• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.219-219
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• 2010

기존의 플로팅 타입의 메모리는 소자의 소형화에 따른 인접 셀 간의 커플링 현상과 전계에 따른 누설전류의 증가 등과 같은 문제가 발생한다. 이에 대한 해결책으로서 전하 저장 층을 폴리실리콘에서 유전체를 사용하는 SONOS 형태의 메모리와 NFGM (Nano-Floating Gate Memory)연구가 되고 있다. 그러나 높은 구동 전압, 느린 쓰기/지우기 속도 그리고 10년의 전하보존에 대한 리텐션 특성을 만족을 시키지 못하는 문제가 있다. 이러한 문제를 해결 하고자 터널베리어를 엔지니어링 하는 TBM (Tunnel Barrier Engineering Memory) 기술에 대한 연구가 활발히 진행 중이다. TBM 기술은 터널 층을 매우 얇은 다층의 유전체를 사용하여 전계에 따른 터널베리어의 민감도를 증가시킴으로써 빠른 쓰기/지우기 동작이 가능하며, 10년의 전하 보존 특성을 만족 시킬 수 있는 차세대 비휘발성 메모리 기술이다. 또한 고유전율 물질을 터널층으로 이용하면 메모리 특성을 향상 시킬 수가 있다. 일반적으로 TBM 기술에는 VARIOT 구조와 CRESTED 구조로 나눠지는데 본 연구에서는 두 구조의 장점을 가지는 Staggered tunnel barrier 구조를 $Si_3N_4$와 HfAlO을 이용하여 디자인 하였다. 이때 HfO2와 Al2O3의 조성비는 3:1의 조성을 갖는다. $Si_3N_4$와 HfAlO을 각각 3 nm로 적층하여 리세스(Recess) 구조의 트랜지스터를 제작하여 차세대 비휘발성 메모리로써의 가능성을 알아보았다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.4
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• pp.443-450
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• 2013

Effects of newly developed functional rice grains Goami (high-amylose rice) and Nokwon (green-kerneled rice) on the glucose metabolism and antioxidative defense system in C57BL/6N mice under high fat diet condition were investigated. Animals were randomly divided into five groups (n = 8) and given experimental diets for eight weeks: normal control diet (NC), high fat diet (HF), and high fat diet supplemented with white rice (HF-WR), Goami rice (HF-GR), and Nokwon rice (HF-NR). At the end of the experimental period, the HF group exhibited markedly higher blood glucose level, insulin concentration, plasma lipid peroxidation and lower hepatic glycogen concentration than that exhibited by NC group. However, diet supplementation of Goami and Nokwon suppressed the high fat diet-induced hyperglycemia and oxidative stress through inhibition of the glucose-regulating enzymes and enhancement of the antioxidant enzymes activities. The results illustrate that the new functional rice Goami and Nokwon may be useful in the development of functional foods with preventive effect against high fat diet-induced hyperglycemia and oxidative stress.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.811-814
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• 2009

The HF band maritime communication is have developing to digital methode that techniques should be readied the automatic link establishment of 1:N by coast station to many ship station. Because can use way by polling simply that communication environment calls particular station wicked fellow HF communication states which is much redundancy times for coast station to set link. In amateur radio particular station selective calling do to be using ALE(Automatic Link Establishment) controller by 1:1 automatic link setting way, but expect 1:N link setting by these way in maritime communication very difficult. That is difficult to avoid collision by traffic overload to induce calling of ship stations. Because HF communication considers channel special quality traffic state radio link should be established, and should be applied automatically secures stability of channel as accommodative at traffic overload. In this paper is studied the new radio protocol by 3 step sequency driving of free access, group free access and polling access using multi-tone in single channel.

• Journal of Korean Medicine Rehabilitation
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• v.31 no.2
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• pp.81-97
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• 2021

Objectives This study was designed to identify the changes of autonomic nervous system (ANS) which was induced by acupuncture at the field of the auricular branch of the vagus nerve. Methods 30 healthy adults were selected and classified into two groups; experimental group, control group. After providing mental stress, acupuncture was applied at external ear in experimental group and no treatment executed in control group. The evaluation of ANS function was measured by heart rate variability (HRV). We statically analyzed the difference of HRV parameters which include mean heart rate (MHRT), standard deviation of all N-N intervals (SDNN), square root of the mean of the sum of the squares of differences between adjacent N-N intervals (RMSSD), total power (TP), low frequency power (LF), high frequency power (HF), LF/HF ratio. Results All subjects showed significant increase in SDNN, LF after stress stimulation (p<0.05). Immediately after intervention, MHRT was significantly decreased (p<0.001) and RMSSD, HF were significantly increased in experimental group (p<0.05). After the end of intervention, SDNN, HF, RMSSD, TP, LF were significantly increased in experimental group (p<0.01, p<0.05). And when comparing baseline HRV, SDNN, LF were significantly increased in control group (p<0.01) and SDNN, RMSSD, TP, LF were significantly increased in experimental group (p<0.05). In the subgroup analysis, normal balance of ANS group showed significant increase in TP, LF, SDNN, HF (p<0.01, p<0.05). Conclusions We suggested that acupuncture at external ear, region of the vagus nerve distribution could increase parasympathetic activity and cause changes and reregulation of the ANS.

• Nutritional Sciences
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• v.8 no.3
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• pp.181-188
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• 2005

We investigated the effects of diet manipulation on pro- and macro-glycogen accumulation and mobilization during exercise in different kinds of muscle fiber and tissue. Thirty-two Sprague-Dawley rats were divided into groups representing one of two dietary conditions: high fat (HF, n=16) or standard chow (CHOW, n=16). Each dietary group was fm1her divided into control (REST, n=8) and exercise (EXE, n=8). After an eight-week dietary intervention period, the animals in EXE swam for 3 hours while the animals in REST remained at rest Skeletal muscle (soleus, red gastrocnemius and white gastrocnemius) and liver samples were then dissected out and used for analyses. 1here was no statistical difference in body weight between the animals in the HF and mow groups (p>.05). Three hours of exercise significantly increased plasma free fatty acid (FFA) concentration in the animals in the CHOW group but not in the animals in the HF group. Both citrate. synthase (CS) and $\beta$-hydroxyacyl dehydrogenase ($\beta$-HAD) activities in skeletal muscles were higher in the HF group than in the mow group. CS and $\beta$-HAD activities were also the highest in red gastrocnemius and the lowest in white gastrocnemius. At both time points (i.e., rest and immediately after exercise) intramuscular triglyceride (IMTG) and liver TG concentrations were significantly higher in the HF compared to the CHOW. IMTG and liver TG changed selectively in the CHOW. Except in white gastrocnemius muscle, there was no significant difference in total glycogen content between HF and mow at rest. Although exercise significantly lowered total glycogen content in all groups and tissues (p<.05), the degree of reduction was markedly greater in the mow than in the HF. Whereas changes in proglycogen concentration showed a trend similar to those of total glycogen, alterations in macroglycogen concentrations clearly differed from those of total glycogen. Specifically, the degree of reduction of macroglycogen following three hours of exercise was substantially greater in the CHOW than in the HF. These results suggest that metabolic alterations induced by a long-term high fat diet may be caused by macro-glycogen rather than pro-glycogen.

• Journal of Yeungnam Medical Science
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• v.24 no.2
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• pp.216-231
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• 2007

Background : An acceleration or deceleration of the heart rate (HR), which reflects autonomic effects, is observed before the onset of paroxysmal atrial fibrillation (PAF). The purpose of this study was to assess the discrepancy in the autonomic interactions before the onset of PAF for different patterns of change in the HR. Materials and Methods : From 105 Holter tapes with the PAF recorded, 55 episodes (42 patients, 34 men, $58{\pm}12$ years) of PAF (>5 min), preceded by a sinus rhythm for more than 1 hour, were selected and submitted to time-domain and frequency-domain HR variability analyses. Fifty-five episodes were divided into 2 groups: group A PAF (n=30) with acceleration of the HR during the last 2 minutes before the PAF and group B (n=25) with deceleration of the HR. Results : A significant linear decrease in the mean R-R interval was observed in group A ($924{\pm}30$ to $835{\pm}28ms$, $P$=0.001) and an increase from $831{\pm}32$ to $866{\pm}31ms$ in group B PAF episodes ($P$=0.046). In the frequency-domain analyses, the LF/HF ratio exhibited a progressive linear increase before the PAF in group A ($P$=0.005). The HF normalized units (HFnu) and natural logarithm-transformed HF ($In$HF) values decreased from $30.8{\pm}4.0$ to $16.1{\pm}1.8$ ($P$=0.003) and $4.49{\pm}0.25$ to $4.07{\pm}0.22$ ($P$=0.001), respectively. Contrary to the results in group A, a significant increase in the HF components (HFnu and $In$HF) (from $22.6{\pm}3.2$ to $30.2{\pm}4.0$, $P$=0.005, and $4.27{\pm}0.27$ to 4.75 0.33, $P$=0.001, respectively) and a resultant decrease in the LF/HF ratio were observed in group B PAF episodes. No significant changes were observed in the LF components in either PAF group. Conclusion : Autonomic stimuli leading to an acceleration or deceleration of the HR before the onset of AF are due to parasympathetic modulation. Parasympathetic modulation plays a key role in the initiation of PAF.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.312.2-312.2
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• 2016

본 연구에서는 $HfO_2$와 $ZrO_2$의 구조적 차이를 통한 Dielectric layer의 특성 변화에 대한 분석을 진행하였다. $HfO_2$와 $ZrO_2$ layer는 용액 공정을 통해 만들고, 용액의 농도는 0.2 M로 제작하여 Spin Coating으로 소자를 제작하였다. 각 소자들의 구조적인 차이를 위해 $HfO_2$/$HfO_2$, $ZrO_2$/$HfO_2$, $HfO_2$/$ZrO_2$, $ZrO_2$/$ZrO_2$ 층 순서로 제작되었다. 각 소자들의 Capacitance 값은 245.72, 259.81, 294.23, $312.12nF/cm^2$으로 측정 되었고, Leakage current 값은 1.01, 1.79, 0.09, $0.0910-1A/cm^2$으로 다소 높은 값으로 확인되었다. 또한 dielectric constant, k 값이 16.6, 17.6, 19.9, 21.2로 각각의 측정값들 모두 substrate쪽의 dielectric layer에 따라 비슷한 특성을 갖게 되는 것을 확인했다. 이를 통해 Electrode 쪽의 layer보다 Substrate 쪽의 layer의 영향이 더 큰 것을 알 수 있다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.12
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• pp.1708-1714
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• 2011

This study investigated the possible anti-obesity effects of Hypsizigus marmoreus on high fat-fed mice. Thirty male C57BL/6 mice were randomly divided into 3 groups: a normal diet group (N), a high-fat diet group (HF), and a high-fat diet with 5% Hypsizigus marmoreus group (HF-H). After 8 weeks, the body weights in the HF group significantly increased, while those of the HF-H group decreased. Also, liver and adipose tissue weights in the HF-H group significantly decreased. Total serum cholesterol, leptin, and insulin levels were significantly higher in the HF group than those of the N group, but lower than those of the HF-H group. Accumulation of hepatic lipids was apparent in the HF group, as indicated by HE staining and hepatic lipid analysis, while these effects were improved by supplements with Hypsizigus marmoreus in the HF-H group. Also, a reduction in adipocyte size of the epididymal adipose tissue was observed in the HF-H group. $PPAR{\gamma}$, SREBP-1c, and SCD-1 protein expressions were down-regulated in the epididymal adipose tissue of the HF-F group compared to the HF group. Taken together, these results suggest that Hypsizigus marmoreus may an effective anti-obesity treatment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.4
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• pp.405-410
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• 2007

This study was to investigate the hypolipidemic effect of powdered mulberry leaves (PML) and water extract of powdered mulberry leaves (WML) on high-fat fed mice. Male C57BL/6 mice were divided into four groups; a normal group (N), a high-fat (HF) group, a high-fat group supplemented with PML (HF-PML) and a high-fat group supplemented with WML (HF-WML). The PML or WML was added to a standard diet based on 1% dried mulberry loaves (1g PML/100g diet and 0.22g WML/100g diet) for 6 weeks. Body weight and organ weights were not different among thle groups in high-fat fed mice, whereas food intake and daily energy intake were significantly (p<0.05) lowered in the HF-PML group. In plasma and liver, the supplementation of PML and WML significantly (p<0.05) lowered cholesterol and triglyceride concentrations compared to the HF group. The HDL-cholesterol/total cholesterol ratio was significantly (p<0.05) higher in the HF-PML and HF-WML groups than in the B:.w group. The fecal triglyceride and cholesterol concentrations were significantly (p<0.05) increased in the HF-PML and HF-WML groups compared to the HF group. Hepatic lipid regulating enzyme activities, fatty acid synthase, fatty acid ${\beta}-oxidation$ and carnitine palmitoyl transferase were significantly lower in the HF group than in the N group. However, the activities of these hepatic lipid regulating enzymes activities were significantly (p<0.05) elevated in the HF-PML and HF-WML groups compared to the HF group. Accordingly, these results suggest that PML and WML improve plasma and hepatic lipid levels partly by increasing fecal lipid excretion and enhancing hepatic lipid regulating enzymes activities.

• Proceedings of the KAIS Fall Conference
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• 2001.05a
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• pp.79-81
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• 2001

저압 기상 영역에서 Anhydrous HF 가스와 Methanol vapor를 사용하는 산화막 식각공정을 수행하기 위하여 (1) 반응기 부피의 최소화, (B) 공정압력의 최소화, (3) 고순도 알루미나 Reactor 적용, (4) Cluster화의 개념을 적용한 VPC 장치를 제작하였다. Wafer의 온도, HF의 분압 및 Working Pressure 등의 공정변수에 따른 Oxide Wafer의 식각특성의 변화를 확인하였다. 또한 Etch Uniformity를 향상시키기 위하여 Shower Head 구조를 변경시켜서 실험하였으며, CFD Simulation을 이용하여 Reactor내에서의 HF gas 및 Methanol vapor의 분율을 예측하였다.