• Journal of IKEEE
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• v.24 no.2
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• pp.619-625
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• 2020

In this paper, we propose a TS-DMOSFET(Trench Shielded DMOSFET) structure in which P+ shielding region is formed in a deeper region than C-DMOSFET(Conventional DMOSFET) and S-DMOSFET(Shielded DMOSFET). Using TCAD simulation to compare the static characteristics of TS-DMOSFET with C- and S-DMOSFET. As for the structure proposed, the doping is followed by the source trench process. Despite the fact that it is a SiC material, this allows it to form a P+ shielding region in a deep area. Followed by completely suppressing the reach-through effect. As a result, when the breakdown voltage of the three structures is 3.3kV, the Ron of TS-DMOSFET is 9.7mΩ㎠. Thus, it is 68% and 54% smaller than the Ron of C-DMOSFET and S-DMOSFET respectively.

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4185-4190
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• 2011

The nucleophilic substitution reactions of ethylene phosphorochloridate (1c) with substituted anilines ($XC_6H_4NH_2$) and deuterated anilines ($XC_6H_4ND_2$) are investigated kinetically in acetonitrile at $5.0^{\circ}C$. The anilinolysis rate of 1c involving a cyclic five-membered ring is four thousand times faster than its acyclic counterpart (1a: diethyl chlorophosphate) because of great positive value of the entropy of activation of 1c (${\Delta}S^{\neq}=+30\;cal\;mol^{-1}K^{-1}$ compared to negative value of 1a (${\Delta}S^{\neq}=-45\;cal\;mol^{-1}K^{-1}$) over considerably unfavorable enthalpy of activation of 1c (${\Delta}H^{\neq}=27.7\;kcal\;mol^{-1}$) compared to 1a (${\Delta}H^{\neq}=8.3\;kcal\;mol^{-1}$). Great enthalpy and positive entropy of activation are ascribed to sterically congested transition state (TS) and solvent structure breaking in the TS. The free energy correlations exhibit biphasic concave upwards for substituent X variations in the X-anilines with a break point at X = 3-Me. The deuterium kinetic isotope effects are secondary inverse ($k_H/k_D$ < 1) with the strongly basic anilines and primary normal ($k_H/k_D$ > 1) with the weakly basic anilines and rationalized by the TS variation from a dominant backside attack to a dominant frontside attack, respectively. A concerted $S_N2$ mechanism is proposed and the primary normal deuterium kinetic isotope effects are substantiated by a hydrogen bonded, four-center-type TS.

• Korean Journal of Animal Reproduction
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• v.24 no.1
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• pp.109-113
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• 2000

This study was carried out to investigate the effect of short-term thermal stress on the serum concentrations of cortisol and DHEAS in BALB / c male mice. Cortisol and DHEAS concentrations in serum were measured by radioimmunoassay(RIA). We found there were significantly increased in the cortisol levels in 30 min-stressed group(T30) compared with control group(p＜0.01), and then declined without significance in 120 min-stressed group (T120) compared with T30. By contrast, DHEAS levels were decreased without significance in both T30 and T120 compared with control group. Though short-term thermal stress, the continuous decline of DHEAS levels were observed. These results show that short-term thermal stress affects the serum levels of cortisol and DHEAS in mice. Furthermore, we found that DHEAS is a stress-related hormone and will be able to utilize as a stress marker.

• Wind and Structures
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• v.10 no.3
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• pp.287-300
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• 2007

Wind action is a factor of fundamental importance in the structural design of light or slender constructions. Codes for structural design usually assume that the incident mean wind velocity is parallel to the ground, which constitutes a valid simplification for frequent winds caused by meteorological phenomena such as Extratropical Storms (EPS) or Tropical Storms. Wind effects due to other phenomena, such as thunderstorms, and its combination with EPS winds in so-called squall lines, are simply neglected. In this paper a model that describes the three-dimensional wind velocity field originated from a downburst in a thunderstorm (TS) is proposed. The model is based on a semi empirical representation of an axially-symmetrical flow line pattern that describes a stationary field, modulated by a function that accounts for the evolution of the wind velocity with time. The model allows the generation of a spatially and temporally variable velocity field, which also includes a fluctuating component of the velocity. All parameters employed in the model are related to meteorological variables, which are susceptible of statistical assessment. A background wind is also considered, in order to account for the translational velocity of the thunderstorm, normally due to local wind conditions. When the translation of the TS is caused by an EPS, a squall line is produced, causing the highest wind velocities associated with TS events. The resulting vertical velocity profiles were also studied and compared with existing models, such as the profiles proposed by Vicroy, et al. (1992) and Wood and Kwok (1998). The present model predicts horizontal velocity profiles that depend on the distance to the storm center, effect not considered by previous models, although the various proposals are globally compatible. The model can be applied in any region of interest, once the relevant meteorological variables are known, to simulate the excitation due to TS winds in the design of transmission lines, long-span crossings, cable-stayed bridges, towers or similar structures.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.1
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• pp.1-13
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• 2006

Response of grain yield and milled-rice protein content to nitrogen topdress (N) timing at panicle initiation stage (PIS) is critical for quantifying real-time N requirement for target grain yield and milled-rice protein content. Two split-split-plot experiments with three replications, one in 2004 and the other in 2005, were conducted in Experimental Farm, Seoul National University, Suwon, Korea. The experiments included three N rates at tillering stage (TS), three N timing treatments at panicle initiation stage (PIS) and two rice cultivars. The N rates at TS, N timing at PIS, and rice cultivars were randomly assigned to main plot, sub plot, and sub-sub plot, respectively. Results showed that the delayed N application at PIS reduced grain yield in 2004 and increased milled-rice protein content in both years significantly at 0.05 probability level. The calculated optimum N timing at PIS from pooled data by N rates and rice cultivars in two years was at 28 days before heading (DBH). However, real-time of N timing at PIS was dependent on plant growth and N status around PIS that in turn was dependent on applied N rates at TS. The optimum N timing at PIS was at 30 DBH for no N treatments at TS while at 27 DBH for 3.6 and 7.2 kg N/10a treatments and at 27 and 29 DBH for Hwaseongbyeo and Daeanbyeo, respectively. In general, earlier applied N at PIS resulted in lower milled-rice protein content but the highest grain yield was expected to be obtained when N topdress at PIS was applied at the time when shoot N concentration started to drop below about 23 mg/g due to dilution effect after transplanting. In conclusion, the results of our experiments imply that the currently recommended N topdress time (24DBH) at PIS in Korea should be reconsidered for the higher grain yield and the better quality of rice.

• Journal of Korean Physical Therapy Science
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• v.26 no.2
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• pp.61-73
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• 2019

Purpose: This study was to evaluate the effect of cranio-cervical flexion based trunk stabilization exercise on gross motor function and posture alignment change in children with spastic cerebral palsy. Design: Randomized Controlled Trial. Methods: Twenty-six children participated in this study. All subjects were randomly assigned to either the Cranio-Cervical Flexion Based Trunk Stabilization Exercise (CCFTS) group (n=13) or the Trunk Stabilization Exercise (TS) group (n=13). In both groups were trained general physical therapy for 10 minutes, in the CCFTS group was trained cranio-cervical flexion based trunk stabilization exercise for 20 minutes and in the TS group was trained trunk stabilization exercise for 20 minutes. The training was provided 2 times a week during 8 weeks. All subjects were measured with the Gross Motor Function Measure (GMFM) and Cranio-Vertebral Angle (CVA) before and after intervention. Results: The results showed that the CCFTS have increased significantly in GMFM (B, C, D and E-dimension) and CVA, and the TS group have increased significantly in GMFM (B, C D and E-dimension). In particular, the CCFTS group improved significantly than TS group in GMFM (B, C and D-dimension) and CVA. Therefore, the cranio-cervical flexion based trunk stabilization exercise improved gross motor function and posture alignment in children with spastic cerebral palsy. Conclusion: These results suggest that cranio-cervical flexion based trunk stabilization exercise is feasible and suitable for individuals with a spastic cerebral palsy and can be used in addition to conventional physical therapy.

• Journal of Community Nutrition
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• v.5 no.1
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• pp.44-50
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• 2003

The iron status and its relations with nutrient intake, coffee drinking, and cigarette smoking were evaluated through the blood analysis and 3-day dietary recalls in 102 apparently healthy Korean adults (48 males, 54 menstruating females) aged 20-49 years and living in Daejeon City. Mean values of hemoglobin (Hb) in males and females were 15.5g/dL and 13.2g/dL, mean corpscular hemoglobin concentration (MCHC) 36.0% and 36.8 %, serum iron (SI) 135 $\mu\textrm{g}$/dL and 97 $\mu\textrm{g}$/dL, transferrin saturation (TS) 39.4% and 29.2%, and serum ferritin (Ft) 88.1 $\mu\textrm{g}$/L and 23.4 $\mu\textrm{g}$/L, respectively. For males the prevalences of abnormal values of iron status indicators were 4.2% in Hb, 2.1% in TS, and 4.2% in Ft, and for females 16.7% in Hb, 25.9% in TS, and 35.2% in Ft. Among females 9.3% had abnormal Ft, TS, and Hb, which was considered as iron-defeciency anemia, and 14.8% had abnormal Ft and TS. As a whole, the impaired iron status prevalences were estimated to be 2.1 - 4.2% for males and 9.3 - 35.2% for females. Mean daily intakes of iron and heme-iron were 13.7mg and 1.51mg in males, and 12.3mg and 1.45mg in females. Ft was positively correlated with dietary energy, protein, iron, and vitamin A, Hb with energy and iron, and MCHC with iron and heme iron. Vitamin A also tended to show positive correlations with Hb, SI, and TS. Coffee drinkers taking 3 cups per day or more had higher levels of Hb, MCHC, and Ft in males and MCHC in females, compared to non-coffee drinkers. Higher levels of Hb and MCHC were found in male smokers than in non-smokers. Coffee drinkers took more energy and vitamin A in males and MPF protein in females than non-coffee drinkers. From the above results, it was suggested that the iron status of men was much better than that of women, and the intakes of energy, iron, heme iron, and especially vitamin A were positively associated with the iron status. Cigarette smoking elevated Hb and MCHC, but the effect of coffee drinking on iron staus was not clear. (J Community Nutrition 5(1) : 44∼50, 2003)

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.6
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• pp.727-731
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• 2009

Effects of various plasticizers (1.5%) such as glycerol, sorbitol, fructose, sucrose, and polypropylene glycol, and ferulic acid on the physical properties of Gelidium corneum (GC) film were examined. GC films containing plasticizer and ferulic acid were prepared by incorporating various amounts (10, 30, 50, 70, 100 mg/100 mL) of ferulic acid into the film. Water vapor permeability (WVP) of the GC film varied depending on the type of plasticizer, and among them the film containing sucrose had the lowest WVP. Tensile strength (TS) and % elongation (%E) of the film were in the range of $1.29{\sim}11.29$ MPa and $5.55{\sim}36.44$ %, respectively, and the WVP values were of $1.30{\sim}1.60\;ng\;m/m^{2}sPa$. In addition, the GC films were prepared using ferulic acid as a cross-linking agent. WVP of the film decreased with the addition of ferulic acid, and the film containing 30 mg ferulic acid had the lowest WVP value. TS value of the GC film containing 10 mg of ferulic acid was significantly higher than that of the control. However, further increase of ferulic acid concentration decreased the TS value. Therefore, 10 mg of ferulic acid was determined to be the optimal concentration for the film.

• IMMUNE NETWORK
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• v.22 no.4
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• pp.35.1-35.16
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• 2022

Tobacco smoking (TS) has been known as one of the most potent risk factors for airway inflammatory diseases. However, there has been a paucity of information regarding the immunologic alteration mediated by TS in patients with chronic rhinosinusitis with nasal polyps (CRSwNP). To identify the effect of TS, we harvested human tissue samples (never smoker: n=41, current smoker: n=22, quitter: n=23) and analyzed the expression of epithelial-derived cytokines (EDCs) such as IL-25, IL-33, and thymic stromal lymphopoietin. The expressions of Th2 cytokines and total serum IgE showed a type-2 inflammatory alteration by TS. In addition, the epithelial marker E-cadherin and epithelial-mesenchymal transition (EMT)-associated markers (N-cadherin, α-SMA, and vimentin) were evaluated. Histological analysis showed that EDC expressions were upregulated in the current smoker group and downregulated in the quitter group. These expression patterns were consistent with mRNA and protein expression levels. We also found that the local Th2 cytokine expression and IgE class switching, as well as serum IgE levels, were elevated in the current smoker group and showed normal levels in the quitter group. Furthermore, the expressions of E-cadherin decreased while those of N-cadherin, α-SMA, and vimentin increased in the current smoker group compared those in the never smoker group. Taken together, these results indicate that TS contributes to the deterioration of pathogenesis by releasing local EDCs and Th2 cytokines, resulting in EMT in patients with CRSwNP. We verified that alterations of immunological response by TS in sinonasal epithelium can play a vital role in leading to CRSwNP.

• Membrane and Water Treatment
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• v.7 no.4
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• pp.277-296
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• 2016

The aim of this research was to investigate the ability of nanofiltration (NF) and ultrafiltration (UF) membranes as a filtration unit for groundwater treatment for drinking water resources. Commercial membranes denoted as TS40, TFC-SR3 and GHSP were used to study the performance based on rejections and fluxes. The investigation has been conducted using natural groundwater obtained from a deep tube well with initial concentration of iron (Fe) and manganese (Mn) at 7.15 mg/L and 0.87 mg/L, respectively. Experimental results showed that NF membranes exhibited higher fluxes than UF membrane with pure water permeability at 4.68, 3.99 and $3.15L.m^{-2}.h^{-1}.bar^{-1}$, respectively. For metal rejection, these membranes have performed higher removal on Fe with TS40, TFC-SR3 and GHSP membranes having more than 82%, 92% and 86% respectively. Whereas, removal on Mn only achieved up to 60%, 80% and 30%, for TS40, TFC-SR3 and GHSP membranes respectively. In order to achieve drinking water standard, the membranes were efficient in removing Fe ion at 1 and 2 bar in contrast with Mn ion at 4 and 5 bar. Higher rejection of Fe and Mn were achieved when pH of feed solution was increased to more than 7 as TFC-SR3 membrane was negatively charged in basic solution. This effect could be attributed to the electrostatic effect interaction between membrane material and rejected ions. In conclusion, this study proved that NF membrane especially the TFC-SR3 membrane successfully treated local groundwater sources for public drinking water supply in line with the WHO standard.