• 전기전자학회논문지
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• 제27권4호
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• pp.556-560
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• 2023

본 연구에서는 4H-SiC Epi Surface에 Nitrogen implantation 공정이 깊은준위결함과 lifetime에 미치는 영향을 비교분석하였다. Deep Level Transient Spectroscopy (DLTS)와 Time Resolved Photoluminescence (TR-PL)을 사용하여 깊은준위결함과 carrier lifetime을 측정하였다. As-grown SBD에서는 0.16 eV, 0.67 eV, 1.54 eV 에너지 준위와 implantation SBD의 경우 0.15 eV 준위에서의 결함을 측정되었으며, 이는 nitrogen implantation으로 불순물이 titanium 및 carbon vacancy를 대체됨으로 lifetime killer로 알려진 Z_1/2, EH_6/7 준위 결함은 감소하였다.

• Archives of Pharmacal Research
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• 제25권5호
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• pp.675-680
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• 2002

In order to investigate the underlying mechanism of HCI in oesophagitis, the inflammatory response to HCI was observed in RBL-2H3 mast cells. Rat basophilic leukemia (RBL-2H3) cells were used to measure histamine release, arachidonic acid (AA) release, reactive oxygen species (ROS) and peroxynitrite generation induced by HCI. Exogenous HCl increased the level of histamine release and ROS generation in a dose dependent manner, whereas it decreased the spontaneous release of [$^3$H] M and the spontaneous production of peroxynitrite. Mepacrine (10 $\mu$M), oleyloxyethyl phosphorylcholine (10 $\mu$M) and bromoenol lactone (10 $\mu$M) did not affect both the level of histamine release and ROS generation induced by HCI. U73122 (1 $\mu$M), a specific phospholipase C (PLC) inhibitor did not have any influence on level of histamine release and ROS generation. Propranolol (200 $\mu$M), a phospholipase D (PLD) inhibitor, and neomycin (1 mM), a nonspecific PLC and PLD inhibitor, significantly inhibited both histamine release and ROS generation. Diphenyleneiodonium (10 $\mu$M), a NADPH oxidase inhibitor, and tiron (5 mM), an intracellular ROS scavenger significantly inhibited the HCI-induced histamine release and ROS generation. These findings suggest that the inflammatory responses to HCI is related to histamine release and ROS generation, and that the ROS generation by HCI may be involved in histamine release via the PLD pathway in RBL-2H3 cells.

• 한국철도학회논문집
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• 제10권5호
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• pp.619-625
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• 2007

본 논문은 인천국제공항철도에서 운행하고 있는 전동차의 동적특성시험을 수행한 결과이다. 인천국제공항철도의 직통형 전동차는 국내 처음으로 120km/h로 주행한 차량으로 탈선계수를 공차와 만차로 구분하여 측정하였다. 탈선계수측정결과 탈선에 대한 안전성을 판단할 때 가장 기본적인 지표로 사용하는 탈선계수는 공차 때가 만차 때보다 높게 나타났으며, 공차와 만차 모두 0.8 미만이었다. 속도에 따른 탈선계수는 80km/h를 전후한 속도 대역으로 운행하는 구간이 선로상태가 좋지 않은 구간으로서 탈선계수도 증가하는 것으로 나타났다. 횡압은 공차 때에는 2.1톤 미만이었으며, 만차 때에는 2.4톤 미만으로 발생하였다. 인천국제공항철도 전동차가 120km/h 주행에서도 안전함을 탈선계수 실측에 의해 확인하였다. 그러나 본 논문에서 적용된 평가방법의 경우 시험방법이 복잡하고, 측정장치 설치의 어려움이 있으며, 비용이 많이 드는 단점이 있었다. 따라서 측정이 간단한 방법으로 영업운전에서도 차량의 안전성을 확인할 수 있는 방안이 연구되어야 할 것이다.

• 대한본초학회지
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• 제38권2호
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• pp.1-7
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• 2023

Objectives : From this study, we sight to identify Anti-stress effect of Chenwangbosim-Dan (Tianwangbuxin-Dan) Extract∘Fermented Rice Extract (GABA : gamma-aminobutyric acid 30%) Complex Methods : In order to measure the degree of functional evaluation of tension relief due to stress, it was evaluated whether the psychological indicators VAS(Visual Analog Scale) and POMS(Profile Of Mood State) were improved. Which is generally used for stress measurement and has a high frequency of clinical use. All clinical trial subjects were required to take the drug once a day at 9 ± 30 min in the morning for 2 weeks. Results : After intake, the group that Chenwangbosim-Dan(Tianwangbuxin-Dan) Extract∘Fermented Rice Extract (GABA : gamma-aminobutyric acid 30%) Complex had a statistically significant improvement effect compared to before intake due to an improved 30.81% of the VAS scores. The POMS-T score improved 54.13%, the POMS-V score improved 117.5% and the POMS-F score improved 59%, which had a statistically significant effect compared to Placebo group (p<0.001). There is a significant difference between two group, so even considering the placebo effect, the anti stress effect was confirmed in the Chenwangbosim-Dan (Tianwangbuxin-Dan) Extract∘Fermented Rice Extract (GABA : gamma-aminobutyric acid 30%) Complex intake group. Conclusions : The above results showed that the Chenwangbosim-Dan(Tianwangbuxin-Dan) Extract∘Fermented Rice Extract (GABA : gamma-aminobutyric acid 30%) Complex had an anti-stress effect. Therefore, it is expected to be developed as a safe and comfortable mental care health functional food that can reduce the risk of drug abuse.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.142.1-142.1
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• 2016

We present bulk diffusion rates of hydroxide ions in amorphous solid water (ASW) at 135 ~ 160 K. Previous researches showed that the diffusion mechanism of hydroxide is different from one of hydronium ions, and this implies that they have different diffusion rates. In ultra-high vacuum (UHV) chamber, low-energy scattering (LES) was used to measure ion population and temperature-programmed desorption (TPD) was conducted for measuring ASW thicknesses. To determine the diffusion rates, a simple model for $H_2O/NaOH/H_2O$ sandwich films was developed using Fick's second law. The measured surface population of hydroxide ions as a function of time was well fitted to the model, and the rates were well agreed to an Arrhenius equation.

• 천문학회보
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• 제39권2호
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• pp.65.1-65.1
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• 2014

We present Palomar/SWIFT integral field spectroscopy of z~0.2 strong $H{\alpha}$ emitters identified in the Sloan Digital Sky Survey. The large Halpha equivalent widths as well as the huge specific star formation rates of these galaxies are comparable with that of z>4 Lyman break galaxies, thus understanding the gas kinematics and the distribution of massive stars in these systems will help to obtain a better understanding of high-redshift star forming environments and the growth of massive galaxies. We measure the velocity dispersion across the entire galaxy, estimate the number density and the spatial distribution of massive stars from the emission line morphologies. The role of minor mergers in powering star formation is investigated as an alternative to cold flow driven star formation.

• Journal of Dairy Science and Biotechnology
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• 제35권2호
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• pp.85-92
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• 2017

Four different types of cheeses were measure detailed changes in the mineral concentrations of cheese-serum during ripening. Concentrations of minerals in cheese juice were measured. The pH value using the low pH method (LPM) cheese was significantly (p<0.05) lower than that of other cheeses. Similarly the total Ca, S, Mg, and P contents of LPM cheese were significantly lower in than those of other cheeses. Ca, S, Mg, and P remained in colloidal form, while other minerals were mostly in soluble forms after 1 day. The minerals associated with the structure of cheese (i.e., casein or colloidal calcium phosphate) remained largely insoluble even after 1 month of ripening.

• 한국축산시설환경학회지
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• 제11권1호
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• pp.1-10
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• 2005

이 연구에서는 하절기에 양돈농가의 육성 비육돈사와 분만돈사에서 얼마만큼의 암모니아, 이산화탄소 등의 환경가스가 발생하는 가를 측정하고, 외기의 환경변화가 내부의 환경에 어떠한 영향을 주는가를 분석하여, 하절기 온도가 높게 올라갈 때 돈사의 생산성 향상을 위한 환경관리 기술을 개발하고, 양돈농장에서 발생하는 악취의 양을 추정함으로써 발생한 악취를 제거하기 위한 기술을 개발하기 위한 기초 자료를 얻기 위해 수행하였으며 그 결과를 요약하면 다음과 같다. 1. 돈사의 하절기 일중 온$\cdot$습도 변화를 측정한 결과 육성$\cdot$비육돈사의 경우 내부온도가 권장 사육온도인 $15{\~}25^{\circ}C$ 보다 높게 유지되는 것으로 나타났고, 분만돈사의 경우도 권장 사육온도인 $20{\~}25^{\circ}C$ 보다 높게 유지되는 것으로 나타났다. 2. 돈사의 내부 상대 습도는 한 낮의 일부시간을 제외하고는 권장환경 습도인 $60{\~}80{\%}$를 유지하는 것으로 나타나 별도의 시설이 필요치 않을 것으로 판단되었다 3. 육성$\cdot$비육돈사와 분만돈사 모두 암모니아 농도가 평균 9ppm 내외로 나타났으며, 평균 환기율은 육성$\cdot$비육돈사가 $110m^3/h{\cdot}pig$로 고온기 권장 환기율 $210m^3/h{\cdot}pig$ 보다 약 $50\%$ 낮게 나타났고, 분만돈사는 평균 $185m^3/h{\cdot}pig$로 권장 환기율 $876m^3/h{\cdot}pig$의 $21\%$ 수준으로 환기율이 낮은 것으로 나타났다. 4. 암모니아 발생률은 육성$\cdot$비육돈사가 평균 $4.37g/h{\cdot}500kg$, 분만돈사가 $4.82g/h{\cdot}500kg$ 으로 분만돈사의 암모니아 발생률이 육성$\cdot$비육돈사의 암모니아 발생률 보다 약 $10\%$ 높은 것으로 나타났다.

• Journal of Communications and Networks
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• 제11권1호
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• pp.47-56
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• 2009

We investigate the connectivity of fading wireless ad-hoc networks with a pair of novel connectivity metrics. Our first metric looks at the problem of connectivity relying on the outage capacity of MIMO channels. Our second metric relies on a probabilistic treatment of the symbol error rates for such channels. We relate both capacity and symbol error rates to the characteristics of the underlying communication system such as antenna configuration, modulation, coding, and signal strength measured in terms of signal-to-interference-noise-ratio. For each metric of connectivity, we also provide a simplified treatment in the case of ergodic fading channels. In each case, we assume a pair of nodes are connected if their bi-directional measure of connectivity is better than a given threshold. Our analysis relies on the central limit theorem to approximate the distribution of the combined undesired signal affecting each link of an ad-hoc network as Gaussian. Supported by our simulation results, our analysis shows that (1) a measure of connectivity purely based on signal strength is not capable of accurately capturing the connectivity phenomenon, and (2) employing multiple antenna mobile nodes improves the connectivity of fading ad-hoc networks.

• 치과방사선
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• 제20권1호
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• pp.63-70
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• 1990

The aim of this study has been to investigate the growth of the pharynx and sexual differences in the lateral cephalograms of Korean children. The material includes 173 cepalograms from two groups composed of 51 males aged 12.0 years and 39 females aged 12.2 years in group 2, and 45 males aged 7.4 years and 39 females aged 7.5 year in group 1, respectively. In order to study and measure the pharyngeal area the following skeletal landmarks were selected: S, N, A, Ptm, B, H, H', M, S-N, FH and CV, and the angle CV-FH was measured to provide a factor for correction of error resulting from improper head positioning of subjects, especially in relative positions of A and H, while radiography. For each variable the statistically treated data have been presented in the table Ⅱ, Ⅲ, Ⅳ. The main results are presented as follows: 1. In general, the measurements of male were larger than those of female in antero-posterior dimension of pharyngeal cavity, but all variables did not show significant sexual differences in both groups when evaluated statistically. 2. All of the measurements were larger in male than in female in vertical dimensions of pharyngeal cavity in group 2, and there were statistical significances of sexual differences in the variables except M-H', but all variables did not show significant sexual differences in group 1 when evaluated statistically. 3. The dimensional increase of the pharynx by the growth in the vertical dimensions was shown to be greater than in the antero-posterior dimensions in the both sexes.