• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.452-455
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• 2007

The geothermal heat pump system is designed for cooling and heating for three stories building (2,435 $m^2$) includes total 79 heat pumps. Therefore, the monitoring system is installed for each floor and the data is automatically transmitted to the monitoring system. Heat exchange rate and temperature of a geothermal heat pump system have been monitored for a long period. The seasonal operation of geothermal heat pump shows the different shape of heat exchange rate for cooling and heating. Ground water flow can influence on heat exchange rate and thermal storage of the system. In order to define the hydraulic characteristics and groundwater temperature variation, the relationships among air temperatures, groundwater temperatures, water table, and precipitation are analysed.

• Journal of Dairy Science and Biotechnology
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• v.24 no.2
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• pp.1-9
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• 2006

Goat milk is digested better than cow milk, because the fat globules in goat milk are smaller and the protein is similar to human milk, and assimilated easily. Goat milk is particularly rich in taurine (4.7mg/100mL) and retinol (40mg/100mL). Therefore, it might be recommened to heal dyspepsia and infants allergy by cow milk. However, during winter, supply of goat milk products are unsteady in Korea, because unbalance of demand and supply is resulted from seasonal breeding. Dairy industry for goat milk will be able to grow much more, if goat milk products can keep steady supply without changing by season. This review includes the physicochemical characteristics of goat milk, domestic production of goat milk, domestic goat milk products and future development.

• Journal of environmental and Sanitary engineering
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• v.13 no.3
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• pp.128-132
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• 1998

In this study, water quality characteristics of lakes in the Seosan area are analyzed. Components water quality were analysed at 10 sampled points in each lakes, and the results were evaluated for seasonal variation. It was found that water quality was over II~III class. Most of lakes in the Seosan area which implies that are suitable as the maintenance water. The concenturation of T-N, T-P was observed IV~V class during all seasons. Particularly, T-N concenturation peaks in spring, while was lowered in other seasons. In the lake, high concenturation of T-N, T-P bring about Eutrophication when algae was growth causing various physico-chemical changes in the water. It is suggested that the water quality management strategies need to be applied for each lake.

• The Korean Journal of Ecology
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• v.26 no.5
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• pp.247-250
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• 2003

The investigation of ecological characteristics of Lycoris radiata was carried out in flooding (site I), half flooding (site II) and dry stands (site III). Seasonal change of air temperature showed similar patterns and that of light intensity showed quite difference among three L. radiata stands. Seasonal change of soil water content showed a great difference among three L. radiata stands. The study area was dominated by Pinus densiflora, P. thunbergii and L. radiata communities. The number of bulb in 1. radiata increased in September with bulb formation and decreased in January. Bulb weight in L. radiata was different from each site. The numbers of blossom were 23, 13 and 9, respectively in site I, II and III. The length of wreath were 17.0, 13.0 and 11.0cm, respectively, the length of stamen were 7.0, 6.4 and 6.5 cm, respectively and the length of stalk were 60.0, 45.0 and 42.0 cm, respectively in site I, II and III. The leaf of L. radiata developed rapidly in site I with sufficient water supply and lower light intensity, the number and the length of rootlets increased considerably in site III with insufficient water supply and higher light intensity, and the ecological characteristics in site II was intermediate between site I and site III. There was no great difference between the numbers of rootlets in site I and site II, which were due to sufficient water supply in two stands.

• Journal of Environmental Science International
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• v.8 no.4
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• pp.465-471
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• 1999

The concentration of air pollution in a large city such as Pusan has been increased every years due to the increase on fuel consumption at factories and by vehicles as well as the gravitation of the population. In this study, we have analyzed $NO_2$ concentration data and various data of meteorological factors during 1994-1997 to investigate the characteristics of $NO_2$ concentration and how the high $NO_2$ concentration is generated under the meterological condition. According to the study, $NO_2$ peak concentration at most sites occured about 1h later after the rush hour. In the characteristics of emissions in sites, sinpyeong-dong was highly contributed to point source while the other sites were highly contributed to line source. The high $NO_2$ concentration had high generation probability when temperature contained typical seasonal characteristics and wind speed was low. Using the relationship between meteorological factors and the daily average $NO_2$ concentration, correlation analysis was practiced. the seasonal variation of the daily average $NO_2$ concentration was correlated with air temperature, solar radiation and wind speed, but the correlation coefficient between meteorological factors and the daily average $NO_2$ concentration was not so much high. Thus we have known that the daily average $NO_2$ concentration is partially explained by meteorological factors.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.10a
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• pp.237-238
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• 2008

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2004.11a
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• pp.395-396
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• 2004

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.04a
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• pp.65-66
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• 1999

• Journal of Korean Elementary Science Education
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• v.41 no.4
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• pp.673-689
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• 2022

To understand seasonal changes it is necessary to understand the relationship between celestial bodies in a three-dimensional space, and to this end, modeling activities in which students directly construct, use, evaluate, and modify three-dimensional models are important. In this study, the process of elementary school students using globes and light bulbs to model Earth's motion in a three-dimensional space as a cause of seasonal changes was analyzed. Seventeen sixth graders participated in the modeling process. After exploring phenomena and concepts related to seasonal change, students constructed models using globes and bulbs and used them to explain seasonal changes. Video data recording students' modeling process, students' activity sheets, and transcripts of post-interview were used as research data, and data triangulation was conducted. The modeling level analysis framework was also developed based on previous studies. In particular, the framework was developed in detail in this study in consideration of the concept of Earth's motion as well as understanding model and implementing modeling. In the final analysis framework, the 3D modeling level was classified from level 1 to level 3, and student performance that may appear at each level was specified. As a result of the study, there were two main levels of modeling using globes for elementary school students to explain seasonal changes. The rotation and tilt of the axis of rotation and revolution of the earth were considered but the level at which empirical evidence was not used (level 2), the level at which empirical evidence was used to explain seasonal chages (level 3). However, even when students use empirical evidence, it did not lead to the construction of a scientific model. In this study, the cause was explored in relation to the characteristics of the tool used for modeling.

• Journal of environmental and Sanitary engineering
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• v.5 no.2
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• pp.89-99
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• 1990

Morphology, anatomy and diurnal acid fluctuations were investigated monthly for the succulent C4 dicot Portulaca grandiflora Hook. growing under natural environmental conditions. Modified Kranz-Type sturcture and typical CAM-like cells were shown in leaves and stems, respectively. Values of indices of mesophyll succulence inleaves stems were 5.62 and 16.68, respectively. The number of stomata were 1476$\textrm{cm}^{-2}$ in leaves while the stomata in stems were not observed through growing seasons from spring to summer. However, on Sep. 16, 1981 in defoliate autumn season, stomata were begun to be produced for the first time in stems and the number were increased gradually to 216$\textrm{cm}^{-2}$ on Oct. 29. This feature can be interpreted as a seasonal plant dimorphism. P. grandiflora exhibited a diurnal fluctuation of titratable acidity in leaves and stems. Seasonal amplitudes of acid fluctuation in stems were as follows: 27 $\mu$eq./g.f.wt. on Sep. 21; 57$\mu$eq/g.f.wt. on Oct. 3; 80$\mu$eq./g.f.wt. on Oct. 21. Such the results in seasonal amplitude were able to consider due to decrease of light period and cool night air temperature according to change of season. Also, the naturally defoliated stems which had already stomata exhibited usual diurnal acid fluctuation, on the other hand the treated stems which possessed artificially closed stomata showed a few of acid fluctuation. Especially, stomata in stems are developed by seasonal dimorphism and activated stomata participate in CAM behavior of stems.