• 한국정보과학회논문지:소프트웨어및응용
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• 제31권3호
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• pp.332-342
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• 2004

엄청난 속도로 증가하고 있는 정보의 홍수 시대에서는 정보들을 선별하기 위하여 정보 필터링기법이 필요하다. 정보 필터링은 내용 기반 방법과 협력에 의한 방법으로 분류할 수 있다. 내용 기반 기법에서는 내용에 기반을 두어 정보를 추출하는 반면 협력 기법은 다른 사람들의 의견을 이용하게 된다. 본 논문에서는 기존 협력 필터링 방법의 문제점을 해결하기 위한 방법의 일환으로 내용 기반 기법과 협력 기법을 보다 유기적으로 결합시키는 연구를 수행하였다. 이를 위해 협력 필터링 틀을 그대로 유지하면서 사용자 프로파일을 효과적으로 이용하는 방법을 제안하였다. 또한, 본 논문에서 제시한 기법을 실험적으로 분석하고 기존의 필터링 기법과 비교하였다. 실험 결과, 본 방법이 예측 질 면에서 상당한 성능 향상이 있었고 새로운 사용자에게도 보다 나은 추천을 할 수 있음을 알 수 있었다.

• Journal of Animal Science and Technology
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• 제55권6호
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• pp.489-500
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• 2013

Daily milk yields on test days were estimated using morning or afternoon partial milk yields collected by official agencies and the accuracy of the estimates was determined. Test-day data for milk yields consisted of 3,156,734 records of AM/PM partial milking measurements of 255,437 milking Holstein cows from 3,708 farms collected from December 2008 to April 2013. A linear regression model (LRM) was applied to estimate daily milk yields using alternate AM/PM milk yield records within lactation stages, milking intervals, and parities on every daily milk yield. The alternate statistical approach was a non-linear hierarchical model (NHM) in which Brody's growth function was implemented by reflecting an animal's physiological milk production cycle. When compared with LRM, daily milk yields predicted by the NHM were assumed to be functionally related to day in milk (or lactation) stage, milking intervals, and partial milk yields. Since the results were in terms of accuracies based on comparisons of different statistical models, accuracies of estimates of daily milk yields by NHM were close to those determined by the LRM. The average of these accuracies was 0.94 for AM partial milk yields and 0.93 for PM partial milk yields for first calving cows. However, the accuracies of AM/PM milk yield estimations from cows under a calving stage higher than the first parity were 0.96 and 0.95, respectively. Correlations between the estimated daily milk yields and the actual daily milk yields ranged from 0.96~0.98. These accuracies were lower for unbalanced AM/PM milking intervals and the first calving cows. Overall, prediction of daily milk yields by NHM would be more appropriate than by LRM due to its flexibility under different milk yield-related circumstances, which provides an idea of the functional relationship between milking intervals and days in milk with daily milk yields from statistical viewpoints.

• Journal of Biosystems Engineering
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• 제40권1호
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• pp.89-93
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• 2015

Purpose: Machine vision-based image processing methods can be useful for estimating the fresh weight of plants. This study analyzes the ability of two different image processing methods, i.e., morphological and pixel-value analysis methods, to measure the fresh weight of lettuce grown in a closed hydroponic system. Methods: Polynomial calibration models are developed to relate the number of pixels in images of leaf areas determined by the image processing methods to actual fresh weights of lettuce measured with a digital scale. The study analyzes the ability of the machine vision- based calibration models to predict the fresh weights of lettuce. Results: The coefficients of determination (> 0.93) and standard error of prediction (SEP) values (< 5 g) generated by the two developed models imply that the image processing methods could accurately estimate the fresh weight of each lettuce plant during its growing stage. Conclusions: The results demonstrate that the growing status of a lettuce plant can be estimated using leaf images and regression equations. This shows that a machine vision system installed on a plant growing bed can potentially be used to determine optimal harvest timings for efficient plant growth management.

• 대한두경부종양학회지
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• 제28권1호
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• pp.27-30
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• 2012

Basaloid squamous cell carcinoma(BSCC) is a high-grade variant of squamous cell carcinoma, with a prediction for multifocal involvement of the base of tongue, pyriform sinus, supraglottic larynx, hypopharynx and palatine tonsil. It primary affects men in the seventh decade of life with frequent cervical lymph-node metastasis at presentation. Grossly, these tumors are usually firm to hard, with associated central necrosis, occuring as exophytic to nodular masses. Histologically, the this infiltrating tumor offers a variety of growth patterns, including solid, lobular, cribriform, cords, trabeculae, nests and glands or cyst. We present a 55-year-old female who was treated with surgical excision and radiotherapy. She was firstly presented as a recurrent inflammatory neck mass and finally diagnosed with basaloid squamous cell carcinoma in the palatine tonsil.

• Journal of Crop Science and Biotechnology
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• 제11권2호
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• pp.141-150
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• 2008

The response of grain yield(GY) and milled-rice protein content(PC) to crop growth status and nitrogen(N) rates at panicle initiation stage(PIS) is critical information for prescribing topdress N rate at PIS(Npi) for target GY and PC. Three split-split-plot experiments including various N treatments and rice cultivars were conducted in Experimental Farm, Seoul National University, Korea in 2003-2005. Shoot N density(SND, g N in shoot $m^{-2}$) and canopy reflectance were measured before N application at PIS, and GY, PC, and SND were measured at harvest. Data from the first two years(2003-2004) were used for calibrating the predictive models for GY, PC, and SND accumulated from PIS to harvest using SND at PIS and Npi by multiple stepwise regression. After that the calibrated models were used for calculating N requirement at PIS for each of nine plots based on the target PC of 6.8% and the values of SND at PIS that was estimated by canopy reflectance method in the 2005 experiment. The result showed that SND at PIS in combination with Npi were successful to predict GY, PC, and SND from PIS to harvest in the calibration dataset with the coefficients of determination ($R^2$) of 0.87, 0.73, and 0.82 and the relative errors in prediction(REP, %) of 5.5, 4.3, and 21.1%, respectively. In general, the calibrated model equations showed a little lower performance in calculating GY, PC, and SND in the validation dataset(data from 2005) but REP ranging from 3.3% for PC and 13.9% for SND accumulated from PIS to harvest was acceptable. Nitrogen rate prescription treatment(PRT) for the target PC of 6.8% reduced the coefficient of variation in PC from 4.6% in the fixed rate treatment(FRT, 3.6g N $m^{-2}$) to 2.4% in PRT and the average PC of PRT was 6.78%, being very close to the target PC of 6.8%. In addition, PRT increased GY by 42.1 $gm^{-2}$ while Npi increased by 0.63 $gm^{-2}$ compared to the FRT, resulting in high agronomic N-use efficiency of 68.8 kg grain from additional kg N. The high agronomic N-use efficiency might have resulted from the higher response of grain yield to the applied N in the prescribed N rate treatment because N rate was prescribed based on the crop growth and N status of each plot.

• 한국전산구조공학회논문집
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• 제21권1호
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• pp.35-42
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• 2008

원자력발전소에서는 열교환 파이프에서 발생하는 열피로 균열을 비파괴 탐상장비를 이용하여 조기에 발견하는 것이 안전을 위해 매우 필요하며, 따라서 이를 모사한 인공균열시편 제작에 많은 노력을 기울이고 있다. 그러나 이러한 균열은 일반 기계가공으로 제작하는 것이 불가능하여 실제 조건과 유사한 열 반복하중 하에서 제작될 수밖에 없는데, 이를 위해 많은 시간이 소요된다. 본 연구에서는 크랙성장 시뮬레이션 기법을 이용하여 이러한 균열 제작시간을 단축하기 위한 최적의 열하중 조건을 찾고자 하였다. 이를 위해 임의조건에서 시뮬레이션 및 열피로균열 발생 기초실험을 수행하여 균열 초기수명과 진전수명을 검증하였고, 이를 바탕으로 다양한 가열 및 냉각시간을 시뮬레이션 함으로써 제작시간을 최소화하는 열하중 조건을 구하였다. 시뮬레이션에서는 응력해석을 위해 상용 소프트웨어 ANSYS를 초기균열수명 계산을 위해 수치계산용 소프트웨어 ZENCRACK을 이용하여 코딩을 균열진전수명 평가를 위해 ZENCRACK 소프트웨어를 이용하였다. 그 결과 1mm 균열 제작에 소요되는 시간은 초기의 418시간에서 319시간으로 24% 단축되는 것으로 예측되었다.

• 대한기계학회논문집
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• 제16권1호
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• pp.53-62
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• 1992

본 연구에서는 약 10년 정도 사용하여 경년 열화가 되었다고 예상되는 실구조 물의 일부를 입수하였으며 열화재의 특성과 비교하기 위하여 열처리에 의해 충격치를 회복시킨 재료를 회복재로 하여 두가지 재료에 대해 시험편을 제작하였따.열확현상 을 파악하기 위하여 평활재로 피로과정, 즉 미소 균열의 발생, 진전 및 복수 균열이 간섭합체하여 파단에 달하는 과정에 대하여 파괴역학적 견지에서 열화재와 회복재를 해석하고 이결과로 부터 확율변수를 추정하여 통계학적인 수명예측방법의 하나를 제시 하여 실구조물에 적용하는 방법에 대해 시도해 보았다.

• Genomics & Informatics
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• 제13권4호
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• pp.137-145
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• 2015

Selective sweep can cause genetic differentiation across populations, which allows for the identification of possible causative regions/genes underlying important traits. The pig has experienced a long history of allele frequency changes through artificial selection in the domestication process. We obtained an average of 329,482,871 sequence reads for 24 pigs from three pig breeds: Yorkshire (n = 5), Landrace (n = 13), and Duroc (n = 6). An average read depth of 11.7 was obtained using whole-genome resequencing on an Illumina HiSeq2000 platform. In this study, cross-population extended haplotype homozygosity and cross-population composite likelihood ratio tests were implemented to detect genes experiencing positive selection for the genome-wide resequencing data generated from three commercial pig breeds. In our results, 26, 7, and 14 genes from Yorkshire, Landrace, and Duroc, respectively were detected by two kinds of statistical tests. Significant evidence for positive selection was identified on genes ST6GALNAC2 and EPHX1 in Yorkshire, PARK2 in Landrace, and BMP6, SLA-DQA1, and PRKG1 in Duroc. These genes are reportedly relevant to lactation, reproduction, meat quality, and growth traits. To understand how these single nucleotide polymorphisms (SNPs) related positive selection affect protein function, we analyzed the effect of non-synonymous SNPs. Three SNPs (rs324509622, rs80931851, and rs80937718) in the SLA-DQA1 gene were significant in the enrichment tests, indicating strong evidence for positive selection in Duroc. Our analyses identified genes under positive selection for lactation, reproduction, and meat-quality and growth traits in Yorkshire, Landrace, and Duroc, respectively.

• The Journal of Asian Finance, Economics and Business
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• 제8권4호
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• pp.83-91
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• 2021

Health is an outset of psychological, social, financial, and physical state. Several macroeconomic factors are entangled with health and mortality. Infant mortality and life expectancy are two keyguard on demographic research context on last few decades. On the other hand, foreign inflows play an unprecedent role for raising economic circulation and providing more opportunities to build a better society. The study aims to investigate the relationship between foreign direct investment (FDI), economic growth, and Bangladesh's health. This study employs time-series data from 1980 to 2018. Results show, with Auto-regressive Distribute Lag (ARDL) model, that there is significant cointegration among variables. Foreign investment and economic output relate significantly and positively to health. On the contrary, education is quasi-linked with a different sign-on different model. For model validation, pitfalls of time-series multicollinearity, heteroscedasiticy, and autocorrelation are not present. Also, CUSUM and CUSUMSQ tests are validating the model as stable and fit for future prediction. Medical assessment and education need more attention from the government as well as the private sector. FDI can play a catalyst role for improving the health sector, raising opportunity in educating and creating a better lifestyle. In order to optimize foreign investment, the government should implement necessary reforms and policies.

• 한국환경농학회지
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• 제37권3호
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• pp.197-206
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• 2018

BACKGROUND: The present study aimed to examine the crops capable of growing and adapting to the external environment and various stresses of reclaimed agriculture land for the development of high value-added agricultural utilization technology based on reclaimed land through standardization and empirical study of cultivation environment for cultivating crops. METHODS AND RESULTS: Two crops namely turnips and beets were selected for the salt tolerance test of soil environmental conditions on reclaimed land. Turnip and beet seedlings were planted on the soil collected at the 'Seokmun' reclaimed land. There are five treatments such as non-treatment, 1.0, 2.0 (control), 4.0 and $8.0dS{\cdot}m^{-1}$ of EC. The contents of betacyanin in beet roots was highest in control and decreased with increasing salt concentration. The GSL contents in the turnip roots waswere highest at EC 2.0 and decreased with increasing salt concentration, whereas those in turnip leaves waswere high both in the non-treated control and atthe EC 1.0-treatment. But, tThere was, however, no statistical differences among the treatments. CONCLUSION: The degree of salt tolerance of crops was examined, and the limit EC iswas expected to be $3.0{\sim}4.0dS{\cdot}m^{-1}$ as reported to date. If the soil improvement is performed and irrigation systems are used in the actual reclaimed land, the EC of supplied irrigation will be low, and desalination effecttreatment by the lower EC of the supplied irrigation on the soil will lead to more favorable soil condition of the rhizosphere and cultivation environment offor the crops than those in the port experiment. Therefore, monitoring the salinity, water content and ground water level will enable prediction of the rhizosphere environment, and setting up irrigation management and supplying irrigation will lead to crop cultivation results that are close to normal.