• 한국어류학회지
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• 제29권3호
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• pp.176-189
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• 2017

경기도 가평군의 가평천 일대에서 2016년 9월과 2017년 2, 4월에 쉬리 245개체를 채집하여 이석과 전장빈도분포법을 이용한 연령추정과 23가지의 계측형질을 이용하여 연령에 따른 성적이형을 조사하였다. 연령추정 결과 만 2년생부터 만 4년생의 비율이 높았고 만 5년생이 최대연령이었다. 23개의 계측형질 중 9개의 형질에서 성별 간에 유의한 차이가 있었다. 이중 뒷지느러미에서 나타나는 성적이형은 수컷의 뒷지느러미 연조가 길게 신장되어 뒷지느러미 폭과 길이가 암컷에 비해 넓고 긴 특징을 보이는 주요한 성적이형으로 나타났다. 또한 산란기에 수컷개체는 뒷지느러미의 연조에 추성이 발달하는 성적이형을 나타내었으나 뒷지느러미를 제외한 다른 계측형질과 외부형질에서 성별에 따른 성적이형이 나타나지 않았다. 성적으로 성숙하는 만 2년생 개체부터 성적이형이 나타났으며, 당년생 치어와 만 1년생 개체에서는 성적이형이 나타나지 않았다. 산란기는 4월에서 5월이었으며, 만 2세부터 산란에 참여하였다. 주요 산란 연령은 만 3세부터였으며, 최대 생식소 도지수(GSI)는 만 5세에서 암컷 14.91, 수컷 8.96으로 나타났다.

• Journal of Animal Science and Technology
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• 제49권2호
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• pp.195-202
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• 2007

돼지의 중요한 경제형질인 성장형질은 검정기간동안의 증체량이나 특정한 체중에 도달하는 일수를 측정한다. 그러나 성장형질은 개체의 능력외의 다른 요인에 의해서도 영향을 받는다. 유전능력 평가를 위해서는 합리적인 측정치를 이용하여 불필요한 오류를 줄여야 한다. 이러한 요인에 의한 성장률의 차이를 줄이기 위하여 경남첨단양돈연구소의 경남흑돈(Berkshire) 1,576두의 자료를 가지고 성장곡선을 추정하여 성장곡선에 의해 일당증체량과 90kg 도달일령을 각각 추정하였다. 기존의 방법들과 정확도를 직접적으로 비교할 수 없으나 추정하는 방법론에 있어서 더 정교하여졌다. 이론적 우수성은 일당 증체량에서는 성장곡선상의 같은 연령을 비교하고, 90kg 도달일령에서는 종료체중 측정일에서 90kg 도달일까지의 일수를 개체의 성장곡선상의 일 증체량으로 계산하는 데에 있다. 또한 컴퓨터를 활용한다면 품종이나 성과 같은 요인들에 대해서도 이 추정방법을 쉽게 각각 적용할 수 있다.

• 대한지역사회영양학회지
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• 제1권3호
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• pp.405-422
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• 1996

The purpose of this study is provide reference data for anthropometry and body composition and also to compare body fat estimation among skinfold thickness, BIA and NIR methods. Anthropometric measurements of height, weight, eight sites of skinfolds and six sites of circumferences were taken from 76 elderly male and 153 elderly female. Skinfold thicknesses, body composition and circumferences except waist were lowered with advancing age in elderly females and males. The degree of change with age vaired among parameters but was consistently and significantly(p<0.05) greater in elderly females than I males. Although sum of skinfold thicknesses and the amount of central and peripheral fat were significantly higher in females than that of males, the ratio of central fat to peripheral fat was significantly greater in males than in females. WHR is also significantly higher in males than that of females. This indicates that fat distribution of males tend to be centralized toward the trunk of the body than females. Estimation of body fat from skinfold thickness(male : 18.5$\pm$4.1$\%$, female : 29.7$\pm$4.0$\%$) and BIA(male : 19.5$\pm$7.3$\%$, female : 29.6$\pm$6.7$\%$) were similar but were significantly different from NIR method(male : 24.7$\pm$5.6$\%$, 34.8$\pm$4.9$\%$). Estimation of body fat by NIR measurement seemed to be more overestimated. Understanding the normal changes in body composition with increasing old age, and the ability to measure these changes and compare them with appropriate reference data are important for the health of the elderly.

• Journal of Ecology and Environment
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• 제32권2호
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• pp.109-113
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• 2009

Tree-ring width analysis has been used to assess the effects of air pollution on tree growth around industrial complexes. Our study was conducted to elucidate the effect of air pollutants on annual ring growth in black pines (Pinus thunbergii) of age 41$\sim$48 years around Ulsan Metropolitan City. The growth data were analyzed by multiple regression and the results are as follows: 1. The annual ring increment of black pines increased with tree age until age 40 years and then decreased gradually after age 40 years. 2. The increment of annual ring width of black pines was affected more by precipitation and evapotranspiration than air temperature. An annual ring decline appeared in the years 1968$\sim$1983, when annual ring indices below zero were observed. Decreased annual ring growth during this period may have been due to air pollution. 3. The heavy metal with the strongest effect on annual ring growth of black pines in the experimental stand was lead (Pb). The concentration of lead in the stand was estimated as over 6 ppm. 4. The technique of tree-ring width analysis may be useful for estimation of the extent of pollution in forest areas near industrial complexes.

• 한국강구조학회 논문집
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• 제25권4호
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• pp.369-377
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• 2013

합성거더 하부 콘크리트에 프리스트레스를 도입한 프리스트레스트 합성거더의 크리프와 건조수축 평가 시 재령보정 유효탄성계수방법을 이용하면 기존의 야쓰미 해법을 이용한 경우보다 더 정확한 결과를 산출할 수 있다. 하지만, 재령보정 유효탄성계수방법은 산출방법이 복잡하므로 실무에서는 야쓰미 해법을 이용하여 장기거동을 해석하는 것이 일반적이다. 이러한 단점을 보완하기 위하여 이 연구에서는 재령보정 유효탄성계수방법에 의해 여러 시공단계별 재령일수에 따른 변수해석을 수행하고, 야쓰미 해법에 의한 장기거동 해석 시 크리프계수를 보정하여 실무에서 합리적으로 반영할 수 있는 방법을 제시하였다.

• 대한의용생체공학회:의공학회지
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• 제27권6호
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• pp.301-309
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• 2006

The main purpose of this study is to derive a regression equation that predicts the individual differences in activity energy expenditure (AEE) using accelerometer during different types of activity. Two subject groups were recruited separately in time: One is a homogeneous group of 94 healthy young adults with age ranged from $20\sim35$ yrs. The other subject group has a broad spectrum of physical characteristics in terms of age and fat ratio. 226 adolescents and adults of age ranged from $12\sim57$ yrs and fat ratio from $4.1\sim39.7%$ were in the second group. The wireless 3-axis accelerometers were developed and carefully fixed at the waist belt level. Simultaneously the total calorie expenditure was measured by gas analyzer. Each subject performed walking and running at speeds of 1.5, 3.0, 4.5, 6.0, 6.5, 7.5, and 8.5 km/hr. A generalized sensor-independent regression equation for AEE was derived. The regression equation was developed fur walking and running. The regression coefficients were predicted as functions of physical factors-age, gender, height, and weight with multivariable regression analysis. The generalized calorie estimation equation predicts AEE with correlation coefficient of 0.96 and the average accuracy of the accumulated calorie was $89.6{\pm}7.9%$.

• Asian-Australasian Journal of Animal Sciences
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• 제17권7호
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• pp.914-918
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• 2004

The random regression model methodology was applied into the estimation of genetic parameters for body weights in Chinese Simmental cattle to replace the traditional multiple trait models. The variance components were estimated using Gibbs sampling procedure on Bayesion theory. The data were extracted for Chinese Simmental cattle born during 1980 to 2000 from 6 national breeding farms, where records from 3 months to 36 months were only used in this study. A 3 orders Legendre polynomial was defined as the submodel to describe the general law of that body weight changing with months of age in population. The heritabilities of body weights from 3 months to 36 months varied between 0.31 and 0.48, where the heritabilities from 3 months to 12 months slightly decreased with months of age but ones from 13 months to 36 months increased with months of age. Specially, the heritabilities at eighteenth and twenty-fourth month of age were 0.33 and 0.36, respectively, which were slightly greater than 0.30 and 0.31 from multiple trait models. In addition, the genetic and phenotypic correlations between body weights at different month ages were also obtained using regression model.

• ALGAE
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• 제37권1호
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• pp.63-74
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• 2022

Perennial stipitate kelps are globally distributed and individual species can inhabit broad latitudinal ranges, expressing notably longevous persistence. Despite the foundational role kelps provide to their communities, little is known about the variability in persistence of the stipitate kelps at local spatial scales. We studied the population persistence of Eisenia arborea, a heat- and wave force-tolerant perennial stipitate kelp with a distributional range extending from British Columbia to south of the range limit of all other northeast Pacific kelps, in Baja California Sur, Mexico. Persistence characteristics for E. arborea among sites were compared and used to test the hypothesis that stand persistence varied at local spatial scales around Isla Natividad, a Pacific island off the Baja California peninsula with documented spatiotemporal environmental heterogeneity. Collected individuals around the island were "aged" using the previously validated age estimation technique of counting annual cortical dark rings. After detecting no significant differences among sites in the covariation between estimated ages for collected individuals and stipe length, we utilized in-situ population-level stipe length measurements to more rapidly predict age structures within six stands around the island. Predicted age structures, and associated stand densities, revealed persistence characteristics and density varied at local scales and a strong positive relationship existed between stand density and stand mean and maximum ages. We speculate that stands responded differently to deterministic influences (e.g., the 2014-2016 marine heatwave and / or competition with Macrocystis) resulting in heterogenous local persistence of this foundation species.

• 천문학회보
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• 제26권1호
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• pp.29-29
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• 2001

• 천문학회보
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• 제25권2호
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• pp.53-53
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• 2000