• 제목/요약/키워드: CSA

검색결과 514건 처리시간 0.036초

Characterizations of High Early-Strength Type Shrinkage Reducing Cement and Calcium Sulfo-aluminate by Using Industrial Wastes

  • Lee, Keon-Ho;Nam, Seong-Young;Min, Seung-Eui;Lee, Hyoung-Woo;Han, Choon;Ahn, Ji-Whan
    • 한국세라믹학회지
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    • 제53권2호
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    • pp.215-221
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    • 2016
  • In this study, the utilization of the by-products of various industries was examined using raw materials of CSA high-functional cement such as coal bottom ash, red mud, phosphate gypsum, etc. Technology to improve energy efficiency and reduce $CO_2$ was developed as part of the manufacturing process; this technology included lower temperature sintering ($150{\sim}200^{\circ}C$) than is used in the OPC cement manufacturing process, replacement of CSA cement with the main raw material bauxite, and a determination of the optimum mix condition. In order to develop CSA cement, a manufacturing system was established in the Danyang plant of the HANIL Cement Co. Ltd., in Korea. About 4,200 tons of low purity expansion agent CSA cement (about 16%) and about 850 tons of the lime-based expansion agent dead burned lime (about 8%) were produced at a rate of 60 tons per hour at the HANIL Cement rotary kiln. To improve the OPC cement properties, samples of 10%, 13%, and 16% of CSA cement were mixed with the OPC cement and the compressive strength and length variation rate of the green cement were examined. When green cement was mixed with each ratio of CSA cement and OPC cement, the compressive strength was improved by about 30% and the expansibility of the green cement was also improved. When green cement was mixed with 16% of CSA cement, the compressive strength was excellent compared with that of OPC cement. Therefore, this study indicates the possibility of a practical use of low-cost CSA cement employing industrial wastes only.

CSA 팽창재를 혼입한 철근보강 모르타르의 인장 경화-연화 특성에 관한 실험적 연구 (Experimental Study on Tension-Hardening and Softening Characteristics in Reinforced Mortar with CSA Expansion Agent)

  • 최세진;안중길;박기태;권성준
    • 한국구조물진단유지관리공학회 논문집
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    • 제18권1호
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    • pp.101-110
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    • 2014
  • 팽창재는 콘크리트의 건조/자기수축으로 인한 균열에 매우 효과적인 혼화재료이며 콘크리트 내부 철근에 화학적 프리스트레스를 인가할 수 있다. 본 논문에서는 CSA 팽창재에 의해 화학적 프리스트레스가 도입된 모르타르의 인장경화성능을 평가하였다. 철근으로 내부구속이 이루어진 철근 모르타르 시편에 대하여 일축인장시험을 수행하였으며, 균열거동 특성과 인장경화 특성을 분석하였다. CSA 모르타르에서는 압축강도 및 탄성계수는 약간 감소하였으나, 화학적 압축응력이 철근에 도입되었으며, 일반 모르타르 부재에 비해 167.5% 초기균열하중이 증가하였다. 높은 인장경화특성을 평가하였으며, 기존의 인장연화모델과 실험값을 비교하여 기존 제안식의 보완점을 제시하였다.

CSA 팽창재를 혼입한 강섬유 보강 모르타르의 균열 저항성능 평가 (Evaluation of Crack Resistant Performance in Cement Mortar with Steel Fiber and CSA Expansion Admixture)

  • 안중길;박기태;권성준
    • 한국구조물진단유지관리공학회 논문집
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    • 제18권3호
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    • pp.125-132
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    • 2014
  • 강섬유는 콘크리트 부재의 인장영역에 효과적으로 작용하여 균열저항성을 높여주고 역학적 성능을 개선하는 것으로 알려져 있다. 본 연구는 팽창재를 사용한 강섬유 모르타르에 화학적 프리스트레싱을 인가하여 균열저항성 및 역학적 성능을 평가하는 연구이다. 이를 위해 시멘트 바인더의 10%를 치환한 CSA 팽장채가 사용되었으며 체적비 1%의 강섬유를 고려한 시멘트 모르타르 배합이 준비되었다. 기본적인 역학적인 성능평가 외에 노치를 가진 보를 제조하여 초기균열하중 및 파괴에너지를 평가하였다. 실험결과 강섬유와 CSA 팽창재를 혼입한 모르타르에서는 보통 강섬유 모르타르에 비하여 평균 1.75배의 균열저항성 하중이 증가하였으며, 파괴에너지 역시 1.41~1.53배 증가하였다. 최적의 강섬유 체적비와 팽창재의 혼입이 고려된다면 강섬유의 내부 화학적 프리스트레싱을 가진 복합재는 다양한 부재에 사용될 수 있으며, 외부하중에 효과적인 균열저감 기법으로 사용할 수 있다.

Magnetic Resonance Imaging Assessment of Paraspinal Muscles in Dogs with Intervertebral Disc Herniation

  • Ye-Jin Kim;Ju-Yeong Kim;Ah-Won Sung;Hyun-Ju Cho;I-Se O;Ho-Jung Choi;Young-Won Lee
    • 한국임상수의학회지
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    • 제39권6호
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    • pp.334-341
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    • 2022
  • A decrease in the paraspinal muscle cross-sectional area (CSA) and functional cross-sectional area (FCSA) are associated with low back pain and disc herniation in humans. This study examined whether chronicity or lateralization of disc herniation affects the CSA and FCSA of the paraspinal muscles. The CSA and FCSA of the paraspinal muscles between the 12th and 13th thoracic vertebrae were measured in 31 dogs with intervertebral disc herniation (IVDH). The muscle CSA and FCSA were evaluated by dividing the values of the body weight, spinal disc CSA, and spinal canal CSA to offset the differences in body type between subjects. In the chronic IVDH group, the ratio of the paraspinal muscle CSA divided by the body weight was significantly lower, and fat infiltration in the paraspinal muscle was significantly higher than in the acute group. The lateralization of the disc herniation was significantly related to the changes in the paraspinal muscle CSA. In the right-sided disc herniation group, right epaxial muscle CSA was significantly reduced compared to the left-sided disc herniation group. The change in the paraspinal muscle might be a helpful indicator to localize less obvious disc pathologies and target the search for the pathology responsible for disc-related symptoms in dogs.

계층화 분석기법(AHP)을 이용한 기후스마트농업(CSA) 기술의 우선순위 분석 (Priority Analysis of Climate Smart Agriculture (CSA) Technology using Analytic Hierarchy Process (AHP))

  • 이현지;이경재;오승은;최윤영;김홍석
    • 농촌계획
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    • 제28권4호
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    • pp.127-138
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    • 2022
  • In responding to climate change in the agricultural sector, Climate Smart Agriculture (CSA) is an approach to establish a sustainable agricultural system through comprehensive management of technology, policy, and investment. The international community is continually expanding CSA implementation, and it became more important to understand the status of the domestic agriculture system and practices that are relevant to CSA. This study explored the available CSA in domestic agricultural systems and presented the order of relative importance of CSA technology. AHP analysis is employed for the evaluation with the following criteria: productivity, marketability, adaptability, and mitigation. The relative importance is evaluated with six agricultural technologies (soil, crop management, water, energy efficiency, alternative energy, and precision agriculture) in 28 agricultural technology sectors. The results of the AHP analysis showed that 'alternative energy' was found to be a top priority among the agricultural technology sectors, and 'shallow depth drain in rice paddy' was a top priority for agricultural technology. Also, the 'marketability' in soil and water sectors, 'mitigation' in crop management, and 'adaptability' in energy efficiency and alternative energy were given higher priority. The results of this study can be used as a good source for strategic CSA preparation and application.

승산시간 향상을 위한 병렬 승산기 어레이 설계에 관한 연구 (A Study on the Design of Parallel Multiplier Array for the Multiplication Speed Up)

  • 이강현
    • 한국정보처리학회논문지
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    • 제2권6호
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    • pp.969-973
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    • 1995
  • 본 논문에서는 기존의 병렬 승산기 어레이에서 사용된 CSA(carry select adder) 셀 구조를 수정하여 승산시간을 감소하는 새로운 병렬 승산기 어레이를 제안한다. MCSA(modified CSA)의 입력에 가수와 피가수가 자리올림보다 먼저 인가된다. 그리고 자리올림 전달 가산기를 위하여 DCSA(doubled inverted imput CSA)를 설계하여 최종 승산항 다음에 추가한다. 제안된 안은 MCSA와 DCSA를 사용하여 설계하고 모의실험을 한다. 회로의 크기는 기존의 CAS셀을 사용한 기존의 승산기 어레이에 비하여 약 13% 증가했지만 연산시간은 약 52% 감소함을 확인하였다.

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CSA도핑된 폴리아닐린 이차 도핑과 전기화학적 특성 (Electrochemical Characteristics of Camphorsulfonic Acid Doped Polyaniline by Secondary Doping)

  • 박종호;조승구
    • 전기화학회지
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    • 제7권3호
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    • pp.138-142
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    • 2004
  • 본 연구에서 CSA로 도핑된 EB와 LEB 형태의 폴리아닐린 필름을 ITO전극위에 m-cresol, chloroform 혼합용액을 도포시켜 제조하였다. UV 실험결과로부터 m-cresol에 의한 이차 도핑 효과를 확인 할 수 있었으며, m-cresol의 양이 증가할수록 폴리아닐린 필름의 전도도는 증가하였다. 폴리아닐린의 전기화학적 실험결과 LEB로 제작된 폴리아닐린 전극의 산화$\cdot$환원 피크 전류는 EB로 제작된 폴리아닐린 전극보다 더 크고 가역적인 것을 CV를 통해 구할 수 있었다. 또한 전하전달 저항은 m-cresol의 양이 증가할수록 감소하였으며, LEB/CSA전극의 전하 전달 저항 갈이 EB/CSA 전극보다 작았다.

Korean country-specific-advantage factors on Chinese consumer's buying intention of Korean rice: focus on the Shanghai area

  • Yang, Suk-Joon
    • 농업과학연구
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    • 제46권4호
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    • pp.915-930
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    • 2019
  • The purpose of this study was to investigate how subcategories of the country-specific-advantage (CSA), which has been discussed in previous studies, affect the buying intention of Korean rice. After reviewing existing studies and examining research models based on them, a research model was verified by questionnaires and statistical analysis. The results of the surveys and statistical analyses reveal that the CSA factors presented in previous studies can also be applied in the context of Korean rice products. The results show that environmental resource, cultural resource and visual element factors influenced the buying intention through perceived quality. In addition, cultural resource perception factors have a direct effect on buying intention. This is consistent with previous studies showing that emotional communication approaches are ineffective for products that are perceived to have functional characteristics. Based on the results of this study, it was confirmed that CSA factors are suitable for the product and export target area. Strategic implications are suggested in that it is necessary to build marketing strategies to improve the perceived quality by the four factors. The theoretical implications are as follows. The sub-factors that constitute COI may have a negative effect and a positive effect; thus, it is necessary to utilize CSA when considering the product and country characteristics. The CSA factors revealed in previous studies are also significant in other regions and products. Finally, the theoretical implication is that consumers use CSA as a clue to evaluate quality.

Impossible Differential Cryptanalysis on DVB-CSA

  • Zhang, Kai;Guan, Jie;Hu, Bin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제10권4호
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    • pp.1944-1956
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    • 2016
  • The Digital Video Broadcasting-Common Scrambling Algorithm is an ETSI-designated algorithm designed for protecting MPEG-2 signal streams, and it is universally used. Its structure is a typical hybrid symmetric cipher which contains stream part and block part within a symmetric cipher, although the entropy is 64 bits, there haven't any effective cryptanalytic results up to now. This paper studies the security level of CSA against impossible differential cryptanalysis, a 20-round impossible differential for the block cipher part is proposed and a flaw in the cipher structure is revealed. When we attack the block cipher part alone, to recover 16 bits of the initial key, the data complexity of the attack is O(244.5), computational complexity is O(222.7) and memory complexity is O(210.5) when we attack CSA-BC reduced to 21 rounds. According to the structure flaw, an attack on CSA with block cipher part reduced to 21 rounds is proposed, the computational complexity is O(221.7), data complexity is O(243.5) and memory complexity is O(210.5), we can recover 8 bits of the key accordingly. Taking both the block cipher part and stream cipher part of CSA into consideration, it is currently the best result on CSA which is accessible as far as we know.

VLSI 설계에서 캐리-세이브 가산기를 이용한 설계 블록들 간의 최적화 (Optimization Between Design Blocks using Carry-Save-Adders in VLSI Design)

  • 김태환;엄준형
    • 한국정보과학회논문지:시스템및이론
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    • 제26권5호
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    • pp.620-626
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    • 1999
  • 캐리-세이브 가산기는 (CSA)는 실제 산업체에서 회로를 설계할 때 연산수식의 계산을 빠르게 처리하기위해 가장 많이 사용되는 구성요소들 가운데 하나이다. [3]의 자료에 의하면 실제 회로 설계에서 나오는 전형적인 연산식에 CSA를 이용했을 때 그렇지 않은 경우보다 최대 54%의 연산처리속도와 42%의 회로 면적 향상을 갖는다고 보고하고 있다. 그러나, 이는 그 연산식이 하나의 설계 블록(sub-design)에 포함되어 있다는 전제하에 도출된 것이다. 회로 설계 규모와 복잡도가 큰 응용이 많아지는 상황에서 설계 블록단위의 계층적 설계는 필수적인 추세이므로, CSA를 이용한 회로 최적화를 실현하기위해서는 설계 블록들간에 걸쳐있는 연산식에 대한 CSA 최적화 또한 매우 중요한 문제이다. 이를 해결하기위해서 이 논문에서는 auxiliary port라는 개념을 이용하여 설계 블록들간의 연산식에 대한 CSA 최적화 방법을 제안한다. 실제 실험에서 우리가 제안한 기법은 회로의 전체적인 영역에 걸쳐 CSA를 적용하는 데 매우 효과적이었으며, 이 기법을 적용하지 않고 얻은 CSA 최적화 회로와 비교했을 때 회로에서의 연산식 계산속도와 그 회로 면적이 상당히 향상되었음을 확인하였다.