• Journal of Ginseng Research
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• v.19 no.2
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• pp.165-170
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• 1995

This study was carried out to investigate the correlation of agronomic characters, their path coefficients in 2, 3 and 4-year old ginseng plants, and to provide a useful information for ginseng breeding. Correlation coefficients between stem fen변h, number of leaves and number of Iraflets in 2-year age, and stem diameter and leaf length in 3-year age showed highly significant correlation with number of fruits and root weight in 4-year age. The path coefficient analysis indicated that stem length and number of leaflets might give indirect effects on root weight regardless of plant age. On the other hand, stem length and number of leaflets in 2-year age and, stem diameter and leaf length in 3-year age showed direct effects on root weight in 4-year old ginseng. These results may be used for selection of high-yielding ginseng plants. Key words Selection information, correlation and path coefficient analysis.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.15
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• pp.33-59
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• 1974

A series of experiments were conducted at Crop Experiment Station from 1968 to 1971 to obtain basic information on effects of selection on yield of wheat varieties. Heritability estimates, correlation and path coefficients computed for yield and yield related characters from fixed variety groups-Korean, U.S., and Japan; early and late-$F_2$ and $F_3$ generations were studied. The same estimates for fixed variety groups grown under different fertilizer levels and years were also studied. The results were summarized as follow: 1. Three variety groups classified by their origins as Korea, United States and Japan showed high heritability estimates for heading date, plant height and spike length. The heritability estimates for grain number per spike and 1, 000 grain weight were moderate and those for the number of spikes per plant and grain yield were low. Very low estimates of heritability were obtained for grain number per spike and yield of variety group from the Unites States. 2. High genotypic correlation coefficients between 1, 000 grain weight and yield were obtained for all variety groups originated from Korea, United States and Japan and early variety group, except late variety group. The genotypic correlation coefficients between grain number per spike and yield were also high for all variety groups except variety group originated from the United States. 3. The direct effects of 1, 000 grain weight in terms of path-coefficients to yield were high for all variety groups except late variety group. 4. High genotypic correlation coefficients were obtained between 1, 000 grain weight and yield in $F_2$ from. two crosses. The same degree of genotypic correlation coefficients were obtained between grain number per spike and yield, although slight differences in its magnitude were found depending upon the cross combination. 5. The analysis of path-coefficients in $F_2$ shows that the direct effects of yield components to yield were negligible. 6. The characters that showed high genotypic correlation coefficients with yield in $F_3$ were 1, 000 gnain weight and grain number per spike. These characters showed also high direct effects to yield. 7. No great variations of heritability estimates for heading date, plant height and spike length were obtained for either fertilizer responsive or non responsive variety group due to fertilizer levels applied. 8. Heritability estimates of 1, 000 grain weight in fertilizer responsive group and yield in fertilizer nonresponsive group were high as level of fertilizer increased. 9. Heritability estimates for grain number per spike and 1, 000 grain weight of fertilizer non-responsive-group were higher than those of fertilizer. responsive group. 10. Genotypic corretation coefficients between yield and 1, 000 grain weight in fertilizer responsive group were getting lower as the level of fertilizer increased and those in fertilizer non-responsive group were vice versa. 11. Genotypic correlation coefficient between yield and spike number per plant in fertilizer responsive group was high. However, the genotypic correlation coefficient between yield and spike number per plant in fertilizer non-responsive group was low. 12. The direct effects of 1, 000 grain weight to yield were higher than other yield components either in fertilizer responsive or non-responsive group regardless of levels of fertilizer applied. The spike number per plant, however, was high only when high level of fertilizers were applied to fitilizer responsive group. 13. Slight variations of heritability estimates for heading dates, plant height, spike length, grain number per spike and 1, 000 grain weight were obtained between years. However, the spike number per plant with low heritabilility showed great variation between years. 14. The character that showed high genotypic correlation coefficients with yield in two years was 1, 000 grain weight, and this character was also high in direct effect to yield in terms of path-coefficients. 15. From the above experimental results, it might be concluded that 1, 000 grain weight would be one of the most important characters to increase the effects of selection for yield in wheat breeding in Korea.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.2
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• pp.417-422
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• 1999

Purpose : The aim of this study was to assess the validity of standard deviation of gray scale histogram in digital subtraction radiography as a test parameter for superimposition error. Materials and Methods : Twenty periapical radiographs were used as baseline images and they were copied to exclude the influence of exposure geomety and contrast differences. These subsequent images were linearly displaced by 0.1-0.5 mm in the x-. y- and xy-directions, rotated by 0.5-3° and distorted by angular contraction of 1-5° in x- and y-axis before subtraction. The standard deviations of gray levels in the subtraction images were obtained and paired t-tests were performed. Pearson correlation coefficients(r) were calculated between the standard deviations and the superimposition errors. Results : Linear displacement showed high correlation coefficients of 0.997, 0.997 and 0.995 in x-. y- and xy-axis respectively. Statistically significant different standard deviation existed among all linearly displaced groups(p<0.05). Distortion showed relatively low correlation coefficients of 0.982 and 0.959 in x- and y-axis. The standard deviations between the two distortion groups were statistically significant different(p<0.05). Conclusion : Standard deviation of gray level distribution in digital subtraction images is satisfactory but not perfect similarity measure to assess the superimposition errors.

• Journal of Internet Computing and Services
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• v.11 no.6
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• pp.111-122
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• 2010

Since educating digital convergence is to unite various sciences and technologies with computer as the central figure, it has different range and methods of education. Therefore, it has problems with recommending limited conceptual information because of difficulties to standardize education plan and teaching strategies. In this paper, I propose education plan and teaching strategy system by using Spearman correlation coefficients. This system is to find a solution against disadvantage of recommending limited conceptual information by ranking relations of teaching strategies from the information based on the demand of industrial and academic fields, and then provides lists of teaching strategy information suitable for user's atmosphere and characteristics. Performance test is to compare effects of precision and recall with existing service systems. The test shows 90.4% of precision and 77.6% of recall.

• Korean Journal of Poultry Science
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• v.24 no.1
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• pp.29-37
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• 1997

An experiment was conducted for 20 days( from July 21 to August 10, 1996) to investigate the differences in thickness of eggshell and eggshell membrane in Korean native chicken. All the eggs were purchased from a farm located in Chinju area. All eggs were categorized into Treatment I (34.89~51.39 g), H (53.32~60.70 g), and III (34.89~60.70 g) according to their weights. Eleven items were measured in all three treatments, i.e., egg weight, egg length, egg width, breaking strength, eggshell thickness of large end(STLE), eggshell membrane thickness of large end(SMTL), eggshell thickness of small end (STSE), eggshell membrane thickness of small end(SMTS), eggshell thickness of middle part(STMP), and eggshell membrane thickness of middle part(SMTM). Correlation coefficients between egg weight and eggshell weight, among eggshell thickness of large end, small end and middle end and eggshell weight were significant (P<0.01). Correlation coefficients between egg weight and large eggshell membrane were nega-tively significant(P<0.01). Breaking strengths were higher in Treatment I than in Treatment H. Correlation coefficients among thickness of eggshell and eggshell membrane at each point at 3 parts of large end, small end and middle end were not significant.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.2
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• pp.730-740
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• 1996

Boiling heat transfer coefficients of pure refrigerants (R22, R32, R134a, R125, R290, and R600a) and refrigerant mixtures (R32/Rl34a, R290/ R600a, and R32/R125) are measured experimentally and compared with Chen's correlation. The test section is a seamless stainless steel tube with inner diameter of 7.7mm and uniformly heated by applying electric current directly to the tube. Heat fluxes range from 10 to 30kW$^2$. Mass fluxes are set to 424 ~ 742kg/m$^{2}$s for R22, R32, R134a, R32/R134a, and R32/Rl25 ; 265 ~ 583kg/m$^{2}$s for R290, R600a, and R290/R600a. Heat transfer coefficients depend strongly on heat flux at a low quality region and become independent as quality increases. Convective boiling term in the Chen's correlation predicts experimental data of the pure refrigerants fairly well (relative error of 12.1% for the data of quality over 0.2). The correlation for pure substances overpredicts the heat transfer coefficients for nonazeotropic refrigerant mixtures.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.9
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• pp.571-580
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• 2008

In this work, pool boiling heat transfer coefficients(HTCs) of 5 refrigerants of differing vapor pressure are measured on horizontal smooth square surface of 9.52 mm length. Tested refrigerants are R123, R152a, R134a, R22, and R32 and HTCs are taken from $10\;kW/m^2$ to critical heat flux of each refrigerant. Wall and fluid temperatures are measured directly by thermocouples located underneath the test surface and by thermocouples in the liquid pool. Test results show that pool boiling HTCs of refrigerants increase as the heat flux and vapor pressure increase. This typical trend is maintained even at high heat fluxes above $200\;kW/m^2$. Zuber's prediction equation for critical heat flux is quite accurate showing a maximum deviation of 21% for all refrigerants tested. For all refrigerant data up to the critical heat flux, Stephan and Abdelsalam's well known correlation underpredicted the data with an average deviation of 21.3% while Cooper's correlation overpredicted the data with an average deviation of 14.2%. On the other hand, Gorenflo's and lung et al.'s correlation showed only 5.8% and 6.4% deviations respectively in the entire nucleate boiling range.

• Journal of the Optical Society of Korea
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• v.18 no.5
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• pp.598-604
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• 2014

A polarization fluorescence correlation spectroscopy system based on a confocal microscope was built to study the rotational and translational diffusion of CdSe/CdS quantum rods (Q-rods), with the same and different polarization states between the polarizer and the analyzer (i.e. the XXX and XYY states). The rotational diffusion amplitude showed the dependences on polarization of $0.75{\pm}0.05$ in the XXX state and $0.26{\pm}0.03$ in the XYY state, when the translational diffusion amplitude was 1. The diffusion coefficients of the Q-rods were found based on their translational and rotational diffusion times in the two polarization states, in solutions with viscosity ranging from 0.9 to 6.9 cP. The translational and rotational diffusion coefficients ranged from $1.5{\times}10^{-11}$ to $2.6{\times}10^{-12}m^2s^{-1}$ and from $2.9{\times}10^5$ to $5.6{\times}10^4s^{-1}$, respectively.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.2
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• pp.175-183
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• 2002

Flow Condensation heat transfer coefficients (HTCs) of Rl2, R22, R32, Rl23, Rl25, R134a, R142b were measured experimentally on a horizontal plain tube. The experi- mental apparatus was composed of three main parts; a refrigerant loop, a water loop and a water-glycol loop. The test section in a refrigerant loop was made of a copper tube of 8.8 mm inner diameter and 1000 mm length respectively. The refrigerant was cooled by passing cold water through an annulus surrounding the test section. All tests were performed at a filed refrigerant saturation temperature of 4$0^{\circ}C$ with mass fluxes of 100, 200, 300 kg/$m^2$s. The experimental result showed that flow condensation HTCs increase as the quality, mass flux, and latent heat of condensation increase. At the same mass flux, the HTCs of R32 and R142b were higher than those of R22 by 35~45% and 7~14% respectively while HTCs of R134a and Rl23 were similar to those of R22. On the other hand, HTCs of Rl25 and Rl2 were lower than those of R22 by 28 ~30% and 15 ~25% respectively Finally, a new correlation for flow condensation HTCs was developed by modifying Dobson and Chato's correlation with the latent heat of condensation considered. The correlaton showed an average deviation of 13.1% for all pure fluids data indicating an excellent agreement.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.3
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• pp.369-377
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• 1998

In this paper, we performed the comparisons between polarization diversity using dual polarization antennal which has $\pm45^{\circ}$slanted linear polarization characteristics and conventional space diversity in rural and residential areas. The analysis was done by evaluating the diversity gain improvement and cross correlation coefficients between two received signals through each diversity branch. From the results, we could confirmed that space diversity has bigger diversity gain than polarization diversity by 1~2 dB, and there is a little difference of $\pm0.1$ in cross correlation coefficients by analyzing CDF under portable mobile phone environments.