provide a relatively simple way to analyze the risk in a study area. However, since empirical equations are applied in these models, yielding different results and variations in input variables across models, the validation of numerical models becomes essential. In this study, a numerical model for debris flows was employed to compare and analyze the mitigation effects of facilities such as check dams and water channel work, aiming to reduce the damage caused by debris flows.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.5 s.182
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• pp.190-196
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• 2006

Transparent materials are widely used in the fields of optic parts and bio industry. We have experiment to find out the characteristics of the micromachining inside transparent materials using femtosecond laser pulses. With its non-linear effects by very high peak intensity, filament (plasma channel) was formed by the cause of the self-focusing and the self-defocusing. Physical damage could be found when the intensity is high enough to give rise to the thermal stress or evaporation. At the vicinity of the power which makes the visible damage or modification, the structural modification occurs with the slow scanning speed. According to the polarization direction to the scanning direction, the filament quality is quite different. There is a good quality when the polarization direction is parallel to the scanning direction. For fine filament, we could suggest the conditions of the high numerical aperture lens, the short shift of focusing point, the low scanning speed and the low power below 20 mW. As the examples of optics parts, we fabricated the fresnel zone plate with the $225{\mu}m$ diameter and Y-bend optical wave guide with the $5{\mu}m$ width.