• Advances in concrete construction
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• 제11권5호
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• pp.357-365
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• 2021

High deformable concrete (HDC) elements have compressive strength rates equal to conventional concrete and have got a high compressive strain at about 20% to 50%. These types of concrete elements as prefabricated parts have an abundance of applications in the construction industry which is the most used in the construction of tunnels in squeezing grounds, tunnel passwords from fault zones or swelling soils as soft supports. HDC elements after reaching to compressive yield stress, in nonlinear behavior have hardening combined with increasing strain and compressive strength. The main aim of this laboratory and numerical research is to construct concrete elements with the above properties so the compressive stress-strain behavior of different concrete elements with four categories of mix designs have been discussed and finally one of them has been defined as HDC element mix design. Furthermore, two columns with and without implementing of HDC elements have been made and stress-strain curves of them have been investigated experimentally. An analysis model is presented for columns using finite element method adopted by ABAQUS. The results obtained from the ABAQUS finite element method are compared with experimental data. The main comparison is made for stress-strain curve. The stress-strain curves from the finite element method agree well with experimental results. The results show that the dimension of the HDC samples is significant in the stress-strain behavior. The use of the element greatly increases energy absorption and ductility.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 1998년도 공동 심포지엄 및 추계학술발표회
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• pp.81-85
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• 1998

In the present study, the design method of containment walls is proposed by utilizing an existing site. The selected remedy for the Source Area of Operable Unit 2 at Hill Air Force Base stipulated containment of the pure-phase trichloroethylene contamination. The in-place-mixed wall construction was selected because of the irregular topography, small area of the site, and the requirement to reach depths of greater than 90 feet below ground surface. Bench-scale compatibility studies were performed for the containment wall mix design on three commercial bentonite clays. The samples were subject to screening tests and long-term tests for evaluation of changed soil properties when exposed to the contaminated groundwater.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.781-782
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• 2006

This treatise proposed environment for Embedded system's development. Virtual platform can help to solve problem that hardware designer can experience at design process of hardware. Compose circuit of most suitable that is verified before mix parts by various kinds method and compose circuit by board level because can do simulation with software and software that is optimized to hardware and offer flexibility that can test. Therefore, can shorten expense that is cost in development and time. Embody development platform for 8051 systems for verification of development platform, and compose and verified system in various kinds structure.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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• pp.129-132
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• 2005

Reclamation coal ash, which is generated as a byproduct at a coal thermal power plant is not recycled but dumped into an ash landfill disposal site. Furthermore, various byproducts and wastes have been proposed for use from the point of reduction in the environmental load. Authors have started research to develope manufacturing technology of concrete mixture design method with large amount of land reclamation coal ash. In this study an optimum mix proportion design for utilizing the reclamation coal ash and containing copper slags as an aggregate for secondary concrete products such as a wave dissipating blocks was successfully developed.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2005년도 추계학술발표대회 논문집
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• pp.183-186
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• 2005

The purpose of this study is to actualize the planning method of the Mixed-use Housing. Enter in 2000 years, contruction of Mixed-use Housing is rapidly increasing with acrovill and tower palace as its starting point. Mixed-use Housing is topology that mix function of residential and business and commercial facilities by kind of mixed-use development. And, Mixed-use Housing which is located in busy urban commercial strict should meet the demand not only as functional city. And it is a type of urban housing that located in busy urban commercial district demands function of residential. As for locational situation and types of public space researched and analyzed in this thesis, those space were left alone with short analyzation on main consumers level as well as short recognition of public space for all of the six combined facilities of dewelling and commercing

• 동서간호학연구지
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• 제16권2호
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• pp.85-95
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• 2010

Purpose: This study aimed to identify major trends and characteristics of studies on aromatherapy in Korea. Methods: Literature on the studies of aromatherapy in Korea was retrieved using RISS, KISS, DBpia, and Pubmed. The studies were analyzed based on publication year, study design, intervention method, and measuring variables. The level of applied intervention was assessed by target group, the types of aroma, and their effects. Results: A total of 111 studies was included in this study. Most of studies on aromatherapy were conducted using a experimental design to test the effects of aromatherapy as a nursing interventions. Conclusion: This study showed that methods of mixing oils, sites of massage, and target groups vary among studies on aromatherapy in Korea. It is suggestive that standardized methods to mix oils and to apply aroma is in need.

• 콘크리트학회논문집
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• 제27권4호
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• pp.419-426
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• 2015

본 연구는 지하식 LNG 저장탱크의 시공에 앞서 연약지반의 개량을 위하여 현장 원위치의 흙과 시멘트, 벤토나이트 등을 사용하는 소일-시멘트 연속벽체를 효과적으로 시공하는 SMW 공법에 대한 배합설계 및 현장적용 사례를 실험적으로 규명하기 위한 것이다. 현장조건을 고려하여, 보통 포틀랜드 시멘트와 벤토나이트를 주재료로 선정하였고, 흙의 단위용적중량은 $1,833kg/m^3$을 적용하였으며, 이에 따른 물-시멘트비 4종류와 배합속도 3수준을 대상으로 블리딩 및 압축강도 실험을 실시하였다. 실험은 실내실험 및 현장적용 사례로 나누어 수행되었으며, 실험을 통하여 얻은 결론은 다음과 같다. (1) 물-시멘트비가 감소할수록, 배합속도(rpm)이 증가할수록, 블리딩량 및 블리딩율이 감소하는 것으로 나타났다. (2) 물-시멘트비 150% 이하에서 현장적용강도(1.5 MPa)를 만족하였으며, 현장 코아강도는 공시체 강도에 비해 8~23% 증가하였다. 따라서 적용현장 조건을 고려하여 단위시멘트량 $280kg/m^3$, 벤토나이트 $10kg/m^3$, 물-시멘트비 150%, 그리고 배합속도 90 rpm을 현장시공의 최적배합으로 제안하였으며, 현장적용 사례의 실험결과로부터 요구되는 성능을 만족하였다.

• Design & Manufacturing
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• 제13권4호
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• pp.1-9
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• 2019

In-mold Coating is a method that can simultaneously perform injection molding and surface coating in injection mold. The material used for coating is two-component polyurethane which is composed of polyol and isocyanate. L-type mixing head can be used to mix polyol and isocyanate uniformly, and inject them inside the mold cavity. The surface quality of the injection molded products by using in-mold coating depends on the mixing uniformity between main agent and hardener. In this study, flow analysis was performed to design a mixing head for uniform mixing of two-component polyurethane. Especially the effects of design parameters of mixing head on mixing uniformity and nozzle pressure were investigated. The parameters of mixing head were mixing chamber diameter, cleaning cylinder diameter, nozzle alignment angle in the horizontal and vertical direction, and cleaning piston position. It was found that optimal design values were mixing chamber diameter of 3.5 mm, cleaning cylinder diameter of 5.0 mm, nozzle horizontal/vertical alignment angles of 140°/160°, and cleaning piston position of 1.8 mm. The optimal values would be used to develop a two-component mixing head achieving an uniform mixing for in-mold coating.

• 전산구조공학
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• 제10권4호
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• pp.349-358
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• 1997

본 논문은 복합 적층구조의 최적설계에 있어서 유전알고리즘(GA)의 응용성을 보여준다. 설계점들의 최기집단이 확률론적 과정에 의해 무작위로 생성되고, 설계점들의 개선을 위해 자연선택과 적자생존의 원리가 적용되었다. 유전알고리즘의 범용성 및 신뢰성 검증을 위해 5가지 검증 함수를 고려하였으며, 수치예에서 연속형 및 정수형 그리고 이산형 설계변수를 동시에 갖는 복합 적층 캔틸레버보의 최소 중량 설계가 외부 벌칙함수가 부가된 유전알고리즘에 의해 수행되었다. 설계 문제는 강도, 변위 그리고 고유진동수 제약조건을 포함하면서 다차 비선형성으로 정식화 되었다. 수치예의 결과에 대한 비교분석을 통해 유전알고리즘 탐색 기법이 높은 범용성을 지니면서 양질의 최적해를 매우 효과적으로 찾게됨을 보였다.

• 대한토목학회논문집
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• 제2권2호
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• pp.47-59
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• 1982

콘크리트공학 분야에서는 된반죽콘크리트의 시공성(施工性)을 개선(改善)하며 묽은반죽콘크리트의 품질향상(品質向上)을 위한 목적으로 유동화제(流動化劑)를 사용한 콘크리트에 관한 연구(硏究)가 활발히 진행되고 있다. 본(本) 논문(論文)에서는 단위시멘트량 400kg, 슬럼프 $19{\pm}1cm$의 범위에 있는 유동화콘크리트의 최적배합(最適配合)을 구하기 위하여 잔골재율, 단위수량 및 유동화제의 사용량을 변화시킨 콘크리트에 대하여 굳지않은 콘크리트 및 경화한 콘크리트의 제(諸) 성질(性質)로써 비교 검토하였다. 또한 이 실험에서 구한 유동화(流動化)콘크리트와 동일 슬럼프의 묽은 반죽콘크리트, 그리고 베이스콘크리트의 제 성질을 비교 고찰해 봄으로써 유동화콘크리트의 배합 및 강도 등에 관한 유익(有益)한 기초자료(基礎資料)를 얻었다. 한편 유동화콘크리트의 시공시 문제점으로 지적되고 있는 믹싱후 경과시간(經過時間)에 따른 슬럼프저하(低下)의 방지(防止)에 대해서도 고찰 했다.