• Korean Journal of Ichthyology
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• v.23 no.3
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• pp.206-216
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• 2011

To investigate seasonal and yearly variation of fishes composition in Yeoja Bay of Korea, fisheries survey were carried out using beam trawl from 2006 to 2009. A total of 44 fish species were collected. The major dominant species were Pennahia argentatus, Thryssa adelae, Thryssa kammalensis and Cynoglossus joyneri, which were occupied over 63% total individuals, and 50% of wet weight. The diversity index (H') was about 1.62 (1.46~1.77) by seasons, and seasons of similarity by fishes were divided into two groups, which were March with December and June with September. ANOVA test showed that there were not significant difference between individuals and catch weight (kg) per unit area (km$^2$) by year and season, except for catch weight per unit area by season.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.6
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• pp.385-392
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• 2005

Seasonal variation of abundance and species composition of ichthyoplankton were studied in the coastal water off Tongyoung, Korea. Monthly samples were collected using a ring net which were towed horizontally at 4 different stations from March, 1998 to February, 1999. A total of 74 species representing 35 families and 8 orders were found. Of these species 40 species (17 families) were Perciformes. Of the fish larvae couected Engraulis japonicus, Repomucenus sp., Parablennius yatabei, Synechogobius hasta, and Tridentiger sp. were the dominant species representing $80.6\%$ in total number of individuals. The number of species was highest in August and lowest in December; number of individuals was highest in May and lowest in November. The diversity index (Shannon and Wiener Index) was highest in march, and lowest in December.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1308-1314
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• 2008

In this paper, Seoulmetro that is the first operation organization which operates a city railroad rolling-stock maintenance RIMS(rolling stock information maintenance system) collected and analyzed a light maintenance data and introduced time a series analysis technique to find the way how to contribute to a use efficiency improvement of a city railroad. The purpose of time a series analysis is to remove a seasonal change including data and to check an irregular fluctuation. First of all, a collection range of the data comes under a light maintenance, however it needs a data of more than 3 years to check the seasonal change. We put a study for an accumulated scope that the data satisfy a period like this and are able to extend a range of the study when time flys forward. The data used for study is filtered using a movement average method after passing proper selection working and is solved with a method which looks for season index. Using the season index that was getten in here, we predict a light working frequency, if it has an irregular change, we will contribute it to a city railroad a use efficiency improvement and establish the cause by carrying out prevent maintenance in advance.

• Journal of Korea Port Economic Association
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• v.24 no.2
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• pp.1-17
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• 2008

In this paper the cargo transportation were forecasted for the North Port in Busan through time series models. The cargo transportation were classified into three large groups; container, oil, general cargo. The seasonal indexes of existing cargo transportation were firstly calculated, and optimum models were chosen among exponential smoothing models and ARIMA models. The monthly cargo transportation were forecasted with applying the seasonal index in annual cargo transportation expected from the models. Thus, the cargo transportation in 2011 and 2015 were forecasted about 22,900 myriad ton and 24,654 myriad ton respectively. It was estimated that container cargo volume would play the role of locomotive in the increase of the future cargo transportation. On the other hand, the oil and general cargo have little influence upon it.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.3
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• pp.285-296
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• 2003

The measurement of the radiation energy, trunk temperature, leaf area index (LAI), air temperature, vapor pres-sure, and precipitation has been conducted under a mixed forest at Kwangneung Arboretum during the period of 2001. Characteristics of the diurnal and seasonal variation of the radiative energy were investigated. The aerodynamic roughness length was determined as about 1.6 m and the mean albedo was about 0.1 The downward short-wave radiation was linearly correlated with the net radiation and its correlation coefficient was about 0.96. From this linear relation, the heating coefficient was calculated and its annual mean value was about 0.21 The albedo and heating coefficient was varied with season, surface characteristics, and meteorological conditions. The diurnal and seasonal variations of radiation energy were discussed in terms of the surface characteristics and meteorological conditions. In the daytime, during clear skies, net radiation was dominated by the shortwave radiation. In presence of clouds and fog, the radiation energy was diminished. At night, the net radiation was entirely dominated due to the net longwave radiation. There was no distinct diurnal variation in net radiation flux during the overcast or rainy days. The net radiation was strongest in spring and weakest in winter. The seasonal development in leaf area was also reflected in a strong seasonal pattern of the radiation energy balance. The timing, duration, and maximum leaf area and trunk temperature were found to be an important control on radiation energy budget. The trunk temperature was either equal or warmer than air temperature during most of the growing season because the canopy could absorb a substantial amount of sunlight. After autumn (after the middle of October), the trunk temperature was consistently cooler than air temperature.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.340-342
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• 2022

Index Terms, or keywords, are an important component of research papers because they present a quick overview of the main subjects covered in the research paper by highlighting the most important nouns. In this study, we extracted the author-assigned index terms from KIICE Conference Proceedings dating back to 2018 for seasonal conferences, and 2016 for the international conference (ICFICE). The extracted index terms were standardized and analyzed to gain an understanding of research topic trends and any over or under-represented research topics. This kind of index term analysis is expected to be useful in helping researchers not only identify additional potential topics for their own research, but also aid them in selecting from a common vocabulary of keywords when they assign index terms to their research papers.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.4
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• pp.261-266
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• 2008

The ocypodid crab, Macrophthalmus japonicus, commonly occurs in tidal flats in areas around Korea. We examined the age and growth of M. japonicus collected from the tidal flats of Haui Island in Jeollanamdo, Korea, from January to December 2006. According to variation in the monthly fatness index, the population spawned from June to August. To estimate parameters of growth, frequencies of monthly carapace lengths were analyzed using FiSAT II. The allometry of females differed from that of males. VBGE(von Bertalanffy growth equation) and seasonal VBGE were determined using monthly average carapace lengths for males and females, and an equation for estimating seasonal growth was calculated using regression coefficients.

• Journal of Nutrition and Health
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• v.28 no.9
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• pp.893-903
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• 1995

This study was attempted to estimate seasonal variations of physical activity level, energy balance & body composition of 38 rural women, aged 31 to 67yrs in three seasons ; farming season(June), harvesting season(October), nonfarming season(February) Energy intake, energy expenditure and body composition were assessed using questionnaire, daily activity diary & bioelectrical impedance. The type of activities & the period of the spent on each activity were changed significantly with the seasons. Daily mean duration(min) of farming activity was significantly higher in June & October than in February(p<0.005) & daily mean energy expenditure for farming activity was significantly high in June & low inFebruary (p<0.005). Daily mean energy expenditure was 2892.9㎉ in June, 2487.4㎉ in October and 2130.9㎉ in February and changed significantly in three seasons(p<0.005). Daily mean energy intake was significantly higher in June(=1950.3㎉) & October (=1946.9㎉) than in February(=1423.3㎉)(p<0.005). According to RDA for koreans, the level of physical activity fell into exceptional activity category in June, heavy in October, moderate in February. Mean energy balance was negative in all seasons ; 0.682 in June, 0.812 in October and 0.698 in February. In three seasons mean body weight, mean obesity rate and mean body mass index(BMI) were not changed significantly. But there were significant seasonal variations in body fat(%) & lean body mass(LBM)(%). The mean percentage of body fat(%) was within normal range(24.44-24.79%) & the mean percentage of lean body mass(LBM)(%) representing long term physical activity was significantly higher in June(75.56%) & October(75.21%) & October (75.21%) than in February(72.75%)(p<0.05).

• Ocean and Polar Research
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• v.27 no.1
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• pp.45-58
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• 2005

Temperature, salinity, dissolved oxygen, COD, dissolved inorganic nitrogen(DIN), dissolved inorganic phosphorus (DIP), and chlorophyll were measured in the surface and bottom waters of Cheonsu Bay in April, August, December 2003, and Hay 2004. DIN showed a large seasonal variation, with higher values in summer and lower in spring. The significant decrease in DIN concentration was observed from April to May, which may imply the occurrence of spring phytoplankton bloom sometime in these periods. In contrast, DIP did not show distinct seasonal variation, with relatively low values compared with other coastal regions. The low DIP concentration in Cheonsu Bay is ascribed to a limited phosphorus input around Cheonsu Bay. The Nf ratios of Cheonsu Bay much higher than the Redfield ratio(16) in all season indicate that phytoplankton growth is limited by phosphorus. Based on low chlorophyll concentrations and eutrophication index, Cheonsu Bay has not been in eutrophic condition during our observation periods. In the artificial lakes located around Cheonsu Bay, however, chlorophyll concentrations were very high, mostly over $10{\mu}g\;l^{-1}$, indicating that they are now in severe eutrophic condition.

• Ecology and Resilient Infrastructure
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• v.5 no.3
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• pp.125-133
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• 2018

Artificial neural network (ANN) is a powerful model to predict time series data and have been frequently adopted to predict groundwater level (GWL). Many researchers have also tried to improve the performance of ANN prediction for GWL in many ways. Dummies are usually used in ANN as input to reflect the seasonal effect on predicted results, which is necessary for improving the predicting performance of ANN. In this study, the effect of Dummy on the prediction performance was analyzed qualitatively and quantitatively using several graphical methods, correlation coefficient and performance index. It was observed that results predicted using dummies for ANN model indicated worse performance than those without dummies.