• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2003년도 춘계학술대회 논문집
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• pp.275-276
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• 2003

산업의 발달에 따른 환경 오염물질의 증가와 오염물질의 종류가 다양화됨에 따라 대기 중의 유해원소 및 미량원소에 의한 환경오염과 그로 인한 인체건강에 대한 영향은 인간생활에 심각한 문제가 되므로 대기 중의 농도를 정확히 측정하는 것은 매우 중요한 일이다. 특히 미세 입자는 오염된 도심지역 분진수의 90∼99%에 이르는 높은 비율을 보이고 있고, 폐 깊숙이 침투하여 폐암을 비롯한 폐질환을 일으킬 수 있다. (중략)

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.469-474
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• 2002

This study was to define the strengthening effect of steel fibers in high strength RC columns. For this, ten specimens of columns were tested under cyclic lateral load and constant axial load. The testing parameters are steel fiber volume fraction of concrete and shear reinforcement ratio of hoop bars. Finally, the optimal content of steel fibers was evaluated as 1.0 - 1.5 % volume fraction of concrete.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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• pp.455-460
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• 2000

Fly ash can be used as cement replacement material and can also produce the durable concrete. According to the results, the compressive strength of concrete containing fly ash is slightly lower than that of normal concrete at early ages, however, the long-term compressive strength is significantly higher beyond 90 days, and it increases the durability of concrete as well.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.142-147
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• 2000

Durability characteristics of controlled low strength material(flowable fill) with high volume fly ash content was examined. The mix proportions used for flowable fill are selected to obtain low-strength material in the 10 to 15kgf/㎥ range. The optimized flowable fill was consisted of 60kgf/㎥ cement content, 280kgf/㎥ fly ash content, 1400kgf/㎥sand content, and 320kgf/㎥water content. Subsequently, durability tests including permeability warm water immersion, repeated wetting & drying, freezing & thawing for high volume fly ash-flowable fill are conducted The test results indicated that flowable fill has has acceptable durability characteristics.

• 한국기계가공학회지
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• 제2권4호
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• pp.11-16
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• 2003

Recently, CNC lathe is in need of higher speed for precision works. So more intensive and compact heat exchanger is necessary to cool down the heat in short time from drills and works during high speed working. In this study, to increase heat transfer coefficient per unit volume, inner groove tube is designed and compact oil cooler, 57% volume of conventional type, is manufactured. The heat transfer performance is experimented and is compared with the performance of conventional type.

• Journal of the Korean Data and Information Science Society
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• 제16권2호
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• pp.237-253
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• 2005

In Korea, the volume of insurance industry has been increased rapidly with helping the economic growth, the increment of GNP and derive of public welfare policy. But the other side of the volume increment, the life insurers have some problems, such as the high rate of turnover, lapses and surrenders, in processing of acquiring more insurance contracts. The object of this paper is the analysis of the causes and properties of the high rate of turnover, lapses and surrenders using statistical survival model. Also we hope that the insurers will use the results of analysis to reduce the rates.

• Journal of Nutrition and Health
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• 제24권1호
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• pp.48-57
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• 1991

The longitudinal changes on human milk volume per day and lactational performance of Korean primiparae(n=9) and multiparae(n=6) from 0.5 month to 5 months after parturition have been studied by test-weighing method. The human milk volume per day tended to increase during lactation. The mean volume to the 3rd month of lactation was 643m1 for primiparae and 654m1 for multiparae, and it was 647 $\pm$ 182m1 for both of them. The mean volume to the 5th month of lactation was 648m1 for primiparae and 668m1 for multiparae, and it was 658$\pm$186$m\ell$ for both of them. The peak volume was observed at the 1st month of lactation in 8 women of 15 lactating women, that is, 53.3% . The high distributions of the individual mean volume to the 5th month were found 550~650$m\ell$(40.0% ) and 650~750$m\ell$(26.7% ). and 13 women of 15 lactating women(86.6% ) were observed below 750m1. The number of feeding per day was 7.7~9.3 to the 5th month and the mean volume per feeding was 65~101$m\ell$. While the former tended to decreased, the latter increased during lactation. The human milk volume was correlated with the peak volume. but not with maternal age. weight before delivery. maternal height and birth weight. As mentioned above, the human milk volume of Koreans was about 658$\pm$ 186$m\ell$ and 86.6% of it was below 750$m\ell$. So the human milk volume, referred to as 800$m\ell$ in recommended dietary allowances for Koreans might be estimated over real amount. It is necessary to study according to regions. socioeconomic levels. maternal nutritional status and the early stage of lactation.

• Radiation Oncology Journal
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• 제37권2호
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• pp.117-126
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• 2019

Purpose: The purpose of this study was to characterize and evaluate the clinical significance of volume changes of soft tissue sarcomas during radiation therapy (RT), prior to definitive surgical resection. Materials and Methods: Patients with extremity or pelvis soft tissue sarcomas treated at our institution from 2013 to 2016 with RT prior to resection were identified retrospectively. Tumor volumes were measured using cone-beam computed tomography obtained daily during RT. Linear regression evaluated the linearity of volume changes. Kruskal-Wallis tests, Mann-Whitney U tests, and linear regression evaluated predictors of volume change. Logistic and Cox regression evaluated volume change as a predictor of resection margin status, histologic treatment response, and tumor recurrence. Results: Thirty-three patients were evaluated. Twenty-nine tumors were high grade. Prior to RT, median tumor volume was 189 mL (range, 7.2 to 4,885 mL). Sixteen tumors demonstrated significant linear volume changes during RT. Of these, 5 tumors increased and 11 decreased in volume. Myxoid liposarcoma (n = 5, 15%) predicted decreasing tumor volume (p = 0.0002). Sequential chemoradiation (n = 4, 12%) predicted increasing tumor volume (p = 0.008) and corresponded to longer times from diagnosis to RT (p = 0.01). Resection margins were positive in three cases. Five patients experienced local recurrence, and 7 experienced distant recurrence, at median 8.9 and 6.9 months post-resection, respectively. Volume changes did not predict resection margin status, local recurrence, or distant recurrence. Conclusion: Volume changes of pelvis and extremity soft tissue sarcomas followed linear trends during RT. Volume changes reflected histologic subtype and treatment characteristics but did not predict margin status or recurrence after resection.

• 한국해양공학회지
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• 제17권1호
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• pp.55-60
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• 2003

The effect of size and volume fraction of ceramic particles, with sliding velocity on the wear properties were investigated for the metal matrix composites fabricated by the pressureless infiltration process. The metal matrix composites exhibited about 5.5 - 6 times the wear resistance compared with AC8A alloy at high sliding velocity, and by increasing the particle size and decreasing the volume fraction, the wear resistance was improved. The wear resistance of metal matrix composites and AC8A alloy exhibited different aspects. Wear loss of AC8A alloy increased with sliding velocity, linearly : whereas, metal matrix composites indicated more wear loss than AC8A alloy at the slow velocity region. However, a transition point of wear loss was found at the middle velocity region, which shows the minimum wear loss. Further, wear loss at the high velocity region exhibited nearly the same value as the slow velocity region. In terms of wear mechanism, the metal matrix composites generally exhibited abrasive wear at slow to high sliding velocity； however, AC8A alloy showed abrasive wear at low sliding velocity and adhesive and melt wear at high sliding velocity.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 추계 학술논문 발표대회
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• pp.111-113
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• 2011

This study investigated about how much the limestone's volume was changed as time passed while maintaining a certain level of moisture condition in the limestone material for concrete under high temperature. The result is summarized as follows: It was appeared that the limestone material under high temperature emitted some CO₂ resulting from the decarboxylation, so that as the heating temperature was increased, the limestone's length change rate was decreased. In the leave time change after heating the stone, the both conditions of 50% and 100% made the limestone create Ca(OH)₂ using some H₂O. So it was appeared that as time passed, the limestone's length change rate first increased because of its volume expansion, but the rate was reduced after the limestone material was crumbled.