• 동의생리병리학회지
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• 제21권6호
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• pp.1431-1436
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• 2007

In order to optimize the extract condition and improve physiological activity of the extract form Tricholoma matsutake, experiments related to extraction methods, totale yield, content of total soluble polysaccharide, SOD-like activity, total polyphenol amount, and volatile flavor compound and the others were carried out, results were obtained as following: Compare with traditional hydrothermal extraction method (Hot water extraction : HWEW), it illustrates that the low temperature extraction method which combines a supersonic waves and microwave (Supersonic microwave extraction : SMEW) causes of increasing the total yield, total soluble polysaccharide. As to the anti-oxident effect, SMEW method leds to increasing of the SOD-like activity, total polyphenol amount as well. Also, cytotoxic effect and growth inhibitory effect against cancer cell line are much higher in SMEW method than HWEW method, especially SMEW5 extracts treated by supersonic 15 min. and microwave 120W, 3 min. and 2 times. The main volatile flavor compound and infinitesimal volatile flavor compound both increase significantly by SMEW method. It is concluded the main components of the volatile flavor compounds extracted from Tricholoma matsutake are 1-octen-3-0l, Methyl cinnamate, 2-octeno1 et al. alcohol typies. Consequently, SMEW5 method is considered as the most effective one for anti-oxidant and is prior to any other methods. And the optimun conditions of this method are : supersonic waves (supersonic, 25KHz, 50W) 15 minutes, microwave spectroscopy (microwave, 2,450MHz, 120W) 3 minutes, and every treatment is performed once followed twice repeats.

• 한국자기학회지
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• 제12권2호
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• pp.68-72
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• 2002

본 연구에서는 터널링 자기저항 소자에서 절연층을 중심으로한 접합면의 정전 용량이 이를 메모리 소자로 사용하였을 때 접근시간에 미치는 영향을 알아보았다. 여기에서 얻어진 결과는 자장을 인가하지 않고 전기적 신호만을 입력하여 측정하였다. 이를 위해 시편에 1 MHz의 양극성 구형파를 인가하고 응답 파형을 오실로스코프로 관찰하여 시정수를 계산하였다. 그리고 각 cell의 접합면 면적에 따라 시정수를 비교하였다. 이렇게 측정된 시정수와 시편에서 각 부분의 전기적 저항 측정자료들을 기초로 전기 패드 리드 그리고 접합면과 같은 시편의 각 부위가 전기적 회로로 모델링 되었다. 그 결과 200$\mu\textrm{m}$$\times$200$\mu\textrm{m}$ cell에서 약 90 pF의 접합면 정전용량이 존재함을 유추할 수 있었다. 또한 모델링 결과와 실제 측정한 결과를 서로 비교하여 그 특성이 매우 유사함을 보였다.

• 동의생리병리학회지
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• 제21권6호
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• pp.1506-1512
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• 2007

In order to investigate the totale yield, the content of soluble polysaccharide and the others of FEW extract from the yeast fermentated Ganoderma lucidium by supersonic method, the yeast strain was inoculated after pretreatment and subsequently followed fermentation and supersonic extract. The main construction of the extract method is composed of the main glucose and together with the xylose, fucose, galactose and mannose. Results show that because of the generated lactic acid and ethanol, pH value of extract decreases and the safety as well as the preservation is improved. The extract yield, the total soluble polysaccharide, SOD-like activity, cytotoxic effect and growth inhibitory effect against cancer cell line are much higher in FE method than RE method, especially FEW3 extracts fermented during 24hrs. It is concluded that yeast fermentation makes the extract yield increase because of the cell disintegration, the useful ingredients of the germ body, the metabolic products, the insoluble ingredients due to the generation of ethanol, and the cell fragmentation caused by the supersonic waves vibration. Content of generated ethanol, total soluble polysaccharide and extract yield all increase during the fermentation time from 24 to 72 hours and the optimum fermentation condition is at $27^{\circ}C$ for 72 hours. The bitter taste and smell of the Ganoderma lucidium extract is diminished, fragrant-bitter taste and smell is generated so that the whole functional quality is improved.

• 디지털융복합연구
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• 제11권1호
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• pp.283-288
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• 2013

본 논문에서는 실내 환경에서 전파특성 분석에 유용한 마이크로 셀용 3D 시뮬레이터를 제시하였다. 지금까지 소개된 대부분의 전파특성 분석 결과들은 2차원 평면에서 거리에 따른 신호의 손실(Path Loss) 위주로 연구가 진행 되었다. 본 연구에서는 실내에서 전파특성을 분석하기 위해 다양한 ITU 모델을 사용하여 입체구조의 실내 환경에서 전파의 수신신호의 세기에 대한 분석을 수행하였다. 시뮬레이션에서 나타난 결과를 분석해보면 저 주파수(150MHz-400MHz) 대역과 고주파수 대역(2GHz-6GHz) 에서 전파특성이 많은 차이를 나타내고 있다. 그리고 각 수신기의 위치에서 수신 신호는 전파경로상의 벽면에서 손실되는 전력에 따라 차이가 생기기 때문에 송신기의 출력도 중요한 요인으로 분석되었다.

• 한국지반공학회논문집
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• 제24권12호
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• pp.103-111
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• 2008

지반은 화학적 및 물리적인 작용으로 인하여 지반 자체가 용해되어 지반 재료 자체가 자연적으로 소실(Vanishing)되는 입자를 포함하고 있다. 지반의 소실은 입자로 구성된 재질에서 국부적인 간극 및 투수계수의 증가와 같은 미소구조의 변화를 유발하여 지반의 강도와 변형에 영향을 미친다. 본 논문에서는 지반 재료의 소실 발생 시 대상지반의 국부적인 강성의 변화특성을 파악하기 위하여 소금과 모래를 여러 가지 부피비로 혼합하여 사용하였다. 실험은 전단파 측정을 위한 벤더 엘리먼트가 설치된 압밀셀을 이용하여 수행하였다. 입자의 용해는 다양한 구속응력 하에서 시료를 포화시켜 수행하였다. 축방향 변형률과 전단파 신호를 매 하중 단계와 입자용해 시 측정하였다. 실험 결과, 입자 용해 후 축방향변형률과 간극비는 증가하였고, 전단파 속도와 최대전단탄성계수는 감소하는 것으로 나타났다. 입자 용해로 인한 간극비 증가와 입자간의 접촉이 감소하여 전단파 속도가 감소하였다. 입자가 용해되는 동안 수직변형률은 포화 시작점에서 급격히 증가하였으며 입자 용해가 완료되면서 수렴하였으며, 전 단파속도는 시작 시 감소하였다가 입자가 재배열되면서 증가하는 것으로 나타났다. 모래와 소금으로 구성된 시료는 지반소실재의 거시적 구조 거동에 의미있는 결과를 보여줄 수 있는 것으로 나타났다.

• 물과 미래
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• 제29권5호
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• pp.139-150
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• 1996

본 논문에서는 수리학적 유역추적 모형인 선형 Muskingum-Cunge(M-C)법에 있어서 격자간격과 같은 수치적 인자의 변화가 단위폭사면에서의 유출수문곡선에 미치는 영향을 소개한다. 수치계산의 결과에 의하면, 유출특성은 수치적 또는 물리적으로 의미를 갖는 Courant 수 C 및 cell Reynolds 수 D의 값에 좌우되는데, C 값은 1에 접근할수록 D 값은 증가할수록 수치분산에 의한 진동은 발생하기 어렵다. C<1인 경우는 수치진동이 이동파의 전방에 발생한다. C>1인 경우는 파의 후방에 발생하는데, 이 때는 수치확산의 효과로 인해 수치진동은 작아지거나 사라진다. 특성구간길이 L의 값이 작은 사면(예, 급경사사면)의 경우, M-C법은 kinematic 법과 마찬가지로 파의 감쇠를 보이지 않는다. 한편 L의 값이 큰 사면(예, 완경사 사면)에서는 M-C법은 큰 거리격자간격 (Δx)에서도 큰 D(= L/ΔX)의 값을 갖게 되어 C에 거의 관계없이 diffusion wave를 잘 재현한다. 따라서 완경사 유역의 추적에 있어 M-C 법의 적용은 매우 유효하리라고 생각된다.

• The Korean Journal of Physiology and Pharmacology
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• 제9권4호
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• pp.209-213
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• 2005

Interstitial cells of Cajal (ICCs) are the pacemaker cells that generate slow waves in the gastrointestinal (GI) tract. In the present study, we investigated the effect of mitochondrial ATP-sensitive potassium (mitoKATP) channel on pacemaking activity in cultured ICCs from murine small intestine by using whole-cell patch clamp techniques. Under current clamp mode, at 10μM glibenclamide, there was no change in pacemaking activity of ICCs. At $30{\mu}M$ glibenclamide, an inhibitor of the ATP sensitive $K^+$ channels, we could find two examples. If pacemaking activity of ICCs was irregulating, pacemaking activity of ICCs was changed into regulating and if in normal conditions, membrane potential amplitude was increased. At $50{\mu}M$ glibenclamide, the resting membrane potential was depolarized. At 3mM 5-HDA, an inhibitor of the mitoKATP channels, inhibited the pacemaking activity of ICCs. Both the amplitude and the frequency were decreased. At 5 mM 5-HDA, both the amplitude and the frequency were completely abolished. Diazoxide, an opener of the mitoKATP channels, was applied to examine its effect on pacemaking activity of ICCs. At $50{\mu}M$ concentration, the pacemaking activity of ICCs was inhibited. Both the amplitude and the frequency were decreased. At 1 mM concentration, both the amplitude and the frequency were completely abolished and the resting membrane potential was shaked.These results indicate that mitoKATP channel has an important role in pacemaking activity of ICCs.

• Nuclear Engineering and Technology
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• 제37권5호
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• pp.447-456
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• 2005

Laser driven accelerators promise to provide an alternative to conventional accelerator technology. They rely on the excitation of large amplitude density waves in a plasma by the photon pressure of an intense laser. The density oscillations in which electrons and ions are separated, result in extremely large longitudinal electric fields that can be several orders of magnitude larger than those that are used in today's radio-frequency accelerators. Whereas this principle had been demonstrated experimentally for nearly two decades, it was not until 2004 that the production of high quality electron beams around 100 MeV was demonstrated. Analysis, aided by particle-in-cell simulations, as well as experiments with various plasma lengths and densities, indicate that tailoring the length of the accelerator, together with loading of the accelerating structure with beam, are the keys to production of mono-energetic electron beams. Increasing the energy towards a GeV and beyond will require reducing the plasma density and design criteria are discussed for an optimized accelerator module. The current progress and future directions are summarized through comparison with conventional accelerators, highlighting the unique short and long term prospects for intense radiation sources and high energy accelerators based on laser-drivenplasma accelerators.

• 대한원격탐사학회지
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• 제33권4호
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• pp.351-358
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• 2017

A new method to decompose the footprints of marine atmosphere boundary layer (MABL) on Synthetic Aperture Radar (SAR) imagery into characteristic spatial scales is proposed. Using two-dimensional Empirical Mode Decomposition (EMD) we obtain three Intrinsic Mode Functions (IMFs), which mainly present longitudinal rolls, three-dimensional cells and atmospheric gravity waves (AGW). The rolls and cells have spatial scales between 3.0 km and 3.8 km and between 5.3 km and 7.1 km, respectively. Based on previous observations and mixed-layer similarity theory, we estimated MABL's depths that vary from 0.95 km to 1.2 km over the rolls and from 3.0 km to 3.8 km over the cells. The AGW has maximum spectrum at 14.3 km wavelength. The method developed in this work can be used to decompose other satellite imageries into individual features through characteristic spatial scales.

• Nuclear Engineering and Technology
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• 제41권8호
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• pp.1045-1052
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• 2009

A calculation model is developed to predict the transient free surface flow on the containment floor following a loss-of-coolant accident (LOCA) of pressurized water reactors (PWR) for the use of debris transport evaluation. The model solves the two-dimensional Shallow Water Equation (SWE) using a finite volume method (FVM) with unstructured triangular meshes. The numerical scheme is based on a fully explicit predictor-corrector method to achieve a fast-running capability and numerical accuracy. The Harten-Lax-van Leer (HLL) scheme is used to reserve a shock-capturing capability in determining the convective flux term at the cell interface where the dry-to-wet changing proceeds. An experiment simulating a sudden break of a water reservoir with L-shape open channel is calculated for validation of the present model. It is shown that the present model agrees well with the experiment data, thus it can be justified for the free surface flow with accuracy. From the calculation of flow field over the simplified containment floor of APR1400, the important phenomena of free surface flow including propagations and interactions of waves generated by local water level distribution and reflection with a solid wall are found and the transient flow rates entering the Holdup Volume Tank (HVT) are obtained within a practical computational resource.