• Animal Bioscience
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• 제37권4호
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• pp.622-630
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• 2024

Objective: Pig breeders cannot obtain phenotypic information at the time of selection for sow lifetime productivity (SLP). They would benefit from obtaining genetic information of candidate sows. Genomic data interpreted using deep learning (DL) techniques could contribute to the genetic improvement of SLP to maximize farm profitability because DL models capture nonlinear genetic effects such as dominance and epistasis more efficiently than conventional genomic prediction methods based on linear models. This study aimed to investigate the usefulness of DL for the genomic prediction of two SLP-related traits; lifetime number of litters (LNL) and lifetime pig production (LPP). Methods: Two bivariate DL models, convolutional neural network (CNN) and local convolutional neural network (LCNN), were compared with conventional bivariate linear models (i.e., genomic best linear unbiased prediction, Bayesian ridge regression, Bayes A, and Bayes B). Phenotype and pedigree data were collected from 40,011 sows that had husbandry records. Among these, 3,652 pigs were genotyped using the PorcineSNP60K BeadChip. Results: The best predictive correlation for LNL was obtained with CNN (0.28), followed by LCNN (0.26) and conventional linear models (approximately 0.21). For LPP, the best predictive correlation was also obtained with CNN (0.29), followed by LCNN (0.27) and conventional linear models (approximately 0.25). A similar trend was observed with the mean squared error of prediction for the SLP traits. Conclusion: This study provides an example of a CNN that can outperform against the linear model-based genomic prediction approaches when the nonlinear interaction components are important because LNL and LPP exhibited strong epistatic interaction components. Additionally, our results suggest that applying bivariate DL models could also contribute to the prediction accuracy by utilizing the genetic correlation between LNL and LPP.

• Journal of Animal Science and Technology
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• 제55권5호
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• pp.343-349
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• 2013

농협젖소개량사업소가 1983년부터 2011년까지 산유능력검정 사업을 통해 수집한 438,019두의 산유능력검정자료 1,372,050개의 기록과 유대수입과 수익자료를 개체별로 산정하여 젖소의 초기의 생산수준이 수익에 영향하는 효과를 조사하였다. 초기 (1산과 2산)의 산유능력의 중간 그룹에 해당하는 개체들이 가장 축군내에 오래 머무는 것으로 나타났다. 1산 기준에서는 9,000 kg 이상의 그룹들은 전체 산차 평균 3.13 보다 낮게 나타났으며, 생애착유일에서는 7,000 kg 이하의 그룹과 10,000 kg 이상의 고능력우 그룹에서 평균 1,076.8일 보다 낮게 나타났다. 수명관련 형질에서의 변이를 나타내는 표준편차는 생산수준이 높을수록 적게 나타나고 있다. 2산 기준에서는 11,000 kg 이상의 고능력우들이 전체 평균 3.43산 보다 낮게 나타났다. 착유일수는 12,000 kg 이상 그룹에서 각각 1,212.0일로 가장 높았고, 대체적으로 생산수준과 비례하여 저능력우들이 착유일 수가 낮게 나타났다. 초기 (1산과 2산)의 생산수준에 따른 순수익은 생산수준이 높아짐에 따라 모두 증가하고 있다. 낮은 생산수준에서는 2산보다 1산이 오히려 수익을 더 많이 내는 것으로 나타났다. 그러나 높은 단계에서는 순수익이 역전되어 2산에서 높은 수익을 얻고 있다. 이러한 결과들로 미루어 볼 때 생산수준이 낮은 개체들이 생산 능력의 수준에 기인하는 것 보다는 번식 또는 기타 관리의 문제로 도태의 위험에 많이 노출되는 것으로 판단된다. 또한 1산 보다 2산에서 산유량 측정에 의한 개체의 평가가 정확성에서 보다 낮을 확률이 높게 나타내어, 생산수준에 의한 수익의 예측은 2산에서 하는 것이 바람직하다. 1산의 경우는 도태를 하는 것은 바람직하지 않지만, 부득이 도태가 필요하면 제한적으로 7,000 kg 이하의 그룹에 속한 개체들을 도태하여야 한다. 결론적으로 수익함수에 포함되는 모든 요소들에 대하여 개량목표에 반영하여야 하나, 생산수준을 활용, 제한적으로 생애수익을 늘릴 수 있도록 하는 데에 이용 될 수 있다.

• 한국광학회:학술대회논문집
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• 한국광학회 2009년도 창립 20주년기념 특별학술발표회
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• pp.199-200
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• 2009

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2008년도 추계학술대회
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• pp.457-463
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• 2008

In this study, the mean time to failures of a system under shock models are derived. The system receives shocks according to a stochastic process. The expected system lifetime under homogeneous Poisson shock process, nonhomogeneous Poisson shock process, and a general renewal shock process are derived. Some numerical examples are presented.

• 대한치과교정학회지
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• 제51권3호
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• pp.189-198
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• 2021

Objective: To estimate the projected cancer risk attributable to diagnostic cone-beam computed tomography (CBCT) performed under different exposure settings for orthodontic purposes in children and adults. Methods: We collected a list of CBCT machines and their specifications from 38 orthodontists. Organ doses were estimated using median and maximum exposure settings of 105 kVp/156.8 mAs and 130 kVp/200 mAs, respectively. The projected cancer risk attributable to CBCT procedures performed 1-3 times within 2 years was calculated for children (aged 5 and 10 years) and adult (aged 20, 30, and 40 years) male and female patients. Results: For maximum exposure settings, the mean lifetime fractional ratio (LFR) was 14.28% for children and 0.91% for adults; this indicated that the risk to children was 16 times the risk to adults. For median exposure settings, the mean LFR was 5.25% and 0.58% for children and adults, respectively. The risk of cancer decreased with increasing age. For both median and maximum exposure settings, females showed a higher risk of cancer than did males in all age groups. Cancer risk increased with an increase in the frequency of CBCT procedures within a given period. Conclusions: The projected dental CBCT-associated cancer risk spans over a wide range depending on the machine parameters and image acquisition settings. Children and female patients are at a higher risk of developing cancer associated with diagnostic CBCT. Therefore, the use of diagnostic CBCT should be justified, and protective measures should be taken to minimize the harmful biological effects of radiation.

• International Journal of Automotive Technology
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• 제2권1호
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• pp.9-16
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• 2001

The lifetime of power train components can be improved dramatically by finding crack initiation points with suitable software tools and optimization of the critical areas. With increasing capacities of computers the prediction of the lifetime for components by numerical methods gets more and more important. This paper discusses some applications of the outstanding fatigue simulation program FEMFAT supporting the assessment of uniaxially and multiaxially loaded components (as well as welding seams and spot joints). The theory applied in FEMFAT differs in some aspects from classical approaches like the nominal stress concept or the local one and can be characterized by the term "influence parameter method". The specimen S/N-curve is locally modified by different influence parameters as stress-gradient to take into account notch effects, mean-stress influence which is quantified by means of a Haigh-diagram, surface roughness and treatments, temperature, technological size, etc. It is possible to consider plastic deformations resulting in mean-stress rearrangements. The dynamic loading of power train components is very often multiaxial, e.g. the stress state at each time is not proportional to one single stress state. Hence, the directions of the principal axes vary with time. We will present the way how such complex load situations can be handled with FEMFAT by the examples of a crank case and a gear box.

• 한국전기전자재료학회논문지
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• 제30권9호
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• pp.551-557
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• 2017

It is extremely important to improve methodologies for the lifetime assessment of porcelain insulators. While there has been a considerable amount of work regarding the phenomena of lifetime distributions, most of the studies assume that aging distributions follow the Weibull distribution. However, the true underlying distribution is unknown, giving rise to unrealistic inferences, such as parameter estimations. In this article, we review several distributions that are commonly used in reliability and survival analysis, such as the exponential, Weibull, log-normal, and gamma distributions. Some properties, including the characteristics of failure rates of these distributions, are presented. We use a Bayesian approach for model selection and parameter estimation procedures. A well-known measure, called the Bayes factor, is used to find the most plausible model among several contending models. The posterior mean can be used as a parameter estimate for unknown parameters, once a model with the highest posterior probability is selected. Extensive simulation studies are performed to demonstrate our methodologies.

• 한국사회복지학
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• 제41권
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• pp.43-67
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• 2000

The main source in financing the National Pension benefits is the contribution raised from the insured's earnings. So, Most of the insured take a great interest in the questions of what return on the payment of contribution National Pension benefits provide and whether there be the difference in return according to earnings level. The Purpose of this study is to assess money's worth of National Pension and to answer the above questions. There are two basic types of money worth analysis, empirical and hopothetical. This study basically belongs to the former in terms that it is based on actual earnings and insured term. For performing money's worth analysis, four different measures which are referred as the "break-even period", the "benefit/tax ratio", the "net lifetime transfer", the "internal rate of return" are used and they all involve the way in which the relationship between the present value of contributions and the present values of benefit is present. The results which evaluate average money's worth of accrued rights before 1999 are le as follows. Break-even period is about 43 months, benefit/tax ratio being 4.9, net lifetime transfers being about 37 mil1ion won, internal rate of return being 33.2%. This verifies that money' worth of National Pension is much higher than actuarially fair. In the mean while, money' worth is proved to be very different according to earnings level. The progressivity relationship between earnings level and rate of return is found in all measures but net lifetime transfer.

• Journal of Ecology and Environment
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• 제33권3호
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• pp.253-260
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• 2010

It has been well established that leaf longevity is linked to the carbon economy of plants. We used this relationship to predict leaf lifetime carbon gains from leaf lifespan, and estimated the gross primary production (GPP) of a young deciduous forest of Japanese beech (Fagus crenata) located in central Japan. The light-saturated photosynthetic rates of the leaves were measured repeatedly during the growing season. We used the leaf lifespan to calculate the conversion coefficient from the light-saturated photosynthetic rate into the realized leaf lifetime carbon gain under field conditions. The leaf turnover rate was estimated using litter traps. GPP was estimated as the product of lifetime carbon gain per unit of leaf mass, and the annual leaf turnover rate. The GPP of the forest in 2007 was estimated to be $1.2{\times}10^3gCm^{-2}y^{-1}$, which was within the range of previously reported GPP values of beech forests in Japan, and was close to the GPP of a European beech forest, as estimated by eddy flux measurements.

• Communications for Statistical Applications and Methods
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• 제24권4호
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• pp.325-337
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• 2017

In this paper, we proposed a new long-term lifetime distribution with four parameters inserted in a risk competitive scenario with decreasing, increasing and unimodal hazard rate functions, namely the Weibull-Poisson long-term distribution. This new distribution arises from a scenario of competitive latent risk, in which the lifetime associated to the particular risk is not observable, and where only the minimum lifetime value among all risks is noticed in a long-term context. However, it can also be used in any other situation as long as it fits the data well. The Weibull-Poisson long-term distribution is presented as a particular case for the new exponential-Poisson long-term distribution and Weibull long-term distribution. The properties of the proposed distribution were discussed, including its probability density, survival and hazard functions and explicit algebraic formulas for its order statistics. Assuming censored data, we considered the maximum likelihood approach for parameter estimation. For different parameter settings, sample sizes, and censoring percentages various simulation studies were performed to study the mean square error of the maximum likelihood estimative, and compare the performance of the model proposed with the particular cases. The selection criteria Akaike information criterion, Bayesian information criterion, and likelihood ratio test were used for the model selection. The relevance of the approach was illustrated on two real datasets of where the new model was compared with its particular cases observing its potential and competitiveness.