• Journal of Oriental Neuropsychiatry
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• v.28 no.3
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• pp.157-164
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• 2017

Objectives: The purpose of this study is the research of the 2D:4D ratio and its correlation with the Sasang constitution and the MBTI preference types. Methods: A measurement of the 2D:4D ratios of 101 South Korean medical students was performed, the QSCC-II and PSSC-2004 were used to diagnose the Sasang constitution, and MBTI testing was performed to classify the preference types. Results: In the relationship between the Sasang constitution and the 2D:4D ratios, a statistically significant difference is absent in the 2D:4D ratios of the group comprising both sexes in the order of Taeumin, Soyangin, and Soeumin. A statistically significant difference is also lacking in the 2D:4D ratios of the male-only group in the order of Taeumin, Soyangin, and Soeumin. The 2D:4D ratios are higher in the female group only, but again a statistically significant difference is absent. In the 2D:4D ratios according to the MBTI preference type, the 2D:4D ratios of the I, S, F, and P types are higher in the unisex group, but a significant difference is not evident. The 2D:4D ratios of the E, N, F, and P types are higher in the male-only group, but again a significant difference is not evident. In the female-only group, the mean of the 2D:4D ratios of the I, S, F, and P types is higher, but a significant difference is not identifiable. Conclusions: The Sasang constitution and the MBTI preference types did not show statistically significant differences regarding the 2D:4D ratios of the male, female, and unisex groups.

• Journal of Korea Technology Innovation Society
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• v.14 no.3
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• pp.466-487
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• 2011

This study analyzed the effect of small and medium businesses' R&D intensity and patents on their price-earnings (P/E) ratios. Regression analysis was conducted on a sample of manufacturers listed on the Korean Securities Dealers Automated Quotations (KOSDAQ) for the past decade (2000~2009). The result is summarized as follows. First, a negative correlation was identified between companies' R&D intensity and their P/E ratios, but no significant relationship was found between their numbers of domestic patent applications and registrations and P/E ratios. Second, the analysis of the effect of the companies' R&D intensity on their P/E ratios resulted in a negative correlation of -1%. Third, the analysis of the effect of the companies' number of domestic patent applications and registrations on their P/E ratios showed that they did not have any significant relationship. Fourth, high-tech firms' R&D intensity had a negative correlation of -1% with their P/E ratios, but had a positive correlation of 1% with their numbers of domestic patent applications. Furthermore, the R&D intensity of middle-to-high and middle-to-low tech enterprises had a negative correlation of -1% with their P/E ratios, whereas their numbers of domestic patent applications and registrations had no significant relationship with their P/E ratios. The above results suggest that to produce successful outcomes from their R&D investment and patents, individual firms need strategies for technological innovation that relate to their technological level.

• Journal of Animal Science and Technology
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• v.45 no.5
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• pp.725-730
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• 2003

This study was conducted to evaluate the adequacy of an alternative a.m.-p.m. testing scheme for milk yield in comparison with the official test method based on weighing two milkings within 24 h. A total of 8,309 p.m. milking weights and 6,767 a.m. milking weights from 72 Holstein cows raised at N.L.R.I. were collected between October 2000 and November 2001. Ratios were computes for daily milk yield to a.m. and p.m. milking weights(direct yield ratios) and ratios of a.m. and p.m. milking weights to daily milk yield (inverse yield ratios). Analysis of variance indicated that the milking interval is the most important source of variation for yield ratios. Adjustment factors for estimating daily milk yield from single milking weights were derived through regression analysis of direct and inverse yield ratios on the length of the milking interval. Daily milk yield was estimated more precisely and accurately when adjustment factors were used than when single milking weights were doubled. In conclusion, alternative recording of a.m. and p.m. milking weights led to reliable estimates of milk yields.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.2
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• pp.166-172
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• 2007

The flow around a rotating circular cylinder near a plane wall is investigated by the measurement of the lift acting on the cylinder and by the flow visualization using the hydrogen bubble technique in the circulating water tank. The experimental parameters are the rotating direction of the cylinder. the space ratios $H/D(H/D=0.05{\sim}0.5)$ between cylinder and plane wall and the velocity ratios ${\alpha}({\alpha}=0{\sim}{\pm}2.0)$. In the case of clockwise, the lift on the rotating circular cylinder was increased with the reduction of the space ratios and with the velocity ratios, the upper separation point was more shifted in the rotating direction with them. In the case of anticlockwise, the absolute value of the lift on the rotating circular cylinder was increased with increasing the space ratios and the velocity ratios. the lower separation point was more shifted in the rotating direction with them.

• 한국가시화정보학회:학술대회논문집
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• 2006.12a
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• pp.42-47
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• 2006

The flow around a rotating circular cylinder near a plane wall is investigated by the measurement of the lift acting on the cylinder and by the flow visualization using the hydrogen bubble technique in the circulating water tank. The experimental parameters are the rotating direction of the cylinder, the space ratios H/D$(H/D=0.05\sim0.5)$ between cylinder and plane wall and the velocity ratios $\alpha(\alpha=0\sim{\pm}2.0)$. In the case of clockwise, the lift on the rotating circular cylinder was increased with the reduction of the space ratios and with the velocity ratios, the upper separation point was more shifted in the rotating direction with them. In the case of anticlockwise, the absolute value of the lift on the rotating circular cylinder was increased with the space ratios and with the velocity ratios, the lower separation point was more shifted in the rotating direction with them.

• Journal of Aquaculture
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• v.19 no.2
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• pp.99-108
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• 2006

Sex of the Nile tilapia Oreochromis niloticus is mainly determined by an XX/XY system. However, accumulating evidences suggest the existence of additional sex modifying factors including environmental, autosomal and parental influences. In order to investigate the possibility of parental effects on sex ratios of tilapia progenies, in this study, a series of crosses was carried out using gynogenetic clonal fish, neomales, normal males and females, and YY fish. Crosses between clonal XX male and clonal female have yielded only female progenies and no parental influences were observed. However, in the crosses between clonal males and normal females, female parents were significantly associated with the progeny sex ratios ($X^2$=20.046, 7 d.f., p<0.01). Progeny sex ratios from the crosses between neomales and normal females ($X^2$=60.491, 5 d.f and $X^2$=28.072, 2 d.f.) also showed significant association with female parents (P<0.001). The stability of progeny sex ratios from repeated spawns were confirmed by using 6 different parental pairs. In 16 crosses between normal males and normal females, sex ratios of progenies showed clear maternal influences, and further analysis of the results revealed a negative correlation ($r^2$=0.7718, p<0.05) between the sex ratios of progenies from two different males, indicating a strong paternal influence. No statistically significant relationship between survival rates and sex ratios of progenies was observed in any genotypic groups. Taken together, the influence of parental pairs on progeny sex ratios in this species is evident although the cause of this influence is not clear.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.11
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• pp.1571-1581
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• 1998

A flow visualization study was carried out for the branch pipe mixing flow in which a jet was issued normally to the fully developed pipe flow. An instantaneous laser tomographic method was used for cross flow Reynolds numbers based on the cross flow diameter D ranged $Re_{cf}=5.26{\times}10^3{\sim}1.13{\times}10^4$, diameter ratios d/D = 0.1 ~ 0.2 and velocity ratios R = 0.5 ~ 10. Oil mist with the size of about $10{\mu}m$ diameter was used for the scattering particle. The main purpose of this study was to reveal the physical mechanism and the structure of vortices formation with varying the velocity ratios and diameter ratios in the branch pipe flow. It was found that the physical mechanism and the structures of vortices formation were quite different depending on the velocity ratios. Particularly in the case of R < 1, the typical vortex shows single loop shape and that for the case of R > 1 depicts mushroom-like structure in the cross flow jet.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.11
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• pp.957-962
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• 2007

The flow around a rotating circular cylinder near a plane wall is investigated by the measurement of the lift acting on the cylinder and by the flow visualization using the hydrogen bubble technique in the circulating water tank. The experimental parameters are the rotating direction of the cylinder, the space ratios H/D($H/D=0.05{\sim}0.5$) between cylinder and plane wall and the velocity ratios ${\alpha}({\alpha}=0{\sim}{\pm}2.0)$. In the case of clockwise, the lift on the rotating circular cylinder was increased with the reduction of the space ratios and with the velocity ratios, the upper separation point was more shifted in the rotating direction with them. In the case of anticlockwise, the absolute value of the lift on the rotating circular cylinder was increased with the space ratios and with the velocity ratios, the lower separation point was more shifted in the rotating direction with them.

• ETRI Journal
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• v.24 no.2
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• pp.109-116
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• 2002

We propose a novel very short (< $300{\mu}m$) vertical directional coupler switch with high extinction ratios larger than 30 dB. The device consists of a switching operation induced section (SOIS), an extinction ratio adjusted section (ERAS), and an extinction ratio enhanced section (ERES). These are achieved by changing the refractive index of one core. The switching operation is induced by changing the refractive index of one core in the SOIS. The improvement of extinction ratios larger than 30 dB for both the cross and bar states is made by controlling the asymmetry of the refractive indices of both cores in the ERES. Through the ERAS, different extinction ratios between the cross and bar states at the end of the SOIS are changed to the same value. For this reason, the optimum asymmetry of the refractive indices of the cores for the maximum extinction ratios and the lengths of ERES are the same for cross and bar states. Design guidelines for high extinction ratios with large tolerances are presented.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.2
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• pp.127-134
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• 2004

Control of drag force on a circular cylinder using multiple detached splitter plates is numerically studied for laminar flow Two splitter plates with the same length as the cylinder diameter (d) are placed horizontally in the upstream of the cylinder and in the near-wake region, respectively. Their positions are described by the gap ratios (G$_1$/d, G$_2$/d), where G$_1$ represents the gap between the cylinder stagnation point and the rear edge of the upstream splitter plate, and G$_2$ represents the gap between the cylinder base point and the leading edge of the rear splitter plate. The drag varies with the two gap ratios; it has the minimum value at a certain set of gap ratios for each Reynolds number The upstream splitter plate decreases the stagnation pressure, while the rear splitter plate increases the base pressure by suppressing vortex shedding. This combined effect causes a significant drag reduction on the cylinder Particularly, the drag sharply increases past an optimum G$_2$/d; this seems to be related to a sudden change in bubble size in the wake region.