• 한국작물학회지
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• 제59권4호
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• pp.521-525
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• 2014

남부지역에 비해 상대적으로 사료맥류의 생산이 적은 중북부지역에서 안정적인 조사료 최대생산과 사료가치 향상을 위한 최적 혼파조합, 혼파비율, 재배법 확립을 위하여 연구한 결과 트리티케일과 크림슨클로버 혼파에서는 건물수량은 트리티케일에 크림슨클로버를 8:2의 비율로 처리한 혼파조합에서 1,464 kg/10a로 가장 많았으며, 트리티케일이나 크림슨클로버 단파보다 혼파에서 수량이 많았다. 혼파 비율에 따른 수량 차이는 없었으나 파종유형에 따른 수량차이를 보면 조파보다는 산파에서 수량이 많았다. 트리티케일과 콩과작물의 혼파조합 및 비율에 따른 사료가치에서 조지방(CP) 함량은 크림슨클로버 단파구가 17.2%로 트리티케일 단파구의 7.4%에 비해 높았으며, 트리티케일과 크림슨클로버를 7:3의 비율로 혼파한 시험구에서 조단백질 함량이 9.0%로 개선되어 트리티케일과 콩과 작물의 혼파에 의하여 단백질을 포함한 사료가치의 향상이 가능할 것으로 생각되었다.

• 한국수산과학회지
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• 제29권6호
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• pp.787-796
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• 1996

The biodegradation experiment, the TOD analysis and the element analysis for dispersant, Bunker-A oil and Bunker-B oil were conducted to study the biodegradation characteristics of a mixture of Bunker-A oil with dispersant and a mixture of Bunker-B oil with dispersant in the seawater. The results of biodegradation experiment showed 1mg of dispersant to be equivalent to 0.26 mg of $BOD_5$ and to 0.60 mg of $BOD_{20}$ in the natural seawater. The results of TOD analysis showed each 1 mg of dispersant, Bunker-A oil and Bunker-B oil to be equivalent to 2.37 mg, 2.94 mg and 2.74 mg of TOD, respectively. The results of element analysis showed carbon, hydrogen, nitrogen and phosphorus contents of dispersant to be $82.1\%,\;13.8\%,\;1.8\%\;and\;2.2\%$, respectively. Carbon and hydrogen contents of Bunker-A oil were found to be $73.3\%\;and\;13.5\%$, respectively, and carbon, hydrogen and nitrogen contents of Bunker-B oil to be $80.4\%,\;12.3\%\;and\;0.7\%$, respectively. Accordingly, the detection of nitrogen and phosphorus in dispersant shows that dispersants should be used with caution in coastal waters, with relation to eutrophication. The biodegradability of dispersant expressed as the ratio of $BOD_5/TOD$ was found to be $11.0\%$. As the mix ratios of dispersant to Bunker-A oil (3 mg/l) and a mixture of Bunker-B oil (3mg/l) were changed from 1 : 10 to 5 : 10, the biodegradabilities of a mixture of Bunker-A oil with dispersant and Bunker-B oil with dispersant increased from $2.1\%\;to\;7.2\%$ and from $1.0\%\;to\;4.4\%$, respectively. Accordingly, the dispersant belongs to the organic matter group of middle-biodegradability while mixtures in the mix ratio range of $1:10\~5:10$ belong to the organic matter group of low-biodegradability. The deoxygenation rate constant $(K_1)$ and ultimate biochemical oxygen demand $(L_0)$ obtained from the biodegradation experiment and Thomas slope method were found to be 0.125/day and 2.487 mg/l for dispersant (4 mg/l), respectively. $K_1\;and\;L_0$, were found to be $0.079\~0.131/day$ and $0.318\~2.052\;mg/l$ for a mixture of Bunker-A oil with dispersant and to be $0.106\~0.371/day$ and $0.262\~1.106\;mg/l$ for a mixture of Bunker-B oil with dispersant, respectively, having $1:10\~5:10$ mix ratios of dispersant to Bunker-A oil and Bunker-B oil. The ultimate biochemical oxygen demands of the mixtures increased as the mix ratio of dispersant to Bunker-A, B oils changed from 1 : 10 to 5 : 10. This suggests that the more dispersants are applied to the sea for the cleanup of Bunker-A oil or Bunker-B oil, the more decreases the dissolved oxygen level in the seawater.

• 한국지하수토양환경학회지:지하수토양환경
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• 제21권1호
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• pp.28-39
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• 2016

Struvite (MgNH₄PO₄ ⋅ 6H₂O) and hydroxyapatite (HAP, Ca₁₀(PO₄)₆(OH)₂) precipitation in urine-separating toilets (NoMix toilets) causes severe maintenance problems and also reduce the phosphate and calcium content. Application of urine separating technique and extraction of by-products from human urine is a cost effective technique in waste water treatment. In this study, we extract urine calcite from human urine by batch scale method, using urease producing microbes to trigger the precipitation and calcite formation process. Extracted urine calcite (calcining at 800℃) is a potential adsorbent for removal of heavy metal(loid)s like (Cd²⁺, Cu²⁺, Ni²⁺, Pb²⁺, Zn²⁺ and As³⁺) along with additional leaching analysis of total nitrogen (T-N), phosphate (T-P) and chemical oxygen demand (COD). The transformations of calcite during synthesis were confirm by characterization using XRD, SEM-EDAX and FT-IR techniques. In additional, the phosphate leaching potential and adsorbate (nitrate) efficiency in aqueous solution was investigated using the calcinedurine calcite. The results indicate that the calcite was effectively remove heavy metal(loid)s lead up to 96.8%. In addition, the adsorption capacity (q_e) of calcite was calculated and it was found to be 203.64 Pb, 110.96 Cd, 96.02 Zn, 104.2 As, 149.54 Cu and 162.68 Ni mg/g, respectively. Hence, we suggest that the calcite obtain from the human urine will be a suitable absorbent for heavy metal(loid)s removal from aqueous solution.

• 경영정보학연구
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• 제24권2호
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• pp.1-20
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• 2022

연구자들은 IT 기술의 발전이 수요분포에 어떠한 영향을 미치는지 슈퍼스타와 롱테일 개념을 통해 상반된 주장을 하고 있다(Brynjolfsson et al., 2010). 본 연구는 거시적 관점의 수요변화에 주목한 선행연구와 달리, 미시적 관점에서 기업의 마케팅 활동과 소비자 반응 간의 관계가 제품의 위치(i.e., 슈퍼스타 vs. 롱테일)에 따라 차이가 있는지 탐색하였다. 마케팅믹스 프레임워크를 기반으로 영화 마케팅 문헌에서 제시된 마케팅믹스 요소에 대한 가설을 개발하고, 영화산업을 대상으로 한국의 63개 영화의 45일 데이터 2,835개를 분위회귀분석 방법으로 검증하였다. 분석결과, 마케팅믹스 요소가 매출액에 미치는 영향은 제품의 위치에 따라 차이가 있다는 점을 발견하였다. 구체적으로 영화의 소구 폭과 소유 미디어의 효과는 슈퍼스타 제품에서 강화되며, 롱테일 제품은 획득 미디어의 효과를 강화하고 경쟁의 부정적 효과를 완화하는 것으로 나타났다. 본 연구는 거시적 수요분포 변화에 집중해온 선행연구와 달리, 미시적 측면의 분석을 통해 실무자에게 적합한 영화 마케팅 전략을 제안하였다.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제18권4호
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• pp.257-272
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• 2014

This paper examines and presents descriptions of 12 prospective primary teachers' views on the nature of mathematics in USA. All the participants were elementary teacher candidates enrolled in the same mathematics method courses. Interview data show that the prospective primary teachers possess two kinds of views on the nature of mathematics: primarily traditional and even mix of traditional and nontraditional beliefs in terms of Raymond's (1997) belief criteria. Implications for teacher education were discussed at the end of the paper.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1994년도 가을 학술발표회 논문집
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• pp.77-82
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• 1994

The maturity concept proposes that concrete of the same mix at the same maturity has the same strength, whatever combination of temperature and time makes up that maturity. Maturity is the integral of time and temperature of concrete above a datum temperature. Tests are conducted in order to determine a datum temperature and to measure compressive strengths and maturity of test specimens. This study also proposes some appropriate functions to represent the relationship between maturity and strength development.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.111-114
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• 2001

This study is a fundamental research for recycling waste vinyl in asphalt concrete mixture for roadway pavement. The mixing method and proper content of waste polyethylene(PE) film were determined through preliminary mix design. This study used 2-type aggregate gradations and two-type waste PE films. The mixtures were applied for a test pavement on a rural road. Quality evaluation of the asphalt concrete confirmed that waste vinyl asphalt concrete was applicable to road pavement.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.639-642
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• 2003

In this paper, fatigue behavior of concrete slab tracks under railway loads by experimental method is discussed. The addition of steel fibers to concrete mix has been receiving more attention as a way of improving the crack behavior of concrete beams an slabs tacks. This study two objectives: 1) to observe the fatigue behavior of fiber reinforced concrete slab in labor, and 2) to present crack propagation and deflection of fiber reinforced concrete slab track under railway loads in the Waghauser test line. Nine beams, two slabs and one test track were experimentally tested.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1993년도 가을 학술발표회 논문집
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• pp.51-56
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• 1993

This is a part a study on the development of High-Performance Concrete ; about experimental results from several test methods to estimate workability in fresh concrete and influences of concrete mix design that affects properties of super-flowing concrete. Super-flowing concrete can be filled in a formwork without any vibration because of its excellent workability of passing narrow space and filling complicated shaped mold, new test methods should be used to estimate the workability and rhelogy in super-flowing concrete instead of slump test method in conventional concrete.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2007년도 가을 학술발표논문집 Vol.34 No.2 (A)
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• pp.100-101
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• 2007