• 임산에너지
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• 제18권2호
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• pp.84-91
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• 1999

The objective of this study was to present creep and the effects of mechano-sorptive deflection of drift pin moment resisting joint between LVL members under changing relative humidity (RH) conditions. The LVL members with steel gusset were jointed by a square pattern of eight injected drift pin. Three diameter drift pins were used to test specimens (6mm, 10mm, and 16mm). The creep test was conducted under two constant loading conditions : one at 30 kgf(840 kgf-cm) and the other at 60 kgf(1680 kgf-cm). The experiment was conducted in an open shed outside. (1)The total rotation creep model of moment resisting joing can be expressed as the sum of the creep of controlled environment (3-parameter model), dimensional change and mechano-sorptive deflection resulting from the variable environment. (2)Mechanosorptive rotation creep is recoverable as moisture content increases during adsorption. Least squares method for linear regression analysis was performed using mechano-sorptive rotation creep as the dependent variable and moisture content as the independent variable. The slope of low moment specimens are compared with those of high moment. This means that low moment condition is more easily affected by changes in humidity than high moment conditions. (3)Although creep deflection is higher for small diameter drift pin than for large diameter drift pin, the shape of creep deflection curves for all specimens is similar.

• Structural Engineering and Mechanics
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• 제45권2호
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• pp.233-257
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• 2013

Given the yield shear of a single-story inelastic structure with simple eccentricity, the problem of strength distribution among the resisting elements is investigated, with respect to minimize its torsional response during a ground motion. Making the hypothesis that the peak accelerations, of both modes of vibration, are determined from the inelastic acceleration spectrum, and assuming further that a peak response quantity is obtained by an appropriate combination rule (square root of sum of squares-SRSS or complete quadratic combination-CQC), the first aim of this study is to present an interaction relationship between the yield shear and the maximum torque that may be developed in such systems. It is shown that this torque may be developed, with equal probability, in both directions (clockwise and anticlockwise), but as it is not concurrent with the yield shear, a rational design should be based on a combination of the yield shear with a fraction of the peak torque. The second aim is to examine the response of such model structures under characteristic ground motions. These models provide a rather small peak rotation and code provisions that are based on such principles (NBCC-1995, UBC-1994, EAK-2000, NZS-1992) are superiors to EC8 (1993) and to systems with a stiffness proportional strength distribution.

• 한국기계가공학회지
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• 제15권3호
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• pp.21-27
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• 2016

The static and dynamic structural integrity qualification was performed through the seismic analysis of a small-size Savonius-type vertical wind turbine at dead weight plus wind load and seismic loads. The ANSYS finite element program was used to develop the FEM model of the wind turbine and to accomplish static, modal, and dynamic frequency response analyses. The stress of the wind turbine structure for each wind load and dead weight was calculated and combined by taking the square root of the sum of the squares (SRSS) to obtain static stresses. Seismic response spectrum analysis was also carried out in the horizontal (X and Y) and vertical (Z) directions to determine the response stress distribution for the required response spectrum (RRS) at safe-shutdown earthquake with a 5% damping (SSE-5%) condition. The stress resulting from the seismic analysis in each of the three directions was combined with the SRSS to yield dynamic stresses. These static and dynamic stresses were summed by using the same SRSS. Finally, this total stress was compared with the allowable stress design, which was calculated based on the requirements of the KBC 2009, KS C IEC 61400-1, and KS C IEC 61400-2 codes.

• 대한기계학회논문집A
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• 제24권12호
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• pp.2952-2962
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• 2000

The design of experiment(DOE) is getting more attention in the engineering community since it is easy to understand and apply. Recently, engineering designers are adopting DOE with orthogonal arrays when they want to design products in a discrete design space. In this research, a design flow with orthogonal arrays is defined for structural design according to the general DOE. The design problem is defined as a general structural optimization problem. Sensitivity information is evaluated by the analysis of variance(ANOVA), and an optimum design is determined from analysis of means(ANOM). Interactions between design variables are investigated to achieve additivity which should be valid in DOE. When strong interactions exit, a method is proposed. Some methods to consider the problem are suggested.

• Wind and Structures
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• 제38권3호
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• pp.161-170
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• 2024

In recent years, there have been an increasing number of experimental studies showing the need to include robustness criteria in the design process to develop complex active control designs for practical implementation. The paper investigates the crosswind aerodynamic parameters after the blocking phase of a two-dimensional square cross-section structure by measuring the response in wind tunnel tests under light wind flow conditions. To improve the accuracy of the results, the interpolation of the experimental curves in the time domain and the analytical responses were numerically optimized to finalize the results. Due to this combined effect, the three aerodynamic parameters decrease with increasing wind speed and asymptotically affect the upper branch constants. This means that the aerodynamic parameters along the density distribution are minimal. Taylor series are utilized to describe the fuzzy nonlinear plant and derive the stability analysis using polynomial function for analyzing the aerodynamic parameters and numerical simulations. Due to it will yield intricate terms to ensure stability criterion, therefore we aim to avoid kinds issues by proposing a polynomial homogeneous framework and utilizing Euler's functions for homogeneous systems. Finally, we solve the problem of stabilization under the consideration by SOS (sum of squares) and assign its fuzzy controller based on the feasibility of demonstration of a nonlinear system as an example.

• Journal of the Korean Data and Information Science Society
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• 제20권2호
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• pp.301-309
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• 2009

다차원척도법은 다변량분석에서 개체들을 대상으로 변수들을 측정한 후에 개체들 사이의 비유사성을 측정하고, 그 값들 혹은 반복하여 측정된 경우에는 그 값들의 평균을 이용하여 개체들을 저차원의 공간상에 도시화시켜 표현하는 분석방법이다. 본 논문에서는 응답자의 답변에 기초하여 비유사성을 측정할 때 이상치 또는 응답자의 답변이 불성실할 경우 발생하는 변이문제와 개체들 간의 거리에 대한 통계적 추론 문제에 붓스트랩 방법을 적용하는 내용을 다루고, 활용가능성을 무료일간지에 대한 유사성 평가 자료를 이용하여 실증적으로 분석하였다.

• 융합보안논문지
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• 제6권3호
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• pp.145-153
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• 2006

본 논문에서는 기록값 통계량을 이용한 무한 고장 NHPP 모형들이 제안되었다. 이 모형들은 결함당 고장 발생률이 단조 증가하거나 단조 감소하는 패턴을 가진다. 그리고 수명 분포에서는 어랑 분포, 랄리 분포와 굼벨를 이용한 소프트웨어 신뢰성 모형을 적용하여 비교연구에 초점을 두었다. 고장 간격 시간 자료를 이용한 무한 고장 NHPP 모형들에 대한 모수 추정법은 최우 추정법을 사용하였고 적용 분포들의 적용을 용이하게 하기 위하여 특수한 형태를 제시하였다. 고장 자료의 분석을 위하여 산술 및 라플라스 추세 검정과 적합도 및 치우침 검정을 실시하여 그 결과를 나열하였다.

• 한국작물학회지
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• 제45권5호
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• pp.316-321
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• 2000

Blast severity data of 39 rice varieties at 11 sites in Korea from 1997 to 1999 were analyzed using AMMI model and pattern analysis. Genotype x Environment (G$\times$E) interaction sum of squares (SS) accounted for 12 % of the total SS. Eight genotype groups and seven location groups were identified based on blast reaction pattern. The data obtained from over 21 sites with 44 test varieties from 1981 to 1996 were also considered. These were compared with the 1997-1999 data using the G$\times$E analysis results. Majority of the variability in the Korean Rice Blast Nursery (KRBN) were attributable to variations due to genotypes. Variations of G$\times$E interaction were maintained though test sites were reduced from 21 to 11 sites. Broadly compatible biological discriminative varieties identified were Nagdongbyeo and Akibare while broadly incompatible biological discriminative varieties identified were Hangangchalbyeo and Seogwangbyeo. Key sites for future evaluation work could be selected from location groups. Each location group should be represented by the site with the strongest interaction pattern. Blast responses in Cheolwon, Gyehwa, Suwon, Iksan, and Icheon showed different patterns from other locations.

• 응용통계연구
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• 제31권1호
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• pp.97-108
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• 2018

회귀모형을 이용하여 자료를 분석하는 경우 이상점이나 영향점의 유무를 검정하는 회귀진단기법은 모형의 적합성을 체크하기 위한 필수적인 도구이다. 이러한 이상점이나 영향점이 존재하는 경우 회귀분석의 결과가 왜곡되어 해석이 된다. Jang과 Anderson-Cook (Quality and Reliability Engineering International, 30, 1409-1425, 2014)은 불꽃그림이란 이름을 붙인 그래픽 방법를 제시하였는데 관측값에 부여된 가중치를 1에서 0으로 변화함에 따라 이상점이나 영향점이 회귀계수 및 잔차제곱합에 어떠한 영향을 미치는지 살펴 보았다. 본 연구에서는 다반응 반응표면분석에서 이러한 불꽃그림을 적용하여 보고자 한다.

• Korean Chemical Engineering Research
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• 제53권1호
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• pp.127-130
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• 2015

본 연구에서는 활성탄을 흡착제로 사용하여 아세트산의 흡착 평형 실험을 313.15, 323.15 K에서 수행하였다. 아세트산의 흡착평형 데이터를 Langmuir, Bi-Langmuir, Freundlich model로부터의 계산 결과와 비교하였다. 이 과정에서 각 model 내 isotherm parameter는 실험값과 계산값의 차이의 제곱의 합을 최소화하는 방식으로 결정하였다. 비교 결과 활성탄상에서의 아세트산의 흡착평형 데이터를 가장 잘 설명해주는 model은 Bi-Langmuir model이었음을 확인하였다.