• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.4
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• pp.173-187
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• 2023

In an era of population decline, depopulated regions facing challenges in attracting inbound population migration must enhance urban vitality through the attraction of living populations. This study focuses on Busan, a city experiencing population decline, comparing the spatiotemporal distribution characteristics of registered residents and living populations in various administrative districts (Eup-Myeon-Dong) using mobile communication big data. Administrative districts are typified based on population change patterns, and regional characteristics are analyzed using indicators related to urban decline and vitality. Spatiotemporal distribution analysis reveals generally similar density patterns between registered residents and living populations; however, a distinctive feature is observed in the city center areas where the density of registered residents is low, while the density of living populations is high. Divergent trends in spatial patterns of change between registered residents and living populations show clusters of registered population decline in low-density areas and clusters of living population decline in high-density areas. Areas adjacent to declining living populations exhibit large clusters of population changes, indicating a spillover effect from high-density to neighboring areas. Typification results reveal that, even in areas with a decline in registered residents, there is active population influx due to commuting or visiting. These areas sustain an increase in the number of businesses, confirming the presence of industrial and economic growth. However, approximately 47% of administrative districts in Busan are experiencing a decline in both registered residents and living populations, indicating ongoing regional decline. Urgent measures are needed for enhancing urban vitality. The study emphasizes the necessity of utilizing living population data as an urban planning indicator, considering the increasing limit distance of urban activities and growing interregional interaction due to advancements in transportation and communication.

• Journal of Korean Society of Forest Science
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• v.66 no.1
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• pp.82-94
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• 1984

The variation of stomatal density and stomatal length of four species of oaks was studied for the purpose of examining the differences among populations and among individual trees within population. Nine populations of Quercus mongolica, four populations of Q. serrata and Q. variabilis respectively, and three populations of Q. acutissima were selected in the natural stands of oaks distributed through the whole country. Twelve leaves were sampled from each of 20 trees from each population. The length of 20 stomata and ten replications of stomatal density were measured from collodion replicas of each leaf under a microscope. Average stomatal densities and lengths ranged through $600-1000/mm^2$ and $19-26{\mu}m$ respectively in all of the species studied. The stomatal densities and lengths presented significant differences statistically at the level of 1 or 5% among populations and among individual trees within population in all the species. Quercus mongolica, especially, showed large variation among populations, while Q. variabilis did very narrow variation compared to the other species. The coefficients of variation of stomatal densities and lengths among individual trees within population exhibited small values of 3.7-12.0% and 1.4-5.3% respectively in all the populations of the species. The average stomatal densities of Q. mongolica showed statistically significant correlation of multiple correlation coefficient of $R_{df{\cdot}2.6}=0.868^*$ and multiple regression equation of $Y=0.041X_1(G.M.T.S.)+0.489X_2(G.M.H.S.)+22.37$ with the sum of growing season mean daily temperature and the sum of growing season mean daily humidity of the stand studied. However the average stomatal lengths showed no relation with the same meteological variables. The figures of frequency distribution of the measurements of leaves or the mean values of individual trees did not show normal distribution curves in some populations. The curves, as well as the results of ANOVA, exhibited the differences among populations.

• Korean Journal of Environment and Ecology
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• v.34 no.4
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• pp.294-303
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• 2020

This study aimed to examine was conducted to the ability of microclimate control in old pine forests by surveying pine forest in Buddhist temples, where the pine forest are stably growing through active protection in the Gyeongnam region, and comparing variation characteristics of microclimate characteristics (temperature and humidity) and distribution of vegetation type. The study sites were pine forests protected well by Buddhist temples (Haein-sa, Beomeo-sa, Tongdo-sa, and Bulguk-sa) in the southeast region of Korea and thus known for stably growing young pine trees. According to the vegetation distribution status analysis, these pine forests did not have a high ratio of pine trees. Except for Tongdo-sa, the ratio of deciduous forest and mixed (deciduous and pine trees) forest had a much larger presence than that of pine forest. Measured data of microclimate showed that the Tongdo-sa area had significantly different characteristics compared to the other three areas. Tongdo-sa area showed a significantly higher diurnal range of temperatures and humidity than the other three areas, in both spring and summer. It is due to the difference in vegetation management. The forests around Tongdo-sa are mostly pine forests, except for the developed areas, while those in the other three areas have a dominant ratio of deciduous brad-leaved forests. Intensive control of pine forest is not effective in mitigating microclimate, i.e., temperature and air humidity. Stress caused by rising temperatures and decreasing air humidity is blamed for the decline of pine forests. Thus, the current active management of pine forests, such as the Tongdo-sa case, has been found to have a greater negative impact on the temperature and humidity stress. Therefore, we believe that a new change in forest management is necessary to increase the effect of mitigating the microclimate of pine forests.

• Journal of Bio-Environment Control
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• v.26 no.1
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• pp.13-18
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• 2017

This study was conducted to investigate optimal temperature of garlic and develop bulb weight model in harvest time. Day and night temperature in chambers was set to $11/7^{\circ}C$, $14/10^{\circ}C$, $17/12^{\circ}C$, $20/15^{\circ}C$, $23/18^{\circ}C$, $28/23^{\circ}C$(16/8h). Bulb fresh and dry weight was heaviest on $20/15^{\circ}C$. In $11/7^{\circ}C$ and $14/10^{\circ}C$, leaf number and total leaf area increased slowly. But in the harvest, leaf number and total leaf area were not significant, except $28/23^{\circ}C$. Models were developed with fresh bulb weight. As a result of analyzing the model, $18{\sim}20^{\circ}C$ certified optimal mean temperature. And the growing degree day base temperature estimated $7.1^{\circ}C$, upper temperature threshold estimated $31.7^{\circ}C$. To verify the model, mean temperature on temperature gradient tunnel applied to the growth rate model. Lineal function model, quadric model, and logistic distribution model showed 79.0~95.0%, 77.2~92.3% and 85.0~95.8% accuracy, respectively. Logistic distribution model has the highest accuracy and good for explaining moderate temperature, growing degree day base temperature and upper temperature threshold.

• Korean Journal of Environment and Ecology
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• v.32 no.2
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• pp.165-175
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• 2018

The purpose of this study is to provide the basic data such as distribution status, growth characteristics, and the structural characteristics of forest stands for the systematic conservation and management of relict forest trees (stem girth of 300cm or larger) established naturally in Gangwon Province, Korea. The survey showed that 434 individuals of 19 species (conifers: 228 individuals of 4 species, broad-leaved trees: 206 individuals of 15 species) were distributed in Gangwon Province, and Taxus cuspidata was the most abundant among them with 203 individuals or about 46.7 % of the total. The stem girth was average of 404cm (conifers: 373cm, broad-leaves: 421cm), and Tilia amurensis with multi-stemmed growing on Sorak mountain range had the largest stem girth at 1,113cm. The average height and the crown width of relict forest trees were 15.4m and 10.0m, respectively. Although the environments of relict forest trees showed a slight difference by species, the relative appearance frequencies of most trees were high in the environments where the altitude was higher than 1,000 m, slope degree was greater than $25^{\circ}$, the slope faced north, and microtopography was at the upper of slopes. Regarding the stand characteristics of relict forest trees per unit area ($/100m^2$), the average total coverage was 294% (max. 475%), the total average number of species was 36 species (max. 60 species), the average species diversity index (H') was 2.560 (max. 3.593), the average canopy closure was 84.8% (max. 94.6%), and the average basal area (/ha) was $52.7m^2$ (max. $116.4m^2$, relict trees $30.0m^2$, and other trees $22.7m^2$). The analysis of the dynamics of the forest stands where relict forest trees were growing showed four types of the maintenance mechanisms of relict forest trees depending on the supply pattern of succeeding trees: "Low-density but persistent type (Quercus mongolica, Abies holophylla, Tilia amurensis, and Pyrus ussuriensis)," "Long ago stopped type (Pinus densiflora)," "Recently stopped type (Abies nephrolepis, Quercus variabilis, and Betula schmidtii)," and "Periodically repeated types of supply and stop (Salix caprea and Quercus serrata).".

• Journal of Korean Society of Forest Science
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• v.85 no.4
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• pp.605-618
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• 1996

Namsan area supposed to be a disturbed ecosystem and Kwangneung area considered to be a natural ecosystem were selected for the study. On the basis of the plant species composition, the study was planned to examine structural plant species diversity so as to provide basic ecological information to restore more stable and healthy ecosystem for Namsan. The stratified sample plot method was employed for collecting vegetation data, establishing $20m{\times}20m$ square plots for overstory trees, $4m{\times}4m$ plots for mid-story woody plants, and $1m{\times}1m$ plots for ground vegetation. The herbaceous plants were periodically investigated by taking into account for seasonal(spring, summer, and autumn) variation in presence. Ecological attributes were evaluated through analyzing species composition, species diversity, life forms, interspecies association, and growing habitat for various forest types, vertical layers, life forms, and seasonal variation. Even though the species diversity index of canopy trees in the deciduous forest of Namsan was estimated higher than that of the natural forest of Kwangneung, overall species diversity of plants in Kwangneung area was greater than that in Namsan area. Herbaceous plants presented in Kwangneung but not in Namsan were Aconitum pseudo-proliferum, Botrychium virginianum, Dryopteris tokyoensis, Scutellaria insignis, Tricyrtis dilatata, and Viola kamibayashii, most of them were endemic species of Kwangneung. Elaeagnus umbellata, and Prunes padus var. seoulensis were found only in Namsan. Such species typically composed of the natural deciduous forest as Acer mono, Acer triflorum, Carpinus laxiflora, Cornus controversa, Fraxinus mandshurica, and Phellodendron amurertse were limited growing in a small size of area in Namsan. The future project should be made for encouraging the growth and expansion of the distribution of such species to restore biodiversity in Namsan area.

• Journal of the Korean association of regional geographers
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• v.6 no.3
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• pp.37-52
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• 2000

Generally speaking, the metropolitan agricultural regions have some advantages from the high accessibility to markets. But agriculture inevitably rests on the biological process. This study shows what characteristics of the agricultural management are found in these less favored metropolitan areas with bad natural conditions and how farm household live there. From the view point of farm household, the quality of labors they can get is quite low, and insufficient in quantity. The shortage of labor can be made up for the farming on Trust Farming System And the relatively less favored agricultural conditions prevent people from immigrating into these kind of areas, if they don't have any relationship with there. With bad natural conditions, the farm households usually cultivate relatively small areas for the purpose of self-sufficiency, and with smaller cultivating units(Baemi) of the land than in open fields. The scale of the agricultural management is largely affected by the ages of agricultural managers. The more aged the managers are, the smaller scale of the agricultural management. How to use lands is determined in accordance with the natural conditions such as percentage of sunshine and accessibility to drainage facilities -the two major factors- and more. Either owner-run farmlands or leased farmlands doesn't show any difference in each growing crops. Depending on the conditions of the lands, rice paddy is used for growing rice and field is used for growing self sufficient plants including vegetables for the farm household. Although the lack of infrastructure causes the inconvenience of living, and there exist less favored agricultural conditions, this kind of life and agricultural management style -self-sufficiency type- seems to be sustained quite longer. The less favored natural conditions for farming keeps the agricultural management style from being developed to be the level of commercialization. And the poor economic situation of farmers are continuing again and again. With the result of this study, there should be two conditions to be established previously if they want to develop these regions. First, each farm household should get to know of the importance of commercialization and try to spread it. The commercialization. should be attained through the expansion of the environmental friendly agriculture and the improvement of the previously established distribution system of the crops. Secondly, there should be a support from the government. The support will include the expansion of the infrastructures for fanning to improve the fanning conditions and the compensation system directly from the government to the farmers.

• Journal of The Korean Society of Grassland and Forage Science
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• v.9 no.1
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• pp.7-14
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• 1989

This experiment was carried out to determine the seasonal herbage production and utilization during the growing season of pasture on the forest (shading 30%). Plant height, leaf area index(LAl), dry matter(DM) production and distribution, chemical composition, in vitro dry matter digestibility(IVDMD), herbage utilization percentage and chewing efficiency were investigated using the Corridale sheep. Experimental field was treated by one plot design(3 rep.) and performed from 1987 to 1988 at Chungnam National University, Daejon. The results obtained are summarized as follows: 1. The highest plant height and LA1 were observed in May(35.0 cm, 4.89), followed by April(28.0 cm, 4.23), while the plant height and LA1 in October (13.0 cm, 0.49) showed very low. 2. During the growing season, about 58.3 % of annual DM production (7240 kg/ha) was produced during the spring (April, May and June) and the highest DM production was obtained in May (2040 kg/ha), which was more than 28.2 % of total DM production. However, DM production in July and August was about 24.2 % and those in September and October (17.5 %) was very low, but the difference of DM production from June to September was small. 3. The maximum DM production per day (65.8 kg/ha) was observed in May, followed by June (28.7 kglha), while DM production per day in October (16.5 kg/ha) showed very low (p <0.01). 4. Crude protein content and IVDMD of herbage samples during the spring (April, May and June) were higher, while crude fiber, ADF, and NDF content were lower in an summer growth herbage samples (July and August), but autumn growth herbage samples was intermediate. Crude ash content and IVDMD of collected herbage samples were slightly more, while crude fiber, ADF and NDF content were slightly less than offered and residued herbage samples during the growing season. 5. The maximum DM intake per metabolic body size was observed in May(68.9 g), followed by October (66.7 g), while very low in August (52.5 g). Significant positive correlation (p <0.05) was found between DM intake and IVDMD. 6. Herbage utilization percentage was very high in April (83.4 %), while very low in August (64.0 %). The percentage of annual herbage utilization was about 75.5 %. 7. The maximum ruminating and chewing efficiency of herbage samples were observed in May, followed by October, while very low in August.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.6
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• pp.509-519
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• 1987

Annual reproductive cycle of the Damselfish, Chromis notatus collected monthly at the four coastal areas around Chejudo, Korea are studied on the bases of histological observations of gonadal tissue and various quantitative variables including gonadosomatic index (GSI), fatness, egg diameter composition and the first maturity. The ovary consisted of a pair of saccular structure with many ovarian sacs. Oogonia proliferated along the germinal epithelium of the ovarian sac. Young oocytes with basophilic cytoplasm showed several nucleoli along the nuclear membrane. When the oocytes reached about $450{\mu}m$ in diameter, nucleus migrate toward the animal pole, nuclear membrane disappeared and most of cytoplasm were filled with yolk materials and oil drops. After ovulation, residual follicle and growing oocytes remaining in the ovarian sacs degenerated. But early young oocytes without follicle layer were not degenerated, and growing continuously till the next year. The testis consisted of a pair of lobular structures in the right and left were united in the posterior seminal vesicle. Cortex of testis was composed of many sperm ducts connected with lobuli. GSI began to increase from March, starting season of longer day length and higher water temperature, and reached the maximum value between June and August. It began to decrease from September with the lowest value appearing between October and February without any evident variation. The annual reproductive cycle could be devided into five successive stage : growing(April to Many), mature(May to August), ripe and spent (June to August) and recovery and resting stage(September to March). The spawning peak occurred from June to August. According to the frequency distribution of egg diameter, Chromis notatus was a polycyclic species to spawn twice or more in a spawning season. Fatness, correlated with gonadal phases, was remarkably decreased by spawning. Percentage of the first maturity . in femate and male fish ranging from 7.0 to 7.9 cm were $50\%$ and from 9.0 to 9.9 cm in total length $100\%$.

• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.667-675
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• 2018

Increasing emissions regulations and demand of high-efficiency cars that travels a lot of distance with less fuel, there is growing interest in Energy Consumption Efficiency. Korean energy consumption efficiency compute combined Fuel Economy by driven city & highway driving mode and present final Energy Consumption Efficiency as using 5-cycle correction formula. Energy consumption efficiency is computed Carbon-balance-method, when used burning fuel play a key role in vehicle performance & Energy Consumption Efficiency. In Korea, vehicle fuel is circulate by Petroleum and Petroleum Alternative Business Act, there is property difference in quality standard because petroleum sector's refine method or type of crude oil. It does not appear a big difference according to fuel, because it sets steady quality standard, it may affect the performance of automobile. Thus, in research We purchase a few diesel fuel which circulated in the market in summer season though directly-managed-gas station by petroleum sector, resolve property each of fuel, we compute Fuel Economy each of them. We analyze into change depend on applying for property as nowadays utilizing Energy Consumption Efficiency calculating formula of gasoline and diesel fuel. As result, Density each of sample fuel has a maximum difference roughly 0.9%, net heat value each of sample fuel has difference 1.6%, result of current Energy Consumption Efficiency each of sample fuel has a difference roughly 1% at city drive mode, 1.4% at highway drive mode. Result of use gasoline calculator formula shows less 6% result than nowadays utilizing Energy Consumption Efficiency calculating formula, each of sample's Energy Consumption Efficiency shows maximum roughly 1.4% result in city & highway drive mode.