• Asian-Australasian Journal of Animal Sciences
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• 제17권10호
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• pp.1355-1359
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• 2004

Japanese Black cattle of Hyogo prefecture (Tajima strain) are famous for its ability to produce high-quality meat and have been maintained as a closed system for more than 80 years. In order to assess the usefulness of microsatellite markers in closed cattle populations, and evaluate the genetic structure of the Tajima strain, we analyzed representative dams of the Tajima strain comprised of the substrains Nakadoi and Kinosaki. Genetic variability analyses indicated low genetic diversity in the Tajima strain. In addition, a recent genetic bottleneck, which could be accounted for by the high level of inbreeding, was detected in both substrains. In phylogenetic analyses, relationship coefficients and genetic distances between individuals were calculated using pedigree and microsatellite information. Two phylogenetic trees were constructed from microsatellite and pedigree information using the UPGMA method. Both trees illustrated that most individuals were distinguished clearly on the basis of the two substrains, although in the microsatellite tree some individuals appeared in clusters of different substrains. Comparing the two phylogenetic trees revealed good consistency between the microsatellite analysis tree and the pedigree information. The correlation coefficient between genetic distances derived from microsatellite and pedigree information was 0.686 with a high significance level (p<0.001). These results indicated that microsatellite information may provide data substantially equivalent to pedigree information even in unusually inbred herds of cattle, and suggested that microsatellite markers may be useful in revealing genetic structure without accurate or complete pedigree nformation. Japanese Black cattle of Hyogo prefecture (Tajima strain) are famous for its ability to produce high-quality meat and have been maintained as a closed system for more than 80 years. In order to assess the usefulness of microsatellite markers in closed cattle populations, and evaluate the genetic structure of the Tajima strain, we analyzed representative dams of the Tajima strain comprised of the substrains Nakadoi and Kinosaki. Genetic variability analyses indicated low genetic diversity in the Tajima strain. In addition, a recent genetic bottleneck, which could be accounted for by the high level of inbreeding, was detected in both substrains. In phylogenetic analyses, relationship coefficients and genetic distances between individuals were calculated using pedigree and microsatellite information. Two phylogenetic trees were constructed from microsatellite and pedigree information using the UPGMA method. Both trees illustrated that most individuals were distinguished clearly on the basis of the two substrains, although in the microsatellite tree some individuals appeared in clusters of different substrains. Comparing the two phylogenetic trees revealed good consistency between the microsatellite analysis tree and the pedigree information. The correlation coefficient between genetic distances derived from microsatellite and pedigree information was 0.686 with a high significance level (p<0.001). These results indicated that microsatellite information may provide data substantially equivalent to pedigree information even in unusually inbred herds of cattle, and suggested that microsatellite markers may be useful in revealing genetic structure without accurate or complete pedigree information.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 II
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• pp.1384-1387
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• 2001

Presented is a method to predict strain responses from displacement measurements on a mechanical structure. The method consists of forming a transformation matrix, which is calculated from displacement and strain modal matrices. The modal matrices can be obtained by either finite element analysis or modal testing. One disadvantage of the method is that it requires displacements on all measuring points be measured simultaneously. The strain prediction method is applied to a simple simulated system.

• 대한기계학회논문집A
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• 제34권6호
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• pp.771-780
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• 2010

본 논문에서는 제작이 용이한 십자형 구조를 기본구조로 사용하여 판스프링 고정단을 가진 유연한 6축 로드셀을 설계하였다. 이를 위하여 유한요소법해석을 이용하여 강체 고정단과 판스프링 고정단에 대한 변형 분석을 하였으며 이로부터 특성이 우수한 6축 힘/토크 센서를 설계하였다. 변형률 분포를 이용하여 각 축의 하중에 대한 출력변형률이 비슷한 수준이 되도록 스트레인 게이지 위치를 정하고 상호간섭 변형률이 최소화 되도록 이들로 연결된 브리지회로를 구성하였다. 강체 고정단 대신에 스프링판 고정단을 이용하면 고정 경계부의 조건을 변화시킬 수 있어서 십자형 로드셀의 특성을 획기적으로 개선시킬 수 있었다. 치수 변경을 통하여 설계된 6축 로드셀에 대한 상호 간섭오차는 모든 축에서 0으로 계산되었으며 각 축에서 발생하는 출력변형률 값도 $400\;{\mu}m/m$의 비슷한 수준으로 결정되었다.

• 한국전산구조공학회논문집
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• 제21권6호
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• pp.607-613
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• 2008

광섬유의 클래딩 부분을 별도의 고정구에 직접 부착하는 방식으로 고정하여, 변형발생 시 광케이블을 구성하는 재료들 사이에서 발생하는 미끄러짐(Slip)현상을 방지하고, 외력에 의해 발생하는 변형을 정확하게 측정이 가능하도록 함과 기존 광섬유격자센서가 자체적으로 압축변형의 측정이 곤란한 점을 개선하기 위해 미리 긴장(Pre-Strain)상태를 유지하기 위하여 두 개의 접점사이를 볼트와 너트로 조절하여 프리스트레인 가변이 가능하도록 하여 인장/압축변형 측정을 가능하게 한 광섬유격자센서 패키지를 사용하는 지하구조물 변위 모니터링시스템이 본 연구에 의해 개발되었다. 이러한 광섬유격자센서 패키지는 콘크리트 라이닝구조물에 콘크리트의 불균일성을 극복하고 대표성을 가지기 위해 1미터 게이지 길이를 갖도록 하여 모니터링시스템에 적용되었으며, 대구 지하철 지하구조물에 현재 운영 중인 이 시스템은 한국전력 공동구 설치공사가 진행되면서 구조물에 미치는 영향을 판단하기 위한 모니터링시스템으로 적용되었다.

• Journal of applied mathematics & informatics
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• 제30권1_2호
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• pp.183-200
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• 2012

A two-strain epidemic model with an age structure mutation and varying population is studied. By means of the spectrum theory of bounded linear operator in functional analysis, the reproductive numbers according to the strains, which associates with the growth rate ${\lambda}^*$ of total population size are obtained. The asymptotic stability of the steady states are obtained under some sufficient conditions.

• 한국생산제조학회지
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• 제19권5호
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• pp.637-644
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• 2010

This paper presents a reliability-based shape optimization (RBSO) using the growth-strain method. An actual design involves uncertain conditions such as material property, operational load, Poisson's ratio and dimensional variation. The purpose of the RBSO is to consider the variations of probabilistic constraint and performances caused by uncertainties. In this study, the growth-strain method was applied to shape optimization of reliability analysis. Even though many papers for reliability-based shape optimization in mathematical programming method and ESO (Evolutionary Structural Optimization) were published, the paper for the reliability-based shape optimization using the growth-strain method has not been applied yet. Growth-strain method is applied to performance measure approach (PMA), which has probabilistic constraints that are formulated in terms of the reliability index, is adopted to evaluate the probabilistic constraints in the change of average mises stress. Numerical examples are presented to compare the DO with the RBSO. The results of design example show that the RBSO model is more reliable than deterministic optimization. It was verified that the reliability-based shape optimization using growth-strain method are very effective for general structure. The purpose of this study is to improve structure's safety considering probabilistic variable.

• 한국BIM학회 논문집
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• 제9권3호
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• pp.1-7
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• 2019

Digital twin technology has been actively developed to monitor and assess the current state of actual structures. The digital twin changes the traditional observation method performed in the field to the real-time observation and detection system using virtual online model. Thus, this study designed a digital twin model for a beam and examined the feasibility of the digital twin for bridges. To reflect the current state of the bridge, model updating was performed according to the field test data to construct an analysis model. Based on the constructed bridge analysis model, the relationship between strain and displacement was used to represent a virtual model that behaves in the same way as the actual structure. The strain and displacement relationship was expressed as a matrix derived using an approximate analytical theory. Then, displacements can be obtained using the measured data obtained from strain sensors installed on the bridge. The coordinates of the obtained displacements are used to construct a virtual digital model for the bridge. For verification, a beam was fabricated and tested to evaluate the digital twin model constructed in this study. The displacements obtained from the strain and displacement relationship agrees well with the actual displacements of the beam. In addition, the displacements obtained from the virtual model was visualized at the locations of the strain sensor.

• International Journal of Precision Engineering and Manufacturing
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• 제8권4호
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• pp.56-62
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• 2007

An analytical method to predict the post-weld deformation at the heat-affected zone (HAZ) is presented in this paper. The method was based on the assumption that the post-weld deformation is caused by external forces resulting from the inherent strain, which is defined as the irrecoverable strain after removing structural restraints and loadings. In general, the equivalent loading method can be used to analyze distortions in welding areas because it is efficient and effective. However, if additional loads are applied after welding, it is difficult to determine the final strain on a welded structure. To determine the final strain of a welded structure at the HAZ more accurately, we developed a modified equivalent loading method based on the inherent strain that incorporated hardening effects. The proposed method was applied to calculate the residual stress at the HAZ. Experiments were also conducted on welded plates to evaluate the validity of the proposed method.

• 소음진동
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• 제5권3호
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• pp.395-402
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• 1995

In general low frequency vibration characteristics like an idleshake is mainly influeced by pillar section properties and joints. So the design technique development of vehicle pillar structures is required to initial design and vehicle development stage. In this paper to develop pillar structure design technique considering low frequency vibration characteristics, strain energy method, design sensitivity analysis method, and design optimization method using commercial finite element analysis program and optimization program are presented.

• International Journal of Safety
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• 제1권1호
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• pp.18-23
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• 2002

A mixture fraction formulation is used to numerically simulate the structure of diluted axisymmetric methane-air nonpremixed counterflow flames. The effects of global strain rate and gravity wert! investigated and results were compared. Fuel of a mixture of 20% methane and 80% nitrogen by volume and oxidizer of pure air at low and moderate global strain rates $a_g= 20, 40, 80 s^{-1}$ in normal and zero gravity were computed. It is shown that the numerical method is capable of predicting the structure of counterflow flames in normal and microgravity environments at low and moderate global strain rates.