• 한국정보처리학회논문지
• /
• 제2권2호
• /
• pp.215-228
• /
• 1995

언어에서 단어가 차지하는 중요성은 매우 크다. 그럼에도 불구하고 단어를 구성하 는 음운론적, 형태소론적 요소에 관한 계산적 연구는 그리 많지 않다. 대개의 전통적 언어학 이론은 추상적인 기저구조와 일련의 명시된 규칙들을 가정함으로 해서 형태음 운현상을 설명한다. 그러나 이러한 접근방법은 (1) 기저구조의 가정, (2) 규칙의 발 견, 그리고 (3) 규칙간의 상호관계 등에서 문제점을 내포하고 있다. 본 연구는 인공신 경망이 단어를 구성하는 음소열과 그 단어의 의미를 학습하는 과정에서 규칙은 생겨난 다는 가정에서 시작한다. 다양한 국어의 형태음운현상에 대한 실험결과는 인공신경망 이 규칙이나 기저구조의 도움없이 형태음운현상을 학습할 수 있음을 보여준다.

• Wind and Structures
• /
• 제36권3호
• /
• pp.149-160
• /
• 2023

Lightness and flexibility of membrane roofs make them very sensitive to any external load. One of the most important parameters that controls their behavior, especially under wind load is the sag/span ratio of edge cables. Based on the value of the pretension force in the edge cables and the horizontal projection of the actual area covered by the membrane, an optimized design range of cable sag/span ratios has been determined through carrying on several membrane form-finding analyses. Fully coupled fluid structure dynamic analyses of these membrane roofs are performed under wind load with several conditions using the CFD method. Through investigating the numerical results of these analyses, the behavior of membrane roofs with cables sag/span ratios selected from the previously determined optimized design range has been evaluated.

• International Journal of Fluid Machinery and Systems
• /
• 제2권4호
• /
• pp.303-314
• /
• 2009

The present paper shows the results of numerical and experimental modal analyses of Francis runners, which were executed in air and in still water. In its first part this paper is focused on the numerical prediction of the model parameters by means of FEM and the validation of the FEM method. Influences of different geometries on modal parameters and frequency reduction ratio (FRR), which is the ratio of the natural frequencies in water and the corresponding natural frequencies in air, are investigated for two different runners, one prototype and one model runner. The results of the analyses indicate very good agreement between experiment and simulation. Particularly the frequency reduction ratios derived from simulation are found to agree very well with the values derived from experiment. In order to identify sensitivity of the structural properties several parameters such as material properties, different model scale and different hub geometries are numerically investigated. In its second part, a harmonic response analysis is shown for a Francis runner by applying the time dependent pressure distribution resulting from an unsteady CFD simulation to the mechanical structure. Thus, the data gained by modern CFD simulation are being fully utilized for the structural design based on life time analysis. With this new approach a more precise prediction of turbine loading and its effect on turbine life cycle is possible allowing better turbine designs to be developed.