• 제목/요약/키워드: design comparison

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인공위성 자세제어를 위한 H-infinity 제어기 설계 알고리즘 비교 연구 (Comparison Study of H-infinity Controller Design Algorithms for Spacecraft Attitude Control)

  • 이승우
    • 한국항공우주학회지
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    • 제44권1호
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    • pp.57-69
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    • 2016
  • 폐루프 기준으로 $H_{\infty}$ 제어기를 설계하는 알고리즘에는 3가지(2-ARE, mu-synthesis, LMI) 방법이 있다. 본 논문에서 3가지 $H_{\infty}$ 제어기 설계 알고리즘에 대한 기초 이론을 종합하고, Matlab$^{TM}$에 구현된 함수가 사용될 경우, 실무입장에서 가장 적절하다고 판단되는 $H_{\infty}$ 제어기 설계 알고리즘 제시를 위해 인공위성 자세 제어기 설계 후 결과를 비교 분석하였다: 2-ARE 방법과 LMI 방법은 robust stability, robust performance 및 control authority 측면에서 거의 유사하였으나, LMI 방법에 비해 2-ARE 방법이 weighting 함수설계에 더 민감하였고, mu-synthesis 방법은 다른 2가지 설계 방법에 비해 성능면에서 다소 떨어지고, control authority가 크게 나타났다. 따라서 인공위성 자세제어 설계를 위해 실무 관점에서 LMI 방법이 더 편리한 설계 알고리즘이라는 결론을 얻었다.

동작 정보를 갖는 가상설비 데이터 재활용 방법론 (A Method of Reusing Kinematic Information for Virtual Facilities)

  • 고민석;신혜선;왕지남;박상철
    • 한국CDE학회논문집
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    • 제16권4호
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    • pp.305-313
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    • 2011
  • This paper proposes a method for reusing kinematic design data for virtual facilities, Making a virtual model of a facility involves two major activities: geometric design (virtual model visualization) and kinematic design that should be remodeled frequently whenever design changes occur, Conventionally, a virtual model of an automated facility focuses on the design level, which mainly deals with design verification, alternative comparison, and geometric model diagnosis, Although a design level model can be designed with the information of past models from PLM system, a simulation level model is not sufficient utilized to be reused for kinematic design purpose, We propose a method for reusing kinematic information of a past simulation model to cope with this problem, We use the concept or the 'center of mass', which is a point representing the mean position of the matter in a body or system. And we also use comparison method of a boundary box to identity which 3D objects have to be involved from the design model to a link structure that is contained in the simulation model. Because a proposed method only use not a historical approach but a geometrical approach, it is more effective to apply to the field.

업무시설 설계단계 BIM 내부마감 속성정보 교체 프로세스 (A Process for Replacing BIM Property Information about Internal Finishing of Office Building in Design Phase)

  • 한지호;남동희;박상헌;구교진
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2023년도 봄 학술논문 발표대회
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    • pp.207-208
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    • 2023
  • The procedure of predicting the construction cost and selecting the best alternative is performed based on comparative review of each building case. In the case of office building, it is required continuously until design is complete, since the owner requirements are various and likely to change during the design process compared to a standardized apartment. However, since the comparison work for each alternative in practice uses only the unit construction cost, there is no correlation between the alternative and the final result, and it is difficult to quantitatively determine the effect of the determined design factor on the total construction cost. It is needed that a means to support the generation of design alternatives using similar building cases during the design phase. This paper proposes a BIM-based data replacing process to support creating and comparison of design alternatives of internal finishing for office building. When design alternatives are created through the proposed process, it is possible to compare several similar cases with current project under equivalent design circumstance. Because only some finishing properties are replaced while maintaining the shape information such as the length, height, and base constraint of the object to be replaced.

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Nonparametric Tests for 2×2 Cross-Over Design

  • Gee, Kyuhoon;Kim, Dongjae
    • Communications for Statistical Applications and Methods
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    • 제19권6호
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    • pp.781-791
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    • 2012
  • A $2{\times}2$ Cross-over design is widely used in clinical trials for comparison studies of two kinds of drugs or medical treatments. This design has many statistical methods such as Hills-Armitage's (1979) method or Koch's (1972) method. In this paper, we propose a nonparametric test for $2{\times}2$ Cross-over design based on a two-sample test suggested by Baumgartner et al. (1998). In addition, a Monte Carlo simulation study is adapted to compare the power of the proposed methods with those of previous methods.

Performance Evaluation of Energy Reduction of Light Shelf Applying Punching Plate

  • Choi, Yuchang;Lee, Heangwoo;Seo, Janghoo;Kim, Yongseong
    • KIEAE Journal
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    • 제14권6호
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    • pp.5-13
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    • 2014
  • Various studies on lighting energy savings are conducted, given that lighting energy consumption accounts 23.5% of building energy consumption. Especially, external type light shelf's efficiency is acknowledged; however, its application is limited in Korea, where high rise building ratio is high, due to high wind pressure. This study delves into natural lighting system to cope with wind pressure, and proposes the punching plate-installed light shelf. This study actually draws lighting energy output, according to whether the punching plate is applied through the test-bed, and verifies the effectiveness of the punching plate-installed light shelf. The conclusion is presented below: First) The result of performance evaluation of light shelf with the punching plate in winter solstice showed that the awning area decreased as the opening ratio increased so that the indoor distributed illumination tended to increase, and $-40^{\circ}$ which was advantageous for awning was determined as the proper angle. Second) The light shelf with the punching plate in spring/autumn equinox shows improved lighting according to the angle, and the appropriate angle of light shelf with the punching plate has increased to $15^{\circ}$ and $20^{\circ}$ according to the opening ratio in comparison to $5^{\circ}C$ which is the appropriate angle of light shelf with no punching plate due to the reflection area reduced by the reflecting plate with holes. Third) The result of performance evaluation of light shelf with the punching plate in summer solstice showed that the lighting performance tended to decrease as the opening ratio increased. 4) The light shelf with the punching plate incurs a 50% energy loss in comparison to the light shelf with no punching plate. However, its effectiveness has been proven in the aspects that it can bring a 50% energy saving in comparison to the case with no installation of light shelf and that it can be designed in response to wind pressure on the high floors.

철골 및 섬유보강 폴리머(FRP) 복합 기둥의 설계강도식에 관한 비교 연구 (A Comparison of Design Strength Equations between Steel and Fiber Reinforced Polymer Composites Columns)

  • 최열;편해완
    • 한국공간구조학회논문집
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    • 제3권3호
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    • pp.85-93
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    • 2003
  • Steel, concrete and their combination materials are the most 6commonly used materials for civil engineering structural systems such as buildings, bridge structures and other structures. Recently, however, fiber reinforced polymer (FRP) composites, a relatively new composite material made of fibers and polymer resins, have been gradually used in structural systems as an alternative structural material. This paper describes a comparison of design strength equations for steel column and FRP composite column based on design philosophies. The safety factors used in allowable stress design (ASD) are relatively higher in FRP structural design than steel structural design. Column critical stress equations of FRP composites column from an experimental study can be represented by Euler elastic buckling equation at the long-range of slenderness, and an exponential form at the short-range of slenderness as defined in Load and Resistance Factor Design (LRFD) of steel column. The column strength of steel and FRP composite columns in large slenderness is independent of material strength, this result verified the elastic buckling equation as derived by Eq. (15) and Eq. (5).

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Optimum design of laterally-supported castellated beams using CBO algorithm

  • Kaveh, A.;Shokohi, F.
    • Steel and Composite Structures
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    • 제18권2호
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    • pp.305-324
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    • 2015
  • In this study, two common types of laterally supported castellated beams are considered as design problems: beams with hexagonal openings and beams with circular openings. The main goal of manufacturing these beams is to increase the moment of inertia and section modulus, which results in greater strength and rigidity. These types of open-web beams have found widespread use, primarily in buildings, because of great savings in materials and construction costs. Hence, the minimum cost is taken as the design objective function and the Colliding Bodies Optimization (CBO) method is utilized for obtaining the solution of the design problem. The design methods used in this study are consistent with BS5950 Part 1 and Part 3, and Euro Code 3. A number of design examples are considered to optimize by CBO algorithm. Comparison of the optimal solution of the CBO algorithm with those of the Enhanced Charged System Search (ECSS) method demonstrate the capability of CBO in solving the present type of design problem. It is also observed that optimization results obtained by the CBO algorithm for three design examples have less cost in comparison to the results of the ECSS algorithm. From the results obtained in this paper, it can be concluded that the use of beam with hexagonal opening requires smaller amount of steel material and it is superior to the cellular beam from the cost point of view.

폐교시설의 활용모형 개발을 위한 예비 분류체계 도출 연구 - 선행연구와 공공 디자인지표의 비교를 중심으로 - (A Study on the Preliminary Classification System for the Development of the Application Model of Closed School Facilities - Focused on the Comparison of Public Design Indicators with Pre-research -)

  • 김재영;이종국
    • 청소년시설환경
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    • 제17권1호
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    • pp.131-141
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    • 2019
  • The purpose of this study is to derive and type utilization indexes by comparing public design indicators with preceding studies related to closed school facilities, and to derive preliminary classification systems through a correlation review between indicators. Pre-research was conducted in the scope of academic papers, academic journals, research reports, and special act for promoting the utilization of closed school assets. Public design indicators were set in the scope of domestic design guidelines, the Seoul city public design assessment system, the 'Good Building' designation system, and the UK Design Quality Index (DQI). and the design review of the British architects. First of all, the research method looked at laws, procedures and utilization of closed schools, and reviewed the preceding study and domestic and international public design indicators sequentially. Next, the association was reviewed through a comparison between the preceding study and the public design indicators, and a preliminary classification system for the use of closed schools was derived from this.