• Journal of Korean Society on Water Environment
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• v.27 no.4
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• pp.433-437
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• 2011

The study is conducted to evaluate loading of organic matter as seasonal changes during non-storm period into Lake Paldang which is used to a major drinking water source. Samples were taken in Lake Paldang intake during non-storm period and were analyzed loading of organic matter. From the results of the survey, improving of the water quality showed remarkable tendency depending on the changing periods from summer to fall and from fall to winter. Dilution effect from the increase of base run-off caused by the concentrated rainfall in rainy season, the characteristics of Korea's climate seems to have to be the reason. On the other hand, deteriorating of the water quality showed tendency depending on the changing periods from winter to spring and from spring to summer. Increase of Cyanobacteria etc. is explained by seasonal effects which are a small amount of the rainfall in winter and spring and gradational increase of water temperature.

• Korean Journal of Ecology and Environment
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• v.52 no.1
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• pp.40-49
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• 2019

Seasonal succession of zooplankton community and species composition was studied from 2003 to 2014 in a deep reservoir, Lake Soyang, in monsoon climate region, Korea. Annual precipitation was concentrated more than 70% between June and September and it showed remarkably that seasonal variation in water quality. Seasonal variation of water quality in Lake Soyang appeared to be more significant than annual variations, and the inflow of turbid water during the summer rainfall was the most important environmental factor. Zooplankton sepecies composition in Lake Soyang showed obvious tendency through two periods (May to June and August to October) every year. Small zooplankton (rotifer; Keratella cochlearis, Polyarthra vulgaris) dominated in spring and mesozooplankton such as copepods and crustaceans were dominant in summer and fall. Zooplankton biomass showed the maximum in September after monsoon rainfall, and chlorophyll showed a similar seasonal variation and it showed a high correlation (r=0.45). The increase of zooplankton biomass is considered to be a bottom-up effect due to the increase of primary producers and inflow of nutrients and organic matter from rainfall. In this study, we found that the variation of zooplankton community was affected by rainfall in monsoon climate region and inflow of turbid water was an important environmental factor, which influenced the water quality, zooplankton seasonal succession in Lake Soyang. It was also considered to be influenced by hydrological characteristics of lake and environment of watershed. In conclusion, seasonal succession of zooplankton species composition was the same as the PEG model. But seasonal succession of zooplankton biomass differed not only in the temperate lake but also in the monsoon region.

• Journal of the Korean earth science society
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• v.25 no.7
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• pp.545-557
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• 2004

The purpose of this study is to classify types of preconception on the seasonal change to middle school students and to find out how the developed multimedia material changes their conception in the seasonal change. The questionnaire about the variation of season consisted of 10 items. Questions are given to 80 ninth graders. Control and experimental group was 23 and 57 students, respectively and they were instructed for two class periods. A learning method using multimedia was applied to the experimental group. On the other hand, traditional teaching-learning method was used for the control group. A learning method using multimedia in this study had an effect on the conceptual changes (p$<$0.01). Data in this study was divided into six levels to classify the changes of concepts in detail. As a result, it showed that a learning method using multimedia was effective for students to make progress from unscientific to scientific concepts, to build up scientific concepts, to build up scientific concepts, and to elaborate scientific concepts as compared with traditional method.

• Journal of the Korean Institute of Landscape Architecture
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• v.34 no.3 s.116
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• pp.12-22
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• 2006

The purpose of this study is to evaluate visual preferences of the methods for river embankment based on seasonal changes and to reveal the relationship between visual preference and effective factors, which are the physical and esthetic elements inside the river. For this research seven river embankment methods including concrete block, concrete wall, gabion, and vegetated concrete block were selected in Dongchon of Gwangyang. Twenty-eight pictures by the four pictures of each embankment method based on seasonal changes, the winter and summer of the first and second years after construction were used for a photo-questionnaire by 49 participants. In the analysis of the relationship between visual preference and effective factors, the independent variables included eight factors: form of the material, harmony with the surroundings, the cleanness of river floor, the green area of embankment methods, the water area in river floor, the stone and sand area in river floor, the planting area in river floor, and the area of embankment itself. The result of this study are as follows. First, visual preference in summer was higher than in winter, and the summer landscape of the second you scored the highest value for visual preference. Second, similarly to the way the vegetated concrete block produced a green effect, cobblestone and gabion embankments made of natural materials scored higher than others, whereas the concrete retaining wall scored the lowest of all methods because of it's artificiality. Third, the seven independent variables, except form of the material, are proved statistically significant at the 5% level. The water area in river floor, harmony with the surroundings, the planting area in river floor, and the cleanness of the river floor were revealed as more effective factors influencing visual preference. The research results suggest that the riverscape has to be controlled in terms of seasonal change and embankment methods. Natural materials and green effects in embankment methods are more important for increasing landscape preference, and the landscape factors inside a river should also be considered important variables. It is recommended that advanced study on other factors affecting visual preference of the riverscape be carried out to support this research.

• Journal of Korean Elementary Science Education
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• v.25 no.1
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• pp.39-50
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• 2006

The purpose of this study was to investigate the effect of metacognitive strategy on conceptual acquisition ofvseasonal change and self-efficacy when it was applied to 6th grade elementary students. This study consists of 2 classes, 76 students in the 6th grade of elementary school, which were divided into the experimental group (38) and the control group (38). First, a pre-test was administrated to check students' levels of metacognitive self-regulation and self-efficacy prior to getting planned lessons and then an instruction program was developed based upon the metacognitive instruction model and students' conception. The control group was exposed to traditional methods mainly using the textbook and teacher's guide book. The experimental group employed a metacognitive learning strategy program and activities with metacognitive questionnaires. After the planned lessons, the students were tested with post-tests about the conception of seasonal change and self-efficacy. One month later the students were tested again with another test to determine the continuation effect. The results were as follows: First, the group that used metacognitive conceptual change instruction did better in forming and continuing to maintain the scientific seasonal change conceptions compared to the control group. Second, the high and intermediate group taught by metacognitive conceptual change instruction was higher in the level of self-regulation than the control group. However, it was not verified in the low group. Third, the group which used metacognitive conceptual change instruction showed a higher level of self-efficacy than the control group did.

• Journal of Veterinary Clinics
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• v.30 no.2
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• pp.95-99
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• 2013

This study was performed to evaluate the seasonal variation of intraocular pressure (IOP) values in normal Sapsaree dogs. Sapsaree dogs (n = 474) clinically free from ophthalmic disease were included in this study, and both eyes were examined in each dog. An applanation tonometer (Tonopen$^{(R)}$ XL) was used to measure IOP values in both eyes. Data obtained from both eyes were stratified by factors thought to affect IOP values including age, gender, hair coat type as well as season of measurement. The IOP results were compared by ANCOVA to verify the effect each factor had on IOP, and an ANOVA test followed by a Bonferroni post hoc test was used for further analysis. The overall mean ${\pm}$ SD IOP value was $19.1{\pm}3.7$ mmHg (range: 8 to 28 mmHg) in the present study. Only seasonal variation showed a significant effect (P < 0.001), on IOP values. IOP values measured in winter ($20.4{\pm}3.4$ mmHg) and summer ($17.1{\pm}3.6$ mmHg) were significantly higher and lower, respectively, than those measured in other seasons. These results suggest a seasonal variation has a significant effect on the IOP of normal dogs. This may prompt further research and possible modification of current veterinary ophthalmic references.

• The Korean Journal of Applied Statistics
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• v.32 no.1
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• pp.161-171
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• 2019

Varied methods have been researched continuously because the past as the daily maximum electricity demand expectation has been a crucial task in the nation's electrical supply and demand. Forecasting the daily peak electricity demand accurately can prepare the daily operating program about the generating unit, and contribute the reduction of the consumption of the unnecessary energy source through efficient operating facilities. This method also has the advantage that can prepare anticipatively in the reserve margin reduced problem due to the power consumption superabundant by heating and air conditioning that can estimate the daily peak load. This paper researched a model that can forecast the next day's daily peak load when considering the influence of temperature and weekday, weekend, and holidays in the Seasonal ARIMA, TBATS, Seasonal Reg-ARIMA, and NNETAR model. The results of the forecasting performance test on the model of this paper for a Seasonal Reg-ARIMA model and NNETAR model that can consider the day of the week, and temperature showed better forecasting performance than a model that cannot consider these factors. The forecasting performance of the NNETAR model that utilized the artificial neural network was most outstanding.

• Nutrition Research and Practice
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• v.12 no.4
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• pp.315-323
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• 2018

BACKGROUND/OBJECTIVES: Available data suggest that seasonal changes may influence the nutritional status and overall health of elderly individuals. Therefore, this study was conducted to investigate the effects of seasonal changes and related factors on energy and nutrient intake of older adults. SUBJECTS/METHODS: Individuals aged 65 years or over were prospectively enrolled in this single-center study (male: 11, female: 20). Data were collected between May 2013 and February 2014 during winter, spring, summer and autumn. Food consumption and biochemical parameters were taken during each season to assess the seasonal nutrition status of the elderly. Upon analysis of biochemical parameters (retinol, vitamin D and vitamin C), an high-performance liquid chromatography device was utilized whereas an Immulite 2000 device was utilized during analysis of serum folic acid and parathyroid hormone. RESULTS: Fruit, fat, egg and bread consumption varied seasonally in males and females (P < 0.05). During winter, daily energy intake was found to be greater than in other seasons in males (557 kcal) and females (330 kcal) (P < 0.05). Additionally, carbohydrates, vegetable protein, n-3 fatty acid and sodium intake increased in winter, while the n-6/n-3 ratio increased in summer among males (P < 0.05). Dietary fiber and sodium intake in winter, vitamin C, iron and zinc intake in spring, and cholesterol, retinol, vitamin D and niacin intake in autumn were found to be higher in females when compared to other seasons (P < 0.05). Serum parathyroid hormone level was higher in winter, and vitamin D level was higher in autumn in both genders (P < 0.05). In males, blood folic acid level was higher in winter, while vitamin C level was higher in females, and there was no seasonal variation in retinol concentration (P < 0.05). CONCLUSION: Food consumption and biochemical parameters showed significant seasonal variations in older adults. It is not clear if nutrition plans in older adults will benefit from consideration of seasonal changes in eating habits.

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.3
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• pp.269-270
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• 1989

• Journal of Astronomy and Space Sciences
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• v.30 no.4
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• pp.231-239
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• 2013

To identify seasonal and latitudinal variations of F2 layer during magnetic storm, we examine the change of daily averages of foF2 observed at Kokubunji and Hobart during high (2000~2002) and low (2006~2008) solar activity intervals. It is found that geomagnetic activity has a different effect on the ionospheric F2-layer electron density variation for different seasons and different latitudes. We, thus, investigate how the change of geomagnetic activity affects the ionospheric F2-layer electron density with season and latitude. For this purpose, two magnetic storms occurred in equinox (31 March 2001) and solstice (20 November 2003) seasons are selected. Then we investigate foF2, which are observed at Kokubunji, Townsville, Brisbane, Canberra and Hobart, Dst index, Ap index, and AE index for the two magnetic storm periods. These observatories have similar geomagnetic longitude, but have different latitude. Furthermore, we investigate the relation between the foF2 and the [O]/[$N_2$] ratio and TEC variations during 19-22 November 2003 magnetic storm period. As a result, we find that the latitudinal variations of [O]/[$N_2$] ratio and TEC are closely related with the latitudinal variation of foF2. Therefore, we conclude that the seasonal and latitudinal variations of foF2 during magnetic storm are caused by the seasonal and latitudinal variations of mean meridional circulation of the thermosphere, particularly upwelling and downwelling of neutral atmosphere during magnetic storm.