• 한국환경성돌연변이발암원학회:학술대회논문집
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• 한국환경성돌연변이발암원학회 2001년도 Korean Environmental Mutagen Society
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• pp.10-10
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• 2001

• Structural Engineering and Mechanics
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• 제27권4호
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• pp.425-438
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• 2007

Large changes in stiffness associated with cracking and yielding of reinforced concrete sections may be expected to occur during the dynamic response of reinforced concrete frames to earthquake ground shaking. These changes in stiffness in stories that experience cracking might be expected to cause relatively large peak interstory drift ratios. If so, accounting for such changes would add complexity to seismic design procedures. This study evaluates changes in an index parameter to establish whether this effect is significant. The index, known as the coefficient of distortion (COD), is defined as the ratio of peak interstory drift ratio and peak roof drift ratio. The sensitivity of the COD is evaluated statistically for five- and nine-story reinforced concrete frames having either uniform story heights or a tall first story. A suite of ten ground motion records was used; this suite was scaled to five intensity levels to cause varied degrees of damage to the concrete frame elements. Ground motion intensity was found to cause relatively small changes in mean CODs; the changes were most pronounced for changes in suite scale factor from 0.5 to 1 and from 1 to 4. While these changes were statistically significant in several cases, the magnitude of the change was sufficiently small that values of COD may be suggested for use in preliminary design that are independent of shaking intensity. Consequently, design limits on interstory drift ratio may be implemented by limiting the peak roof drift in preliminary design.

• Journal of Communications and Networks
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• 제13권6호
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• pp.655-663
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• 2011

Diffuse optical wireless (DOW) systems have the advantage that they do not require point-to-point siting so one transmitter can communicate with several receivers. In this paper, we investigate multiple access scheduling methods for downlink orthogonal frequency division multiplexing (OFDM) in diffuse optical wireless networks. Unlike the radio frequency (RF) channel, the DOW channel has low-pass filter characteristics and so requires different scheduling methods than those developed for the RF channel. Multi-user diversity orthogonal frequency division multiple access (OFDMA) systems nominate a cluster of subcarriers with the largest signal-to-noise-ratio for transmission. However, in a DOW channel, most users would choose the lowest frequency clusters of subcarriers. To remedy this problem, we make two proposals. The first is to use a variable cluster size across the subcarriers; the lower frequency clusters will have fewer subcarriers while the higher frequency clusters will have more subcarriers. This will equalize the capacity of the clusters. The second proposal is to randomize a user's cluster selection from a group of clusters satisfying a minimum threshold. Through simulation it is shown that combining these strategies can increase the throughput while ensuring a fair distribution of the available spectrum.

• 대한치과의사협회지
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• 제10권4호
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• pp.209-212
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• 1972

The effect of pyridoxine on the incisors were histochemically studied for the purpose of identifying the phosphoric acid. The microscopic observations were carried out by means of phosphoric acid reaction(Serraet Queiroz-Lopes method), mucoprotein reaction (Clara method), periodic acid-Schiff reaction (McManus method), methylen blue stain and hematoxylin-eosin stain. In the experimental result, it was found that phosphoric acid reactions of ameloblast, Tomes' process and preenamel were remarkably increased after pyridoxine administration.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2001년도 International Symposium on Dietary and Medicinal Antimutgens and Anticarcinogens
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• pp.10-10
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• 2001

Selenium is an essential nutritional element for several animal species and human. It has been also seen, that low levels of selenium in the diet can cause many diseases. This metalloid was defined like a "double face" element because it possesses antioxidant, antimutagen, anticarcinogen but also mutagenic and carcinogenic effects. The most important metabolic role of selenium in the animal species is its presence in the Glutathione Peroxidase(GSH-Px). (omitted)

• International Journal of Concrete Structures and Materials
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• 제11권2호
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• pp.275-284
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• 2017

A formula to estimate the yield displacement observed in the pushover analysis of coupled wall lateral force-resisting systems is presented. The estimate is based on the results of an analytical study of coupled walls ranging from 8 to 20 stories in height, with varied amounts of reinforcement in the reinforced concrete coupling beams and walls, subjected to first-mode pushover analysis. An example illustrates the application of these estimates to the performance-based seismic design of coupled walls.

• 방사선산업학회지
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• 제4권3호
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• pp.253-257
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• 2010

This experiment was carried out to investigate the effects of gamma-radiation on the rooting, growth, and color mutation in poinsettia. Using 10 poinsettia varieties ('Lollipop', 'Little Peace', 'Happy Day', 'Early Bird', 'Pixy Red', 'Happy Time', 'Heidi', 'Red Bell', 'Clara', and 'Scarlet') bred by National Institute of Horticultural and Herbal Science, 100 Gy of gamma ray was irradiated at the stage of callused cuttings. Four weeks after sticking cuttings in the rooting media, 8 cultivars showed 100% of root formation, but 'Early Bird' rooted 24.4% and even died off during the cutting propagation. After planting rooted cuttings, survival rate until flowering time varied among irradiated cultivars. While 'Pixy Red' and 'Heidi' survived about 98%, 'Clara', 'Happy Day', and 'Early Bird' survived lesser than 30%. All irradiated plants showed remarkably shorter plant height, lesser branch numbers than non-irradiated control plants. Thirty color mutants were obtained among 281 plants survived until flowering time. Nine mutants were complete color mutated branches, whereas 21 mutants were partially color mutated bracts and transitional leaves. Color patterns mutated by 100 Gy of gamma ray were divided into pink, hot pink, light red and spotted (pink spots with red main color). Pink mutants were commonly obtained. Complete color mutants were discovered from 4 plants of 'Pixy Red', 2 plants of 'Red Bell' and 3 plants of Lollipop.

• Tuberculosis and Respiratory Diseases
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• 제53권2호
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• pp.127-135
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• 2002

배 경 :특발성 간질성 폐렴은 만성적 염증과 폐 섬유화가 특징적인 병이다. clara cell 10 kD protein(CC10)은 기관지 상피세포에서 만들어지는 강력한 항염 작용을 가진 것으로 알려진 단백질이다. 따라서, CC-10은 특발성 간질성 폐렴 환자의 염증 조절자로서의 역할을 기대할 수 있다. 본 연구에서는 폐 섬유화의 정도와 기관지 폐포 세척액 내의 CC-10 발현 사이의 연관성을 알아 보고자 하였다. 방 법 : 29명의 환자와 10명의 대조군에서 기관지 폐포 세척이 시행되었으며, 세척액을 이용하여, 정량적 Western blot 분석을 시행하였다. 각각의 band의 RI (relative intensity)를 산출하여, 환자의 진단, 기관지 폐포 세척액 내의 염증 세포 분율, 방사선학적 폐 섬유화의 정도와 비교하였다. 결과 : 환자군 ($77.5{\pm}75.8%$)과 대조군 ($70.7{\pm}39.8%$)의 RI 값에는 유의한 차이가 없었다 (p>0.05). 그리고, 통상형 간질성 폐렴 환자의 폐섬유화의 정도 및 기관지 폐포 세척 액 내의 염증 세포 분율에 따라서도 RI 값에 유의한 차이가 없었다 (p>0.05). 결 론: 통상형 간질성 폐렴 환자의 폐 섬유화 정도와 기관지 폐포 세척 액내의 CC-10 농도는 관련이 없다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.193-194
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• 2009

This report makes an important correction to estimating angular dependent emission pattern of Organic Light-Emitting Diodes (OLEDs). Today, experiments on measuring angular light intensity of OLEDs are conducted without considering the difference between the view angle identified by photodiode and the actual angle being measured. ITO-TPD-$Alq_3$-LiF-Al Organic Light-Emitting Diode was used to find out the degree of the error. In this case, the difference in average was about $1^*$, which is highly significant. Since the difference varies from case to case, the need for adjustment must be evaluated for each case.

• Structural Engineering and Mechanics
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• 제23권4호
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• pp.369-386
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• 2006

The influence of reinforcement buckling on the flexural response of reinforced concrete members is studied. The stress-strain response of compression reinforcement is determined computationally using a large-strain finite element model for bars of varied diameter, length, and initial eccentricity, and a mathematical expression is fitted to the simulation results. This relationship is used to represent the response of bars in compression in a moment-curvature analysis of a reinforced concrete cross section. The compression bar may carry more or less force than a tension bar at a corresponding strain, depending on the relative influence of Poisson effects and bar slenderness. Several cross-section analyses indicate that, for the distances between stirrups prescribed in modern concrete codes, the influence of inelastic buckling of the longitudinal reinforcement on the monotonic moment capacity is very small and can be neglected in many circumstances.