• 한국도로학회논문집
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• 제19권1호
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• pp.1-9
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• 2017

PURPOSES : The objective of this study is to develop an optimized method of mix design for rapid-set lightweight-formed mortar mix. To achieve this objective, the workability, setting time, and compressive strength of mixes under various conditions of mix design were evaluated. METHODS : The water-bonder ratio, fly-ash substitution ratio, and forming agent injection amount were selected as design variables in the study. The fluidity, setting time, density, and strength of the mortar mix were considered as major evaluation criteria of the mixture, and were subsequently utilized to evaluate the characteristics of the mortar mix under various conditions. RESULTS : The observations made from the mix design process are as follows: 1) the air content and fluidity increase as the forming agent ratio and forming agent ratio increase, respectively; 2) the maximum air content is approximately 20%; 3) the accelerating agent decreases the fluidity of the mortar mix by 15% on average; 4) the forming agent injection ratio and fly-ash substitution ratio yield significant effects on the initial and final set times of the mortar mix; 5) as the forming agent injection ratio and fly-ash substitution ratio increase, the compressive strength of the mortar mix decreases; and 6) the 28-day compressive strengths of the forming agent injection ratio and fly-ash substitution ratio yield the most significant effects. CONCLUSIONS : It is concluded that the governing design variables for the rapid-set lightweight-formed mortar mix are the forming agent injection ratio and fly-ash substitution ratio.

• Composites Research
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• 제32권1호
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• pp.29-36
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• 2019

본 논문의 목적은 소재대체법과 치수최적화 기법을 이용한 2층 고속열차 알루미늄 압출재 차체의 경량 설계를 제시하는 것이다. 소재대체법을 수행하기 위해 위상최적화 기법을 이용하여 차체 구조물의 샌드위치 복합재 적용 부위를 결정하였다. 해석결과, 루프와 2층 언더프레임에 샌드위치 복합재가 적용 가능함을 보여주었다. 치수최적화는 알루미늄 압출재와 카본/에폭시 복합재의 두께를 결정하는데 사용되었다. 치수최적화를 수행하기 위해, 설계변수, 제약조건, 목적함수를 정식화 하였으며 이러한 조건에 의해 유효설계를 도출하였다. 경량 설계의 결과로 2층 고속열차 하이브리드 차체의 무게를 2.18 ton(17.70%)까지 줄일 수 있음을 보여주었다.

• 한국가구학회지
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• 제28권4호
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• pp.259-267
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• 2017

Furniture should change according to space. Therefore, it is important that the flexibility of the furniture, the functional efficiency, the economical efficiency and the convenience of the furniture of today. These characteristics are also important for seminar tables that are used temporarily by a large number of people. The seminar furniture currently in use has no shielding plate, there are two forms of table and shielding plate folding table. Therefore, in this research, furniture design and product development that can complement the shortcomings of the seminar furniture currently in use were done. Analysis of problems through overseas investigation and domestic market research, design planning and design, and prototyping. We have sought to optimize the volume by applying the characteristics of RTA furniture to develop a lightweight, lightweight, lightweight, easy to install and easy to use shielding plate, and open and closed system. Basically developed two types of shielding board seminar table basic shape and Roll Screen type, we expanded the scope of application such as each color and pattern. In order to reduce the weight, we replaced the parts such as anchor bolts and hinges and the shielding plate with Roll Screen and pursued volume optimization. As a result of this research, it is expected that the system of mechanisms such as packaging standardization and damage prevention for weight reduction and volume optimization will contribute to building competitiveness by domestic office prefabricated furniture industry's original technology.

• 한국항공우주학회지
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• 제38권12호
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• pp.1209-1216
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• 2010

본 연구는, 위성에 장착되는 각종 전자장비 하우징을 종래의 알루미늄 합금에서 복합재료로 대체함으로써 위성 경량화를 극대화할 수 있는 대안을 다루었다. 이를 위해, 기존 전자장비 하우징 재료로 널리 사용되는 알루미늄 합금에 비해 가벼우면서, 충분한 내구성과 다양한 기능성을 제공하는 복합재료 전자장비 하우징 설계를 위한 요구사항을 정의하였다. 또한, 열전도도, 전기전도도, EMI 보호, 방사차폐 특성과 더불어 강도가 우수한 구조적 특성을 갖춘 경량 복합재료 전자장비 하우징을 모듈화 방식으로 제작하기 위한 개념설계를 수행하고, 위성설계에 있어 무게절감을 크게 향상할 수 있는 가능성을 제시하였다.

• 한국통신학회논문지
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• 제42권2호
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• pp.307-315
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• 2017

암호시스템에서 난수발생기는 필수적인 요소이다. 최근에 IoT, Sensor Network, SmartHome와 같은 소형 디바이스를 사용하는 환경이 등장하면서, 이에 적합한 다양한 경량 암호들이 개발되고 있다. 하지만 리소스 제한, 엔트로피 수집의 어려움 등의 문제로 인하여, 기존의 데스크 탑에 초점을 두고 만들어진 난수발생기가 제대로 동작하는 것이 어려워지고 있다. 본 논문에서 경량 환경에서 안전한 난수를 생성하는 방법으로 경량 난수발생기 설계를 소개한다. 구조는 헨켈 매트릭스와 블록암호를 사용하고 잡음원으로 센서를 사용한다. 또한 소형 디바이스 중에서 가장 대표적인 Arduino보드에 설계한 경량 난수발생기를 구현하고, 구현 결과로 센서 데이터와 최종 출력 난수의 엔트로피 값을 측정하고 평가함으로써 효율성과 안전성을 확인한다.

• Design & Manufacturing
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• 제18권2호
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• pp.17-22
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• 2024

Lightweight of plastic containers is becoming an important issue due to increasing environmental legislation and consumer awareness. In this study, the CAE analysis was conducted to optimize the shape of a 500 ml lightweight square polyethylene terephthalate(PET) bottle. First, the linear buckling alaysis using the finite element method was performed to analyze the correlation between the primary geometric parameters of the bottle and the buckling critical load. Then, the optimal geometry parameters were derived, and the actual buckling load was predicted by non-linear buckling simulation. The validity of the simulation results was verified by top-loading tests of PET bottles molded with the optimized geometry. The elastic modulus and tensile yield strength of PET through tensile tests were measured to improve the accuracy of the simulation. As a result of the tensile tests, the modulus of elasticity of PET increased from 2,900 MPa to 4,275 MPa, and the tensile yield strength increased from 52.4 MPa to 88.1 MPa. Finally the buckling load of the optimized PET bottle was found to be approximately 236 N, which is very similar to the simulation precition of 238 N. This study shows the feasibility and accuracy of the CAE analysis approach for the lightweight design of PET bottles, and will provide useful guidelines for the design of PET bottles.

• 한국산학기술학회논문지
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• 제10권3호
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• pp.589-595
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• 2009

본 논문은 스프링 프레임워크 2.5와 연관된 객체지향 소프트웨어 개발에 대한 지침과 평가 지표를 제공하는데 목적이 있다. Non EJB와 EJB 아키텍처가 가지고 있는 문제점을 해결하고 장점들을 지원하기 위하여 새롭게 등장한 아키텍처가 경량 컨테이너 아키텍처이다. 이 구조는 EJB 아키텍처와 같이 무겁지 않으면서도 EJB 컨테이너의 모든 가능을 제공하는 구조이다. 현재까지 경량 컨테이너 아키텍처로 현업에서 가장 많이 사용되고 잘 알려진 아키텍처로 스프링 프레임워크가 있다. 따라서 본 연구에서는 Non EJB와 EJB 아키텍처가 가지고 있는 단점들을 해결하고 장점들을 지원하기 위하여 개발된 최신 경량 컨테이너 아키텍처인 스프링 프레임워크 2.5를 기반으로 호텔예약시스템의 설계 및 구현을 통하여 이전의 사양과의 객관적인 소프트웨어 개발 생산성 지침을 제공하고자 한다.

• 한국공간구조학회:학술대회논문집
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• 한국공간구조학회 2005년도 춘계학술발표회 및 정기총회 2권1호(통권2호)
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• pp.52-66
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• 2005

Tension and Membrane have the potential to enable the realization of lightweight structures that have the attractive features of structures efficiency and aesthetical expression. Compared with pure (thorough-bred) tension structures such as cable net, air dome and tensegrity, so called hybrid tension structures such as beam string, tensegric system and other mixed structures have Potential still to be realized. After synnaruzubg the simple definition of tensegric structure, some holistic designs for hybrid tension structures completed recently in the author's practice are given.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2017년도 추계학술발표회
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• pp.206-206
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• 2017

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2002년도 봄 학술발표회 논문집
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• pp.257-264
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• 2002

This study presents a life-cycle cost (LCC) effectiveness of a concrete with lightweight aggregate. A number of researchers have made their efforts to develop a lightweight concrete, since it is difficult to apply conventional concrete using general aggregate to heavy self-weight structures such as long span bridges. In this study, an optimum design for minimizing the life-cycle cost of concrete slab bridges is performed to evaluate the life cycle cost effectiveness of the lightweight concrete relative to conventional one from the standpoint of the value engineering. The data of physical properties for new concrete can be obtained from basic experimental researches. The material properties of conventional one are acquired by various reports. This study presents a LCC effectiveness of newly developed concrete, which is made by artificial lightweight aggregate. A number of researchers have made their efforts to develop a lightweight concrete, since it is difficult to apply conventional concrete using general aggregate to heavy self-weight structures such as long span bridges. From the results of the numerical investigation, it may be positively stated that the new concrete lead to, the longer span length, the more economical slab bridges compared with structures using general concrete.