• Title/Summary/Keyword: 정수비

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A Study on Image Magnification Scheme using the Surface Characteristics in Image (영상의 곡면 특성을 이용한 영상 확대 기법에 관한 연구)

  • Jung, Soo-Mok
    • Proceedings of the Korea Contents Association Conference
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    • 2014.11a
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    • pp.473-474
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    • 2014
  • 본 논문에서는 자연 영상에 존재하는 영상의 곡면 특성을 효과적으로 이용하여 영상을 확대하는 기법을 제안하였다. 제안된 기법이 기존의 기법에 비하여 성능이 향상되었음을 실험을 통하여 확인하였다.

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정수지 소독능 진단에 관한 고찰

  • 박승철;이창수
    • Proceedings of the Korean Environmental Sciences Society Conference
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    • 2004.11a
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    • pp.205-206
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    • 2004
  • 국내 정수처리에 있어 기존 장티프스, 콜레라 등과 같은 병원성 세균의 소독 뿐만아니라 최근에는 지아디아, 크립토스포리디움과 같은 병원성 원생동물의 불활성화에 대하여 많은 관심을 가져야 하며 적정한 소독능을 확보하기 위해서는 정수지의 도류벽 설치, 용량확장, 수위비조절 및 잔류염소 농도 조절 등의 운영 및 시설개선이 필요한 것으로 판단된다.

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한전의 축열식 전력공조 보급지원제도

  • 김정수
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • v.30 no.6
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    • pp.27-32
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    • 2001
  • 여름철 냉방전력을 심야시간대로 분산시킴으로서, 발전설비 투자비 절감, 설비이용률 향상, 이산화탄소 배출 감소 효과가 있는 축열식 전력공조시스템에 대한 한전의 지원제도를 알아 보고자 한다.

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Selection of Emergent Plants as for the Nesting Site by the Breeding Birds on the Marsh of Paldang Dam and Gyungan-cheon (팔당댐과 경안천 습지에 번식하는 조류의 둥지 장소로서의 정수식물의 선택)

  • Lee, Ki-Sup;Kim, Mi-Ran
    • Journal of Wetlands Research
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    • v.11 no.1
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    • pp.29-37
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    • 2009
  • This study was conducted on the marsh of Paldang dam and Gyungan-cheon, Gyeonggi-do province. 6 species bred on the emergent plants and the nests of Common Coots Fulica atra, Common Moorhens Gallinula chloropus, Great Reed-Warblers Acrocephalus orientalis, Yellow Bitterns Ixobrychus eurhythmus, Little Grebes Podiceps ruficollis and Great Crested Grebes Podiceps cristatus were found. The main vegetations of the nests were Narrow Leaf Cattails Typha angustata, Reeds Phragmites communis, and Wild Rices Zizania latitolia. Particularly, Narrow Leaf Cattails were the most favorite plants for breeding birds. Few nests were found on the emergent plants covered with rubbish, or on high density. And no nests found on the inside shrubs. The mean density of nests on the marsh was 3.1 nests per ha and the nests were highest in Non-island as 17 nests per ha. The nest density on the area of Sonae-islands was higher than the area of Kyangdong-kyo bridge. This would be related on the bulk of narrow-leaf cattails and the quality of water.

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Microwave Absorber Prepared by Using the Wasted Mn-Zn Ferrite and the Cement (Mn-Zn ferrite 廢棄物과 시멘트를 이용한 電波吸收體)

  • 조완식;김종오
    • Resources Recycling
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    • v.9 no.6
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    • pp.31-35
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    • 2000
  • The complex permeability, the complex permittivity and the reflection loss are investigated in the composite microwave absorbers which are mixed with the wasted Mn-Zn ferrite and the industrial cement. The cement has larger the complex permittivity than that of the rubber. The complex permittivity is decreasing with the increment of the mixing ratio of Mn-Zn ferrite to cement (F/C in weight) and the complex permeability is increasing with the increment of F/C. The maximum reflection loss is above -40 dB at all samples. The matching frequency is in the range of 1.3 GHz to 2.9 GHz and is decreasing with the increment of F/C from 1 to 3. The matching thickness is increasing with the increment of F/C. The wasted Mn-Zn ferrite and the cement is very useful material for the composite microwave absorber.

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Critical State of Crushable Jeju Beach Sand (파쇄성이 큰 제주해사의 한계상태 특성)

  • Lee, Moon Joo;Bae, Kyung Doo;An, Sung Mo;Lee, Woo Jin
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.2C
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    • pp.133-140
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    • 2010
  • A series of triaxial test was performed in order to determine critical state parameters of calcareous Jeju sand, which comprises angular shape particles with many pores in the surface. It is observed that Jeju sand mainly shows the contractive behavior during triaxial shear due to high extreme void ratios and large compressibility. The peak friction angle of Jeju sand decreases slightly with increasing mean effective stress due to the particle crushing of carbonate materials. However, the peak friction angle of Jeju sand is higher than that of other silica sands because of the more angular particle shape. The critical state friction angle of Jeju sand gradually decreases when the mean effective stress at a critical state increases. Whereas, there is not a clear influence of void ratio on the critical state friction angle. Critical state parameters of Jeju sand are similar to those of calcareous sands, but significantly larger than those of common sands.

Directional Variation of Apparent Elastic Constants and Associated Constraints on Elastic Constants in Transversely Isotropic Rocks (횡등방성 암석에서 겉보기 탄성정수의 방향성 변화와 탄성정수 제약조건)

  • Youn-Kyou Lee
    • Tunnel and Underground Space
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    • v.33 no.3
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    • pp.150-168
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    • 2023
  • The anisotropic behavior of rocks is primarily attributed to the directional arrangement of rock-forming minerals and the distribution characteristics of microcracks. Notably, sedimentary and metamorphic rocks often exhibit distinct transverse isotropy in terms of their strength and deformation characteristics. Consequently, it is crucial to gain accurate insights into the deformation and failure characteristics of transversely isotropic rocks during rock mechanics design processes. The deformation of such rocks is described by five independent elastic constants, which are determined through laboratory testing. In this study, the characteristics of the directional variation of apparent elastic constants in transversely isotropic rocks were investigated using experimental data reported in the literature. To achieve this, the constitutive equation proposed by Mehrabadi & Cowin was introduced to calculate the apparent elastic constants more efficiently and systematically in a rotated Cartesian coordinate system. Four transversely isotropic rock types from the literature were selected, and the influence of changes in the orientation of the weak plane on the variations of the apparent elastic modulus, apparent shear modulus, and apparent Poisson's ratio was analyzed. Based on the investigation, a new constraint on the elastic constants has been proposed. If the proposed constraint is satisfied, the directional variation of the apparent elastic constants in transversely isotropic rocks aligns with intuitive predictions of their tendencies.

A Study on CBR Characteristics of National Highway in Yeongnam Region (영남지역 국도에 사용된 흙의 CBR 특성에 관한 연구)

  • Park, Yeong-Mog;Lee, Go-Hyeun;Kim, Nak-Seok;Cho, Gyu-Tae
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.36 no.3
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    • pp.535-543
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    • 2016
  • This study has been carried out to evaluate the CBR characteristics and the correlations among every soil properties of National road in Yeongnam region. Total of 480 soil samples were collected from 41 administrative districts for more than 30 years. Their physical and mechanical properties such as natural water content, the Atterberg limit, No. 200 sieve passing, the compaction test and the CBR test results were involved. The soils in Yeongnam region, SM, SC, SP and CL by USCS have predominated approximately 79%. The test results show that average CBR values of gravel and sand range from 12.7% to 20.3% and those of silt and clay range from 4.8% to 7.1%. It means that average CBR values of fine grained soils are less than a half of coarse grained one. Natural water content, No. 200 sieve passing, optimum moisture content and maximum dry density of soils are well correlated with CBR values. Especially, it presents that No. 200 sieve passing is the best correlation factor with CBR value. If consider the partition off this region into 6 zones of classified by mother rock, the correlation between CBR value and every soil properties tends to increase. It is suggested that tables, figures and the regressions described in this paper may be available for designers and engineers to understand the characteristics of an embankment materials in Yeongnam region.