• ALGAE
• /
• v.19 no.4
• /
• pp.293-301
• /
• 2004

A chain-forming toxic din flagellate, Gymnodinium catenatum (Graham) was known as a paralytic toxin-producer among Gymnodinoid group. In the study, the effects of water temperature, salinity and irradiance on the growth of G. catenatum isolated from Yeosuhae Bay, Korea were investigated. Water temperature range in which G. catenatum showed specific growth rate higher than 0.3 day$^{-1}$ were above about 18${^{\circ}C}$. However, salinity did not have such an effect on growth of G. catenatum. The maximum growth rate (0.5 day$^{-1}$) was obtained at 25${^{\circ}C}$ and 30 psu. The specific growth rate (u) expressed as a polynomial equation as functions of temperature (T; ${^{\circ}C}$) and salinity (S; psu) was $\mu$ = 0.005·T$^2$ - 0.0001164 T$^3$ - 0.063-S + 0.005-S$^2$ - 0.00007608-S$^3$ - 0.003-T-S + 0.00005308-T$^2$-S. Thus, in aspects of water temperature and salinity, the species may be expected to survive in most Korean coastal waters from early summer to autumn. The irradiance-growth curve was described as = 0.16 (I - 10.4)/(1 + 21.8) at 18${^{\circ}C}$ and 30 psu, indicating a half-saturation (Ks) photon flux density (PFD) of 42.6$\mu$mol m$^{-2}s^{-1}$ and compensation PFD (I$_0$) of 10.4$\mu$mol m$^{-2}s^{-1}$. These characteristic responses to irradiance suggest that G. catenatum can reside at the sub-surface.

• Journal of Korean Society for Geospatial Information Science
• /
• v.23 no.4
• /
• pp.43-48
• /
• 2015

We studied on pseudo-range correction(PRC) modeling in order to improve differential GNSS(DGNSS) accuracy. The PRC is the range correction information that provides improved location accuracy using DGNSS technique. The digital correction signal is typically broadcast over ground-based transmitters. Sometimes the degradation of the positioning accuracy caused by the loss of PRC signals, radio interference, etc. To prevent the degradation, in this paper, we have designed a PRC model through polynomial curve fitting and evaluated this model. We compared two quantities, estimations of PRC using model parameters and observations from the reference station. In the case of GPS, the average is 0.1m and RMSE is 1.3m. Most of GPS satellites have a bias error of less than ${\pm}1.0m$ and a RMSE within 3.0m. In the case of GLONASS, the average and the RMSE are 0.2m and 2.6m, respectively. Most of satellites have less than ${\pm}2.0m$ for a bias error and less than 3.0m for RMSE. These results show that the estimated value calculated by the model can be used effectively to maintain the accuracy of the user's location. However;it is needed for further work relating to the big difference between the two values at low elevation.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.24 no.1
• /
• pp.98-105
• /
• 2013

This paper presents a finite-difference time-domain(FDTD) simulation and a data processing technique for radar sensing of the internal structure of a wall using an ultra-wide band antenna. We first designed an ultra-wide band anti-podal vivaldi antenna with a frequency range of 0.3~7 GHz which is chosen to be relatively low after considering the characteristics of wave attenuation, wall penetration, and range resolution. In this study the two-dimensional FDTD technique was used to simulate a wall-penetration-radar experiment under practical conditions. The next, the measured radiation pattern of the practical antenna is considered as an equivalent source in the FDTD simulation, and the reflection data of a concrete wall and targets are obtained by using the simulation. Then, a data processing technique has been applied to the FDTD reflection data to get a radar image for remote sensing of the internal structure of the wall. We compared the two different source excitations in the FDTD simulation; (1) commonly-used isotropic point sources and (2) polynomial curve fitting sources of the measured radiation pattern. As a result, when we apply the measured antenna pattern into the FDTD simulation, we could obtain about 2.5 dB higher signal to noise level than using a plane wave incidence with isotropic sources.

• Journal of Animal Science and Technology
• /
• v.45 no.5
• /
• pp.739-748
• /
• 2003

The objective of this study was to estimate genetic parameters for test-day milk production and somatic cell score using field data collected by dairy herd improvement program in Korea. Random regression animal models were applied to estimate genetic variances for milk production and somatic cell score. Heritabilities for milk yields, fat percentage, protein percentage, solid-not-fat percentage, and somatic cell score from test day records of 5,796 first lactation Holstein cows were estimated by REML algorithm in single trait random regression test-day animal models. For these analyses, Legendre polynomial covariate function was applied to model the fixed effect of age-season, the additive genetic effect and the permanent environment effect as random. Homogeneous residual variance was assumed to be equal throughout lactation. Heritabilities as a function of time were calculated from the estimated curve parameters from univariate analyses. Heritability estimates for milk yields were in range of 0.13 to 0.29 throughout first lactation. Heritability estimates for fat percentage, protein percentage and solid-not-fat percentage were within 0.09 to 0.11, 0.12 to 0.19 and 0.17 to 0.23, respectively. For somatic cell score, heritabilities were within 0.02 to 0.04. Heritabilities for milk productions and somatic cell score were fluctuated by days in milk with comparing 305d milk production.

• Journal of Korean Society of Forest Science
• /
• v.78 no.2
• /
• pp.143-150
• /
• 1989

This research was performed to estimate the influence of relative light intensity and planting density on the growth of dry weight of needles and other organs growth in Korean white pine seedlings raised in the transplanting bed. 1. As treated with various light intensities, relationships between needle dry weight and growth of other organs(dry weight of shoot, root and diameter of seedlings) had significantly positive correlations and linear regressions, but regression between needle dry weight and seedling elongation was a second degree polynomial. As treated with various planting densities, the second degree regression curve was found between needle dry weight and shoot dry weight, and seedling elongation, And linear regression between needle dry weight and root dry weight, and seedling dry weight could be estimated, while any regression between needle dry weight and diameter was not recognized. 2. As treated with various light intensities, linear regression between leaf area and shoot dry weight, and seedling dry weight, exponential regression between leaf area and seedling elongation were significantly recognized, while a tendency of logarithmic regression between leaf area and diameter appeared. According to the different density treatment, logarithmic regression between leaf area and shoot dry weight, linear regression between leaf area and root dry weight, and seedling dry weight, but quadric regression between leaf area and seedling elongation and diameter were significantly found.