• 대한기계학회논문집A
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• 제24권6호
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• pp.1557-1564
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• 2000

When the half infinite crack in the orthotropic material strip with a large anisotropic ratio(E11>>E22) propagates with constant velocity, dynamic stress component $\sigma$y occurre d along the $\chi$ axis is derived by using the Fourier transformation and Wiener-Hopf technique, and the dynamic stress intensity factor is derived. The dynamic stress intensity factor depends on a crack velocity, mechanical properties and specimen hight. The normalized dynamic stress intensity factors approach the maximum values when normalized time(=Cs/a) is about 2. They have the constant values when the normalized time is greater than or equal to about 2, and decrease with increasing a/h(h: specimen hight, a: crack length) and the normalized crack propagation velocity( = c/Cs, Cs: shear wave velocity, c: crack propagation velocity).

• 한국생활과학회지
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• 제19권6호
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• pp.1053-1062
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• 2010

To assist the further development of hight-visibility clothing this study compared the visibility and subjective wear sensation of commercial protective vests with retro-reflecting materials or LEDs. Nine subjects compared high-visibility vests to evaluate how easy they were to see when exposed to the headlight of a car at night, and the subjects assessed the wear sensation of the vests also. The intensity and visibility of five different colored LEDs assembled on the five substrates separately were also evaluated to select the suitable LED color for night protective clothing. The intensity of illumination was measured by an illuminometer, and the visibility was evaluated by 11 participants both in a dark room and in front of a car outdoors at night. Results showed, the most effective LEDs were high intensity LEDs which shift blinking red and white were most effective. However, excessively high intensity of illumination could decrease the working efficiency. In subjective wear evaluation, the most favorable vest had a front opening, were adjustable at the sides, and had an electric power switch on the front of the vest.

• 컴퓨터교육학회논문지
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• 제13권6호
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• pp.99-104
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• 2010

USN 화재방재 시스템은 온도, 습도, 조도, 가속도, CO2 등의 다양한 센서로부터 얻는 데이터를 이용해 관리자에게 전달하고, 화재를 판별하는 화재 판별 알고리즘을 이용하여 소화설비를 동작시키는 지능적인 시스템이다. USN 화재방재 시스템은 센서의 데이터에 전적으로 의지하여 동작함으로 본 논문에서는 분산된 각각의 센서 데이터들을 임베디드 시스템 환경에서 효율적이고 안전하게 수집, 전달하기 위한 모델을 제안한다. 패킷의 구성과 패키징은 저 전력 소모를 위해 최대한 가볍고 빠른 처리 과정을 거치게 설계하였으며, 현재 나와 있는 암호화 알고리즘 중 DES, 3DES, AES, HIGHT를 각각 적용, 빠른 암복호화에 목표를 두어 최종적으로 국내에서 제안한 표준 암호화 알고리즘인 HIGHT가 잦은 센싱 시간을 요구하는 화재방재 시스템에 적합함을 확인하였다.

• 생명과학회지
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• 제8권4호
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• pp.373-380
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• 1998

A considerable change observed in X-ray diffraction during the muscle contraction was that the movement of myosin head and conformational change of contractile monecules were occurred in the muscle contraction. Time slice requires tension peak after the onset of stimulation and the height of tension peak depends on the number of twitch cycle. The intensity of I$_{11}$, I$_{10}$, 143${\AA}$ reflection is measured with 5ms time resolution and is recorded in isometric tension. The peak height of I$_{11}$ and 143${\AA}$ intensity is changed after the onset of a stimulation I$_{i}$, and the length of twitch is shortened by successive twitches in the case of stimulation TI$_{i}$. On the other hand, the peak height of I$_{11}$ and 215${\AA}$ intensity starts to decrease at the 1st twitch and remains constant at low peak hight without appreciable recovery during the contraction term. In the case of uccessive twitch stimulation, the myosin heads of muscle are once moved from their resting position and never returned to their initial position.

• 한국자원식물학회지
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• 제26권4호
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• pp.503-510
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• 2013

본 연구는 졸참나무의 건전한 1-1 조림용 묘목을 생산하기 위해 초기 묘고가 다른 묘목에서 적절한 단근의 강도를 구명하기 위해 실시하였다. 이를 위해 1-0 노지묘의 크기를 구분하여 단근(5, 10, 15 cm)을 실시하였다. 1년의 생육기간이 지난 시점에서 묘고를 비롯한 지상부 생장량과 주근 및 측근의 발달 특성을 비교 분석하였다. 지상부의 생장은 초기 묘목 크기와 단근에 의해 다양한 차이가 나타났으며, 측근의 발달은 묘목 크기에 따른 영향이 큰 것으로 나타났다. 초기 묘고가 큰 묘목군에서는 15 cm로 단근된 묘목이 가장 우수한 지상부 생장량을 나타내었으며, 초기 묘고가 작은 묘목군에서는 15 cm와 10 cm로 단근된 묘목이 우수한 생장량을 나타내었다. 묘목 크기에 따른 생장은 초기 묘고가 큰 묘목이 작은 묘목보다 우수한 지상부 생장을 나타내었으며, 주근의 재생산량과 새롭게 발달된 측근의 수도 많았다. 하지만 측근의 길이 및 무게 생장은 작은 묘목이 더 많았다. 결론적으로 본 연구결과를 종합해 보면, 고품질의 묘목을 생산하기 위해서는 묘고가 큰 1-0묘를 생산하는 것이 다양한 장점을 가지며, 초기 묘고가 26 cm 이상의 큰 묘목은 15 cm로 단근하고, 초기 묘고가 24 cm 이하의 묘목은 10 cm로 단근하는 것이 가장 이상적인 단근길이라고 판단된다.

• 한국미생물·생명공학회지
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• 제21권4호
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• pp.342-347
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• 1993

It was proved that the cell growth followed a photo-inhibition model in light-limited turbidostat cultivation, having 1.06 (1/h) of maximum specific growth rate and 0.00094(kcal/$cm^2$/h) and 0.063 (kcal/$cm^2$/h) as half saturation and light inhibition constants, repectively. ${\beta}$-carotene production showed a growth related porcess. And the activation energy of Dunaliella salina was roughly estimated as 12.36 (kcal/mole) in employing Arrhenius relationship. It should also point out that relatively much porduction of ${\beta}$-carotene was observed at hight light intensity with yieding 1.04 (mg-carotene/g-dry cell/day) of specific product production rate while the cell growth was decreased. The optimal conditions of producing ${\beta}$-carotene in turbiodostat cultivation were as follows: $7.5{\times}10^{-3}$(kcal/$cm^2$/h)of light intensity, 2 (mM) and 50(mM) of nitrate and sodium bicarbonate concentrations and 100(ml/h) of $CO_2$ flow rate.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 추계학술대회(한국공작기계학회)
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• pp.375-380
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• 2001

This study is on the precision of the optical scanner which is suitable for shape modeling and non-contact equipment, comparing with a razer scanner. The optical scanner not only has all merits that non-contact methods have but also improve a veil phenomenon which is a razer scanner's demerits. However, the optical scanner has not been used extensively because the measurements are not very precise and there are not the definite methods of measurement. Hence, this study is to find out how parameters such as camera's hight, angle, luminous intensity, distance to object, and so on have an influence on measuring using the optical scanner and to establish the methods of measuring precision.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.1013-1017
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• 1997

This study is on the precision of the optical scanner which is suitable for shape modeling and non-contact equipment, comparing with a razer scanner. The optical scanner not only has all merits that non-contact methods have but also improve a veil phenomenon which is a razer scanner's demerits. However, the optical scanner has not been used extensively because the measurements are not very precise and there are not the definite methods of measurements, Hence, this study is to find out how parameters such as camera's hight, angle, luminous intensity, distance to object, and so on have an influence on measuring using the optical scanner and to establish the methods of measuring precision.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.841-847
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• 2001

This study is on the precision of the optical scanner which is suitable for shape modeling and non-contact equipment, comparing with a razer scanner. The optical scanner not only has all merits that non-contact methods have but also improve a veil phenomenon which is a razer scanner's demerits. However, the optical scanner has not been used extensively because the measurements are not very precise and there are not the definite methods of measurement. Hence, this study is to find out how parameters such as camera's hight, angle, luminous intensity, distance to object, and so on have an influence on measuring using the optical scanner and to establish the methods of measuring precision.

• 한국화재소방학회논문지
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• 제34권2호
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• pp.97-102
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• 2020

본 연구는 소방공무원 16명을 대상으로 8주간 고강도 인터벌 트레이닝(HIIT) 중 타바타(Tabta) 프로그램을 진행하였으며 자료처리는 윌콕슨 순위검증(Wilcoxon signed rank test)와 대응표본 t검정(Paired t-test)분석을 실시하였다. 체력요인 중 하버드 스텝(Harvard step, 회)은 운동 전 87.19 ± 12.33에서 운동 후 93.81 ± 13.27 (p < .009), 윗몸일으키기(회)는 운동 전 35.75 ± 10.73에서 운동 후 39.00 ± 8.80 (p < .001), 악력(kg)은 운동 전 53.35 ± 6.11에서 운동 후 55.65 ± 6.74 (p < .035)으로 각각 유의한 차이가 나타났다. 신체조성 중 체지방률(%)은 운동 전 17.69 ± 4.32에서 운동 후 15.66 ± 3.33 (p < .003), 근육량(%)은 운동 전 36.65 ± 4.38에서 운동 후 36.41 ± 4.24 (p < .043), 체중(kg)은 운동 전 75.50 ± 6.40에서 운동 후 74.24 ± 6.40 (p < .000)으로 각각 유의한 차이가 나타났다. 37층 도착시간은 운동 전 8 min 13 s ± 1 min 8 s에서 운동 후 7 min 19 s ± 1 min 6 s (p < .002) 유의하게 감소시켰다. 따라서 HIIT는 화재 및 재난상황 대비 업무능력 향상에 긍정적 영향을 미칠 것으로 판단된다.