• Journal of Environmental Science International
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• v.17 no.1
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• pp.57-66
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• 2008

The frequency analysis and the probability plot were applied to heavy metal contents of soils collected from the Goseong Cu mine area as a statistic method for the determination of the threshold value which was able to partition a population comprising largely dispersed heavy metal contents into the background and the anomalous populations. Almost all the heavy metal contents of soil showed a positively skewed distributions and their cumulative percentage frequencies plotted as a curved lines on logarithmic probability plot which represent a mixture of two or more overlapping populations. Total Cu, Pb and Cd data and extractable Cu and Pb data could be partitioned into background and anomalous populations by using the inflection in each curve. The others showed a normally distributed population or an largely overlapped populations. The threshold values obtained from replotted frequency distributions with the partitioned populations were Cu 400 mg/kg, Pb 450 mg/kg and Cd 3.5 mg/kg in total contents and Cu 40 mg/kg and Pb 12 mg/kg in extractable contents, respectively. The thresholds for total contents are much higher than the tolerable level of soil pollution proposed by Kloke(Cu 100 mg/kg, Pb 100 mg/kg, Cd 3 mg/kg), but those for extractable contents are not exceeded the worrying level of soil pollution proposed by Ministry of Environment(Cu 50 mg/kg, Pb 100 mg/kg). When the threshold values were used as the criteria of soil pollution in the study area, $9{\sim}19%$ of investigated soil population was in polluted level. The spatial distributions of heavy metal contents greater than threshold values showed that polluted soils with heavy metals are restricted within the mountain soils in the vicinity of abandoned mines.

• Molecules and Cells
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• v.25 no.3
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• pp.417-427
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• 2008

Comparison of maps and QTLs between populations may provide us with a better understanding of molecular maps and the inheritance of traits. We developed and used two reciprocal $BC_1F_1$ populations, IP/DS//IP and IP/DS//DS, for QTL analysis. DS (Dasanbyeo) is a Korean tongil-type cultivar (derived from an indica x japonica cross and similar to indica in its genetic make-up) and IP (Ilpumbyeo) is a Korean japonica cultivar. We constructed two molecular linkage maps corresponding to each backcross population using 196 markers for each map. The length of each chromosome was longer in the IP/DS//IP population than in the IP/DS//DS population, indicating that more recombinants were produced in the IP/DS//IP population. Distorted segregation was observed for 44 and 19 marker loci for the IP/DS//IP and IP/DS//DS populations, respectively; these were mostly skewed in favor of the indica alleles. A total of 36 main effect QTLs (M-QTLs) and 15 digenic epistatic interactions (E-QTLs) were detected for the seven traits investigated. The phenotypic variation explained (PVE) by M-QTLs ranged from 3.4% to 88.2%. Total PVE of the M-QTLs for each trait was significantly higher than that of the E-QTLs. The total number of M-QTLs identified in the IP/DS//IP population was higher than in the IP/DS//DS population. However, the total PVE by the M-QTLs and E-QTLs together for each trait was similar in the two populations, suggesting that the two $BC_1F_1$ populations are equally useful for QTL analysis. Maps and QTLs in the two populations were compared. Eleven new QTLs were identified for SN, SF, GL, and GW in this study, and they will be valuable in marker-assisted selection, particularly for improving grain traits in tongil-type varieties.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.22
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• pp.10009-10013
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• 2014

Background: Vitamin D receptor (VDR) gene has been a subject of extensive pharmacogenetic research recently. Association studies between different types of cancers including prostate cancer (PCa) and VDR gene polymorphism have also been conducted. The objective of this study was to find possible associations between PCa and VDR gene polymorphisms in the Pakistani population. Materials and Methods: A total of 162 subjects, including prostate cancer patients and controls, were genotyped for Apa I, Taq I and Fok I polymorphisms in the VDR gene using allele specific PCR, PCR-RFLP and direct DNA sequencing. Allelic frequencies were tested for Hardy-Weinberg equilibrium and associations between the genetic markers and PCa were calculated using logistic regression. Results: Apa I CC genotype was found to have strongest association with PCa risk, and "A" genotype was found to have protective effect. Fok I and Taq I did not have appreciable levels of association with PCa, although Taq I "TC" heterozygotes seemed to have some protective effect. Similarly the "C" allele of Fok I also seemed to have protective effect. Conclusions: To our knowledge, this is the first report showing association between VDR gene polymorphisms and PCa in Pakistan. Our findings may be somewhat skewed because of small sample size and tendency of consanguineous marriages in Pakistani society; nevertheless, it shows the trend of association and protective effects of certain VDR gene polymorphisms against PCa.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.151-151
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• 2017

In Asia, rice production has some difficulties with reduction of farm household population and increase of elderly population. As a result, it has resulted in inefficiency and we needs to reduce labor force and improve labor productivity. Direct-seeding in rice could reduce labor and production costs, the area of direct seeding is increasing in japonica rice production in Asia. In direct seedling cultivation competition against weeds is one of most important concern. So, low temperature germinability and mesocotyl elongation should be considered. In this study, we evaluated the mesocotyl length and low temperature germination conducted association analysis using 137 korea core collections. An average length of mesocotyl among 137 core collections was skewed range from 0mm to 43mm. we searched candidate gene around target SNP. Such related traits, genome-wide association study (GWAS) analysis was carried out using GAPIT. Also, average mesocotyl length of 394 korea landrace cultivars was measured ranging from minimum 0 mm to maximum 34mm. 30 out of 394 Korea landrace cultivar conducted re-sequencing, and haplotype analysis of candidate gene. we searched these related resources, which including germination of low temperature and mesocotyl elongation. This could be used for the development of direct-seeding cultivars. The valiated accession of core collection and landrace cultivars will be used development of direct-seedling cultivar in the future.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.1
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• pp.86-94
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• 1999

A set of rice recombinant inbred lines was developed from a cross between a Tongil type variety, Nonganbyeo, and an indica variety, BG276, by the single seed descent method. The number of the lines in the population was 272. All the agronomic characters studied except ADV (alkali-digestion value) showed continuous variation among the RILs, implying that their inheritance mode should be quantitative. The patterns of the variation in the RILs were either normal or skewed distribution. ADVs of RILs were segregated into two groups with 1:1 ratio, indicating that ADVs in this KIL population might be controlled by one major gene. Transgressive variations were also observed in all characters. Heritability values of the characters varied from 0.488 in brown/rough rice ratio to 0.895 in alkali-digestion value. In the analysis of genotypic and phenotypic correlations, the character of yield was positively correlated with 8 different agronomic characters. The number of panicles per hill was negatively correlated with culm length, panicle length, and number of spikelets per panicle. Grain length was positively correlated with grain width, grain thickness, grain length/width ratio, white belly, ADV, and amylose. However, grain length/width ratio was negatively correlated with grain width. White core was also negatively correlated with white belly and ADV.

• Interdisciplinary Bio Central
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• v.2 no.2
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• pp.4.1-4.6
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• 2010

The most common type of microarray experiment has a simple design using microarray data obtained from two different groups or conditions. A typical method to identify differentially expressed genes (DEGs) between two conditions is the conventional Student's t-test. The t-test is based on the simple estimation of the population variance for a gene using the sample variance of its expression levels. Although empirical Bayes approach improves on the t-statistic by not giving a high rank to genes only because they have a small sample variance, the basic assumption for this is same as the ordinary t-test which is the equality of variances across experimental groups. The t-test and empirical Bayes approach suffer from low statistical power because of the assumption of normal and unimodal distributions for the microarray data analysis. We propose a method to address these problems that is robust to outliers or skewed data, while maintaining the advantages of the classical t-test or modified t-statistics. The resulting data transformation to fit the normality assumption increases the statistical power for identifying DEGs using these statistics.

• Journal of Korean Society for Quality Management
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• v.38 no.4
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• pp.587-592
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• 2010

This paper deals with the performance evaluation of determining production size specifications. A customer who does not find the size specification he or she wants may purchase rather a larger or smaller one, but the purchasing desire decreases as the difference between the required and the prepared sizes increases. Introducing a generalized quality loss function which reflects how much the purchasing desire changes according to the difference, Park and Kim(1992) formulated a mathematical model for determining the size specifications so as to minimize the expected loss. Afterward the model has been applied to the determination of sizing system for mail order clothing and brassiere (Lee and Choi, 1996; Chun, et.al., 1996). The performance of the size determination method proposed by Park and Kim is evaluated in this paper. Usually the intervals between two successive size specifications are determined to be equal, but the size determination method compares favorably with the equidistance case, and more favorably if the population distribution is more skewed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.5
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• pp.709-735
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• 2010

The reciprocal virtue of peer-to-peer networking has stimulated an explosion of peer population and service capacity, ensuring rapid content distribution in peer-to-peer networks. Critical issues such as peer churn, free riding, and skewed workload significantly affect performance results such as service agility, fairness, and resource utilization. To resolve these problems systematically, this study proposes a peer assignment scheme that supports fair peer-to-peer file sharing applications. The proposed scheme exploits the peer duality of both server-oriented peer capacity and client-oriented peer contribution. Accordingly, the system server can prioritize download requests and appropriately assign server peers to uploading file objects. Several functional extensions, including peer substitution and elimination, bandwidth adjustment, and distributed modification, help cope with subtle situations of service starvation and download blocking, and hence make the system design robust and amenable. Simulation results show this design is examined under both centralized and distributed peer-to-peer environments. Performance results confirm that the proposed mechanisms are simple but effective in maintaining service agility and fairness, without loss of overall service capacity in peer-to-peer files sharing systems.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.38.3-38.3
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• 2019

We investigate the stellar population properties of nine passive spiral galaxies in the CALIFA survey. They have NUV-r > 5 and no/weak nebular emission lines in their spectra. They lie in the redshift range of 0.001 < z < 0.021 and have stellar mass range of 10.2 < ${\log}(M{\star}/M{\odot})$ < 10.8. We analyze the stellar populations out to two effective radius, using the best-fitting model to the measured absorption line-strength indices in the Lick/IDS system. We compare the passive spirals with S0s selected in the same mass range. S0s cover a wide range in age, metallicity, and [${\alpha}/Fe$], and stellar populations of the passive spirals are encompassed in the spread of the S0 properties. However, the distribution of passive spirals are skewed toward higher values of metallicity, lower [${\alpha}/Fe$], and younger ages at all radii. These results show that passive spirals are possibly related to S0s in their stellar populations. We infer that the diversity in the stellar populations of S0s may result from different evolutionary pathways of S0 formation, and passive spirals may be one of the possible channels.

• Phonetics and Speech Sciences
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• v.16 no.1
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• pp.11-16
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• 2024

The fundamental frequency (f0), representing an acoustic measure of vocal fold vibration, serves as an indicator of the speaker's emotional state and language-specific pattern in daily conversations. This study aimed to examine the f0 distribution in an English corpus of spontaneous speech, establishing normative data for American speakers. The corpus involved 40 participants engaging in free discussions on daily activities and personal viewpoints. Using Praat, f0 values were collected filtering outliers after removing nonspeech sounds and interviewer voices. Statistical analyses were performed with R. Results indicated a median f0 value of 145 Hz for all the speakers. The f0 values for all speakers exhibited a right-skewed, pointy distribution within a frequency range of 216 Hz from 75 Hz to 339 Hz. The female f0 range was wider than that of males, with a median of 113 Hz for males and 181 Hz for females. This spontaneous speech corpus provides valuable insights for linguists into f0 variation among individuals or groups in a language. Further research is encouraged to develop analytical and statistical measures for establishing reliable f0 standards for the general population.