• 한국생태학회:학술대회논문집
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• 1998.05a
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• pp.91-92
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• 1998

• Monthly Duck's Village
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• s.67
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• pp.64-65
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• 2009

따뜻한 날씨에서 추운 날씨로, 혹은 추운 날씨에서 따뜻한 날씨로 변하는 환절기에는 사람과 동물 모두 계절적인 변화를 견딜 수 있도록 적절한 대책과 배려를 필요로 하기 때문에 가축의 효과적인 유지 관리를 위해서는 각 계절에 따라 생산성의 효율을 증진시킬 수 있는 환경을 제공해야 한다.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1998.10a
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• pp.138-139
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• 1998

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.1
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• pp.58-63
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• 2022

The daily number of confirmed cases of Coronavirus disease 2019(COVID-19) ranges between 1,000 and 2,000. Despite higher vaccination rates, the number of confirmed cases continues to increase. The Mu variant of COVID-19 reported in some countries by WHO has been identified in Korea. In this study, we predicted the number of confirmed COVID-19 cases in Korea using the SARIMA for the Covid-19 prevention strategy. Trends and seasonality were observed in the data, and the ADF Test and KPSS Test was used accordingly. Order determination of the SARIMA(p,d,q)(P, D, Q, S) model helped in extracting the values of p, d, q, P, D, and Q parameters. After deducing the p and q parameters using ACF and PACF, the data were transformed and schematized into stationary forms through difference, log transformation, and seasonality removal. If seasonality appears, first determine S, then SARIMA P, D, Q, and finally determine ARIMA p, d, q using ACF and PACF for the order excluding seasonality.

• Proceedings of the Korean Statistical Society Conference
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• 2005.05a
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• pp.113-119
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• 2005

경제적성과는 생산자, 소비자, 정부 등과 같은 경제주체들이 생산, 투자, 소비 등의 활동을 얼마나 유기적이며 효율적으로 잘 하느냐에 달려있고, 소비자전망조사는 경제주체 중 소비자의 향후 경기 및 소비에 대한 심리를 조사하고 이를 지수화하여 소비 및 경기 예측자료로 활용하는데 그 목적이 있다. 이렇게 작성된 소비자기대지수와 소비자평가지수는 서로 높은 상관관계를 가지고 움직이며, 이들의 차는 동행지수 순환변동치보다 3개월 정도 선행하는 것으로 나타났다. 또한 소비자기대지수는 계절성 검토결과 계절성이 있으며, 원계열보다 계절조정계열이 움직임이 뚜렷하며, 동행지수 순환변동치와 비교결과 선행성도 더 큰 것으로 나타났다. 이외에도 소비자기대지수는 소비관련 지표인 GDP 민간소비와 가계소비지출과도 서로 상관관계가 있는 것으로 나타나 정보변수로서의 유용성이 있는 것을 확인하였다.

• The Korean Journal of Applied Statistics
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• v.28 no.5
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• pp.885-893
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• 2015

It is important to improve the forecasting accuracy of one-year-ahead seasonal factors in order to produce seasonally adjusted series of the following year. In this paper, seasonal factors of 8 monthly Korean economic time series are examined and forecast based on the functional principal component regression. One-year-ahead forecasts of seasonal factors from the functional principal component regression are compared with other forecasting methods based on mean absolute error (MAE) and mean absolute percentage error (MAPE). Forecasting seasonal factors via the functional principal component regression performs better than other comparable methods.

• Proceedings of the Korean Society of Crop Science Conference
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• 1985.05a
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• pp.39.2-40
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• 1985

• Korean journal of applied entomology
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• v.54 no.4
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• pp.303-310
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• 2015

The diamondback moth, Plutella xylostella, overwinters in some protected areas in Korea. Using a sex pheromone trap, the adults were monitored since the occurrence of the overwintering populations. In Andong, P. xylostella exhibited four adult peaks in a year. Biological characters, such as cold tolerance, insecticide susceptibility, and developmental rate, were analyzed and showed a significant variation among different local overwintering populations. Population genetic variation was assessed with molecular markers, in which the initial high genetic variation among the overwintering populations decreased with the progress of seasons. These results suggests that there may be a significant migration of P. xylostella to decrease the genetic variation among the different local populations that are different in biological characters.

• Korean Journal of Ecology and Environment
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• v.40 no.1
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• pp.110-120
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• 2007

The objective of this study was to analyze temporal trends of water chemistry and spatial heterogeneity for 13 sampling sites of the Keum River watershed using water quality dataset (obtained from the Ministry of Environment, Korea) during $2001{\sim}2005$. The water quality, based on eight physical and chemical parameters, varied largely depending on the years, seasons, and sampling sites. Seasonal and annual means of conductivity, used as a key indicator for a ionic dilution declined during the monsoon season, and nutrients (TN and TP), based on overall mean of all sites, showed marked declines during the monsoon, compared to those of the premonsoon. In the mean time, BOD and COD had no significant relations with a precipitation, in spite of some differences in the sampling sites. In contrast, major input of SS occurred during the period of summer monsoon. and the variation of TN was similar to that of TP. Spatial trend analyses of all parameters, except for DO and temperature, showed that Site 9 acted as a point source, and thus, water quality at the locations of $S9{\sim}S13$ declined abruptedly over 2 fold, compared to locations of $S1{\sim}S8$. Based on the overall dataset, efficient water quality management in the point source tributary streams is required for better water quality of the main Keum River.

• Korean Journal of Environmental Agriculture
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• v.32 no.4
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• pp.294-303
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• 2013

BACKGROUND: It is well known that rice-fields can provide excellent foraging places for birds including seasonal migrants, wintering, and breeding and hence the high biodiversity of rice-fields may be expected. However, how environmental change including climate-changes on life-history and population dynamics in birds on rice-fields has not been fully understood. In order to investigate how climate-change affects population migratory patterns and migration timing, I modeled a population dynamics of birds in rice-fields over a whole year. METHODS AND RESULTS: I applied the Lotka-Volterra equation to model the population dynamics of birds that have been foraging/visiting rice-fields in Korea. The simple model involves the number of interspecific individuals and temperature, and the model parameters are periodic in time as the biological activities related to the migration, wintering and reproduction are seasonal. As results, firstly there was a positive relationship between the variation of seasonal population sizes and temperature change. Secondly, the reduced lengths of season were negatively related to the population size. Overall, the effects of the difference of lengths of season on seasonal population dynamics were higher than the effects of seasonal temperature change. CONCLUSION(S): Climate change can alter population dynamics of birds in rice-fields and hence the variation may affect the fitness, such as reproduction, survival and migration. The unstable balances of population dynamics in birds using paddy rice field as affected by climate change can reduce the population growth and species diversity in rice fields. The results suggest that the agricultural production is partly affected by the unstable balance of population in birds using rice-fields.