• 지질공학
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• 제31권4호
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• pp.493-506
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• 2021

액상화 현상이란 지반이 포화된 느슨한 사질토 지반에 지진과 같은 동적하중이 급속히 작용할 때 과잉간극수압이 발생하고, 지반이 유효응력을 상실하고 액체화 되는 현상을 말한다. 액상화 평가를 위한 실내반복시험은 반복삼축압축시험과 반복전단시험을 통하여 확인이 가능하다. 이와 관련하여 본 연구에서는 반복삼축압축시험을 이용한 모래의 상대밀도와 입도분포에 따른 액상화 저항 강도를 확인하고자 하였고, 실험장비의 신뢰도 검증과 결과의 타당성을 확인하고자 기존의 선행연구와 대조하여 비교·분석하였다. 실험결과, 흙의 분류에 상관없이 상대밀도가 증가함에 따라 액상화 저항 강도가 높아짐을 확인하였고, 모래의 입도분포에 따른 액상화 저항강도는 SW에 가까운 SP시료의 액상화 저항강도가 상당히 높게 확인되었다. 또한 세립분 0% 대비 세립분 30%를 분석한 결과, 상대밀도 40~70%까지 증가함에 따라 액상화 저항강도가 5~20% 가까이 감소하였고, 국내 풍화토 지반이 주문진 표준사 대비 액상화 저항 강도가 세립분이 10%일 때는 30% 이상, 세립분이 30%일 때는 50% 이상 낮게 측정되었다.

• Toxicological Research
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• 제16권2호
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• pp.163-172
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• 2000

Recently, there is a worldwide concern that a great number of man-made chemicals have a hormone-like action both in humans and in animals. DECD is developing screening programs using validated test systems to determine whether certain substances may have an effect in humans. In the present study. the establishment oj repeated-dose toxicity test method was tried. Flutamide. an anti-androgenic agent. was administered by gavage to Sprague-Dawley rats for 28 days at dose levels of 0. 0.5. 3 and 18 mg/kg body weight (10-15 rats/sex/group) to examine the effects on general findings. especially reproductive and endocrine parameters. Clinical signs. body weights, food consumption, and sexual cycle were checked and measured. For the gross and microscopic examinations. 10 rats/sex/group were sacrificed at the end of dosing period and the remaining animals of control and high dose groups (5 each) were sacrificed after 14 days recovery. Examinations for hematology and clinical chemistry were carried out at necropsy. There were no treatment-related changes in clinical signs. body weights, food consumption. gross necropsy. hematology and clinical chemistry at all doses of both sexes. The period and regularity of sexual cycle were not adversely affected at all doses by the test agent. At 18 mg/kg. both decreased weights of prostate, seminal vesicle and epididymis in males and increased weights of spleen and thymus in females were observed. In addition, decreased number of spermatids and sperms. increased serum testosterone concentration and increased incidence (100%) of interstitial cell hyperplasia were seen in males. At 18 mg/kg of the recovery group. decreased prostate weight. reduced sperm count and increased incidence (20%) of interstitial cell hyperplasia in males and increased thymus weight in females were observed. At 3 mg/kg. reduced sperm count was found. There were no adverse effects on parameters examined at 0.5 mg/kg of both sexes. The results suggested that the potential target organs of flutamide may be accessory sexual glands including testes for males and spleen and thymus for females. Taken together. this test method was found to be a useful screening test system for endocrine disrupting chemicals.

• 전산구조공학
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• 제5권1호
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• pp.119-132
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• 1992

반복하중을 받는 짧은 I보(Beam)의 횡-비틀림 좌굴(Lateral-Torsional Buckling)에 대한 광범위한 Parametric Study를 수행하여 보의 좌굴현상을 좀 더 깊이 고찰하고자 한다. 유한한 비틀림변형의 뒤틀림(Warping)이외에 미소한 절단변형의 뒤틀림도 고려한 기하학적(완전) 비선형의 일차원 보를 해석적 모델로 사용하고, 또한 금속의 주기적소성(Cyclic Plasticity)거동을 보다 잘 나타내기 위해 다축 주기적소성모델을 Consistent Return Mapping Algorithm과 결합시켜 적용한다. 기준치 근방에서 아래와 같은 여러가지 Parameter Study를 수행하므로써 반복하중을 받는 짧은 I보의 횡-비틀림 좌굴의 일반적 응답을 고찰한다 : 재료의 강복강도, 강복플래토(Yield Plateau), 변형율경화, 이동경화(Kinematic Hardening), 잔류응력, 작용하중의 절단중심에 대한 편심률, 작용하중의 보 단면에 대한 높이, 작용하중의 보 길이방향의 위치, 보 단면의 치수, 작용하중으로부터 멀리 떨어진 지지단의 고정도.

• 한국게임학회 논문지
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• 제16권2호
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• pp.7-16
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• 2016

본 논문은 게임을 수행하는 개별 사용자의 특별한 행동 탐지를 효율적으로 수행하는 시스템을 제안한다. 제안하는 시스템은 일반적인 게임 플레이 환경에서 비 침투적 방법을 통해 포착 가능한 사용자 특징과 반복적인 패턴에 기반을 두어 특이 행동 탐지를 한다. 본 논문에서는 표정과 사용자 움직임과 같이 관찰되는 자료를 분석하기 위해 카메라를 사용했다. 게다가 반복 행동 탐지를 위해 게임 사용자로부터 멀티 모달 데이터를 사용하여 고차원의 행동 분석하기 위해 사용했다. 특이 행동 탐지에 효과적인 Support Vector Machine 을 사용했으며, 특이 행동 탐지 수행의 유용성을 평가하여 약 70% 확률로 탐지하는 이상 행동 탐지 재현율을 보였다. 또한 반복 행동 분석이 가능함을 보였다. 제안된 기법을 사용하였을 때 PC 환경에서 제공하는 모든 콘텐츠의 분석에 대한 피드백과 정량화하는데 도움이 될 수 있다.

• 대한토목학회논문집
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• 제32권1D호
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• pp.33-39
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• 2012

겨울철의 영하의 날씨와 잦은 눈으로 인해 도로 포장의 파손이 증가하고 있다. 본 연구에서는 도로 포장의 동결융해 메커니즘을 살펴보고, 다양한 평가 방법을 통해 배수성 아스팔트 포장의 동결융해 저항성을 평가하였다. 동결융해 저항성의 평가방법은 강성 포장과 연성 포장이 각각의 특성에 따라 다양한 평가 방법을 사용하고 있다. 본 연구에서는 변형률의 측정, 수정 로트만 실험, 반복 동결융해 실험, 표면 박리 저항성 실험과 같은 강성 포장과 연성 포장의 대표적인 동결융해 저항성 실험을 적용하여 평가를 실시하였다. 연구결과 배수성 아스팔트 콘크리트는 20%의 공극으로 인해 밀입도 아스팔트 콘크리트에 비해 온도에 따른 변형이 작은 것으로 평가되었다. 또한, 수분의 영향을 받는 동결융해 반복 실험에서도 수분의 원활한 배수와 수분의 동결 시 발생하는 팽창압을 분산시킬 수 있는 충분한 공극으로 인해 다른 종류의 아스팔트 혼합물에 비하여 동결 융해 저항성이 우수한 것으로 나타났다.

• Toxicological Research
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• 제14권3호
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• pp.393-400
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• 1998

As a series of safety studies on DA-3585, a recombinant human erythropoietin, its local irritancy was examined in rabbits after the following treatments; application into the conjunctival sac of the eye(single), subcutaneous injection (single and -day repeated)and intravenous injection (7-day repeated.)In addition, perivascular irritation of DA-3585 was investigated in mice. In the result of ocular irritation test, 10,000IU/ml solution of DA-3585 could be considered as a non-irritating material. The local irritation of DA-3585 by a single and 7-day repeated subcutaneous injection was negligible and not so much different from that of saline. In the vascular irritancy test, macro-and microscopic observations revealed that local irritation of DA-3585 was comparable to that of saline when injected into retroauricular vein of rabbits for 7 consecutive days. Furthermore the perivascular administration of DA-3585 upto the concentration of 10,000 IU/ml did not induce any morphological abnormalities at injection sites. The results obtained from the present study suggest that the local irritancy of DA-3585 is not different from that of saline when injected through intravenous or subcutaneous route for clinical practice.

• 대한물리의학회지
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• 제9권4호
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• pp.363-373
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• 2014

PURPOSE: The purpose of this study was of scale using auditory biofeedback training and kinging training on walking speed and weight bearing ratio in patients hemiplegia with stroke to determine of the effects of such training would be maintained even after stopping the intervention. METHODS: The 30 subject were classified into three groups : 12 times, 3 times a week receiving the control, the experimental group scale using auditory and kicking training for 4 weeks. In addition, all subjects in the control group and experimental groups received the same general exercise treatment 12 times, 3 times a week for 4 weeks, and underwent follow-up tests. The significance of differences between the control group and the experimental groups was analysis by repeated-ANOVA, Interaction time and groups was analysis by repeated-ANOVA. In case where there were differences, post-hot tests were conducted using repeated measure ANOVA. RESULTS: There were significant differences in 10 m walking speed and weight bearing ratio between the control group and experimental group after the performance of the scale using auditory training and kicking training. Scale using auditory biofeedback training 4 weeks was more effective than kicking training. After 8 weeks weight bearing ratio maintained on scale using auditory training. CONCLUSION: These finding suggest that the scale using auditory biofeedback training and kicking training has positive effects on hemiplegia with stroke.

• 한국산학기술학회논문지
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• 제12권3호
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• pp.1117-1121
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• 2011

전차에 전기를 공급하는 장치인 가동 브래킷 구조물은 전차가 통과할 때 반복적인 하중을 받는다. 이러한 반복하중은 가동 브래킷 구조물을 구성하는 나사들을 풀리게 하는 가진원이 되고 있다. 본 논문에서는 전산 시뮬레이션을 이용하여 반복적인 진동에 의한 볼트 풀림에 대한 원인과 대책에 대하여 연구하였다. 그 결과 전산 시뮬레이션 모델이 구축되어 가동브래킷 구조물의 동적응답 해석이 가능하게 되었다. 가동 브래킷 구조물의 볼트 풀림에 대한 주된 가진 주파수 영역이 200 Hz 미만임을 확인하였으며, H 빔의 강성을 증가함으로써 볼트풀림을 방지할 수 있음을 알 수 있었다. 아울러 볼트 풀림 원인이 되는 300, 600Hz 대역에서 발생하는 하부밴드 브라킷의 진동 모드를 확인 하였으며, 강성을 올리는 것은 200Hz 이상에서의 볼트 풀림을 방지할 수 있는 효과를 나타냄을 확인하였다.

• 대한한의학회지
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• 제38권4호
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• pp.55-61
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• 2017

Objectives: In order to accurately measure skin moisture and accumulate normal skin moisture data, analyzing the uncertainty of the skin moisture measurement and establishing standard reference data is essential. It helps to evaluate the skin's condition and has great significance in diagnosis and treatment. In this study, the traceability of the equipment and the uncertainty of the results were analyzed for their potential use in the field of Korean medicine. The data was collected measuring skin moisture on the sole of the foot. Methods: One professional measured the moisture of the adult male's foot 10 times following a determined protocol. The standard uncertainty of repeated measurements was calculated from the mean value of 10 repeated measurements. Ten trainee participants also measured the adult male's foot following a determined protocol. The standard uncertainty by tester was calculated from the value of repeated measurements. Results: As a result of analyzing the difference between the mean and standard uncertainties in both the expert and trainees, it was confirmed that the variance in this study did not satisfy the normal distribution. In addition, the Mann-Whitney U-test was carried out, and it was found that there was no significant difference in the measured values of the two groups. The authorized uncertainty of measurements and traceability of all the equipment was not confirmed. Conclusions: This paper establishes the basis for later measurement-equipment research to provide the objective indicators to approach the dryness of plantar skin from dehydration, the Korean medicine perspective.

• The Korean Journal of Physiology and Pharmacology
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• 제17권1호
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• pp.89-97
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• 2013

Developing an animal model for a specific disease is very important in the understanding of the underlying mechanism of the disease and allows testing of newly developed new drugs before human application. However, which of the plethora of experimental animal species to use in model development can be perplexing. Administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is a very well known method to induce the symptoms of Parkinson's disease in mice. But, there is very limited information about the different sensitivities to MPTP among mouse strains. Here, we tested three different mouse strains (C57BL/6, Balb-C, and ICR) as a Parkinsonian model by repeated MPTP injections. In addition to behavioral analysis, endogenous levels of dopamine and tetrahydrobiopterin in mice brain regions, such as striatum, substantia nigra, and hippocampus were directly quantified by liquid chromatography-tandem mass spectrometry. Repeated administrations of MPTP significantly affected the moving distances and rearing frequencies in all three mouse strains. The endogenous dopamine concentrations and expression levels of tyrosine hydroxylase were significantly decreased after the repeated injections, but tetrahydrobiopterin did not change in analyzed brain regions. However, susceptibilities of the mice to MPTP were differed based on the degree of behavioral change, dopamine concentration in brain regions, and expression levels of tyrosine hydroxylase, with C57BL/6 and Balb-C mice being more sensitive to the dopaminergic neuronal toxicity of MPTP than ICR mice.