• Korean Journal of Environmental Agriculture
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• v.38 no.3
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• pp.173-184
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• 2019

BACKGROUND: This study was carried out to investigate pesticide residues from fifty streams in Korea. Water samples were collected at two times. Thee first sampling was performed from april to may, which was the season for start of pesticide application and the second sampling event was from august to september, which was a period for spraying pesticides multiple times. METHODS AND RESULTS: The 136 pesticide residues were analyzed by LC-MS/MS and GC/ECD. As a result, eleven of the pesticide residues were detected at the first sampling. Twenty eight of the pesticide residues were detected at the second sampling. Seven pesticides were frequently detected from more than 10 water samples. Ecological risk assessment (ERA) was carried out by using residual and toxicological data. Four scenarios were applied for the ERA. Scenario 1 and 2 were performed using LC50 values and mean and maximum concentrations. Scenarios 3 and 4 were conducted by NOEC values and mean and maximum concentrations. CONCLUSION: Frequently detected pesticide residues tended to coincide with the period of preventing pathogen and pest at paddy rice. As a result of ERA, five pesticides (butachlor, carbendazim, carbofuran, chlorantranilprole, and oxadiazon) were assessed to be risks at scenario 4. However, only oxadiazon was assessed to be a risk at scenario 3 for the first sampling. Oxadiazon was not assessed to be a risk at the second sampling. It seems to be temporary phenomenon at the first sampling, because usage of herbicides such as oxadiazon increased from April to march for preventing weeds at paddy fields. However, this study suggested that five pesticides which were assessed to be risks need to be monitored continuously for the residues.

• The Journal of the Korea Contents Association
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• v.9 no.12
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• pp.826-835
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• 2009

This study is to examine the relation between leisure constraints and participation by leisure type of security agents. By using purposive sampling method, this study collected 387 questionnaires in 14 private security service registered in 2009 at the Seoul National Police Agency. Cronbach's $\alpha$ .673. The conclusion are as follow. First, leisure constraints difference in socio-demographic characteristics such as sex, age, education level, income, position, job pattern. Second, in case of hobby and cultural activities, higher time constraints showed lesser frequency of participation, higher structural constraints showed lesser period of participation, higher personal constraints showed lesser intensity of participation. On the other hand, high time constraitns had high intensity of participation. In case of play and entertainment activities, even with high self-conscious constraints, it showed increased frequency and period of participation and high personal constraints showed increased period of participation but in contrast, higher structural constraints showed decreased frequency of participation and period. In case of viewing and appreciative activities, even with high interpersonal constraints, frequency and period of participation increased and higher time constraints also had increased period of participation. On the other hand, higher structural constraints showed decrease in frequency of participation and period.

• Journal of The Geomorphological Association of Korea
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• v.17 no.1
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• pp.39-48
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• 2010

This is a case study to research the environmental changes that occurred during the Latter Half of the postglacial age around the Basin of Onyang River in Asan, Korea. In line with this purpose, the author performed a pollen analysis and a radiocarbon dating on the deposits of alluvial fan around the upper Geumgok River, a tributary of Onyang River. Sampling point was at the altitude of about 67.5 meters, which belongs to the central zone of the cool temperate forest. The followings are the results of the study. The study area has passed through SC-I (the coniferous forest period in which Pinus was dominant), SC-II (the deciduous broad-leaved forest period in which Quercus and Castanea were dominant) and SC-III (the mixed conifer and deciduous broad-leaved forest period, in which Pinus, Quercus and Ulmus/Zelkova were dominant) respectively since about 3,000 yrB.P. SC-I period and SC-II period are presumed to be between about 3,000 and 2,000 yrB. P., and SC-III period to begin after 2,000 yrB.P. In comparison with the nationwide pollen zone during the postglacial age, SC-I and SC-II periods are contrasted with the R-IIIa zone and also the SC-III zone with the RIIIb zone. In addition, it is assumed that Pinus densiflora forest luxuriated there since 2,000 yrB.P. due to the destruction of forests, and that a lot of Fagopyrum pollen appeared; altogether, it was the so-called human interference period, from which forests began to be markedly destroyed. It is concluded that in those days inhabitants leaded agricultural life.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.4
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• pp.368-374
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• 1998

The study was conducted on six multiparous Murrah buffaloes which were earlier artificially induced into lactation. During the experimental period of 15 days, buffaloes were managed in a loose housing system. All the buffaloes were administered a single injection of bromocryptine (@ $100{\mu}g/kg$ body weight) subcutaneously in the neck region at 08:30 A.M., 50 days postpartum (early lactation). Blood samples were collected from four buffaloes for a period of 5 days before the administration of bromocryptine i.e. on days -5, -4, -3, -2, -1, on day of treatment (day 0) and thereafter daily for a period of 9 days i.e 1, 2, 3, 4, 5, 6, 7, 8 and 9 to determine the hormones and blood metabolites. Homogeneous milk samples from all the buffaloes were collected at morning and evening milkings on days coinciding with the days of blood sampling for analysis of milk constituents. Administration of bromocryptine resulted in a significant inhibition of plasma prolactin within 24 hrs of treatment, but the response in all the buffaloes was not uniform. The effect of bromocryptine on plasma prolactin hormone lasted for 1-4 days but Cortisol concentration were not altered. Administration of bromocryptine neither affected blood glucose nor plasma non-esterified fatty acids concentration. Irrespective of level of milk production from different buffaloes, there was no effect of bromocryptine on milk yield which indicated that prolactin is not required for milk secretion during early lactation in buffaloes. Milk constituents like fat, protein and lactose were not affected by bromocryptine may be due to no effect of bromocryptine of milk yield.

• 한국방재학회:학술대회논문집
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• 2007.02a
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• pp.133-136
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• 2007

Cross correlation of seismic-background motions (Campillo and Paul, 2003; Shapiro et al., 2005) is applied to observations from the Korean Meteorological Administration seismic network to estimate the short-period Rayleigh and Love wave dispersion characteristics of the region. Standard processing procedures are applied to the cross correlation, except that signal whitening is used in place of one-bit sampling to equalize power in signals from different times. Multiple-filter analysis is used to extract the group velocities from the estimated Green's functions, which are then used to image the spatially varying dispersion at periods between 0.5 and 20 sec. The tomographic inversion technique used inverts all periods simultaneously to provide a smooth dispersion curve as a function of period in addition to the usual smooth spatial image for a given period. The Gyeongsang Basin in the southeastern part of the peninsula is clearly resolved with lower group velocities.

• Journal of Korean Society on Water Environment
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• v.26 no.6
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• pp.903-909
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• 2010

The purpose of this study was evaluated on the applicability of Load Duration Curve Method (LDC Method) using HSPF watershed model and sampling data for efficient TMDLs in Korea. The LDC Method was used for assessment pollutant characteristics in watershed and water quality variation in each water flow level. Load Duration Curve is applied for judge the level of impaired water-body and can be estimated the impaired level by pollutant, such as BOD, T-N, and T-P in this study depending on variation of stream flow. As a result, BOD, T-P was usually exceed the standard value at low flow and dry hydrologic period. Improvement of effluent concentration from WWTP and riparian buffer protection zone are effective to improve the water quality. T-N showed the worst condition at mid-range hydrologic period and moist hydrologic period. Therefore, soil erosion control program and BMPs for non-point source pollution control is effective for recovery the water quality, which can be useful method for management of water quality in the plan of recovery water quality spontaneously. Applicability of LDC Method was evaluated in the Nakbon A watershed. However, we need to consider more detailed and accumulated data set such as accurate GIS data and detail pollution data, and WWTP discharge water quality data for accurate evaluation of watershed. Overall, The LDC Method is adequate for evaluation of watersheds characteristics, and its application is recommended for watershed management and TMDL Implementation.

• Journal of The Korean Society of Agricultural Engineers
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• v.47 no.3
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• pp.77-86
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• 2005

A monitoring study has been conducted to identify hydrologic conditions, water quality and nutrient loading characteristics of small watershed in Juam Lake. Climate data of the watershed were collected; flow rate was measured and water quality sampling was conducted at the watershed outlet for this study. Water quality data revealed that T-P concentrations meet I grade of lake water quality standard during non-storm period, but degraded up to II-III grade of lake water quality standard during storm period. The observed T-N concentrations always exceeded lake water quality standard. Therefore, T-P was identified as limiting chemical constituent for eutrophication of Juam Lake. T-P concentration of non-storm period also revealed that point source pollution is not serious in the watershed. Three year monitoring results showed that the observed T-N losses were $10.85\~18.88$ kg/ha and T-P losses were $0.028\~0.323$ kg/ha during six month (Mar. - Oct.), respectively. Major portion of runoff amount discharged by a few storm events a year and nutrient load showed apparent seasonal variation. Huge runoff amounts were generated by intense storms, which make application of water treatment or detention facilities ineffective. Monitoring results confirmed that water quality improvement by abating nonpoint source pollution in rural watershed of monsoon climate should be focused on source control. T-P losses from paddy field seemed to consist of significant amount of total load from study watershed. Therefore, management of drainage from paddy field is considered to be important for preventing algal blooming problem in Juam Lake.

• Journal of Korean Academy of Nursing
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• v.27 no.3
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• pp.588-600
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• 1997

Postpartum depression is one of the most serious problems in maternal health because it affects not only the mother but also her family. Postpartum depression disturbs the maternal-infant interaction and attachment. However, most postpartum depression patients ignore this problem and do not seek treatment. Many clinicians and researchers realiza there is a need to develop a postpartum depression scale. Thus, this study has been designed to development of a postpartum depression scale. Data were collected through a survey over a period of three months. Subjects who participated in the study were 167 Korean mothers in their postpartum period. The author used a convenience sampling method. The analysis of the data was done with SPSS PC/sup ＋/ for descriptive statistics, item analysis and factor analysis. Initially 62 items were generated from the interview data of eight postpartum depression patients and from a literature review. This preliminary scale was analyzed for reliability and validity. The results of this analysis are as follows. 1. Initially 62 items were analyzed through the Index of Content Validity(CVI) and 48 items were selected. 2. Seven factors were extracted through the principal component analysis, and these contributed 61% of the variance in the total score. Finally 46 items in the scale loaded .41∼ .84 on one of seven factors. 3. Each factor was labeled. Factor 1 was labeled 'emotional phenomena-emotional upset' and included 13 items, factor 2 was labeled' cognitive phenomena-self concept disturbance' and included seven items, factor 3 was labeled 'relationship to baby-negative feeling' and included six items, factor 4 was labeled 'relationship to baby- overload' and included eight items, factor 5 was labeled 'negative maternal identity' and included five items, factor 6 was labeled 'biophysiological phenomena-disturbance of physical functioning' and included four items, and factor 7 was labeled' interpersonal relationship phenomena-blamed others' and included three items. 4. Cronbach Coefficient Alpha for internal consistency was .95 for the total 46 items. Finally, the author suggests that this scale could be adequately applied in assessing the postpartum depression of mothers during the postpartum period. The results of this study can contribute to designing an appropriate postpartum depression prevention strategy.

• 한국지구물리탐사학회:학술대회논문집
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• 2006.06a
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• pp.41-50
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• 2006

The crustal structure of Korean Peninsula have been investigated by analyzing group velocity dispersion data of surface wave. Cross.correlation of seismic background motions (Campillo and Paul, 2003; Shapiro et al., 2005) has been applied to estimate the short.period Rayleigh. and Love.wave group velocity dispersion characteristics of the region. Standard processing procedures were applied to the cross.correlation, except that signal whitening was used in place of one.bit sampling equalize power in signals from different times. Multiple.filter analysis was used to extract the group velocities from the estimate Green's functions, which were then use to image the spatially varying dispersion at periods between 0.5 and 20 seconds. The tomographic inversion technique used inverted all periods simultaneously to provide a smooth dispersion curve as a function of period in addition to the usual smooth spatial image for a given period. The Gyeongsang Basin in the southeastern part of the peninsula is clearly resolved with lower group velocities.

• Environmental Analysis Health and Toxicology
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• v.13 no.1_2
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• pp.43-53
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• 1998

Ambient air levels of polycyclic aromatic hydrocarbons(PAHs) are of concern because of their potential for adverse health effects including transformation of some of these substances to mutagens and carcinogens by mammalian microsomal enzyme system. Airbone particulate samples were collected by a conventional high-volume sampler and by an Anderson cascade impactor on 2 to 3 days in each month over a period of 1 year at a representative site of the heavy traffic area of Seoul from beptember 1994 to August 1995. Ten individual PAHs in sizable air particulates of each stage of two months were separated and analyzed by gas chromatography/mass spectrometry. As a results of analysis, the gross concentrations of PAHs in the fine and coarse particles were higher in the winter month than in the spring, followed in descending order by in the fall and summer. In a study of dependency of 10 PAHs compounds on size distribution of particles at heavy traffic area found that about 85% of the total PAHs content was associated with particles less than 2.0um (fine particles) in diameter of winter sampling period. while 79% were associated with this size fraction during summer period. In according to the mean concentrations of the 10 PAHs in 7 size classification from < 0.38 to> 10.1, the 'size was the smaller, PAHs concentration was the higher. Thus it was found that PAHs concentration was greatly affected by air particle size. Annual mean benzo(a)pyrene equivalents was 5.88ng/m$^3$ and obtained by applying, toxic equivalency factor developed by Nisbet and Lagoy.