• 한국식품영양과학회:학술대회논문집
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• 한국식품영양과학회 2001년도 International Symposium on Food,Nutrition and Health for 21st Century
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• pp.38-47
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• 2001

L-theanine is a unique amino acid, found almost solely in tea plants. It is the main component responsible for the exotic taste of green tea. In our studies of L-theanine, we have found a variety of biological activities including relaxation and the alleviation of PMS. In general, animals generate very weak electric pulses on the surface of the brain, called brain waves. Brain waves are classified into four types, namely $\alpha$, $\beta$, $\delta$ and $\theta$-waves, based on their frequency. Brain waves correlate with individual mental conditions. For example, generation of $\alpha$-waves is considered an index of relaxation. In human volunteers, $\alpha$-waves were generated on the occipital and parietal regions of the brain surface within 40 minutes after the oral administration of 50 or 200 mg Suntheanine$^{TM}$ without causing drowsiness. Premenstrual Syndrome (PMS) is a symptom unique to women which appears in the luteal phase from the ovulation period through the first day of menstruation. It possesses characteristics of having a peak just prior to menstruation and disappearing 1 - 2 days following the start of menstruation. Symptoms of PMS are generally categorized as mental, physical and social symptoms. When comparing the reported Symptoms of PMS by the methods of MDQ score, the Suntheanine$^{TM}$ group was found to have a lower incidence of PMS symptoms, including physical, mental and social symptoms. Overall, a significant alleviation of PMS symptoms by the administration of 200 mg Suntheanine$^{TM}$ was observed. With the successful industrial production of L-theanine, we are now able to supply Suntheanine$^{TM}$, offering a tremendous opportunity for designing functional foods targeting relaxation and the alleviation of PMS.

• 한국광학회지
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• 제13권1호
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• pp.58-64
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• 2002

마하젠더형 광세기 변조기를 이용하여 l0 GHz 고조모드잠금된 분산보상 어븀첨가 광섬유 레이저의 출력 안정화 되먹임 제어를 하고 출력의 안정도를 측정하였다. 레이저의 출력 불안정성이 발생하였을 때 나타나는 완화진동 주파수 성분을 억압하도록 공진기 길이를 조정하여 16시간 이상 출력 안정화를 시켰다. 이때, 안정화가 진행되는 동안 rms 위상잡음과 rms진폭잡음은 각각 260 fsec-524 fsec와 4-11.5%의 사이에 분포하였고, BER은 $10^{-13}$ 으로 측정되었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.879-882
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• 1992

In order to study electrical properties of epoxy composites with various additives rates and curing conditions, dielectric measurements have been performed over a frequency range from 30 [Hz] to 3 [MHz] and a temperature range of 20[$^{\circ}C$]$\sim$180[$^{\circ}C$] The observed higher values of dielectric permittivity and loss In the case of filled epoxy are attributed to MWS polarization effect. The low temperature peak assigned to the $\beta$-relaxation process is attributed to the enhenced rotation of the methyl group attached to the main chain and the presence of filler. And the high temperature peak ($\alpha$-relaxation process)is associated with the segmental motion or glass transition process.

• Journal of Biosystems Engineering
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• 제28권3호
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• pp.253-260
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• 2003

In this study, the feasibility of magnetic resonance techniques for nondestructive internal quality evaluation of Korean red ginseng was examined. Relaxation time constants were measured using various grades of red ginsengs. Solid state magnetic resonance imaging technique was applied to image dried red ginsengs which have low moisture contents (about 13%). A 7 tesla magnetic resonance imaging system operating at a proton resonant frequency of 300 ㎒ was used for acquiring MR images of dried Korean red ginseng. The comparison test of cross cut digital images and magnetic resonance images of heaven grade, good grade with cavity inside, and good grade with white part inside red ginseng suggested the feasibility of the internal quality evaluation of Korean red ginsengs using MRI techniques. A good grade red ginseng included abnormal tissues such as cavities or white parts inside was observed by the signal intensity of MR image based on magnetic resonance properties of proton nucleus. Analysis on an one dimensional profile of acquired MR image of Korean red ginseng showed easy discrimination of normal and abnormal tissues. MR techniques suggested ways to detect internal defects of red ginsengs effectively.

• 대한수의학회지
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• 제34권4호
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• pp.727-734
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• 1994

To elucidate the effect of calcitonin gene-related peptide(CGRP), vasoactive intestinal peptide(VIP) and substance P was investigated with perivascular nerve stimulation and treatment of peptides from polygraph in the isolated renal artery of rabbit. 1. The neurogenic contraction induced by perivascular nerve stimulation was the frequency-dependent manner(264 Hz) in the isolated renal artery of rabbit. 2. CGRP and VIP caused the relaxation on the precontraction with noradrenaline($10{\mu}m$) on the presence and absence of endothelium in the isolated renal artery of rabbit. 3. Substance P caused the endothelium-dependent relaxation on the precontraction with noradrenaline($10{\mu}m$) in the isolated renal artery of rabbit. 4. CGRP and VIP inhibited the neurogenic contraction by the perivascular nerve stimulation(0.3 ms, 80 V, 50 Hz, 1 sec) on the absence and presence of endothelium in the isolated renal artery of rabbit. 5. Substance P inhibited on the neurogenic contraction by the perivascular nerve stimulation with the endothelium-dependent in the isolated renal artery of rabbit.

• 말소리와 음성과학
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• 제4권4호
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• pp.147-154
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• 2012

The purpose of this study is to examine the effect of voice improvement when vocal training, which relaxes the vocal contact, is applied to children with vocal nodules. Subjects included 20 5- to 12-year-old boys with vocal nodules in Otolaryngology and for whom voice therapy had been advised. The vocal therapy was conducted for 40 minutes per a week for a total of eight times. Results were evaluated by videostroboscopy, auditory-perceptual evaluation of GRBAS Scale, aerodynamic test, and acoustic analysis before and after therapy. As a result, first, the size of vocal nodules was reduced and the unstable pattern of vocal contact was improved. Glottic closure was increased and Phase symmetry was decreased during vocal vibration. Mucosal wave was increased and muscle tension of the larynx was reduced. Second, auditory-perceptual evaluation showed that subjects' overall quality of voice improved. GRBAS Scale Evaluation showed that the characteristics of the subjects' voice which were rough, breathy, and strained and breathy were reduced after therapy. Third, the measurements of acoustic parameters showed a statistically significant improvement. The fundamental frequency of the subejects' voice was increased and values of Jitter and Shimmer, NHR, [H1-H2] decreased. Fourth, the maximum phonation time of children was increased. These results imply that vocal relaxation training conducted in this study has a very positive effect to improve the voice of children with vocal nodules.

• 한국인쇄학회지
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• 제23권2호
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• pp.1-14
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• 2005

Generally, printing inks are composed of pigment, vehicle and additive. Among others, the vehicle transfers the pigment to substrate and then binds it on the surface. So, rheological properties of the vehicle are an important factor which has influence on printability. Thus, in this study, rheology of the vehicle was investigated by using rotational rheometer according to molecular weight of resin. Also, emlusion rheology of water in oil type and its microstructure were examined with increasing the shear rate. Consequently, the following results were obtained: (1) By viscometric flow test, zero shear viscosity and shear thinning index of vehicle increased with increasing the molecular weight of resin. (2) By relaxation and creep test, relaxation time and retardation time of vehicle increased with increasing the molecular weight of resin. (3) By frequency sweep test, crossover point of vehicle increased with increasing the molecular weight of resin. (4) G' and G" of emlusions increased with increasing the molecular weight by amplitude sweep test. (5) The shape of water drop in emlusions was changed to the capillary tube.

• 한국전기전자재료학회논문지
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• 제12권1호
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• pp.35-43
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• 1999

Microstructures and dielectric properties of (Sr$\_$1-x/Ca$\_$x/) TiO$_3$-0.006Nb$_2$O$\_$5/ (0.05$\leq$x$\leq$0.2) boundary layer ceramics were investigated. The samples fired in a reducing atmosphere(N$_2$) were painted on the surface with CuO paste for the subsequent grain boundary diffusion, and then annealed at 1100$^{\circ}C$ for 2 hrs. The metal oxide of CuO infiltrated by thermal diffusion from surface of sample presents continuously in not grain but only grain boundary, and makes up thin boundary phase. The SEM photo, and EDAX revealed that CuO was penetrated rapidly into the bulk along the grain boundaries during the annealing. The average grain sizes is continuously increased as the content of substitutional Ca is increased from 5[mol%] to 15[mol%], but the average grain size of the sample with content of 20[mol%] Ca is slightly decreased. In the samples with content of 10∼15[mol%] Ca, excellent dielectric properties were obtained as follows; dielectric constant <25000, dielectric loss <0.3[%], and capacitance change rate as a function of temperature <${\pm}$10[%], respectively. All samples in this study exhibited dielectric relaxation with frequency as a functior of the temperature.

• 한국광학회지
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• 제9권4호
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• pp.270-273
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• 1998

본 연구에서는 능동형 모드록킹 방식을 이용하여 10 GHz의 고반복률을 가지는 초단펄스 광섬유 고리형 레이저를 제작하였다. 레이저 공진기의 모든 부분을 편광유지 광섬유로 구성하여 편광변화에 의한 불안정성이 없는 비교적 안정된 펄스를 얻을 수 있었으며, 투과 대역폭 2.4 nm의 파장가변 필터를 공진기 내부에 삽입하여 발진파장을 1530 nm에서 1560 nm 까지 조절할 수 있었고, 0.4 nm 파장 선폭과 8 psec 펄스폭, 그리고 1.2mW평균출력을 갖는 펄스를 발생시킬 수 있었다. 또한, 여기광의 세기에 따른 relaxation oscillation 주파수 변화를 측정함으로써 레이저 공진기의 손실을 알 수 있는 방법을 제안하였다.

• Nuclear Engineering and Technology
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• 제56권4호
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• pp.1296-1309
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• 2024

The aim of this work is to explore the effect of the double subdiffusion on the stability in BWRs. A BWR novel reduced order model with double subdiffusion effects: reduced order fractional model (DS-F-ROM) to describe the neutron and heat transfer processes was proposed for this study. The double subdiffusion was developed with a fractional-order two-equation model, and with different fractional-orders and relaxation times. The stability analysis was carried out using the root-locus method and change from the s to the W domain and were confirmed using the time-domain evolution of neutron flux for a unit step change in reactivity. The results obtained using the reduced fractional-order model are presented for different anomalous diffusion coefficient values. Results are compared with normal diffusion and P1 equations, which are obtained straightforwardly with DS-ROM when relaxation time tends to zero, and when the anomalous diffusion coefficient tends to one, respectively.