• Journal of the Institute of Electronics Engineers of Korea SP
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• v.43 no.6 s.312
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• pp.28-35
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• 2006

Statistical models of shape variability based on active shape models (ASMs) have been successfully utilized to perform segmentation and recognition tasks in two-dimensional (2D) images. Three-dimensional (3D) model-based approaches are more promising than 2D approaches since they can bring in more realistic shape constraints for recognizing and delineating the object boundary. For 3D model-based approaches, however, building the 3D shape model from a training set of segmented instances of an object is a major challenge and currently it remains an open problem in building the 3D shape model, one essential step is to generate a point distribution model (PDM). Corresponding landmarks must be selected in all1 training shapes for generating PDM, and manual determination of landmark correspondences is very time-consuming, tedious, and error-prone. In this paper, we propose a novel automatic method for generating 3D statistical shape models. Given a set of training 3D shapes, we generate a 3D model by 1) building the mean shape fro]n the distance transform of the training shapes, 2) utilizing a tetrahedron method for automatically selecting landmarks on the mean shape, and 3) subsequently propagating these landmarks to each training shape via a distance labeling method. In this paper, we investigate the accuracy and compactness of the 3D model for the human liver built from 50 segmented individual CT data sets. The proposed method is very general without such assumptions and can be applied to other data sets.

• Journal of Animal Science and Technology
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• v.50 no.5
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• pp.621-632
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• 2008

Genetic polymorphisms was investigated at five single nucleotide polymorphisms(SNP) sites in four porcine genes(ADCYAP1R1, FABP3, MC4R, and MYL2) and analyzed their statistical association with growth traits in F2 reciprocal-crossbred population between Landrace and Jeju native black pig(JNP). All populations, JNP, Landrace and their F2 were polymorphic for all five SNP loci tested, however, the homozygote T/T of FABP3 g.-158T>C and the homozygote G/G of ADCYAP1R1 intron 2 337A>G were not found in JNP and Landrace, respectively. The genotypes of ADCYAP1R1 were significantly associated with body weights(BW) at 3 weeks and at 20 weeks(P<0.05), respectivley, those of FABP3 g.-135delT were associated with late average daily gain(LADG) (P<0.01), and those of FABP3 g.-158T>G were associated with body weights during late growth period such as, BW20 and LADG(P<0.01). Those of MC4R were also significantly associated with BW10 suggesting by the difference of early average daily gain(EADG) (P<0.05), and with LADG(P<0.01). The body length of F2 animals was affected by the genotypes of ADCYAP1R1, MC4R, and MYL2(P<0.05), respectively. Among these, MC4R A/A homozygotes showed over 3 cm longer in body length than those of other genotypes. As the useful basic information, these results suggested that SNP markers showing statistical association with growth traits and the results help to select the sires of JNP for improving the productivity in JNP-related crossbreeding system in pig industry and also to construct the molecular breeding system for breed improvement of JNP itself.

• Journal of Animal Science and Technology
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• v.45 no.5
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• pp.711-724
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• 2003

Some growth curve models were used to fit individual growth of 1,083 Hanwoo cows born from 1970 to 2001 in Daekwanryeong branch, National Livestock Research Institute(NLRI). The effects of year-season of birth and age of dam were analyzed. In analysis of variance for growth curve parameters, the effects of birth year-season were significant for mature weight(A), growth ratio(b) and maturing rate(k)(P〈.01). The effects of age of dam were significant for growth ratio(b) but not significant for mature weight(A) and maturing rate(k). The linear term of the covariate of age at the final weights was significant for the A(P〈.01) and k(P〈.01) of Gompertz model, von Bertalanffy model and Logistic model. For the growth curve parameters fitted on individual data using Gompertz model, von Bertalanffy model and Logistic model, resulting the linear contrasts(fall-spring), Least square means of A in three nonlinear models were higher cows born at fall and A of Logistic model was significant(P〈.05) between the seasons. According to the results of the least square means of growth curve parameters by age of dam, least square means of mature weight(A) in Gompertz model was largest in 6 year and smallest estimating for 3 and 8 years of age of dam. The growth ratio(b) was largest in 2 year of age of dam and smallest estimating in 8 year. The A and k were not different by age of dam(p〉.05), On the other hand, the b was different by age of dam(p〈.01). The estimate of A in von Bertalanffy model was largest in 6 year and smallest in 8 and 9 years of age of dam. The b was largest in 2 year and tend to decline as age of dam increased. The A and k were not different by age of dam(p〉.05), On the other hand, the b was highly significant by age of dam(p〈.01).

• Journal of Korean Society of Forest Science
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• v.89 no.5
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• pp.634-644
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• 2000

Sterba's theory that stem number maintaining maximum basal area per ha is maximum stem number of a stand, had been applied to data from 103 temporary plots in even-aged Pinus densiflora stands in Kangwon province, Korea and a maximum stem number and mortality model was prepared. DBH growth model which estimates dbh with the independent variables of stem number per ha and dominant height shows the good statistical performance, and explains well differences in dbh growth that would be caused by stem number per ha and dominant height. Basal area model derived from dbh growth model also explains well differences in basal area according to stem number per ha and dominant height. The maximum stem number curve, which is derived from stem number per ha at maximum basal area for dominant height and dbh, represents well the upper range of stem number per ha observed. And maximum stand density index derived from the maximum stem number model for dbh could be used for the index of maximum potential density of a stand. The maximum stem number model and maximum stand density index in this study were not based on stand data with maximum density but based on the temporary data from stands with various density. This maximum stem number model can be applied to the estimation of mortality and maximum potential volume.

• Korean Journal of Agricultural and Forest Meteorology
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• v.3 no.2
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• pp.114-120
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• 2001

Ginkgo biloba L. has been planted in the city as street trees because reported as resistant species to air pollutant. Especially, the trees planted on the street of 'Cheongro', Mt. 'Nam', and 'Jamsil' have been exposed to air pollutant for a long time. This study was conducted to examine chlorophyll contents and genetic variation of Ginkgo biloba in the areas. Chlorophyll contents measured in the above three areas were variable although the the diameter at breast height measured in 'Cheongro' and Mt. 'Nam' were constant. In addition, the result showed positive relation between chlorophyll contents and DBH in this study. Eight enzyme systems were analyzed in megagametophytes which were collected in the areas and separated to two groups based on chlorophyll contents. All the enzymes appeared to be polymorphic : Got-2, Pgi-2, Pgm, Acon, Mnr, Mdh, Skdh, and 6Pgd. The sensitive (S) groups varied from 1.253 to 2.571 in the genetic diversity and the tolerant (T) groups ranged from 1.416 to 2.825. The observed single locus heterozygosities (H$_{0}$) ranged from 0.056 to 0.611 in the S groups, and from 0.179 to 1.643 in the T groups. The expected heterozygosities (H$_{e}$) ranged from 0.208 to 0.629 in the S groups and from 0.321 to 0.658 in the T groups. In addition, the H$_{0}$ values averaged over all loci were 0.326 for the T groups and 0.299 for the S group, respectively. A difference between the two groups was 0.027. The T groups had the unique alleles and genotypes and all the parameters for genetic diversity showed that the T groups had higher genetic diversity than the S groups.s. genetic diversity than the S groups.

• Korean Journal of Poultry Science
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• v.32 no.1
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• pp.29-34
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• 2005

This study was conducted to estimate the effects of genotype for chicken major histocompatibility complex (MHC) B-LB genes on economic traits. To detect polymorphism, 400 bp fragments of MHC B-LB genes were obtained and sequenced. After digestions using restriction enzyme Hea III, two restriction enzyme sites were observed. There were two mutations at position 427 and 651 those were decided as Type I and Type II, respectively. Using RFLP analyses, type I were genotyped to TT, TC and CC, and type II to MM, Mm and mm. The relatively higher TC genotype frequencies (0.8) of Type I and Mm genotype frequencies (0.88) of Type II were observed in Korean native chickens. The effects of the genotype on 150 days body weight trait were investigated by the associations of CC and Mm genotypes (P<0.05) in Korean native chickens. This result suggests that a significant association exists between the SNP and 150 days body weight.

• Journal of the Korean Society of Radiology
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• v.82 no.3
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• pp.626-637
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• 2021

Purpose To explore cerebrovascular reservoir (CVR) and arterial transit time (ATT) changes using acetazolamide-challenged multi-phase arterial spin labeling (MP-ASL) perfusion-weighted MRI in chronic cerebrovascular steno-occlusive disease. Materials and Methods This retrospective study enrolled patients with chronic steno-occlusion who underwent acetazolamide-challenged MP-ASL between June 2019 and October 2020. Cerebral blood flow, CVR, basal ATT, and ATT changes associated with severe stenosis, total occlusion, and chronic infarction lesions were compared. Results There were 32 patients (5 with bilateral steno-occlusion) in our study sample. The CVR was significantly reduced during total occlusion compared with severe stenosis (26.2% ± 28.8% vs. 41.4% ± 34.1%, respectively, p = 0.004). The ATT changes were not significantly different (p = 0.717). The CVR was marginally lower in patients with chronic infarction (29.6% ± 39.1% vs. 38.9% ± 28.7%, respectively, p = 0.076). However, the ATT was less shortened in patients with chronic infarction (-54 ± 135 vs. -117 ± 128 ms, respectively, p = 0.013). Conclusion Acetazolamide-challenged MP-ASL provides an MRI-based CVR evaluation tool for chronic steno-occlusive disease.

• Clinical and Experimental Pediatrics
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• v.49 no.2
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• pp.187-191
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• 2006

Purpose : Malformation of cortical development(MCD) constitutes an important etiology of intractable epilepsy and is considered an indication for surgical treatments, though their efficacy is limited and variable depending on MCD's location or distribution. Ketogenic diets are widely known to be effective, but as little study has been made concerning their efficacy on epilepsy with MCD, we evaluated the efficacy of ketogenic diets on MCD patients compared with that of epileptic surgery, which is more invasive. Methods : We performed retrospective studies and analyse on 30 patients with MCD diagnosed by brain MRI and treated with ketogenic diets for intractable epilepsy since 1998, checking decreases in their seizure episodes after starting the diets. Results : Cortical dysplasia was observed in 24(80.0 percent) patients as the most common type of MCD. Also, MCD was observed in unilateral hemisphere most commonly, in 23(76.7 percent) patients; it was observed in both hemispheres in 7(23.3 percent) patients. Nine(30.0 percent) out of 30 patients became seizure-free after starting ketogenic diets, and 14(46.7 percent) patients experienced 50 percent seizure reductions as well. Age of starting the diet or the duration of epilepsy period before starting showed no statistical relationship with the efficacy of the diet. Though the younger the patient and the longer the treatment the more effective the diet seemed to be, there was no statistical correlation between them. The location of MCD showed no significance neither. Conclusion : Considering various limits and invasiveness of surgical treatment, a ketogenic diet could be a good tool in treating children with intractable epilepsy with MCD.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.3
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• pp.163-172
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• 2013

The aquatic insect collected at six areas (each 2 for mountain area, plain field, and urban area) from 2009 to 2011 were classified to analyze the distribution and diversity of species. Frequency (number of aquatic insect: N), number of species (S), similarity index (C), richness index (R1, R2), variety index (V1, V2), evenness index (E1, E2, E3, E4, E5), and dominance index (D1) were investigated. Total N and S were 143 and 84, respectively. C matrix of 153 combinations was constructed with the average of 0.542. The average C of 3 years (0.659) was 9.9% P, more higher than the average C of 6 areas (0.560). The average values of the index of 18 plots were 2.28, 0.17, 1.24, 1.08, 0.07, 0.06, 0.01, 0.87, 0.31, 0.93 for R1, R2, V1, V2, E1, E2, E3, E4, E5, D1, respectively. The order in the coefficient of variation (CV) of the indicator for 18 plots was N (70.0%) > E3 (54.9%) > E1 (49.6%) > R2 (40.5%) > S (35.3%) > R1 (33.7%) > E2 (28.4%) > E5 (15.9%) > V1 (11.1%) > E4 (6.3%) > V2 (5.1%) > D1 (4.8%). The correlation matrix with 66 combinations between the indexes was constructed with statistical significance for 33 combinations. However, R1, V1, E2 and D1 were the proper indexes to represent species diversity of aquatic insect based on the correlation matrix and the theory of statistical independence. The richness index was highest in mountain, variety index in urban area, and evenness index in plain field. However, the dominance index was lowest in urban area.

• Journal of the Korean Society of Food Culture
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• v.5 no.1
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• pp.169-180
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• 1990

An experimental study on the effect of milk diet on carcinogenesis induced by N-methyl-N-nitro-N-nitrosoguanidine (MNNG) was designed in rats to elucidate its mechanism. A total of 136 Sprague-Dawley rats were divided into 6 groups according to the milk dosagnes in each diet. The entire group of 136 rats was fed the MNNG (100 g/ml) and milk for the initial 28 weeks. Thereafter for the next 12 weeks the group was fed a normal diet only. After this 40 week experiment 109 rats survived. These rats were then dissected with the results being summarized as follows: Suppression of gastroduodenal malignancy was evidenced by the increase of milk concentration in the diet except for the group given MNNG and the lowest concentration of milk (6% milk). Significant differences in the rate of cancer association were present between the regenerative hyperplasia (22.2%) and adenomatous hyperplasia (57.9%). The incidence of benign lesions increased proportionally with the concentration of milk in the diet, especially in regenerative hyperplasia. In the group which had been given the lowest concentration of milk there was a significant increase of the serum gastrin level in the rats with gastric cancer or precancerous benign lesions like regenerative hyperplasia or adenomatous hyperplasia.