• Structural Engineering and Mechanics
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• 제66권2호
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• pp.273-283
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• 2018

Currently, the dynamic amplification effect of suction is described using the wind vibration coefficient (WVC) of external loads. In other words, it is proposed that the fluctuating characteristics of suction are equivalent to external loads. This is, however, not generally valid. Meanwhile, the effects of the ventilation rate of louver on suction and its WV are considered. To systematically analyze the effects of the ventilation rate of louver on the multi-dimensional WVC of ultra-large cooling towers under suctions, the 210 m ultra-large cooling tower under construction was studied. First, simultaneous rigid pressure measurement wind tunnel tests were executed to obtain the time history of fluctuating wind loads on the external surface and the internal surface of the cooling tower at different ventilation rates (0%, 15%, 30%, and 100%). Based on that, the average values and distributions of fluctuating wind pressures on external and internal surfaces were obtained and compared with each other; a tower/pillar/circular foundation integrated simulation model was developed using the finite element method and complete transient time domain dynamics of external loads and four different suctions of this cooling tower were calculated. Moreover, 1D, 2D, and 3D distributions of WVCs under external loads and suctions at different ventilation rates were obtained and compared with each other. The WVCs of the cooling tower corresponding to four typical response targets (i.e., radial displacement, meridional force, Von Mises stress, and circumferential bending moment) were discussed. Value determination and 2D evaluation of the WVCs of external loads and suctions of this large cooling tower at different ventilation rates were proposed. This study provides references to precise prediction and value determination of WVC of ultra-large cooling towers.

• International Journal of Naval Architecture and Ocean Engineering
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• 제9권6호
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• pp.598-612
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• 2017

The recently developed Harmonic Polynomial Cell (HPC) method has been proved to be a promising choice for solving potential-flow Boundary Value Problem (BVP). In this paper, a flux method is proposed to consistently deal with the Neumann boundary condition of the original HPC method and enhance the accuracy. Moreover, fixed mesh algorithm with free surface immersed is developed to improve the computational efficiency. Finally, a two dimensional (2D) multi-block strategy coupling boundary-fitted mesh and fixed mesh is proposed. It limits the computational costs and preserves the accuracy. A fully nonlinear 2D numerical wave tank is developed using the improved HPC method as a verification.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 G
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• pp.3089-3091
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• 1999

To control IWR-III Biped Waking Robot, those complex modules are necessary that concurrent control multi-axes servo motors, PID & Feedforward gain tuning, initial value calibration, display current status of system, user interface for emergency safety and three-dimensional rendering graphic visualization. It is developed for various-type gait $data^{[1]}$ and for control modes (i.e open/closed loop and pulse/velocity/torque control) that Integrated Control Enviroment with GUI( Graphic User Interface) consist of time-buffered control part using MMC (Multi-Motion Controller) and 3D simulation part using DirectX graphic library.

• 전기학회논문지
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• 제57권3호
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• pp.375-383
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• 2008

This paper deals with reduction and analysis of cogging torque for permanent magnet synchronous generators with multi-pole rotor for wind power applications. Open-circuit field solutions are derived using a magnetic vector potential and a two-dimensional (2-d) polar coordinate systems. On the basis of derived open-circuit field solutions and 2-d permeance functions, we also derive open-circuit field solutions considering stator slotting effects. By using open-circuit field solutions considering stator slotting effects and energy variation methods, this paper analytically predicts the cogging torque considering skew effects. All analytical results are shown in good agreement with those obtained from finite element (FE) analyses. In order to reduce the cogging torque, by predicting the variation of the cogging torque according to pole arc/pitch ratio using analytical and FE methods, pole arc/pitch ratio which makes the cogging torque minimum are determined. However, we confirm that measured value for cogging torque of the PMG with determined pole arc/pitch ratio is twice higher than predicted value. Therefore, the reason for an error between measured and predicted cogging torque is discussed in terms of a shape of PMs and is proved experimentally.

• 대한후두음성언어의학회지
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• 제31권2호
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• pp.71-77
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• 2020

Background and Objectives OperaVOXTM (Oxford Wave Research Ltd.) is a portable voice analysis software package designed for use with iOS devices. As a relatively cheap, portable and easily accessible form of acoustic analysis, OperaVOXTM may be more clinically useful than laboratory-based software in many situations. The aim of this study was to evaluate the agreement between OperaVOXTM and Multi-Dimensional Voice Program (MDVP; Computerized Speech Lab) to assess voice quality before and after laryngeal microsurgery in patient with vocal polyp. Materials and Method Twenty patients who had undergone laryngeal microsurgery for vocal polyp were enrolled in this study. Preoperative and postoperative voices were assessed by acoustic analysis using MDVP and OperaVOXTM. A five-seconds recording of vowel /a/ was used to measure fundamental frequency (F0), jitter, shimmer and noise-to-harmonic ratio (NHR). Results Several acoustic parameters of MDVP and OperaVOXTM related to short-term variability showed significant improvement. While pre-operative value of F0, jitter, shimmer, NHR was 155.75 Hz (male: 125.37 Hz, female: 183.37 Hz), 2.20%, 6.28%, 0.16, post-operative values of these parameter was 164.34 Hz (male: 129.42 Hz, female: 199.26 Hz), 2.15%, 5.18%, 0.14 Hz in MDVP. While pre-operative value of F0, jitter, shimmer, NHR was 168.26 Hz (male: 135.16 Hz, female: 201.37 Hz), 2.27%, 6.95%, 0.26, post-operative values of these parameters was 162.72 Hz (male: 128.267 Hz, female: 197.18 Hz), 1.71%, 5.36%, 0.20 in OperaVOXTM. There was high intersoftware agreement for F0, jitter, shimmer with intraclass correlation coefficient. Conclusion Our results showed that the short-term variability of acoustic parameters in both MDVP and OperaVOXTM were useful for the objective assessment of voice quality in patients who received laryngeal microsurgery. OperaVOXTM is comparable to MDVP and has high intersoftware reliability with MDVP in measuring the F0, jitter, and shimmer

• 산업경영시스템학회지
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• 제40권1호
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• pp.95-104
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• 2017

This paper deals with solution methods for discrete and multi-valued optimization problems. The objective function of the problem incorporates noise effects generated in case that fitness evaluation is accomplished by computer based experiments such as Monte Carlo simulation or discrete event simulation. Meta heuristics including Genetic Algorithm (GA) and Discrete Particle Swarm Optimization (DPSO) can be used to solve these simulation based multi-valued optimization problems. In applying these population based meta heuristics to simulation based optimization problem, samples size to estimate the expected fitness value of a solution and population (particle) size in a generation (step) should be carefully determined to obtain reliable solutions. Under realistic environment with restriction on available computation time, there exists trade-off between these values. In this paper, the effects of sample and population sizes are analyzed under well-known multi-modal and multi-dimensional test functions with randomly generated noise effects. From the experimental results, it is shown that the performance of DPSO is superior to that of GA. While appropriate determination of population sizes is more important than sample size in GA, appropriate determination of sample size is more important than particle size in DPSO. Especially in DPSO, the solution quality under increasing sample sizes with steps is inferior to constant or decreasing sample sizes with steps. Furthermore, the performance of DPSO is improved when OCBA (Optimal Computing Budget Allocation) is incorporated in selecting the best particle in each step. In applying OCBA in DPSO, smaller value of incremental sample size is preferred to obtain better solutions.

• 대한가정학회지
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• 제44권11호
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• pp.67-78
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• 2006

Self-concept is a multi-dimensional characteristic including self-image and self-evaluation. Self-image is the descriptive side of self-concept and is composed of the real self-image and the ideal self-image. Self-evaluation is the appraisable side self-concept and is composed of the internal self-concept, external self-concept and total score of self-concept. The purposes of this study were to determine the correlation of self-image and self-evaluation and to identify the effects of self-image and self-evaluation on consumption value. The data were collected from 237 college women residing in Gwangju using a questionnaire to investigate real/ideal self-image, self-evaluation and consumption value. The results were analyzed with factor analysis, Pearson's correlation and multiple regression analysis using statistical program SPSS 10.0. The results of this research were as follows. 1. The real self-image and ideal self-image had a significant correlation with internal self-concept, external self-concept and total score of self-concept. It was ensured that self-image and self-evaluation are one side of the multidimensional self-concept. 2. The real/ideal self-image and internal/external self-evaluation had a significant influence on consumption value. The real self-image and external self-evaluation were the most important variables explaining the consumption value.

• 한국의상디자인학회지
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• 제15권3호
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• pp.119-135
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• 2013

The purpose of this study was to investigate the relationship between consumption values of preschooler clothing and purchasing satisfaction, company brand loyalty and involvement of preschooler clothing with the mothers of preschoolers. An online survey was adapted as methodology of this study. The collected 323 questionnaires were collected and statistically analyzed. The nine consumption value of preschooler clothing(vicarious satisfaction value, social value, functional value, convenient value, economic value, coordination value, aesthetic value, distinctive value, and fashionable value) resulted from the analysis of survey. Purchasing satisfaction, company brand loyalty, involvement of preschooler clothing was Uni-dimensional. Statistical analysis was performed with frequency analysis, descriptive statistics, exploratory factor analysis, multi-group analysis, confirmatory factor analysis, bivariate correlation analysis, distribution, structural equation, cluster analysis, independent sample t-test, one-way analysis of variance. The results of this study are as follows. In the consumption value of preschooler clothing influencing on the purchasing satisfaction was evaluated depending on the involvement of preschooler clothing group (high-involvement group, low-involvement group). In the low-involvement group, the most significant consumption value of preschooler clothing are economic value, convenient value, social value in order of importance; though in the high-involvement group, aesthetic value, social value, economic value in order of importance. Also the brand royalty was more affected by the purchasing satisfaction in the high-involvement group than in the low-involvement group. In conclusion, the relations of consumption value of preschooler clothing with purchasing satisfaction, company brand loyalty, involvement of preschooler clothing was established in study. The significances of this study is to provide the market segmentation strategy depending on the characteristics of preschooler clothing consumers and establish the information and direction to increase the company brand royalty and purchasing satisfaction.

• 인터넷정보학회논문지
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• 제6권1호
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• pp.85-93
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• 2005

본 논문은 다량의 고차원 얼굴 표정 모션 데이터를 2차원 공간에 분포시키고, 애니메이터가 이 공간을 항해하면서 원하는 표정들을 실시간 적으로 선택함으로써 얼굴 표정 애니메이션을 생성하는 방법을 기술한다. 본 논문에서는 약 2400여개의 얼굴 표정 프레임을 이용하여 표정공간을 구성하였다. 표정공간의 생성은 임의의 두 표정간의 최단거리의 결정으로 귀결된다. 표정공간은 다양체 공간으로서 이 공간내의 두 점간의 거리는 다음과 같이 근사적으로 표현한다. 임의의 마커간의 거리를 표시하는 거리행렬을 사용하여 각 표정의 상태를 표현하는 표정상태벡터를 정의한 후, 두 표정이 인접해 있으면, 이를 두 표정 간 최단거리(다양체 거리)에 대한 근사치로 간주한다. 그리하여 인접 표정들 간의 인접거리가 결정되면, 이들 인접거리들을 연결하여 임의의 두 표정 상태간의 최단거리를 구하는데, 이를 위해 Floyd 알고리즘을 이용한다. 다차원 공간인 표정공간을 가시화하기 위해서는 CCA 투영기법을 이용하여 2차원 평면에 투영시켰다 얼굴 애니메이션은 사용자 인터베이스를 사용하여 애니메이터들이 2차원 공간을 항해하면서 실시간으로 생성한다.

• Journal of Platform Technology
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• 제11권5호
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• pp.23-36
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• 2023

이 연구는 내용 분석 기법과 해밍 거리 측정 방법을 적용하여 <흥부전> 이본의 계열과 계통을 미시적, 거시적으로 분석하는 것을 목적으로 한다. <흥부전>의 28개 이본을 내용 단락으로 분절하고 각 단락마다 내용 유형에 따라 내용 유형의 값을 인코딩하여서, 모든 이본의 유형 차이를 비교하였다. 28개 이본의 내용 단락 유형에 따른 차이를 종합하여서 이본의 친소 관계를 분석하기 위하여 거리 행렬로 변환하였다. 거리 행렬은 차원 축소 기법의 일종인 다차원 척도법을 적용하였고 그 결과 거리 행렬을 2차원 공간으로 축소하여 2차원 좌표를 구하였다. 다차원 척도법 분석 결과를 시각화하여서 흥부전 이본은 크게 2가지 계통으로 구분이 된다는 것을 확인하였다. 동일한 거리 행렬을 활용하여 28개 이본의 친소 관계 군집을 분석하기 위한 방법으로는 계층적 군집 분석과 계통분기분석방법을 적용하였다. 그 결과 2개의 이본 계통은 친소 관계의 미시적 분석 결과에 따라 5개의 계열이 존재하는 것을 확인하였다. 이 연구에서는 디지털 인문학 연구 방법을 적용하여 고전 문학 이본의 내용을 인코딩하고 그 데이터를 분석하는 방법을 적용하여 문헌의 내용 유사도에 따른 군집 분석 기법이 유용함을 보여주었다.