• 한국산림과학회지
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• 제77권4호
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• pp.421-428
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• 1988

본(本) 연구(硏究)는 표본점(標本點)의 크기와 형태에 따른 작업(作業) 시간을 비교분석하고 효율성(效率性)을 검정(檢定)하여 적정 표본점 크기와 형태를 선택(選擇)하기 위한 것으로, 지형이 평탄(平坦)하고 임목생립(林木生立)이 고르게 분포된 2개 임분(林分)을 택하여 각각 198 plot, 306 plot를 조사하였다. 표본점 설치방법의 시간상 유리함을 알아보기 위하여 방형(方形)에서는 Blumeleiss-$Me{\beta}$ trommel을 이용하는 방법과 줄자를 이용하는 방법을 비교하였다. 1. 방형(方形)에서는 직접 4면 설치법이 대각선으로 설치하는 방법보다 시간적으로 유리하였다. 2. 원형(圓形)에 있어서는 Blumeleiss-$Me{\beta}$ trommel을 이용한 방법이 줄자를 이용하나 방법보다 유리(有利)하였다. 3. 원형(圓形) 표본점(標本點)이 방형(方形) 표본점(標本點)에 비해 시간적으로 유리하였다. 특히 작은 표본점에서는 원형이 방형에 비해 2배 정도 유리하였지만, 점차 면적이 커지면서 원형 표본점의 시간적(時間的) 유리성(有利性)이 줄어들었다.

• 한국산림과학회지
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• 제4권1호
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• pp.26-29
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• 1965

1) 본시험(本試驗)은 area sampling의 Form과 unit의 크기를 결정(決定)짓고져 행(行)하여진 실험(實驗)이다. 2) unit가 작은 것은 큰것에 비(比)해 과대추정치(過大推定値)를 주었다. 3) incular sample plot는 타(他)에 비(比)하여 과대추정치(過大推定値)를 준다. 4) area sampling에 있어서는 rectangular plot $0.06ha(20m{\times}30m)$가 가장 경제적(經濟的) unit가 된다. 또 circular plot를 사용(使用)할 때는 0.10 ha, square plot를 사용(使用)할 때는 0.08ha 보다 큰 unit를 사용(使用)해야만 population mean과 유의차(有意差)없어 추정(推定)할 수 있다.

• 한국생산제조학회지
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• 제4권3호
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• pp.58-66
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• 1995

It is very important to test motion accuracy and performance of NC machine tools as they affect that of all other machines machined by them in industry. In this paper, in has become possible to detect errors of linear displacement of radial direction for circular motion test using newly assembled magnetic type of linear scales so called Magnescale ball bar system, and to calculate time interval getting error motion data and revolution angle of circular motion in machining center using tick pulses come out from computer. And a set of error data gotten from test is expressed to a plot by computer treatment and to numerics of error motion by statistical treatment and results of test are compared with those of Renishaw ball bar system.

• 한국멀티미디어학회논문지
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• 제4권1호
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• pp.29-36
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• 2001

본 논문에서는 회전 주사 패턴을 사용하여 영상 검색을 위한 효율적인 영상 기술 방법을 제안하였다. 본 논문에서 근회전 주사 패턴을 영상 중심부에 위치시키고, 이를 이용하여 공간 칼라 정보를 기술하였다. 사용된 특징은 회전 대표 칼라와 회전 칼라 질감 그리고 회전 칼라 변화도이다. 제안 방식은 영상의 색상 정보와 그와 관련된 국부적 공간 분포를 효율적으로 기술할 수 있었다. 따라서 위 방식은 영상 검색에 있어 기존방식에 비하여 계산량, 메모리 사용량 등을 줄일 수 있었다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.270-275
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• 2000

In this study, heat transfer and Pressure drop characteristics for R-718 in the plate and shell heat exchanger (P&SHE) investigated experimentally. The plates are circular and welded into a stack which fits into a cylindrical shell in P&SHE. Although apparently very different from rectangular the compact brazed plate heat exchanger (CBE), the underlying flow passage structure through the P&SHE is the same as in the CBE. The R-718 between plate side and shell side was performed a counterflow heat exchange. Heat transfer characteristic of R-718 were measured for turbulent flow in P&SHE by using wilson plot technique. Heat transfer experiment Ivas performed in the $200{\leq}Re{\leq}500$ regime and Pressure drop experiment was performed in the $150{\leq}Re{\leq}1600$ regime. The purpose of this study is to investigate heat transfer and friction factor correlations for R-718 in P&SHE and to offer fundamental data for experiment

• The Korean Journal of Physiology and Pharmacology
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• 제4권2호
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• pp.105-111
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• 2000

Stimulation of muscarinic receptors by carbachol (CCh) in the circular smooth muscle of the guinea pig gastric antrum causes muscle contraction. In the present study, muscarinic receptor subtype controlling the muscle contraction in response to CCh was studied using putative muscarinic receptor antagonists. Isometric force of the isolated circular muscle strips was measured in an organ bath. CCh contracted the muscle in a dose-dependent way, and each of the three muscarinic receptor antagonists, 4-diphenylacetoxy- N-methylpeperdine methiodide (4-DAMP), methoctramine and pirenzepine shifted the concentration- response curves to the right without significantly reducing the maximum force. The affinities of the muscarinic antagonists $(pA_2\;values)$ obtained from Schild plot analysis were 10.15, 7.05 and 6.84 for 4-DAMP, methoctramine and pirenzepine, respectively. These results suggest that the $M_3-subtype$ mainly mediate the muscle contraction in response to CCh in guinea pig gastric antrum.

• Composites Research
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• 제29권6호
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• pp.388-394
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• 2016

Fiber reinforced plastic (FRP) composites have drawn increasing attentions worldwide for decades due to its outstanding properties. Stress concentration factor (SCF) as an essential parameter in materials science are critically considered in structure design and application, strength assessment and failure prediction. However, investigation of stress concentration in FRP composites has been rarely reported so far. In this study, three resource-conserving analyses (Isotropic analysis, Orthotropic analysis and Finite element analysis) were introduced to plot the $K_T^A-d/W$ curve for E-glass/epoxy composite plate with the geometrical defect of circular hole placed centrally. The plates were loaded to uniaxial direction for simplification. Finite element analysis (FEA) was carried out via ACP (ANSYS composite prepost module). Based on the least squares method, a simple expression of fitting equation could be given based on the simulated results of a set of discrete points. Finally, all three achievable solutions were presented graphically for explicit comparison. In addition, the investigation into customized efficient SCFs has also been carried out for further reference.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 춘계학술대회
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• pp.189-192
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• 2021

항적추적 기술에 딥러닝 기반 LSTM(Long Short-Term Memory) 모델을 적용하는 연구로서 기존의 항적추적기술의 경우, 항공기의 등속, 등가속, 급기동, 선회(3D) 비행 등 비행 특성에 따른 칼만 필터 기반의 LMIPDA를 활용한 실시간 항적 추적 시 등속, 등가속, 급기동, 선회(3D) 비행 가중치가 자동으로 변경된다. 이러한 과정에서 등속 비행 중 급기동 비행과 같이 비행 특성이 변경될 때, 항적 손실 및 항적 추적 성능이 하락하여 비행 특성 가중치 변경성능을 향상시킬 필요성이 있다. 본 연구는 레이더의 오차 모델이 적용된 시뮬레이터의 Plot과 표적을 딥러닝 기반 LSTM(Long Short-Term Memory) 모델을 적용하여 학습시키고, 칼만 필터를 활용한 항적추적 결과와 딥러닝 기반 LSTM(Long Short-Term Memory) 모델을 적용한 항적추적결과를 비교함으로써 미리 비행 특성의 변경과정을 예측하여 등속, 등가속, 급기동, 선회(3D) 비행 가중치변경을 신속하게 함으로써 항적추적성능을 향상하기 위한 연구이다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 하계학술대회 논문집
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• pp.215-220
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• 1990

A.C. impedance properties of $RuO_2$ based thick film resistors which having different resistivity value (DuPont 1721 : $100{\Omega}$/ sq., 1741 : $10K{\Omega}$/sq.) were investigated using by impedance analyzer. In case of lower resistivity 1721 system, the complex impedance was composed nearly R component for all speciman sintered at above $600^{\circ}C$, and the frequency dependancy on impedance was not affected very much up to 5MHz and again gradually increase with increasing the frequency. In case of higher resistivity 1741 resistor system, impedance properties were very depandant on sintering temperature. When sintering temperature was $600^{\circ}C$, the complex impedance plot shows a vertical line, which correspond to lone capacitance equivalant circuit, and the impedance linearly decreased with increasing frequency. In case of speciman sintered at $700-900^{\circ}C$, the complex impedance plot shows semi-circular are correspond to a lumped RC combination, and the impedance shows constant value to 5MHz, again decreased with increasing frequency. But the complex impedance behavior of speciman sintered at $1000^{\circ}C$ was shows the equivalent circuit correspont to parallel combined LCR component, and the impedance was not varied with frequency.

• The Korean Journal of Physiology
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• 제26권1호
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• pp.55-68
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• 1992

The effects of changes in extracellular $Na^+\;and\;Ca^+$ concentration on the membrane potential and contractility were studied in the antral circular muscle of guinea pig stomach in order to elucidate the existence and the nature of $Na^+/Ca^{2+}$ exchange mechanism. All experiments were performed in tris buffered Tyrode solution which was aerated with 100% $O_2$ and kept at $35^{\circ}C.$ The treatment of $10^{-5}$ ouabain was performed to induce intracellular $Na^+$ loading prior to the start of experiment. The results were as follows: 1. $Na^+$-free Tyrode or high $Ca^{2+}$-Tyrode solution hyperpolarized the membrane potential and induced contracture. The time course of contracture was similar to that of change in membrane potential. 2. The degree of hyperpolarization and the amplitude of contracture decreased in accordance with the increase of extracellular $Na^+$ concentration. 3. $Na^+$-free contracture was developed even after blocking the influence of intrinsic nerves by the pretreatment with atropine, guanethidine and TTX. 4. $Ca^{2+}$-channel blockers(D-600 or $Mn^{2+}$) and the blocker of intracellular $Ca^{2+}$ release from sarcoplasmic reticulum(ryanodine) did not suppress the development of $Na^+$-free contracture. And also, dinitrophenol had no effect on $Na^+$-free contracture. 5. Dose-response relationship between extracellular $Na^+$ concentrations and the magnitude of contractures showed a sigmoid pattern. The slope of straight line from Hill plot was 2.7. 6. In parallel with the increase of extracellular $Ca^{2+}$ concentration, the amplitude of contracture increased dose dependently and was maximum at 8 mM $Ca^{2+}$-Tyrode solution. 7. The relationship between extracellular $Ca^{2+}$ concentrations and the magnitude of contractures showed hyperbolic pattern. The slope of straight line from Hill plot was 1.1. From the above results, it is suggested that $Na^+/Ca^{2+}$ exchange mechanism exists in the antral circular muscle of guinea pig stomach and this mechanism affects the membrane potential electrogenically.