• Asian Journal of Atmospheric Environment
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• v.4 no.3
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• pp.166-176
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• 2010

In this research, the environmental behavior of carbon dioxide ($CO_2$) was investigated in a mountainous site in the proximity of a highly industrialized megacity, Seoul, Korea. The concentration data of $CO_2$ monitored routinely at hourly intervals at Mt. Gwan-Ak (GA), Seoul, Korea throughout 2009 were analyzed in several respects. The mean $CO_2$ value was $405{\pm}12.1$ ppm (median=403 ppm) with a range of 344 to 508 ppm (N=8548). The analysis of its seasonal trend indicated that the $CO_2$ levels peaked in the winter but reached a minimum in fall. If the short-term trend is analyzed, the $CO_2$ values generally peaked during daytime along with the presence of two shoulders; this is suspected to be indicative of strong man-made effects (e.g., traffic activities). It is seen that the general patterns of $CO_2$ distribution in this study area are highly comparable to those typically found in urban areas with strong signals of anthropogenic activities.

• Magazine of the Korean Society of Agricultural Engineers
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• v.17 no.4
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• pp.4001-4008
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• 1975

The economic evaluation of the feasibility of expanding fully irrgated agriculture in the Ogseo project must consider preproject yields of rice under rainfed and partially irrigated paddy cultivation in order to assess incremental incomes from irrigation. Statistical data on yields available from official sources and field surveys conducted in the project area do not specify whether given unit yields refer to actually cropped or potentially cropped lands. This latter factor obviously affects any evaluation of marginal benefits to be derived from irrigation as the extent of rainfed areas actually cropped varies from year to year according to rain fall at the critical growth periods for low land rice. Although less dependent on direct rainfall, yields from partially irrigated lands are also highly affected by seasonal rainfalls. In this paper on attempt has been made to determine average yield under rainfed and partially irrigated conditions by relating yields to a available water. For rainfed paddy cultivation, the analysis discriminates between effects of rain deficiencies during transplanting and subsquent growth periods. For partially irrigated paddy cultivation, seasonal rainfalls have been considered, implying sufficient storage capacity for supplementary irrigation. The average yield of rainfed paddy has been calculated as 2.11 t/ha and that of partially irrigated paddy as 2.8 t/ha. Assuming even division between these two water supply patterns of areas not fully irrigated, a composite yield of 2.46 t/ha is oftained. This figure will be adopted as the basis for the on-going studies and project evaluation.

• Journal of Nutrition and Health
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• v.29 no.9
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• pp.1003-1012
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• 1996

We examined the relationship among riboflavin intake, work activity, erythrocyte glutathione reductase activity coefficient(EGR AC)and urinary riboflavin excretion. We also attempted to determine factors affecting seasonal riboflavin status of rural women. All information about nutrient intake, work activity and riboflavin biochemical status was repeatly collected in three seasons ; farming season(June), harvest season(October), nonfarming season(February). EGR AC was negatively correlated with riboflavin intake(P<0.005) and positively correlated with the duration(min) of farming activity(P<0.005) and the percentage of lean body mass(LBM) (%) representing long term physical activity(P<0.05) in harvestseason. Urinary riboflavin excretion was positively correlated with the ratio of riboflavin intake to 1,000kcal of energy expenditure (P<0.05) in farming season and negatively correlated with the duration(min) of farming activity (P<0.05) and crude nitrogen balance(P<0.005) in harvest season. It appeared that EGR AC seems to increase and urinary riboflavin excretion seems to decrease as work activity increase. Therefore work activity would be expected to deteriorate riboflavin status. Multiple regression analysis of variables showed that in general EGR AC was affected by riboflavin and energy intakes, energy expenditure, energy balance, the duration(min) of farming activity, LBM (%). Urinary riboflavin excretion was affected by riboflavin and protein intakes, LBM(kg) and crude nitrogen balance. Crude nitrogen balance affected urinary riboflavin excretion in all seasons. The result indicated that work activity as well as nutrient intake seemed to affect riboflavin status, especially EGR AC was affected preferentially be work activity in all seasons.

• Journal of Environmental Science International
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• v.10 no.3
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• pp.209-216
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• 2001

Dustfall particles were collected by the modified American dust jar (wide inlet bottle type) at 6 sampling sites in Pusan area from March, 1999 to February, 2000. Thirteen chemical species (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Ni, Pb, Si, and Zn) were analyzed by AAS and ICP. The purposes of this study were to estimate qualitatively various bulk deposition flux of dustfall and insoluble components by applying regional and seasonal distribution. Dustfall amount of regional variations were found in order of coastal zone, industrial zone, commercial zone, agricultural zone and residential zone, and seasonal total dustfall had higher concentrations during spring for 6.741 ton/${km}^2$/season, lower concentrations during summer for 1.989 ton/${km}^2$/season, and annual total concentration was 17.742 ton/${km}^2$/year. The regional distributions of enrichment factor show well-defined anthropogenic metals (Cd, Cu, Pb, and Zn) at industrial and agricultural zone, and contribution rate of soil particles were found in order of summer, fall, winter and spring. Factor loading effects of chemical composition of dustfall were found in order of road traffic emission source and combustion processed source, industrial activity source, soil source and marine source.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.2
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• pp.315-323
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• 2015

Nowadays, it is expected that mobility loads such as electric railways and electric vehicles will be penetrated gradually and affect on the power system stability by their load characteristics. Various researches have been carried out about electric vehicles for the recent decade though the load of electric railway could be forecasted because of the specified path and timetable, is a field with a long historic background. Some precise 5th polynomial equations are required to analyze the power system stability considering mobility load to be increased in the immediate future while the electric railway dispatching simulator uses load models with constant power and constant impedance for the system analysis. In this paper, seasonal urban railway load models are established as the form of 5th polynomial equations and substation load modeling methods are proposed merging railway station load models and general load models. Additionally, load management effects by the load modeling are confirmed through the case studies, in which seasonal load models are developed for Seoul Subway Line No. 2, Gyeongui Line and Airport Railroad and the substation load change is analyzed according to the railway load change.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.529-531
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• 2003

In order to investigate the level of heavy metal contamination and the seasonal variation of metal concentrations in soils and sediments influenced by past mining activities, tailings, soil and sediment samples were collected from the Hwacheon mine in Korea. The main pollution sources in this mine site are suggested as tailings and mine waste rocks. Elevated levels of Cd, Pb and Zn were found in soils and sediments. In a study of seasonal variation on the heavy metals in soils and sediments, heavy metals were higher enriched collected from before rainy season ($2^{nd}$ sampling) than after rainy season ($1^{st}$ sampling). Also, in order to estimate the microbial effects on Cd speciation in sediments, bacteria which can adsorb Cd was isolated and Cd adsorption characteristics of isolated bacteria in Cd solution was evaluated. The Cd bioremoval efficiency in Cd solution (5 ppm) by bacteria was more than $90\%$. Bioremoval efficiency in single metal solution was higher than that in mixed metal solution of Pb and Zn.

• The Korean Journal of Applied Statistics
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• v.23 no.2
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• pp.275-284
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• 2010

In this study, we introduce filters that used for the prior adjustment of the holiday effect in seasonal adjustment. And we propose new filters having more various and flexible patterns than conventional ones. Under the practical assumption that patterns of effects before and after the holiday are different, we compare adjustment effect of the proposed filters and the existing ones. In comparison study, we estimate the effect from all possible combinations of shapes of filter by RegARIMA. And then, to adjust holiday effect, we apply the estimated results to time series data of industrial production and shipment index data in South Korea.

• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.387-392
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• 1998

To establish a monthly data collection planning for the Ocean Scanning Multispectral Imager (OSMI), we have examined the global patterns of three impacting factors: pigment concentration, cloud cover, and sun glint. Other than satellite mission constraints (e.g., duty cycle), these three factors are considered critical for the OSMI data collection. The Nimbus-7 Coastal Zone Color Scanner (CZCS) monthly mean products and the International Satellite Cloud Climatology Project (ISCCP) monthly mean products (C2) were used for the analysis of pigment concentration and cloud cover distributions, respectively. And the monthly simulated patterns of sun glint were produced by performing the OSMI orbit prediction and the calculation of sun glint radiances at the top-of-atmosphere (TOA). Using monthly statistics (mean and/or standard deviation) of each factor in the above for a given 10$^{\circ}$ latitude by 10$^{\circ}$ longitude grid, we generated the priority map for each month. The priority maps of three factors for each month were subsequently superimposed to visualize the impact of three factors in all. The initial results illustrated that a large part of oceans in the summer hemisphere was classified into the low priority regions because of seasonal changes of clouds and sun illumination. Sensitivity tests were performed to see how cloud cover and sun glint affect the priority determined by pigment concentration distributions, and consequently to minimize their seasonal effects upon the data collection planning.

• Journal of Korean Society on Water Environment
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• v.28 no.3
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• pp.384-393
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• 2012

Saemangeum lake is an artificial lake created by reclamation works and an estuary embankment since 2006. The sea water flows into the lake by the operation of two sluice gates, and the freshwater enters into the lake by the upper streams. For the reflection of hydrology and hydrodynamics effects in Saemangeum area, a hydrodynamics model was developed by connecting Hydrological Simulation Program with Fortran (HSPF) and Environmental Fluid Dynamic Code (EFDC). The HSPF was applied to simulate the freshwater discharge from the upper steam watershed, and the EFDC was performed to compute water flow, water temperature, and salinity based on time series from 2008 to 2009. The calibration and validation are performed to analyze horizontal and vertical gradients. The horizontal trend of model simulation results is reflected in the trend of observed data tolerably. The vertical trend is conducted an analysis of seasonal comparisons because of the limitation of vertically observed data. Water temperature reflects on the seasonal changes. Salinity has an effect on the near river input spots. The impact area of salinity is depending on the sea water distribution by gate operation, mainly.

• Korean Journal of Microbiology
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• v.22 no.3
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• pp.157-165
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• 1984

Seasonal and spatial variations in propagule numbers of Trichoderma species were investigated every other month for one year in deciduous and coniferous forest soils and evaluated the relationships of Trichoderma spp. populations to soil environmental factors. The total population of Trichoderma spp. increased until summer and then declined until winter. The yearly mean frequency of Trichoderma spp. exceeded 1.4% of total fungal propagules in two sites. Decreases of absolute an relative propagule numbers of Trichoderma spp. with increasing soil depth were found and variation in Trichoderma spp. propagules caused by differences in soil depth ($0{\sim}50cm$) was greater than that caused by differences in sampling time. The most common species occurring in two sites was T. viride, followed by T. polysporum, T. koningii, and T. hamatum. Individual species of Trichoderma showed diferent abundance trend in accordance with sampling time. T. viride was dorminant from spring to autumn, while T. polysporum dominated over the other speicies in winter. Variations in propagule number of Trichoderma sppp. were principally mediated by the actions of biotic environmental factors rather than by the direct effects of abiotic factors. In multiple-regression analyses, 48% of the total vaiation in Trichoderma spp. propagules in deciduous site could be accounted for by total fungal propagules and soil CMCase actvity. In coniferous site, 65% of total variation could be accounted for by total fungal and bacterial propagules, moisture content and organic carbon content.