• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1994년도 가을 학술발표회 논문집
• /
• pp.267-272
• /
• 1994

This work presents a method of optimum design for reinforced concrete building frames with rectangular cross sections. The optimization techniques used is based on the principle of divided parameters. The design variable parameters are divided into two groups, external and internal, and the optimization is also divided into external and internal procedure. This principle overcomes difficulties arising from the presence of two materials in one element, the property peculiar to reinforced concrete. Several search algorithms are tested to verify their accuracy for the external optimization. Among them pattern search algorithms has been found consistent. This work proposes a new method, modified pattern search, and a number of sample problems prove its accuracy and usefulness. Exhaustive search for all local minima in the design spaces for two sample problems has been carried out to understand the nature of the problem. The number of local minima identified is quite more than expected and it has become understood that the researcher's task in this field is to find a better local minimum if not global. The designs produced by the method preposed have been found better than those from other method, and they are in full accord with ACI Building Code Requirments(ACI 318-89).

• 설비공학논문집
• /
• 제26권9호
• /
• pp.424-433
• /
• 2014

The purpose of this study is to evaluate the effectiveness in the lighting performance of mixed type light-shelf, by comparing and analyzing the internal light-shelf, external light-shelf, and mixed-type light-shelf. The performance of light-shelf was evaluated according to the angle of light-shelf at summer solstice, winter solstice, vernal equinox, and autumn equinox. The comparative analysis between the internal light-shelf, external light-shelf, and mixed-type light-shelf was carried out using the performance evaluation and analysis method. The result of performance evaluation is shown as follows. The mixed type light-shelf showed the highest lighting performance all at summer solstice, winter solstice, vernal equinox, and autumn equinox, followed by the external light-shelf and the internal light-shelf in the same order. The mixed type light-shelf was the most favorable for bringing daylight to indoors by adjusting the angle of light-shelf, and it also showed the highest lighting performance in terms of uniformity ratio of illumination which indicates the quality of light.

• 대한조선학회논문집
• /
• 제47권4호
• /
• pp.613-627
• /
• 2010

Ships and off-shore plants have very long lifecycles. Design data of ships and off-shore plants are used as master data in the subsequent phases after the design phase. Therefore, it is an important issue how to convert native design data generated from commercial shipbuilding CAD systems into neutral data with the use of international industrial data standards. International standard-based exchange of ship outfitting and off-shore plant data needs the construction of a library for specifications data of equipment and materials and the provision of external referencing mechanism for retrieving data stored in the library. This paper proposes an approach to construct a specifications data library with the use of ISO 15926 process plants. This library is used for providing specifications data through external referencing when translating ship outfitting data from TRIBON system into ISO 10303 STEP AP 227-formed data.

• 콘크리트학회지
• /
• 제9권1호
• /
• pp.133-141
• /
• 1997

본 연구에서는 사각형단면을 가진 철근콘크리트구조물의 한 최적설계방법을 제시하고자 한다. 철근콘크리트는 한 단면이 2가지의 재료로 구성되어 있으므로 이로인해 야기될 수 잇는 어려움을 해소하기 위해 변수분리의 원리를 도입하였다. 이 원리에 사용된 설계변수 및 제약조건은 외부 및 내부의 두 그룹으로 분류하고, 최적화과정도 외부 및 내부로 나누어진다. 최적화기법에는 Pattern Search을 수정한 Modified Pattern search 방법을 제시하며, 이의 정확도를 여러 가지의 다른 최적화기법들과 서로 비교함으로 이 방법의 우수성을 입증하였다. 이 방법으로부터 얻어지는 모든 설계는 하나의 최적설계이며 ACI318-89의 규정을 모두 만족하는 설계이다.

• 복식
• /
• 제61권8호
• /
• pp.1-17
• /
• 2011

Ever since Homeros in Greece, Mimesis was thought to be an art that imitates nature, especially the classicism of nature. Mimetic theories were used in the artworks in the era of the Renaissance, and the terminology 'mimesis' replaced the idea of originality in the 15th century. The purpose of this study is to understand the aesthetics of mimesis expressed in Online video game apparel design. For this purpose, I researched different theories of 'mimesis' and applied them to Online video game apparel designs. The research was conducted using various books on aesthetics and fashion, and demonstrative studies were processed by analyzing photos from Internet video game websites. In the history of aesthetics, the term mimesis is divided into three categories: external, internal and multiple mimesis. External mimesis represented the historical point of view in the design, which showed the beauty of the ancient times. Internal mimesis displayed the metaphorical symbols of religion, character, psychology, sexuality and fear. Multiple mimesis was the hybrid and the distortion of the different aspects of mimesis. Applying this research on mimesis and expressing them in Online video game design may be an excellent method for understanding human aesthetics in video game apparels.

• 한국정밀공학회지
• /
• 제21권9호
• /
• pp.77-84
• /
• 2004

The attachment of mobile vehicle is necessary for the automated operation on the inclined or vertical walls of steel structures. Since the vehicle requires attaching devices additionally, its overall efficiency can be reduced by the devices. Therefore, external shapes of mobile vehicles have to be researched to give the effective movement on the vertical face. For the design of mobile vehicle, the guideline has been derived from the modeling of wall-climbing, so that the vehicle should have a specific external shape for vertical movement due to the gravitational force. Hence, some adequate arrangement of attaching device to the mobile vehicle has been presented for the effective movement. In the experiments with four permanent magnetic wheels, a plausible result was achieved as a vertical attaching force of 185.2(N), a friction force of 153.8(N) and a curvature radius of 1.4m. The mobile vehicle should be modified according to the proposed design guideline, and then it could be applied to a specific operation as an appropriate external shape. Also, Further research is recommended on an optimal posture and a moving method in a specific application, as the attaching force of the vehicle can be affected by its posture.

• Educational Technology International
• /
• 제13권1호
• /
• pp.145-173
• /
• 2012

The purpose of this study is to develop collaboration scripts as an instructional means to facilitate argumentation in computer-supported collaborative learning, and to analyze their effects. To develop collaboration scripts for argumentation, researchers used activity theory as a conceptual framework and refined the design principles by design-based research. Using LAMS, collaboration scripts for argumentation were developed based on the ArgueGraph. To examine their effects, 72 participants were divided into two groups by internal scripts and randomly allocated to one of three external scripts. Applying mixed methods, researchers analyzed argumentation competence related to the cognitive aspect, examined self-efficacy related to the motivational aspect, and identified the factors influencing collaborative learning processes and outcomes. Researchers found that the internal script is a critical factor to determine the dimensions, degrees, and duration of improvement in argumentation competence. That is, learners with higher internal scripts improved highly in the quality of single arguments, while learners with lower internal scripts improved continuously in the quality of argumentation sequences. The effects of the external scripts varied with the internal script levels and supporting periods. Besides, collaboration scripts for argumentation had positive effects on learners' self-efficacy, and learners with higher internal scripts had better self-efficacy. The factors influencing collaborative learning processes and outcomes showed different results depending on the learning context. Therefore, when scripting learner's interaction in CSCL, researchers should design the scripts adaptable to a natural context of activities.

• 대한인간공학회지
• /
• 제23권4호
• /
• pp.45-56
• /
• 2004

The purpose of this study is to evaluate perceived discomfort of working postures in terms of upper body (back, shoulder, and elbow) flexions when an external load varies. Eighteen subjects participated in an experiment of appraising perceived discomfort of varying upper body postures with three levels of external loads given. The ANOVA results showed that the perceived discomfort of upper body postures was significantly affected by the external load. It was also apparent that the interactions between external load and upper body posture were significant (p< 0.001). The result implies that a new posture classification scheme for workload assessment methods may be in need to reflect such interactions between external load and upper body posture. In order to support the statement, a regression model of perceived discomfort of upper body postures obtained from the experiment was developed and compared to that of perceived discomfort of seven work-related postures found in automobile assembly operations. The correlation coefficient between predicted and actual values of perceived discomfort was about 0.96. It is expected that the result help to properly estimate the body stress resluting from worker's postures and external loads and can be used as a valuable design guideline on preventing work-related musculoskeletal diseases in industry.

• Steel and Composite Structures
• /
• 제46권2호
• /
• pp.211-220
• /
• 2023

Welded hollow spherical joints are commonly used joints in space grid structures. An internal stiffener is generally adopted to strengthen the joints when large hollow spheres are used. To further strengthen it, external stiffeners can be used at the same time. In this study, axial compression tests are conducted on four full-scale 550 mm spherical joints. The failure modes and strengths of the tested joints are investigated. It shows that the external stiffeners are able to increase the strength of the joint up to 25%. A numerical model for large spherical joints with stiffeners is established and verified against the experimental results. Parametric studies are executed considering six main design factors using the verified model. It is found that the strength of the spherical joint increases as the thickness, height and number of the external stiffeners increase, and the hollow sphere's diameter has a neglectable effect on the enhancement caused by the external stiffeners. Based on the experimental and numerical results, a practical formula for the compressive bearing capacity of large welded hollow spherical joints with both internal and external stiffeners is proposed. The proposed formula gives a conservative prediction on the compressive capacity of large welded hollow spherical joints with both internal and external stiffeners.

• 한국항행학회논문지
• /
• 제19권3호
• /
• pp.224-229
• /
• 2015

본 논문은 비균등 Gysel 전력 분배기에서 사용되는 두 개의 외부저항을 ABCD 파라미터 해석을 통하여 한 개의 저항으로 변환하는 식을 유도하고, 구현한 내용이다. 기존의 비균등 Gysel 전력 분배기는 두 개의 외부 저항을 이론적인 값으로 구현하기 어렵기 때문에 출력포트 사이의 격리도 및 반사 손실을 얻기가 어렵다. 이러한 문제를 해결하기 위해서 새롭게 설계한 비균등 Gysel 전력분배기는 전송선로와 한 개의 저항을 사용하여 기존 전력 분배기와 동일한 전기적 특성을 얻었다. 이러한 설계방법의 타당성을 보기위해 중심 주파수 1 GHz에서 4:1 비균등 Gysel 전력분배기를 제작하였고, 이것의 특성이 시뮬레이션과 동일함을 확인하였다.