• Journal of the Korean earth science society
• /
• v.21 no.1
• /
• pp.51-58
• /
• 2000

This study was performed to accumulate database for natural sulfur emissions in the Yellow Sea region of Korea. The atmospheric concentrations of dimethylsulfide(DMS) were measured during two intensive field experiments (April and September 1999) from Duk-Juk Island located in the Yellow Sea. Ship-measurement of DMS was made additionally between Chungdo(China) and Inchun(Korea) across the Yellow Sea during June 1999. The mean(and ISD) of DMS concentrations in Duk-Juk Island during two field campaigns was $24.0{\pm}40.5$(n=40, April) and $61.1{\pm}37.9$ pptv(n=35, September), respectively. The atmospheric DMS measured from ship experiments was generally low and close to the background concentrations in the open sea area. The temporal distributions of DMS concentration were complicated in some sense but comparable to those of ambient meteorological parameters. On the basis of our measurements of atmospheric DMS(and evidence found from previous studies), the sea-to-air flux of DMS in the Yellow Sea is estimated to be about 4Gg S/yr. This amount of natural S emissions is relatively lower than the estimates derived for Cheju Island. Therefore, additional experiments may be desperate to derive more reliable figures for natural sulfur emissions in the Yellow Sea region.

• Journal of the Korean earth science society
• /
• v.35 no.1
• /
• pp.19-28
• /
• 2014

The radiative transfer for TIROS operational vertical sounder (RTTOV) and the community radiative transfer model (CRTM) are two fast radiative transfer models (RTM) that are used as observation operators in numerical weather prediction (NWP) systems. This study compares the basic structure and input data of the two models. With data from Advanced Microwave Sounding Unit-A (AMSU-A), which has channels of various frequencies, observed brightness temperature ($T_B$) and simulated $T_B$s from the two models are compared over the ocean surface in two cases-one where cloud information is included and the other without it. Regarding AMSU-A sounding channels (5-14), the two models produce no large significant differences in their calculated $T_B$, but RTTOV produces smaller first guess (FG) departures (i.e., better results) in window and near-surface sounding channels than does CRTM. When adding cloud water and ice particles from Unified Model (UM), the $T_B$ bias between observations and simulations are reduced in both models and the bias at 31.4 and 89 GHz is substantially decreased in CRTM compared to those of RTTOV.

• Korean Journal of Remote Sensing
• /
• v.29 no.2
• /
• pp.173-182
• /
• 2013

The early Sea-viewing Wide Field-of-view Sensor(SeaWiFS) atmospheric correction algorithm which is the basis of the atmospheric correction algorithm for Geostationary Ocean Color Imager(GOCI) assumes that water-leaving radiances is negligible at near-infrared(NIR) wavelengths. For this reason, all of the satellite measured radiances at the NIR wavelengths are assigned to aerosol radiances. However that assumption would cause underestimation of water-leaving radiances if it were applied to turbid Case-2 waters. To overcome this problem, Management Unit of the North Sea Mathematical Models(MUMM) atmospheric correction algorithm has been developed for turbid waters. This MUMM algorithm introduces new parameter ${\alpha}$, representing the ratio of water-leaving reflectance at the NIR wavelengths. ${\alpha}$ is calculated by statistical method and is assumed to be constant throughout the study area. Using this algorithm, we can obtain comparatively accurate water-leaving radiances in the moderately turbid waters where the NIR water-leaving reflectance is less than approximately 0.01. However, this algorithm still underestimates the water-leaving radiances at the extremely turbid water since the ratio of water-leaving radiance at two NIR wavelengths, ${\alpha}$ is changed with concentration of suspended particles. In this study, we modified the MUMM algorithm to calculate appropriate value for ${\alpha}$ using an iterative technique. As a result, the accuracy of water-leaving reflectance has been significantly improved. Specifically, the results show that the Root Mean Square Error(RMSE) of the modified MUMM algorithm was 0.002 while that of the MUMM algorithm was 0.0048.

• Journal of Broadcast Engineering
• /
• v.17 no.2
• /
• pp.411-421
• /
• 2012

The stagnant growth in 3D market due to 3D movie contents shortage is encouraging development of techniques for production cost reduction. Elimination of vertical disparity generated during image acquisition requires heaviest time and effort in the whole stereoscopic film-making process. This matter is directly related to competitiveness in the market and is being dealt with as a very important task. The removal of vertical disparity, i.e. image rectification has been treated for a long time in the photogrammetry field. While computer vision methods are focused on fast processing and automation, photogrammetry methods on accuracy and precision. However, photogrammetric approaches have not been tried for the 3D film-making. In this paper, proposed is a photogrammetry-based rectification algorithm that enable to eliminate the vertical disparity precisely by reconstruction of geometric relationship at the time of shooting. Evaluation of proposed algorithm was carried out by comparing the performance with two existing computer vision algorithms. The epipolar constraint satisfaction, epipolar line accuracy and vertical disparity of result images were tested. As a result, the proposed algorithm showed excellent performance than the other algorithms in term of accuracy and precision, and also revealed robustness about position error of tie-points.

• Korean Journal of Organic Agriculture
• /
• v.26 no.2
• /
• pp.281-296
• /
• 2018

This study was conducted to evaluate the effect of different processing of rice on rumen fermentation in in vitro and in situ experiments. Different processing treatments (extruding, roasting, and steaming) were used in this study and all treatments were ground through a cyclone mill (Foss, Hillerød, Denmark) fitted with a 1 mm screen. Non-treated rice was considered to a control substrate. Then, all treatments were used in in vitro and in situ experiments. Total gas production and dry matter digestibility in control were lower than any other treatment at all incubation times (P<0.01). The lowest ammonia nitrogen ($NH_3-N$) concentration was observed in control among treatments at 6, 12, and 24 h incubation (P<0.01). Extruding had a highest total volatile fatty acids (VFA) concentration at 6, 12 h incubation (P<0.01) and Steaming exhibited a highest total VFA at 24 h (P<0.01). The lowest total VFA concentration was observed in control at 6, 12, and 24 h (P<0.01). In an in situ, The highest value of soluble fraction, degradation rates, effective degradability was observed in extruding (P<0.01). It was considered that feed processing increased dry matter digestibility, total VFA concentration, and decreased pH as well as $NH_3-N$ concentration indicating that processing may increase nutrient degradation of rice in the rumen.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.9 no.3
• /
• pp.209-215
• /
• 2007

To improve the accuracy of frost warning system for pear orchard in a complex terrain in Naju area, the daily minimum temperature forecasted by Korea Meteorological Administration (KMA) was interpolated using a regional climate model based on topoclimatic estimation and optimum scale interpolation from 2004 to 2005. Based on the validation experiments done for three pear orchards in the spring of 2004, the results showed a good agreement between the observed and predicted values, resulting in improved predictability compared to the forecast from Korea Meteorological Administration. The differences between the observed and the predicted temperatures were $-2.1{\sim}2.7^{\circ}C$ (on average $-0.4^{\circ}C$) in the valley, $-1.6{\sim}2.7^{\circ}C$ (on average $-0.4^{\circ}C$) in the riverside and $-1.1{\sim}3.5^{\circ}C$ (on average $0.6^{\circ}C$) in the hills. Notably, the errors have been reduced significantly for the valley and riverside areas that are more affected by the cold air drainage and more susceptible to frost damage than hills.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.15 no.1
• /
• pp.40-49
• /
• 2013

Current service system of the Korea Meteorological Administration (KMA) for blooming date forecasting in spring depends on regression equations derived from long term observations in both temperature and phenology at a given station. This regression based system does not allow a timely correction or update of forecasts that are highly sensitive to fluctuating weather conditions. Furthermore, the system cannot afford plant responses to climate extremes which were not observed before. Most of all, this method may not be applicable to locations other than that which the regression equations were derived from. This note suggests a way to replace the location restricted regression equations with a thermal time based phenology model to complement the KMA blooming forecast system. Necessary parameters such as reference temperature, chilling requirement and heating requirement were derived from phenology data for forsythia, azaleas and Japanese cherry at 29 KMA stations for the 1951-1980 period to optimize spring phenology prediction model for each species. Best fit models for each species were used to predict blooming dates and the results were compared with the observed dates to produce a correction grid across the whole nation. The models were driven by the KMA's daily temperature data at a 5km grid spacing and subsequently adjusted by the correction grid to produce the blooming date maps. Validation with the 1971-2012 period data showed the RMSE of 2-3 days for Japanese cherry, showing a feasibility of operational service; whereas higher RMSE values were observed with forsythia and azaleas.

• Journal of Astronomy and Space Sciences
• /
• v.15 no.2
• /
• pp.401-415
• /
• 1998

This paper reports the results obtained from the Langmuir probe (LP) and Electron Temperature Probe (ETP) experiments on the sounding rocket KSR-II (Korean Scientific Rocket - II) which was launched on Jun 11, 1998 at 10:00 KST from Tae-An peninsula (37$^{\circ}$ N, 126$^{\circ}$ E). The instruments successfully measured the electron density, electron temperature, and the floating potential at altitudes of 73km to 130km. While the electron temperature measurement is not easy in this region, since the temperature is very low and the contamination effect of the probe may give rise to a problem, we were able to obtain a reasonable electron temperature profile by employing two independent methods, the pulse modulated Langmuir Probe and Electron Temperature Probe. The preliminary results show that electron density increases sharply at about 90km, and forms a peak at 102km. The density profile is roughly consistent with IRI (International Reference Ionosphere)95-model or PIM (Parameterized Ionospheric Model) results except that the peak density appears at 110km in the model and model electron density is slightly lower than the observed one. Electron temperature obtained from ETP fluctuates between 200$^{\circ}$K and 700$^{\circ}$K, an effect presumably coming from the wakes developed by LP, and it tends to increase with the altitude, which is consistent with the LP results.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.10 no.5
• /
• pp.372-379
• /
• 2017

Software reliability factor during the software development process is elementary. Case of the infinite failure NHPP for identifying software failure, the occurrence rates per fault (hazard function) have the characteristic point that is constant, increases and decreases. In this paper, we propose a reliability model using the chi - square distribution which depends on the degree of freedom that represents the application efficiency of software reliability. Algorithm to estimate the parameters used to the maximum likelihood estimator and bisection method, a model selection based on the mean square error (MSE) and coefficient of determination($R^2$), for the sake of the efficient model, were employed. For the reliability model using the proposed degree of freedom of the chi - square distribution, the failure analysis using the actual failure interval data was applied. Fault data analysis is compared with the intensity function using the degree of freedom of the chi - square distribution. For the insurance about the reliability of a data, the Laplace trend test was employed. In this study, the chi-square distribution model depends on the degree of freedom, is also efficient about reliability because have the coefficient of determination is 90% or more, in the ground of the basic model, can used as a applied model. From this paper, the software development designer must be applied life distribution by the applied basic knowledge of the software to confirm failure modes which may be applied.

• Environmental and Resource Economics Review
• /
• v.20 no.3
• /
• pp.489-529
• /
• 2011

When greenhouse gas mitigation policies are implemented, energy intensive manufacturing industries are influenced much due to an increase in cost. However, industries that have price setting power are damaged less by the policies. Therefore, this paper analyzes vulnerability of energy intensive manufacturing industries to the policies by measuring price setting power of the industries. We analyzed price setting power model through ECM, employing the import prices and wages as independent variables. The industries that their prices react to import prices are price takers, which their prices are determined by rival's ones. On the other hand, the industry that their prices react to wages that mean domestic cost are price setters, and they will be less vulnerable to the policies. In addition, fluctuation of energy prices would be reflected in import prices because it influences other countries than my one. Thus, we employed energy prices as control variable to measure the net effects of import prices. As empirical results, petroleum products, chemical products, non-metallic mineral products, textiles, and motor vehicles sector have price setting power, so the industries have competitiveness on greenhouse gas mitigation policies.