라텍스개질 콘크리트의 열팽창 특성 분석

최성용,이주형,임홍범,윤경구 강원대학교 산업기술연구소 2003 産業技術硏究 Vol.23 No.A

The properties of mechanics and durability of LMC have been performed actively. However. little studies on analysis and properties of thermal expansion has been on the temperature variation. Especially. the low of bonding strength and tensile cracking are caused by difference of thermal expansion between LMC and the substrate concrete Therefore, this study focused on effect of thermal expansion behavior and properties of LMC according to temperature variation. To identify the property of thermal expansion of LMC. tests of modulus of thermal expansion were carried out at 28 days after casting specimen. subjected to temperature variation between 10℃ and 60℃ The results of this study showed the modulus of elastic of LMC was similar to that of ordinary portland concrete(OPC) It means that stresses caused by difference of modulus of elastic did not occur on interface between LMC and existing concrete The modulus of thermal expansion of LMC had a little smaller than that of OPC The modulus of thermal expansion of polymer modified concrete is generally larger than OPC. but the result of this test IS disagree with the fact. which may be due to the humidity evaporation difference and aggregate properties

4세대 이동 멀티미디어 시스템의 연구동향 분석

최명수,박형준,박남철,김경호,이성로 목포대학교 정보산업연구소 2000 情報産業硏究誌 Vol.8 No.-

In this paper, we first define 4th-generation multimedia systems that play an important role in 21C information society. Nest, we investigate and analyze the international trend of the related research and then predict the evolutionary model for 155Mbps wireless mobile multimedia systems.

위성 ATM망에 적합한 응용서비스 모형 개발

최명수,박남철,박형준,김경호,이성로 목포대학교 정보산업연구소 2000 情報産業硏究誌 Vol.8 No.-

The use of the Internet is much increased and the multimedia data such as voice and image should be processed in the Internet. The required characteristics of the communication networks for the 21-st century Internet are the fusion between communications and broadcasting, high speed, large capacity, high intelligence, and personalization. In realizing the characteristics mentioned above, the ATM is the only technique that can practically guarantee QoS and is the core technique in super high-speed service networks. In this paper, we will investigate the international study of the high-speed the satellite communication and then research plans for developing and providing optimum application services.

콘크리트 포장의 플라이애쉬 재활용 방안연구

정영화,최성용,윤경구,용석응,김태경 강원대학교 석재복합신소재제품연구센터 1998 석재연 논문집 Vol.3 No.-

한국 대부분의 고속도로는 콘크리트로 포장되고 있으며, 플라이애쉬를 포장용 콘크리트에서 재활용하면 콘크리트의 성능을 향상시킴과 동시에 경제적 이익과 환경보호에 큰 기여를 할 것이다. 본 연구에서는 플라이애쉬를 포장 콘크리트에 재활용하고자, 플라이애쉬 치환율, 물-시멘트비, 굵은골재 최대치수를 주요실험 변수로 하여 이들이 플라이애쉬를 혼입한 포장용 콘크리트의 역학적 특성에 미치는 영향을 살피기 위해서 실험하여 통계처리 분석하였다. 이러한 분석결과를 바탕으로 포장 콘크리트의 적정배합을 제시하였으며 결과는 다음과 같다. 플라이애쉬를 혼입한 포장콘크리트의 휨강도에 영향을 미치는 인자는 플라이애쉬 치환율이 가장 큰 것으로 나타났으며, 다음으로 굵은골재 최대치수와 물-시멘트비 순으로 영향을 미친다. 또한, 플라이애쉬 치환율과 굵은골재 최대치수의 상관관계가 가장 큰 것을 알 수 있었다. 목표압축강도를 목표 휨강도의 6배로 선택하여 적정구간을 결정하였으나, 적정배합구간이 목표압축강도에 의해서 결정되었다. 이는 플라이애쉬의 작은 수화물이 공극을 효과적으로 채움으로써 휨강도의 증진에 크게 기여하기 때문으로 판단된다. 고속도로 포장에 적용할 수 있는 32mm의 굵은골재 최대치수와 45%의 물-시멘트비를 사용하는 목표 휨강도 45kg/㎠의 적정배합에서는 5.0%까지 플라이애쉬를 치환 가능하고, 50kg/㎠의 적정배합에서는 2.5%까지 치환 가능하다. 공항 포장에 적용할 수 있는 40mm의 굵은골재 최대치수와 37%의 물-시멘트비를 사용하는 목표 휨강도 45kg/㎠의 적정배합에서는 4.5%까지 플라이애쉬를 치환 가능하고, 50kg/㎠의 적정배합에서는 2.0%까지 치환 가능하다. The most of highway in Korea have been paved by concrete since last ten years. The recycling of fly ash in pavement concrete may result in economics, the improvement of concrete quality and the reservation of environment. This paper focused on the series of experiment and statistics analysis with experimental variables such as fly ash substitute ratio, water-cement ratio and maximum size of coarse aggregate in order to investigate the feasibility of recycling of fly ash in pavement concrete, to see the strength characteristics and t propose the optimum mix design based on previous results. The results of experiments and analysis were follows; The fly ash substitute ratio affected most seriously to the flexural strength of concrete among main variables, followed by maximum size of coarse aggregate and water-cement ratio. The interaction between fly ash substitute ratio and coarse aggregate size was the biggest. The optimum mix design was determined by target compressive, which was selected as 6 times of flexural strength. This indicated that the small hydrate of fly ash in concrete filled in effectively and resulted in the enhancement of flexural strength. the optimum mix design for highway pavement concrete with 32mm of maximum size of coarse aggregate and 45% of W/C can incorporate up to 5.0% and 2.5% of fly-ash at 45 kg/cm² and 50 kg/cm² of target flexural strength, respectively. The optimum mix design for airport pavement concrete with 40mm of maximum size of coarse aggregate and 37% of W/C can incorporate up to 4.5% and 2.0% of fly ash at 45 kg/cm² and 50 kg/cm² of target flexural strength, respectively.

플라이애쉬를 혼입한 콘크리트포장의 배합특성에 관한 실험적 연구

이주형,최성용,윤경구,정영화 江原大學校 産業技術硏究所 1997 産業技術硏究 Vol.17 No.-

As the weight of trucks increases, the need for concrete pavement also increases. Therefore, the addition of fly-ash may improve the properties of pavement concrete as well as recycle fly-ash. A full factorial experiment was performed using the primary variables, such as water-cement ratio, fly-ash substitution ratio, and maximum size of coarse aggregate, as a preliminary study for optimum mixture design for pavement concrete. The results of preliminary study indicates that the addition of fly-ash is the most important factor determining concrete strength, followed by the maximum size of coarse aggregate and water-cement ratio. It, also, shows the relative importance of fly-ash substitution ratio, compared to the water-cement ratio, and the interaction effects between the primary variables. Optimum mixture designs for pavement concrete incorporating fly-ash, that satisfied the target responses, were proposed in terms of fly-ash substitution ratio, water cement ratio and maximum size of coarse aggregate.

LMC와 RSLMC의 열팽창 특성에 관한 연구

임홍범,최성용,최판길,윤경구 江原大學校 産業技術硏究所 2004 産業技術硏究 Vol.24 No.A

Latex modification of concrete provides the material with higher flexural strength, as well as high bond strength and reduced water permeability. However, If the thermal expansion properties of overlay concrete (latex-modified concretes) are big different from that of substrate (ordinary portland cement concrete), these would cause a big interfacial stresses and result in premature failure. Therefore, the purposes of this study were to investigate thermal expansion characteristics of latex-modified concrete with cement types. The result of thermal expansion showed the coefficient of thermal expansion of concretes increased with latex inclusion. The coefficient of thermal expansion of RSLMC was a little smaller than that of LMC, which might be due to the finer cement grain, compacter internal, and stiffer properties of concrete. However, the coefficients of LMC and RSLMC were quite similar to that of ordinary cement concrete. Thus, this would not cause an interfacial stresses and will enable to ensure long-term performance of concrete bridge deck overlays.

다차원 신호모형 해석을 통한 DOA 추정기법

박남철,최명수,박형준,김경호,이성로 목포대학교 정보산업연구소 2000 情報産業硏究誌 Vol.8 No.-

The Location-Informing service is based on the GPS data from the satellite. Until now, the service has been free. However, it may become charged. Therefore, we research the methods that can find the location-information using the antennas in future mobile communication systems and investigate the signal arrival direction estimation methods with considering practical environments.

급성 충수염에서 의사에 의한 수술지연이 수술후 경과에 미치는 영향

조병욱,박성흠,윤서구,최경우 대한대장항문학회 1998 Annals of Coloproctolgy Vol.14 No.3

헤어리베치 신품종 조생종 콜드그린과 중만생종 청파의 생육특성 및 수량성

신정남(Chung Nam Shin),고기환(Ki Hwan Ko),김종탁(Jong Tak Kim),이종경(Joung Kyong Lee),서성(Sung Seo),성병렬(Byung Ryul Seong),최기준(Gi Jun Choi),김종덕(Jong Duk Kim),오명곤(Myung Gon Oh) 한국초지조사료학회 2007 한국초지조사료학회지 Vol.27 No.4

본 시험의 목적은 대구 경북에 자생하는 헤어리베치로 다수성 조생품종과 중만생품종을 개발하기 위하여 수행하였다. 경북 성주와 경남 사천에서 1998년부터 2006년까지 자료수집 및 순화, 생육이 왕성한 조생 및 중만생계통선발, 상호교잡의 단순순환선발법으로 조생종인 콜드그린과 중만생종인 청파를 육성하였다. 육성종자는 2004년부터 2006년까지 경북성주와 경남사천에서 생육특성과 수량을 평가하였다. 줄기의 털은 콜드그린과 청파는 있었으나, 헤이메이커프러스와 라티고는 없었다. 잎의 모양은 콜드그린은 엽폭이 넓은 장타원형이고, 청파, 헤이메이커프러스, 라티고는 좁은 장타원형이었다. 꽃색은 콜드그린은 자주색이고 청파는 보라색이었다. 내한성은 성주에서 콜드그린, 청파, 라티고가 헤이메이커프러스 보다 높았으며 사천에서는 차이가 적었다. 개화기는 콜드그린과 헤이메이커프러스가 조생종으로 유사했고 중만생종인 청파는 라티고 보다 다소 빨랐다. 성주에서 건물수량은 콜드그린이 다른 품종 보다 높았으며 청파와 헤이메이커프러스는 라티고 보다 높았다(P<0.05). 2005년 사천에서는 콜드그린과 헤이메이커프러스는 다른 품종보다 높았으며, 청파는 라티고 보다 높았다(P<0.05). 베치의 조단백질 함량은 높고 ADF의 함량은 낮았다. The objective of this research was to develop a high yielding, early and medium-late flowering new hairy vetch(Vicia villosa Roth) varieties derived from an accession in Korea. Most vigorous early and medium-late flowering hairy vetch lines were selected and crossed by open pollination and their seeds were bulked and plants were reselected at Seongju in the Keongbuk and at Sacheon in the Keongnam. A performance trial was conducted to evaluate agronomic characteristics, forage quality and dry matter(DM) yield of new hairy vetch early-maturing 'Cold green' and medium-late maturing variety 'Cheong pa' at Seongju and Sacheon. 'Cold green' and 'Cheong pa' are hair but 'Haymaker plus' and 'Latigo' are nearly hairless. 'Cold green' has purple flowers while 'Cheong pa' has violet. The cold tolerance of 'Cold green,' 'Cheong pa' and 'Latigo' was higher than 'Haymaker plus' at Seong-ju, Keongbuk province, in inland region but there were a little differences at Sacheon, Keongnam province in southern coast region. Fifty percent-flowering dates of 'Cold green' and 'Haymaker plus' had earlier than others and 'Cheong pa' was earlier than 'Latigo'. The DM yield of 'Cold green' was higher than that of others, but 'Cheong pa' and 'Haymaker plus' had higher than 'Latigo' at Seong-ju(P<0.05). In Sacheon, The DM yield of 'Cold green' and 'Haymaker plus' was higher than others and 'Cheong pa' had higher than 'Latigo'.

Polymorphisms in the Ghrelin Gene Are Associated with Serum High-Density Lipoprotein Cholesterol Level and not with Type 2 Diabetes Mellitus in Koreans

Choi, Hyung Jin,Cho, Young Min,Moon, Min Kyong,Choi, Hye Hun,Shin, Hyoung Doo,Jang, Hak Chul,Kim, Seong Yeon,Lee, Hong Kyu,Park, Kyong Soo The Endocrine Society 2006 The Journal of clinical endocrinology & metabolism Vol.91 No.11