• Title/Summary/Keyword: Craig

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A Geometric Derivation of the Craig Representation for the Two-Dimensional Gaussian Q-Function (이변량 가우시안 Q-함수의 Craig 표현에 대한 기하학적인 유도)

  • Park, Seung-Keun;Lee, Il-Kyoo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.4A
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    • pp.325-328
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    • 2011
  • In this paper, we present a new and simple derivation of the Craig representation for the two-dimensional (2-D) Gaussian Q-function in the viewpoint of geometry. The geometric derivation also leads to an alternative Craig form for the 2-D Gaussian Q-function. The derived Craig form is newly obtained from the geometry of two wedge-shaped regions generated by the rotation of Cartesian coordinates over two correlated Gaussian noises. The presented Craig form can play a important role in computing the probability represented by the 2-D Gaussian Q-function.

A Generic Craig Form for the Two-Dimensional Gaussian Q-Function

  • Park, Seung-Keun;Choi, U-Jin
    • ETRI Journal
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    • v.29 no.4
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    • pp.516-517
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    • 2007
  • In this letter we present a generic Craig form for the two-dimensional (2-D) Gaussian Q-function. The presented Craig form provides an alternative solution to the problems of computing probabilities involving a form of the 2-D Gaussian Q-function.

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An Assessment on the Preliminary Coupled Load Analysis Results for Advanced Low Earth Orbit Earth Observation Satellite (고성능 저궤도 지구관측위성의 예비연성하중 해석결과에 대한 평가)

  • Kim, Kyung-Won;Lim, Jae-Hyuk;Kim, Sun-Won;Kim, Chang-Ho;Kim, Sung-Hoon;Hwang, Do-Soon
    • Aerospace Engineering and Technology
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    • v.10 no.2
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    • pp.94-100
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    • 2011
  • In this paper, an assessment on the preliminary coupled load analysis results for advanced Low Earth Orbit Earth Observation satellite was performed. Spacecraft FE-model was converted into Craig-Bampton model consisting of mass matrix, stiffness matrix, acceleration transformation matrix, displacement transformation matrix, and it was delivered to the launch vehicle developer. Launch vehicle developer performed a coupled load analysis with launch vehicle model and spacecraft Craig-Bampton model, and the coupled load analysis results were provided to us. From the assessment on the analysis results, it was verified that spacecraft is safe under launch environment.

Morphological Characterization of 'Ailsa Craig' Tomato Callus and Effect on Plant Regeneration (`Ailsa Craig` 토마토 캘러스의 형태학적 특성과 식물체 재분화에 미치는 영향)

  • Seong, Eun-Soo;Wang, Myeong-Hyeon
    • Applied Biological Chemistry
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    • v.50 no.4
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    • pp.253-256
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    • 2007
  • In an attempt to optimize the in vitro-regeneration conditions necessary for the genetic manipulation of tomato species, we examined 'Ailsa Graig' cultivar of Lycopersicon for regeneration ability. The basal medium used for callus formation and shoot regeneration was MS (MS + vitamin) supplemented with six combinations of zeatin 2 mg/l, zeatin 2 mg/l + IAA 0.1 mg/l, zeatin 2 mg/l + IAA 0.5 mg/l, zeatin 4 mg/l, zeatin 4 mg/l + IAA 0.1 mg/l and zeatin 4 mg/l + IAA 0.5 mg/l. When all conditions tested were considered, however, only zeatin 2 mg/l was shown to be the best in shoot regeneration. The morphological characterization from in vitro-cultured callus of Lycopersicon esculentum L. var. 'Ailsa Craig' was investigated with scanning electron microscope (SEM). The surfaces of in vitro-cultured callus had well-defined epidermal cell in condition of zeatin 2 mg/l, but those of different treatments were twisted. These results suggested that shape of callus was involved in efficiency of shoot regeneration in tomato 'Ailsa Craig'.

Coupled Load Analysis Using MSC/Nastran Superelement (MSC/Nastran Superelement를 이용한 연성하중해석)

  • Kim, Gyeong-Won;Kim, Jin-Hui;Lee, Ju-Hun;Kim, Seon-Won
    • Aerospace Engineering and Technology
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    • v.5 no.2
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    • pp.60-66
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    • 2006
  • This paper is a study on the coupled load analysis using MSC/Nastran superelement method. After selecting the hunch vehicle, coupled load analysis is performed. From the results of coupled load analysis the loads and displacements on the major parts of satellite structure are calculated Based on the loads and displacements, the safety of satellite structure is judged. Coupled load analysis has been executed using MSC/Nastran DMAP code so far. Because DMAP code was very complicated and long in 1ength it was difficult to analyze and modify the DMAP code. To solve out these problems, coupled load analysis was executed using MSC/Nastran 2005 superelemnt method. At first, satellite FE-model was converted to the Craig-Bampton model using MSC/Nastran 2005 superelement method and verified Finally, coupled load analysis was performed using satellite Craig-Bampton model and launch vehicle FE-model and verified.

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A Development of the Tire Interfacing Using the Reduction Method (모델 축소법을 이용한 타이어 인터페이싱 개발)

  • 임문수;김영배;조규종;정광용
    • Korean Journal of Computational Design and Engineering
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    • v.8 no.2
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    • pp.109-114
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    • 2003
  • In order to develop the reduced tire modal model for analyzing a full tire model, the Craig-Bampton method is utilized in this paper. When the tire contacts the road, the Abaqus solver extracts the condensed stiffness, coupled mass and mode shape matrix about the node, which contacts the road. The Abaqus full tire model is reduced using the substructure method utilizing Craig-Bampton algorithm. Then, the extracted matrices are interfaced with the superelement, which is fed to the Nastran reduction algorithm. Eventually, the reduced tire model is verified from experiment and various reduction parameters (i.e. modal number, reduction point, etc.) are studied for the effectiveness of the proposed paper.

Study on Fashion Illustration as Viewed from the Allegorical - Based on the theory of Craig Owens - (알레고리 관점의 패션 일러스트레이션에 관한 연구 - 크렉 오웬스의 이론을 중심으로 -)

  • Kim, Mi-Hyun
    • Journal of the Korean Society of Costume
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    • v.62 no.4
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    • pp.81-90
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    • 2012
  • The contents of this study are as follows. First, an academic understanding has been achieved by exploring the theoretical concept "allegory", and a new theoretical approached methodology has been sought. Second, an analysis-index of fashion illustration cases has been suggested based on the allegory theory of Craig Owens. Third, in order to draw the characteristics of fashion illustration as viewed from the allegorical viewpoint and find out its feasibility, the case studies has been referred and the internal significance, external significance that combines different characteristics has been extracted. In regards to this study method, literature studies and case studies has been done in parallel with each other. This study was done in the following sequence: the establishment of the study system, the drawing of the allegory-associated concepts and the discovering the characteristics of aesthetic expressions. The results of this study on the expression characteristics of fashion illustration as viewed from the allegorical viewpoint of Craig Owens are as follows. First, the borrowing of image, which is a characteristic of allegory, contains the meaning of uncertainty in the fashion illustration as it expresses the image-synthesis and forms a completely different meaning as the fixed meaning is dissolved and it is utilized as a photo-montage technique. Second, the inference of pictogram is the mixture of linguistic medium and visual medium. Fashion illustration utilizes the characters and transmits the fashion information visually and immanently. It has the characteristic of making the information into pictograms and the internal significances of mutual-text with communication function. Third, the uniqueness of location in the fashion illustration has the special nature of utilized mediums as it is used for advertising or publicizing. The fashion illustration from the viewpoint of allegory has the impermanency of existing only for a limited time and reflects the coincidence that gives the meaning of utilized location according to the season trend. Fourth, the cross-breeding is expressed as the mixture of various materials in the fashion illustration. The expressions made by the mixture of media, such as the use of computer graphic programs mixed together with various materials showed the trend of diversity and genre dissolution.

System Target Propagation to Model Order Reduction of a Beam Structure Using Genetic Algorithm (유전자 알고리즘을 이용한 시스템 최적 부분구조화)

  • Jeong, Yong-Min;Kim, Jun-Sik
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.35 no.3
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    • pp.175-182
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    • 2022
  • In many engineering problems, the dynamic substructuring can be useful to analyze complex structures which made with many substructures, such as aircrafts and automotive vehicles. It was originally intended as a method to simplify the engineering problem. The powerful advantage to this is that computational efficiency dramatically increases with eliminating unnecessary degrees-of-freedom of the system and the system targets are concurrently satisfied. Craig-Bampton method has been widely used for the linear system reduction. Recently, multi-level optimization (such as target cascading), which propagates the system-level targets to the subsystem-level targets, has been widely utilized. To this concept, the genetic algorithm which one of the global optimization technique has been utilized to the substructure optimization. The number of internal modes for each substructure can be obtained by the genetic algorithm. Simultaneously, the reduced system meets the top-level targets. In this paper, various numerical examples are tested to verify this concept.

Topology Optimization of a Lightweight Multi-material Cowl Cross Member Using Matrix Input with the Craig Bampton Nodal Method

  • Son, Dong il;So, Sangwoo;Choi, Dong hyuk;Kim, Daeil
    • Composites Research
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    • v.32 no.5
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    • pp.243-248
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    • 2019
  • As demand of light weight in the automotive industry has increased, the cowl cross member has been investigated using various methods to change the material. Conventionally, a cowl cross member has been made of steel and aluminum, but recently researchers tested multi-material such as aluminum and plastic. We studied a new model of the cowl cross member made of composite and non ferrous materials. For products with a high degree of freedom in design, generally, the method of topology optimization is advantageous and for the partial bracket part of the cowl cross member had a degree of freedom in the design, a topology optimization is appropriate. Considering the characteristics of the cowl cross members, we need research to minimize the weight while having the performance of noise, vibration and harshness(NVH). Taking the mounting status of the product into consideration, we used an assembly model to optimize the cowl cross member. But this method took too much time so we considered simple cowl cross member assemble conditions using the direct matrix input method(DMI) with the Craig-Bampton Nodal Method. This method is capable of considering the status of the assembly without assembling the model, which reduced the solving time and increased the accuracy comparison with a cowl cross member without DMI.