• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.386-392
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• 2020

The self-weight of the 3D printing concrete increases with increasing printing height. Therefore, the lower layer must be hardened within a suitable time to secure continuous printing performance. In particular, the hardening speed of concrete is slow in the winter season when the temperature was low. Hence, the early strength of 3D printing concrete requires improvement. In domestic and international literature, cases of increasing the early strength of concrete using inorganic chemical additives, such as amine-based, nitrate-based, sodium-based, and calcium-based, have been reported. In this study, early strength improvement-type additive samples (amine-based, nitrate-based, sodium-based) were prepared, and their performance was evaluated. When using a nitrate-based additive, the early strength was increased significantly in a 10 ℃ environment. In addition, it was possible to secure a higher early strength than the existing 3D printing concrete mixed at 20 ℃.

• Journal of the Korean Recycled Construction Resources Institute
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• v.1 no.1
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• pp.58-66
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• 2013

This study investigated quality properties of alkali activated cement free mortar using industrial by-product such as cement kiln dust(CKD), silica fume(SF) and quartz sand powder(SP) to compare with previous research about blast furnace slag(BS) and fly ash(FA). The results were as following. All materials were effective to increase compressive strength, however they showed different tendency on flowability. CKD and SP increased flowability, but on the other hand SF did not because it's blain was great difference with other materials. Flowability and compressive strength were related with grading distributions of binders because CKD, SP and SF which had small particle size filled up BS and FA. Application of industrial by-products with various grading distributions could be effective for the high early strength and flowability of alkali activated cement free mortar using BS.

• Journal of the Korean GEO-environmental Society
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• v.12 no.11
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• pp.13-21
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• 2011

To recover basic functions of river such as water control, irrigation, environment, culture, a national river improvement project, the four river restoration projects were currently planned and under construction in Korea. This project is designed to preserve cultural assets and ecosystem from flooding, for that reason, environmentally friendly materials of construction are strongly emphasized. In this study, the soil and cement admixtures are developed. And, the compaction test and the unconfined compressive strength test to evaluate applicability of probiotics as environmentally friendly materials are conducted the soil and cement admixtures. As a result, the probiotic culture was not active in completely dried specimen to obtain accurate mixing proportion. It indicates that the probiotics cannot influence on the development the soil and cement admixtures. A further research will focus on the effect of response between polysaccharide environmentally friendly soil stabilizer and natural specimen.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.3
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• pp.269-275
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• 2022

In this study, the setting time and compressive strength of cement paste composites applied with nano-micro pozzolanic binders were experimental analyzed. The pozzolanic binder was reduced initial and final setting time and the compressive strength was increased. Micro silica was effective in decrease the initial setting and final setting time and impressing the compressive strength. When two or more cement binders were used, the using of silica fume and a small amount of nano silica at reduced the setting time to 62-64 % to OPC cement and the compressive strength was increased to 117 %. A small amount of mixing the nano silica was effect to pore filling and pozzolanic activation. However, the addition of a chemical admixture should be considered when mixing table design because pozzolanic binders high specific surface area causes a decrease in cement composites flow.

• Korean Journal of Health Education and Promotion
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• v.5 no.1
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• pp.17-20
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• 1988

$\ulcorner$20세기의 페스트$\lrcorner$로 불리우는 후천성 면역결핍증(AIDS)이 지난 81년 처음보고된 이후 세계곳곳에서 무서운 속도로 퍼져 인류생존 자체를 위협하고 있다. 세계보건기구(WHO)의 집계에 따르면 올 3월말 현재 AIDS환자는 전세계적으로 8만5천여 명에 이르렀고 항체양성자는 수백만명선으로 잡고 있어 이들중 상당수에서 병적증상이 나타날 경우 이 전염병은 걷잡을 수 없이 확산될 전망이다. 한편 우리나라에도 지난 85년 주한미국인에서 첫 AIDS환자가 발견된 후 내국인에서도 항체양성자들이 잇달아 발견 모두 18명에 이르고 있다.

• Research in Community and Public Health Nursing
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• v.2 no.1
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• pp.273.1-273.1
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• 1990

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2001.04a
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• pp.111-115
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• 2001

• KOREAN POULTRY JOURNAL
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• v.40 no.10
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• pp.136-139
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• 2008

본고에 저자는 식품으로써 활용가치가 떨어지고 있는 산란노계육의 활용 증진을위해 계육수리미 생산 및 식육푸레이크 생산에 대해서 소개를 한 바 있다. 이번호에서는 산란노계육의 활용을 위한 세 번째 방안으로써 축산과학원에서 수행되었던 과제의 일부 결과물에 대해 소개를 하고자 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.1093-1096
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• 2011

현대 의료 분야는 질병의 진단과 치료뿐만 아니라 질병의 예방 및 건강증진을 위한 관리, 유지의 역할도 중요하게 대두되고 있다. 즉, 질병의 조기 발견과 진단으로 예방 및 관리를 생활화하고 건강수준을 높이는 방향을 제시하는 등 건강증진을 유도하는 계기를 증대시키고 있다. 따라서 본 논문에서는 간질환이 음성에 미치는 영향을 연구하기 위해 간 질환자를 대상으로 공명강과 발성의 변화를 측정하는 실험을 수행하였다. 이를 위해 간 질환자를 피실험자 집단으로 구성하여 간질환으로 인해 입원했을 때와 치료 후에 퇴원했을 때의 음성을 각각 수집하여 음성 분석 요소 중 제3포먼트 주파수 대역폭과 무성음 추출 패턴수를 측정하여 간 질환으로 인해 공명강과 발성에 미치는 영향을 분석하는 연구를 수행하였다.

• The Journal of the Korea Contents Association
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• v.15 no.11
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• pp.165-176
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• 2015

The purpose of this study was to identify the relationships among school-aged children's perceived parenting style, children's self-esteem, health promoting behavior and to determine whether self-esteem was a the mediator of the relationship between parenting style and health promoting behavior. Participants were 425 school-aged children of 5th and 6th grade. Data were analyzed using t-tests, Pearson correlation, and hierarchical multiple regression. The child's health promoting behavior was positively associated with receptive parenting style and positively associated with self-esteem. Also, the results showed that the effect of receptive parenting style on health promoting behavior was significantly partially mediated by self-esteem. Therefore, parenting style and children's self-esteem need to be factored in when designing and applying health education program for school-aged children. Also, the program need to be designed to enhance receptive parenting style that can lead to children's increase self-esteem.