• 한국환경복원기술학회지
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• 제20권4호
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• pp.77-87
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• 2017

In this study, we investigated the physical form of planting foundation of the parks and green spaces in the waterside of Korea and classified them into groups showing common features. It was clssified into 7 kinds of parks and green spaces of 27 waterside parks in Korea including landscape, ecology, art, shields, site boundaries, windbreaks, and soundproofing. As a result, the study was carried out on the detailed type and size estimation through the sampling survey of planting foundation of landscape and ecological type mounding which can be statistically analyzed. Landscape and ecological mounding have the characteristics of securing the ecological stability of the waterside planting areas and the diversity of planting landscape. It is possible to create a green landscape through various terrain changes such as enclosing, focusing, and panoramic view. The physical characteristics of ecological and landscape type mounding can be expressed as height, width, and length And physical data can appear in various forms and sizes depending on the purpose and function of the buffer effect of the land use in the waterside planting areas, the landscape creation, the ecological buffer. In this study, the range of the physical scale for landscape and ecological mounding of waterside parks and green spaces was calculated. The range of the mounding height was analyzed to be less than 1.25m and more than 1.25m and the average height was 0.74~1.08m and 1.75~2.75m respectively. In addition, the range of width of mounding was less than 6.13m, 6.13~17.5m, and more than 17.5m, and the average width of each was 3.45~4.95m, 7.05~10.85m and 31.54~51.54m respectively. The range for the length of mounding was less than 50m, 50~500m, and more than 500m. The mean length of each mounding was 34.0m, 116.3m and 955.8m. It is difficult to distinguish the difference between the waterside planting areas and the urban greenery in the purpose and function of landscape and ecological mounding. However, considering the average distance of 60m from the waterside and the average height of 1.26m, we can conclud that opened planting foundation is prefered to high mounding designs in waterside planting areas. It is expected that the results presented for the improvement of the logical and spatial value of the waterside parks and green areas planting foundation design can be served as the basic data helpful for practical application in landscape architecture planning and design.

• Steel and Composite Structures
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• 제26권4호
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• pp.513-531
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• 2018

In this article, static, buckling and free vibration analyses of a sinusoidal micro composite beam reinforced by single-walled carbon nanotubes (SWCNTs) with considering temperature-dependent material properties embedded in an elastic medium in the presence of magnetic field under transverse uniform load are presented. This system is used at micro or sub micro scales to enhance the stiffness of micro composite structures such as bar, beam, plate and shell. In the present work, the size dependent effects based on surface stress effect and modified strain gradient theory (MSGT) are considered. The generalized rule of mixture is employed to predict temperature-dependent mechanical and thermal properties of micro composite beam. Then, the governing equations of motions are derived using Hamilton's principle and energy method. Numerical results are presented to investigate the influences of material length scale parameters, elastic foundation, composite fiber angle, magnetic intensity, temperature changes and carbon nanotubes volume fraction on the bending, buckling and free vibration behaviors of micro composite beam. There is a good agreement between the obtained results by this research and the literature results. The obtained results of this study demonstrate that the magnetic intensity, temperature changes, and two parameters elastic foundations have important effects on micro composite stiffness, while the magnetic field has greater effects on the bending, buckling and free vibration responses of micro composite beams. Moreover, it is shown that the effects of surface layers are important, and observed that the changes of carbon nanotubes volume fraction, beam length-to-thickness ratio and material length scale parameter have noticeable effects on the maximum deflection, critical buckling load and natural frequencies of micro composite beams.

• 대한한방내과학회지
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• 제40권3호
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• pp.312-330
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• 2019

Objectives: The present study aimed to provide clinical evidence on the effect of herbal medicine on the treatment of hepatitis C using a systematic review and meta-analysis of randomized controlled trials (RCTs). Methods: This study included RCTs that verified the effects of herbal medicine for the treatment of hepatitis C. A literature search of English, Chinese, and Korean databases was performed, and the selected literature was assessed to investigate the risk of bias. Results: The analysis included 14 RCTs. The total effective rate was the most commonly used outcome measure. The meta-analysis revealed that the total effective rate and total bilirubin difference were higher and that the recurrent rate was lower in the herbal medicine group than in the western medicine group (RR: 1.20, 95% CI: 1.06-1.35, p=0.003, I2=52; MD: 0.52, 95% CI: -0.62 to 1.66, p=0.37, I2=0; RR: 0.35, 95% CI: 0.11-1.09, p=0.07, I2=0). The included RCTs had relatively poor quality and a small sample size. Conclusion: Treatment with herbal medicine was found to be partially effective in treating hepatitis C. The included RCTs had relatively poor quality and a small sample size. This study can serve as a foundation for further clinical studies on the development of treatment methods for hepatitis C based on herbal medicine.

• 한국지진공학회논문집
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• 제18권2호
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• pp.89-94
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• 2014

Spatial variations of a seismic wave are mainly wave passage and wave scattering. Wave passage effect is produced by changed characteristics of exciting seismic input motions applied to the bedrock. Modified input motions travel horizontally with time differences determined by apparent shear wave velocity of the bedrock. In this study, wave passage effect on the seismic response of a structure-soil system is investigated by modifying the finite element software of P3DASS (Pseudo 3-Dimensional Dynamic Analysis of a Structure-soil System) to apply inconsistent (time-delayed) seismic input motions along the soft soil-bedrock interface. Study results show that foundation size affected on the seismic response of a structure excited with inconsistent input motions in the lower period range below 0.5 seconds, and seismic responses of a structure were decreased considerably in the lower period range around 0.05 seconds due to the wave passage. Also, shear wave velocity of the bedrock affected on the seismic response of a structure in the lower period range below 0.3 seconds, with significant reduction of the seismic response for smaller shear wave velocity of the bedrock reaching approximately 20% for an apparent shear wave velocity of 1000m/s at a period of 0.05 seconds. Finally, it is concluded that wave passage effect reduces the seismic response of a structure in the lower period range when the bedrock under a soft soil is soft or the bedrock is located very deeply, and wave passage is beneficial for the seismic design of a short period structure like a nuclear container building or a stiff low-rise building.

• 벤처창업연구
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• 제12권5호
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• pp.13-28
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• 2017

기업가정신은 창업을 위한 중요 요인이기도 하지만 창업 이후 기업의 성장(Scale-up)을 위해서도 마찬가지로 중요하며 창업과 성장이라는 두 가지 측면이 기업가정신을 통해 균형적으로 발현되어야 하는 것으로 볼 수 있다. 그러나, 그간의 연구나 정부의 정책 방향에 있어 기업가정신이 전자에 편향되어 왔던 것이 사실이다. 이에 본 연구에서는 성장 관점에서 우리나라 기업의 기업가정신 특성과 제안성과, 활동성과, 사업성과 등으로 측정된 경영성과간의 인과관계를 실증적으로 살펴보고 작동 기제를 설명하는 모형을 도출하여 이에 대한 정책적 시사점을 제공하고자 하였다. 연구를 수행함에 있어 (재)한국청년기업가정신재단에서 수행한 '2016년 기업가정신 실태조사(기업편)'의 변인간 관계에 대한 가설을 설정하고 구조방정식모델을 통하여 분석하였다. 또한, 기업 규모에 따른 조절효과와 기업가정신과 경영성과간 매개효과를 분석하였다. 본 연구의 결과로, 사내 기업가정신이 경영성과에 영향을 미치며 이를 위해서는 비전과 전략이 선행되어야 함을 밝혔고, 특히 중소기업의 기업가정신 수준 대비 운영체계 확보 필요성을 확인하였다. 도출된 시사점은 향후 정부가 중소기업의 기업가정신을 제고하는 데 있어 정책적 방향성을 수립하는데 활용될 수 있을 것으로 기대된다.

• 대한수학교육학회지:수학교육학연구
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• 제26권3호
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• pp.543-563
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• 2016

본 연구는 국내와 국외의 수학학습장애 분야에서 수행된 연구들의 전체적인 흐름을 분석하고, 수학학습장애 학생에 대한 중재 연구의 효과를 메타분석 하였다. 연구 결과, 분석 대상 논문 201편은 크게 4가지의 주제로서 수학학습장애 학생의 특성, 수학학습장애 학생의 선별, 수학학습장애 학생을 위한 중재 교수, 기타(메타분석, 교사인식 및 교육과정)로 구분되었다. 또한 수학학습장애 중재 연구는 집단 대상 연구의 전체 평균 효과 크기가 .958로 나타나 수학학습장애 학생의 중재는 효과가 큰 것으로 파악되었다. 특히, 교수방법의 효과크기는 전략교수와 직접교수를 혼합한 교수에서 가장 크게 나타났다. 중재횟수는 16회 이상 20회 이하일 때 효과가 크게 나타났으며 횟수가 증가할수록 효과크기가 작아졌다. 이러한 메타분석 결과는 후속 수학학습장애 연구 방향을 설정하는데 기여할 수 있을 것이다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 연약지반처리위원회 학술세미나
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• pp.93-112
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• 2000

The permeability of converter slag, replacing material of sand mat on improving soft clay foundation, was evaluated in the laboratory. The effects of grain size, flow water time and aging were investigated using sea and fresh water. Converter slag being submerged with fresh water, the coefficients of permeability in A and B samples less than 10mm grain sizes were measured as 6.52${\times}$10$\^$-2/cm/sec and 5.99${\times}$10$\^$-1/cm/sec, while changed as 1.88${\times}$10$\^$-2/cm/sec, 3.86${\times}$10$\^$-1/cm/sec under sea water condition. Also, the condition of turbulent flow may exit and was experimentally identified from the relationship between hydraulic gradient and seepage velocity. After 180 days on using sea water, the coefficients of permeability of sample A and B samples decreased ten times smaller than those initial values. And after that time continually decreased as for till 360 days. The reduction of permeability coefficient was considered to influence filled with voids in high-calcium quicklime(CaO). However, in-situ coefficient of permeability was practically satisfactory.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 연약지반처리위원회 학술세미나
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• pp.12-31
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• 2000

The permeability of converter slag, replacing material of sand mat on improving soft clay foundation, was evaluated in the laboratory. The effects of grain size, flow water time and aging were investigated using sea and fresh water. Converter slag being submerged with fresh water, the coefficients of permeability in A and B samples less than 10mm grain sizes were measured as 6.52${\times}$10$\^$-2/cm/sec and 5,99${\times}$10$\^$-1/cm/sec, while changed as 1,88${\times}$10$\^$-2/cm/sec, 3.86${\times}$10$\^$-1/cm/sec under sea water condition. Also, the condition of turbulent flow may exit and was experimentally identified from the relationship between hydraulic gradient and seepage velocity. After 180 days on using sea water, the coefficients of permeability of sample A and B samples decreased ten times smaller than those initial values. And after that time continually decreased as for till 360 days. The reduction of permeability coefficient was considered to influence filled with voids in high-calcium quicklime(CaO). However, in-situ coefficient of permeability was practically satisfactory.

• Asian-Australasian Journal of Animal Sciences
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• 제5권3호
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• pp.567-570
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• 1992

Variance components were estimated for calf daily gain from birth to 45 days of age in small (S), medium (M) and large (L) lines of beef cattle. Analyses involved records collected on 682 (S), 510 (M) and 228 (L) calves in Iowa, USA from 1978 to 1986. Cytoplasmic lines were determined based on the foundation female in the maternal lineage of each animal. Data were analyzed separately by size line using a derivative-free restricted maximum likelihood procedure under an animal model including additive direct (a), additive maternal (m), cytoplasmic lineage effects and covariance (a, m). The heritabilities for direct and maternal, and the cytoplasmic effects, were 0.13, 0.35 and 0.00 for S, 0.14, 0.32 and 0.00 for M, and 0.05, 0.33 and 0.03 for L. Genetic correlations (a, m) for S, M and L were -0.33, -0.57 and -1.00, respectively. The maternal genetic effect was the most important for calf growth between birth and 45 dyas of age and cytoplasmic variances were not important in any line.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 가을 학술발표회 논문집
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• pp.389-396
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• 1999

In this study compressive and tensile load tests have been performed to investigate reinforcing effect and load transfer mechanism of small diameter piles installed in the foundation soil for the marine suspension bridge. Load tests were carried out on steel plate with diameters of 50cm, 100cm and 150cm varying loads starting from 39 tons up to 314 tons. Small diameter piles were proved to behavior like as friction piles and loads were not transmitted to the bottom of piles. From pull-out tests, the uplift capacity of small diameter piles was largely influenced by reinforcing materials compared to frictional resistance between piles and adjacent soils. The bearing capacity of small diameter piles appeared to be higher than the ultimate bearing capacity evaluated using static formulae. The load carrying capacity of small diameter piles was superior to the bored piles with a similar size. Thus, ultimate bearing capacity estimated from static formulae can provide conservative designs and thereby resulting in economic disadvantages. A further study to accumulate data regarding various soil conditions is recommended for an improved estimation of bearing capacity of piles with small diameter.