• 한국산학기술학회논문지
• /
• 제18권6호
• /
• pp.44-52
• /
• 2017

본 논문에서는 전자전장비에 사용할 수 있는 주파수 분석의 정확도가 높으면서 소형화된 디지털주파수판별기 설계방안을 제안하였다. 전자전 장비는 레이더 신호로부터 주파수, 펄스폭, 펄스도착시간, 신호세기, 도달 방위각, 펄스 내 신호변조 등의 정보를 분석할 수 있어야 한다. 전자전장비는 레이더의 매우 좁은 펄스(100ns 이하) 신호를 분석 할 수 있어야 한다. 따라서 전자전장비는 특별한 형태의 수신기 구조가 필요하며, 주파수 측정을 위하여 순시주파수측정방식 구조의 설계가 일반적으로 사용된다. 이 중 대표적으로 사용되는 방식이 디지털주파수판별기다. 기존 디지털주파수판별기는 회로 소자가 개별부품으로 구성되어 부피와 중량이 크며, 고가인 단점이 있다. 이러한 단점을 보완하기 위해, 기존의 디지털주파수판별기는 4개의 지연선($1{\lambda}$, $4{\lambda}$, $16{\lambda}$, $64{\lambda}$)을 사용하는 반면, 제안한 디지털주파수판별기는 3개의 지연선($1{\lambda}$, $4{\lambda}$, $16{\lambda}$)을 사용하였으며, 국내에서도 비약적인 발전을 하고 있는 마이크로 집적회로 기법으로 설계하였다. 주파수 정확도를 향상하기 위한 방법으로 신호세기 검출과 온도보정을 실시하였다. 제안한 디지털주파수판별기는 실험결과 1.5MHz 이하의 높은 주파수정확도를 가지는 것을 확인하였다. 이것은 국외 도입되는 디지털주파수판별기보다 우수한 성능을 가진다고 볼 수 있다.

• 한국결정성장학회지
• /
• 제24권2호
• /
• pp.65-69
• /
• 2014

A1100, A5052, A6061, A6063, A7075 규격의 시판 알루미늄 합금 판재를 $Na_2SiO_3$와 $Na_2P_2O_7$ 전해질에서 pulse폭 $2000{\mu}sec$, + impulse 420 V, $400{\mu}sec$, -impulse $300{\mu}sec$의 bipolar pulse로 플라즈마 전해 산화 코팅(plasma electrolytic oxidation coating)한 산화피막의 결정상을 분석하였다. 표면에 형성된 산화물의 결정상은 ${\alpha}-alumina$, ${\gamma}-alumina$, ${\eta}-alumina$, $Al_{4.95}Si_{1.05}O_{9.52}$, 그리고 $(Al_{0.9}Cr_{0.1})_2O_3$가 관찰되었다. Bipolar pulse에 의해서 전해액의 성분인 Si가 산화피막에 포함되며, 포함된 Si는 결정상을 형성하기도 하지만 유리상을 형성시킨다. 이때 합금의 Mg 성분은 유리상의 양을 증가시킨다. Micro plasma에 의해서 용융된 표면은 유리상이 먼저 형성되고 이후 계속된 micro plasma의 열에 의하여 새로운 결정상으로 전이가 일어나는 과정을 거치며, 이에 따라 기존에 보고된 결정상이외에도 다양한 결정상이 형성될 수 있음을 추측할 수 있다.

• Journal of Plant Biotechnology
• /
• 제44권1호
• /
• pp.42-48
• /
• 2017

본 연구는 윤판나물의 효과적인 기내 증식을 위한 배양 최적 조건을 구명하기 위해 수행되었다. 신초 유도 및 생장에 영향하는 배지(MS, B5 및 WPM) 및 절편체 종류에 따른 실험에서 줄기 유도는 액아 절편을 식물생장조절물질 무첨가 MS 배지에 배양 시 절편 당 2.5개로 가장 좋았고, 줄기 신장은 정아 절편을 식물생장조절물질 무첨가 MS 배지 배양 시 7.2 cm로 가장 효과적이었다. BA 침지 처리 시 신초 유도 효과는 액아배양 유래 신초를 BA 침지 무처리구에서 신초 유도(2.29개/절편) 및 신초 신장(7.28 cm)이 가장 효과적이었으며, BA 침지 시간이 길어짐에 따라 신초 유도 및 길이 생장은 감소하였다. 발근에 영향하는 IBA 농도 효과는 정아유래 신초를 1.0 mg/L 처리구에서 배양 시 최대 발근율(100%) 및 뿌리 유도수(21.3개/절편)를 보였으며, 정아 혹은 액아 유래 신초지 종류에 따른 발근율의 차이는 크지 않은 것으로 관찰되었다. 발근된 식물체는 상토로 이식하여 형태적인 변이 없이 정상적인 생장을 보였다.

• 콘크리트학회논문집
• /
• 제29권2호
• /
• pp.169-177
• /
• 2017

북한은 최근 핵무기의 일반적인 열, 폭풍, 방사능 피해가 아닌 전자 장비를 무력화시키기 위한 고고도 전자기파 탄을 개발 중인 것으로 예측되고 있다. 현재 군용 목적으로 사용되고 있는 HEMP 차폐 시설 중 차폐 판의 경우 전자파 차폐 효과가 뛰어난 금속 판이 사용되고 있으나 이러한 금속판들은 차폐 시설 제작 시 용접 부위에서의 전자파 유입 가능성 등 시공상의 어려움과 높은 비용이 문제시 되고 있는 실정이다. 이에 본 연구에서 차폐 시설을 따로 구축하지 않고 콘크리트 구조물 자체로써 전자파 차폐 효과를 확보하기 위하여 콘크리트 실험체에 전기전도성이 높은 재료를 혼입하였다. 또한, 실험체 중 가장 높은 차폐효과를 보인 2가지 수준과, 가장 낮은 차폐 효과를 보인 2가지 수준에 $100{\mu}m$ 아연-알루미늄 합금 금속용사 피막을 적용하였다. 실험 결과 전기전도성이 높은 재료를 혼입한 실험체는 MIL-STD-118-125-1 규격 최소 차폐 기준을 만족하지 못하였으나, 금속용사 피막을 적용한 실험체에서는 모두 최소 차폐 기준을 만족하였다. 결론적으로, $100{\mu}m$ 아연-알루미늄 합금 금속용사 피막이 HEMP 차폐에 높은 효율성을 가지고 있다고 판단된다.

• Journal of Welding and Joining
• /
• 제18권2호
• /
• pp.213-213
• /
• 2000

This study was performed to investigate types and formation mechanism of cracks in two Al alloy welds, A5083 and A7NO1 spot-welded by pulse Nd: YAG laser, using SEM, EPMA and Micro-XRD. In the weld zone, three types of crack were observed: center line crack($C_{C}$), diagonal crack($C_{D}$), and U shape crack($C_{U}$). Also, HAZ crack($C_{H}$), was observed in the HAZ region, furthermore, mixing crack($C_{M}$), consisting of diagonal crack and HAZ crack was observed.White film was formed at the hot crack region in the fractured surface after it was immersed to 10%NaOH water. In the case of A5083 alloy, white films in C crack and $C_D crack region were composed of low melting phases, Fe₂Si$Al_8$ and eutectic phases, Mg₂Al₃ and Mg₂Si. Such films observed near HAZ crack were also consist of eutectic Mg₂Al₃. In the case of A7N01 alloy, eutectic phases of CuAl₂, $Mg_{32}$ (Al,Zn) ₃, MgZn₂, Al₂CuMg and Mg₂Si were observed in the whitely etched films near $C_{C}$ crack and $C_{D}$ crack regions. The formation of liquid films was due to the segregation of Mg, Si, Fe in the case of A5083 alloy and Zn, Mg, Cu, Si in the case of A7N01 aooly, respectively.The $C_{D}$ and $C_{C}$ cracks were regarded as a result of the occurrence of tensile strain during the welding process. The formation of $C_{M}$ crack is likely to be due to the presence of liquid film at the grain boundary near the fusion line in the base metal as well as in the weld fusion zone during solidification. The $C_{U}$ crack is considered a result of the collapsed keyhole through incomplete closure during rapid solidification. (Received October 7, 1999)

• 대한한방내과학회지
• /
• 제30권1호
• /
• pp.144-152
• /
• 2009

Background : Ephedra (Ephedra sinica) has been widely used to treat respiratory disease in traditional medicine of East Asia for over a hundred years. Despite safety concerns raised by some, the use of ephedra in traditional medicine is documented over more than 1,800 years. It is well established that ephedra is one of the central medicines in Korean 'Seseng constitution' medicine. In Sasang constitution medicine, all humans can be divided into one of four types: Soeumin, Soyangin, Taeumin or Taeyangin, and each constitution type has their own typical characteristics. Accordingly, it is hypothesized that the adverse effects of ephedra differ depending on the Sasang constitution classification. Objectives : The aim of this study was to determine adverse effects of ephedra which is classified as a Taeumin herb, and to observe whether the response differs or not. according to Sasang constitution classification. Methods : The study design was a double-blind randomized controlled trial. The subjects were healthy adults 20 - 50 years old who agreed to participate in this study. They were allocated through randomization to either ephedra group (N=55) or placebo group (N=24). where ephedra extract (6 g of dried ephedra) and placebo with similar opaque capsules were given twice for one day. To compare the adverse events of ephedra according to Sasang constitution classification, we analyzed blood pressure (systolic and diastolic), pulse rate, the morning questionnaire, and patient's global assessment scale score for well known adverse events: palpitation, headache, sweating, tiredness, dyspepsia, and dry mouth. Results : After ingestion of ephedra, the pulse rate had a significant increase in all constitution types. The changes of diastolic pressure in Soeumin and the changes of pulse rate in Soeumin, Soyangin and Taeumin had a significant increase in the ephedra over the control group. In the ephedra group, the palpitation and dyspepsia score of the patients' global assessment scale had a significant increase in Soeumin, with palpitation and sweating score increasing in Soyangin. Others observations were insignificant results. Conclusion : The results of this study may confirm that the physical responses or adverse effects of herbs differ for each type of Sasang constitution. Future studies using other herbs will be required to ascertain the herbal drug reaction of Sasang constitutions.

• 한국지열·수열에너지학회논문집
• /
• 제12권3호
• /
• pp.1-8
• /
• 2016

In this study, we evaluated the flow characteristics of various types of waveguide-below-cutoff (WBC) arrays and their shielding effectiveness (SE) of electromagnetic pulses (EMP) based on computational fluid dynamics (CFD). Three types of waveguides were selected for analysis: (1) grid type, (2) honeycomb type, and (3) multi-layer types (2-ply, 4-ply, 6-ply, and 8-ply). To analyze the air flow characteristics, the flow velocities in the longitudinal center of the WBC and the differential pressures between the WBC array inlet and outlet were evaluated. Consequently, we derive the following conclusions: (1) despite an increase in the inlet velocity, the pressure drop of the 6-ply multi-layer type did not significantly increase as compared to that of other types of waveguides (waveguide thickness of 0.1 mm, SE of 100 dB); (2) the grid and honeycomb type had the fastest flow rate of 17.5 m/s, which is approximately 2.5 m/s faster than that at the inlet (waveguide thickness of 1 mm, module size of 30 mm); and (3) the average pressure drop of the grid type waveguide is the lowest in the overall model, whereas that of the 8-ply is the highest (waveguide thickness of 1 mm, module size of 30 mm, and SE of 80, 100 dB).

• International Journal of Vascular Biomedical Engineering
• /
• 제4권2호
• /
• pp.19-24
• /
• 2006

Background: Pulse wave velocity (PWV), which is inversely related to the distensibility of an arterial wall, offers a simple and potentially useful approach for an evaluation of cardiovascular diseases. In spite of the clinical importance and widespread use of PWV, there exist no standard either for pulse sensors or for system requirements for accurate pulse wave measurement. Objective of this study was to assess the reproducibility of PWV values using a newly developed PWV measurement system in healthy subjects prior to a large-scale clinical study. Methods: System used for the study was the PP-1000 (Hanbyul Meditech Co., Korea), which provides regional PWV values based on the measurements of electrocardiography (ECG), phonocardiography (PCG), and pulse waves from four different sites of arteries (carotid, femoral, radial, and dorsalis pedis) simultaneously. Seventeen healthy male subjects with a mean age of 33 years (ranges 22 to 52 years) without any cardiovascular disease were participated for the experiment. Two observers (observer A and B) performed two consecutive measurements from the same subject in a random order. For an evaluation of system reproducibility, two analyses (within-observer and between-observer) were performed, and expressed in terms of mean difference ${\pm}2SD$, as described by Bland and Altman plots. Results: Mean and SD of PWVs for aorta, arm, and leg were $7.07{\pm}1.48m/sec,\;8.43{\pm}1.14m/sec,\;and\;8.09{\pm}0.98m/sec$ measured from observer A and $6.76{\pm}1.00m/sec,\;7.97{\pm}0.80m/sec,\;and\;\7.97{\pm}0.72m/sec$ from observer B, respectively. Between-observer differences ($mean{\pm}2SD$) for aorta, arm, and leg were $0.14{\pm\}0.62m/sec,\;0.18{\pm\}0.84m/sec,\;and\;0.07{\pm}0.86m/sec$, and the correlation coefficients were high especially 0.93 for aortic PWV. Within-observer differences ($mean{\pm}2SD$) for aorta, arm, and leg were $0.01{\pm}0.26m/sec,\;0.02{\pm}0.26m/sec,\;and\;0.08{\pm}0.32m/sec$ from observer A and $0.01{\pm}0.24m/sec,\;0.04{\pm}0.28m/sec,\;and\;0.01{\pm}0.20m/sec$ from observer B, respectively. All the measurements showed significantly high correlation coefficients ranges from 0.94 to 0.99. Conclusion: PWV measurement system used for the study offers comfortable and simple operation and provides accurate analysis results with high reproducibility. Since the reproducibility of the measurement is critical for the diagnosis in clinical use, it is necessary to provide an accurate algorithm for the detection of additional features such as flow wave, reflection wave, and dicrotic notch from a pulse waveform. This study will be extended for the comparison of PWV values from patients with various vascular risks for clinical application. Data acquired from the study could be used for the determination of the appropriate sample size for further studies relating various types of arteriosclerosis-related vascular disease.

• 대한한의학회지
• /
• 제17권1호
• /
• pp.374-406
• /
• 1996

This study has been carried out to investigate the types of differential diagnosis of amnesia. The results are as follows; 1. Amnesia has various types of differential diagnosis(辨證分型) ; deficiency of both the heart and spleen(心脾兩虛型), deficiency of the heart(心虛型), deficiency of the kidney(腎虛型), breakdown of the coordination between the heart and the kidney(心腎不交型), mental confusion due to phlegm(痰迷心竅型), accumulation of stagnant blood(蓄血型), internal injury by seven emotion (七情所傷型). 2. The type of deficiency of both the heart and spleen(心脾兩虛型) occurs when the heart and spleen is injured by overthinking(思慮過度), The symptoms are heart palpitation(心悸), continuous palpitation(??), insomnia(少寐), hypochondric discomfort(心煩), dream disturbed sleep(多夢), being easy to be scared(易驚), dizziness(眩暈), these are caused by blood deficiency of the heart(心血不足), poor appetite(飮食不振), loss of appetite(納?), short breath(氣短), sense of turgid abdormen(腹部膨滿感), loose stool(泥狀便), these are caused by deficiency of the spleen(脾虛), lassitude and weakness (身倦乏力), lassitude of the extremities (四肢無力), dim complexion (面色少華), pale lips(舌質淡), thready and feeble(脈細弱無力), these are caused by deficiency of both qi and the blood(氣血虛損). The remedy is nourishing the heart-blood(養心血) and regulating the spleen(理脾土). I can prescribe the recipes such as Guibitang(歸脾湯), Gagambosimtang(加減補心湯), Seongbitang(醒脾湯), Insin-guisadan(引神歸舍丹), Insamyangyoungtang(人蔘養榮湯), Sojungjihwan(小定志丸), Yungjigo(寧志膏), Palmijungjihwan(八味定志丸), etc., 3. The type of deficiency of the heart(心虛型) occurs when the heart-blood is injured by the mental tiredness(神勞) and so blood cannot nourish the heart. The symptoms are amnesia(健忘), short breath(氣短), heart palpitation(心悸), perspire spontaneously(自汗), facial pallidness(顔面蒼白), pale lips (舌質淡白), feeble pulse and lassitude(脈虛無力), intermittent pulse(結代脈). The remedy is nourishing the hart and blood and allaying restlessness(補心益血安神). I can prescribe the recipes such as Chenwangbosimdan(天王補心丹), Jeongji-hwan(定志丸), Gaesimhwan(開心丸), Youngjigo(寧志膏), Chilseonghwan(七聖丸), Baegseogyoungtang(白石英湯), Oseohwan(烏犀丸), Yangsinhwan(養神丸), Guisindan(歸神丹), Bogsinsan(茯神散), Jinsamyohyangsan(辰砂妙香散), Cheongeumboksinsan(千金茯神散), Samjotang(蔘棗湯), jangwonhwan(壯元丸), Sa gunjatang(四君子湯) minus rhizoma atractylodis macrocephalae(白朮) plus rhizoma acori graminei(石菖蒲), radix polygalae(遠志), cinnabaris(朱砂), etc. 4. The type of deficiency of the kidney(腎虛型) occurs when the kidney-qi and kidney-essence is deficient(腎氣腎精不足) and so it cannot nourish the brain. The symptoms arc amnesia(健忘), ache at the waist and lassitude in the lower extremities(腰산腿軟), dizziness and tinnitus(頭暈耳嗚), emmission and premature ejaculation(遺精早泄), burning sensation of the five centres(五心煩熱), flushed tongue(舌紅), rapid and small palse(脈細數). The remedy is nourishing the kidney and strengthen the essence(補腎益精). I can prescribe the recipes such as Gagamgobonhwan(加減固本丸), Jeongjihwan(定志丸), Gongseongchlmjungdan(孔聖枕中丹), Yugmigihwanghwan(六味地黃丸) plus ra-dix polygalae(遠志), fructus schizandrae(五味子), Yugmigihwanghwan(六味地黃丸) plus radix polygalae(遠志), fructus schizandrae(五味子), rhizoma acori graminei(石菖蒲), semen zizyphi spinosae(酸棗仁), Palmihwan(八味丸) plus fructus schizandrae(五味子), semen zizyphi spinosae(酸棗仁). etc., 5. The type of breakdown of the coordination between the heart and the kidney (心腎不交型) occurs when the heart-fire(心火) and kidney-fluid(腎水) are imbalanced. The symptoms are amnesia(健忘), hypochondric discomfort(心煩), insomnia(失眠), dizziness and tinnitus(頭最耳嗚), feverish sensation m the palms and soles(手足心熱), emmision(遺精), ache at the waist and lassitude in the lower extremities(腰?腿軟), flushed tongue(舌紅), rapid pulse(脈數). The remedy is coordinating each other(交通心腎). I can prescribe the recipes such as Gangsimdan(降心丹), Jujaghwan(朱雀丸), Singyotang(神交湯), Simsinyang- gyotang(心腎兩交湯), Yugmihwan(六味丸) plus fructus schizandrae(五味子), radix polygalae(遠志), Yugmihwan(六味丸) plus fructus schizandrae(五味子), radix polygalae(遠志), rhizoma acari graminei(石菖蒲), semen zizyphi spinosae(酸棗仁), etc., 6. The type of mental confusion due to phlegm(痰迷心竅型) occurs when the depressed vital energy(氣鬱) create phlegm retention(痰飮) and phlegm stagnancy(痰濁) put the heart and sprit(心神) out of order. The symptoms arc amnesia(健忘), dizziness(頭暈), chest distress(胸悶), nausea(惡心), dull(神思欠敏), dull and slow facial expression(表情遲鈍), tongue with yellow and greasy fur(舌苔黃?), sliperry pulse(脈滑). The remedy is removing heat from the heart to restore consciousness and dispersing phlegm(淸心化痰開竅) I can prescribe the recipes such as Gamibogryeongtang(加味茯?湯), Goa-rujisiltang(瓜蔞枳實湯), Jusaansinhwan(朱砂安神丸), Dodamtang(導痰湯) plus radix saussurea(木香), Yijintang(二陳湯) plus succus phyllostachyos(竹瀝), rhizoma zingiberis(生薑) Ondamtang(溫膽湯) plus rhizoma acori graminei(石菖蒲), rhizoma curcumae aromaticae(鬱金), etc., 7. The type of accumulation of stagnant blood(蓄血型) occurs when the blood is accumulated in the lower part of body. The symptoms are amnesia(健忘), chest distress(胸悶), icteric skin(身黃), rinsing the mouth but don't wanting eat(漱水不欲燕), madness(發狂), black stool(屎黑), pain in the lower abdomen(小腹硬痛). The remedy is dispersing phlegm and absorb clots (化痰化瘀), I can prescribe the recipes such as Jeodangtang(抵當湯), Daejeodanghwan(代抵當丸), Hyeolbuchugeotang (血府逐瘀湯) plus rhizoma acori graminei (石菖蒲), rhizoma curcumae aromaticae(鬱金), Jusaansinhwan(朱砂安神丸) plus rhizoma curcumae aromaticae(鬱金), radix polygalae(遠志), semen persicae(桃仁), cortex moutan radicis(收丹皮), etc., 8. The type of internal injury by seven emotion(七情所傷型) occurs when the anger injures the will stored in the kidney(腎志). The symptoms are amnesia(健忘), heart palpitation(心悸). hot temper(易怒), being easy to be scared(善驚), panic(易恐). The remedy is relieving the depressed liver and regulating the circulation of qi(疏肝解鬱). I can prescribe the recipes such as Tongultang(通鬱湯), Sihosogantang(柴胡疏肝湯) plus rhizoma acari graminei(石菖蒲), rhizoma curcumae aromaticae(鬱金), etc.

• 대한한의학원전학회지
• /
• 제11권2호
• /
• pp.146-168
• /
• 1998

This thesis is a study on the diagnostic theory and methods of Macjin(checking of pulse) as described in the Whang Di Nei Qing. There are four methods of Macjin in this text, namely: Dong Macjin(動脈法), Sam Bu Gu Who Macjin(三部九脈診). In Young Gi Gu Macjin(人迎氣口脈診法), Nei Qing's Gi Gu Macjin(內徑의 氣口脈法). Each method developed in it's own way, but they are all closely related and became the basis of today's Macjin. I examined the methods of Macjin in the Whang Di Nei Qing from a perspective of "change". The main questions of this study are: "What brought about the development of the different methods?". "How do the methods differ?", and "how did these methods evoke into today's Macjin?". The method of Macjin generated spontaneously from the observation and treatment of disease. Dong Macjin was the first method developed and became the basis of subsequent forms of Macjin. The accumulation of medical knowledge and the influence of oriental philosophy fueled the evolution of Macjin. Chronologically, Macjin methods developed starting with Dong Macjin and eventually into Sam Bu Gu Who Macjin. In Young Gi Gu Macjin, and Nei Qing's Gi Gu Macjin. The different methods of Macjin vary in how many pulse points are checked, and were established with simplicity and effectiveness in mind. Dong Macjin involves the checking the whole body. Sam Bu Gu Who Macjin involves nine points. In Young Gi Gu Macjin involves four points. and Nei Qing's Gi Gu Macjin involves two. In it's early development, the checking of a patient's pulse was used to diagnose only localized disorders in comparison with symptoms. It evolved with Oh Jang Mad(五臟脈, five main types of pulse) to be able to check internal organs with the introduction of Nei Qing's Gi Gu Macjin. After the division of Chon Kwan Chuck(寸關尺), it evolved further to be able to make a detailed diagnosis by using the result of pules checks. Nowadays, we can make 28 forms of diagnostic indices from these development. In conclusion, Macjin can be used practically and effectively in the diagnosis of disease. In using three methods of Macjin(In Young Gi Gu Macjin, Nei Qing's Gi Gu Macjin, and today's Gi Gu Macjin, which can determine the whole body's Siate of well-being) in conjunction with Dong Macjin(which helps pinpoint the localized disorder), an exact diagnosis can be obtained. I strongly feel that we should acquire objectivity by accommodating Macjin with modern methods of medicine.