• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.1
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• pp.120-132
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• 2022

Recently, the rapid increase in vacant houses in urban areas has caused various problems such as worsening urban landscape, causing safety accidents, crime accidents, and hygiene problems. According to the Statistics Korea Future Population Estimation results, the growth rate of Korean population and households is expected to continue to decrease, which is likely to lead to an increase in the occurrence of vacant houses. If the problem caused by the occurrence of vacant houses is neglected, it causes not only a physical decline such as a deterioration of the residential environment but also a social and economic decline. In order to solve this problem, it is necessary to grasp the spatial distribution characteristics of vacant houses at the local level considering the existence of regional characteristics and spatial influence. Therefore, in this study, in order to measure global spatial autocorrelation, the analysis was conducted centering on the old downtown area of Busan, where there are many vacant houses through Moran's I and Geographically Weighted Regression(GWR). In addition, the distribution of vacant houses in different spatial units in Eup_Myeon_Dong and Census was analyzed to evaluate the possibility of Modifiable Areal Unit Problem(MAUP), which differ in the results of spatial analysis as the spatial analysis units change. As a result of the analysis, the occurrence of vacant houses by Eup_Myeon_Dong in the old downtown area of Busan had spatial heterogeneity, and the spatial analysis results of vacant houses were different as the spatial analysis units were different. Accordingly, in order to understand the exact distribution characteristics of vacant house occurrence, spatial dimensions using the GWR model should be considered, and it is suggested that consideration of the MAUP is necessary.

• Ecology and Resilient Infrastructure
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• v.9 no.3
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• pp.183-193
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• 2022

The growth inhibitory effect of Microcystis aeruginosa according to the ultrasonic irradiation time was evaluated using a large algae sample volume (10 L) for various ultrasonic irradiation times (0.5, 1, 1.5, 2, 2.5 and 3 hr) at a laboratory scale. Based on the analysis of Chl-a and cell number of M. aerginosa, algae growth inhibition was observed with the decrease in Chl-a and cell number in all experimental groups after the ultrasonic irradiation. For the experimental group (T_B, T_C, T_D) with an ultrasonic irradiation time of less than 2 hours, rapid regrowth of algae was observed after growth inhibition, but the experimental group (T_E, T_F, T_G) with an irradiation time of more than 2 hours successfully inhibited algal growth lasting one or two more days. Based on the comparison of the recovery time to initial cell number the experimental group (T_B, T_C, T_D) took less than 20 days whereas the experimental group (T_E, T_F, T_G) took about 30 days. Correspondingly, the experimental group showed a high first order decay rate (𝜅) in proportion to the ultrasonic irradiation time during the growth inhibition period. Additionally, the specific growth rates (𝜇) during regrowth in the experimental group with irradiation time of more than 2 hours were relatively low compared to those in the experimental group with less than 2 hours. Therefore, ultrasonic irradiation for more than 2 hours is required for long-term (30 days) inhibition of algal growth in stagnant waters. However, the appropriate ultrasonic irradiation time for algae growth inhibition should be determined according to various field conditions such as the volume of stagnant water, water depth, flow rate, algae concentration, etc. Finally, damages to the algal cell surface and cell membrane were clearly observed, and both destruction and disturbance of gas vesicles of M. aeruginosa in the experimental group were discovered, indicating the growth inhibitory effect of Microcystis aeruginosa according to the ultrasonic irradiation time was confirmed.

• Journal of Wetlands Research
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• v.24 no.3
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• pp.185-195
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• 2022

This study conducted a survey over spring and autumn from 2014 to 2020 to confirm the ecological characteristics of the size of streams and habitats, centering on the ecological landscape conservation area, and a total 256 species of benthic macroinvertebrates in 105 families, 25 orders, 8 classes, and 5 phyla appeared. In terms of appearance species, by region, the rate of appearance of Ephemeroptera and Trichoptera was high in regions consisting of lotic area and the rate of appearance of Coleoptera and Odonata was high in regions consisting of lentic areas. When comparing the population of Ephemeroptera-Plecoptera-Trichoptera (EPT) groups by region, they were classified into three groups: upstream area, mainstream area, and lentic areas, and it was confirmed that the population ratio of EPT changed as it moved from upstream to downstream. As the stream order increased, the number of species and populations increased. The Shredder group (SH) tended to decrease as the size of stream increased(r=0.9925), and the Collector-Filtering (CF) tended to increase as the size of stream increased(r=0.9319). It was confirmed that the Scraper (SC) replaced each other between species with the same ecological status as it went downstream from upstream, and it is thought that the SC did not differ significantly by stream order. In order to maintain a healthy ecosystem in the designation and management of ecological landscape conservation areas, it is necessary to consider ecological factors such as competition and physico-chemistry factors such as water quality and substrate conditions. Therefore, if the competent authority designated survey areas including buffer areas that include streams and physical habitats of various sizes, it will be advantageous to the conservative area and securing more biological resources.

• Analyses & Alternatives
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• v.6 no.1
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• pp.115-162
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• 2022

The Rules of the Workers' Party of Korea (WPK), revised at the eighth Party Congress in 2021, reflect the Kim Jong Un regime's changes in strategic lines and ideological justifications on North Korea's socialism and communism, and its recent stances against the external environment. Moreover, they contain critical changes in the party's organizational system encompassing the central and the provinces. This study explores the organizational changes of the "monolithic guidance system of the party core" stipulated by the new party rules in January 2021, based on the analysis of the entire nine revised rules of the WPK since 1945. In the 2021 Party Congress, the Kim Jong Un regime, which officially came to power after the fourth Party Conference in 2012, has institutionalized the monolithic guidance system centered on the party core, or the head of state, Kim Jong Un. The newly set leadership and execution system, which reorganized party, government, and military organizational structure and accompanied the relevant personnel changes, was derived from the attempts for reinstating the Kim Jong Un regime as a more normalized party-state structure before its 10th year in power in April 2022. The "monolithic leadership system of the party core" established a system of "organizational leadership" through the organization of the Central Committee, directed by the Party Head, or General Secretary. The institutionalization of the new system resulted from the ten-year development of the revival of the party-state structure, which compromised the status of the military and reconfirmed the party's control of the military. This study explains the new system from the perspectives of both institutionalization and top-down unity, shedding light on the new party-military-government relations of the Kim Jong Un regime. The analysis contributes to a better understanding and forecasting of the Kim Jong Un regime's governance, which currently strengthens the monolithic leadership system as a crisis management system in the face of the "triple hardships" of sanctions, Covid and disaster.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.1
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• pp.104-115
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• 1992

The rice culture techniques included 'Jodosukyungbeob'(旱稻水耕法 : culture techniques of early-ripening paddy rice), 'Mandosukyungbeob' (晩稻水耕法) : culture techniques of late-Ripening paddy rice 'Handobeob'(旱稻＆lt;山稻＆gt;法 : culture techniques of upland rice), 'Myojongbeob'(苗種法 : culture techniques of paddy rice by transplanting), 'Kunangbeob'(乾秧法 : culture techniques of rice by transplanting which rears seeding in dry paddy) and 'Sudogunpanongbeob'(水稻乾播農法 : culture techniques of paddy rice seeding in dry field). Especially, 'Kunangbeob' and 'Sudogunpanongbeob' were originally developed in Korea as seen in 1600s(Kyoungje : 經濟) and early 1800s (Yoji : 要旨). In 'Jodosukyungbeob' it took 9 days for seed dipping, water-sprouting and prevent damage by birds, each for 3 days in China, but in Korea seed dipping in water took 3 days and the rest of the procedures were flexibly established. In matured soils, practices were fall plowing right after harvest, recognition of effective tillering and additional fertilization use of human manure, and stimulation of sprouting by lime application. The unique culture techniques adequate for Korean situations were practiced, which included weed control after draining accurately for 3 to 4 times, draining at mid season for improving wind and drought tolerance, rice harvesting at appropriate time for preventing grain shattering, and seeding in rows. 'Mandosukyungbeob' was improved techniques contrast to those of China, and the major contents were selection of proper varieties, good stand establishment by seeding high rates, induction of vigorous tillers, and adoption of 'Jokjongbeob'(足種法 : seeding method by foot). Also, one of the most prominent rice cultures by our ancestors was 'Kunpanongbeob' that was systemized form habitual practice of Pyongan Province. The unique technique actualized was 'Hando [旱稻(山稻)]' culture technique which was the combinations of 'Jokjongbeob', root stimulation method, and disaster-tolerant mixture cropping with adoptation of variety theory, although it was originated from China. The transplanting techniques has come before 'Jikseol'($\ulcorner$直說$\lrcorner$) and its merits were sufficiently realized. However, this method was basically prohibited from the early Chosun dynasty because extremely bad harvest was expected under drought conditions and insufficient conditions of water storage. But, it was permitted in the areas that contained water all the times and in case of large-scale farming especially. Most of rice culture was transplanted in the end of the Chosun dynasty because transplanting was continuously spreaded in the three southern provinces of Korea. Under these circumstances, transplanting technique was improved from the early to the end of the Chosun dynasty by weed control, fertilizing, water management, and quadratic transplanting. Based on these techniques, agricultural productivity was improved 5 times by that time. 'Kunpanongbeob' was created and developed properly for Korean conditions that is dry in early season and flooding in late season. This was successively developed and established into transplanting technique of nursery seedling.

• Korean Journal of Ecology and Environment
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• v.55 no.2
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• pp.132-144
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• 2022

The fish community in the Seomjin River-Seomjin River Estuary-Gwangyang Bay coast continuum was investigated three times from March 2019 to October 2019. The collected species at the eight sites during the survey period were 49 species belonging to 31 families, including two endangered species. According to Bray-Curtis similarities, observations were divided into four groups based on the fish community composition; two groups (group 1, 2) and two uncategorized groups (group 3, 4). ANOSIM based on spatial and temporal groupings indicated that the spatial differences in fish communities (R=0.398, P=0.001) were relatively more important than the temporal differences (analysis of similarities, R=0.273, P=0.002). In particular, there were significant differences between groups 1 and 2 (analysis of similarities, R=0.556, P=0.001), and similarity percentage analysis revealed that Argyrosomus argentatus (9.4%), Favonigobius gymnauchen (6.9%) and Konosirus punctatus (5.9%) contributed to these differences of fish assemblages for each group. The fish fauna distributed in the Seomjin River-Gwangyang Bay ecosystem were spatially divided and the number of species and number of individuals showed seasonal differences. This study could be a basis for understanding changes in the fish community and implementing conservation and management strategies on major species within a continuous environment of the river-estuary-ocean continuum.

• Korean Journal of Ecology and Environment
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• v.55 no.3
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• pp.201-211
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• 2022

The macroinvertebrate community in the Singal reservoir, Yedang and Juam lake was investigated three times from April 2021 to October 2021. Each lake was investigated by dividing it into inflow, middle-flow, and outflow. Additionally, sampling was conducted again by dividing it into the edge and center parts at each inflow, middle-flow, and outflow. Eight families of benthic macroinvertebrates were collected except for chironomids in the sampling sites. Dominant macroinvertebrates were investigated as chironomids, and Tubificidae was sub-dominant organisms. The density of macroinvertebrate community was higher in the edge area than in the center bottom of the lakes. The density of chironomids was low when the water level was high but was high when the water level was low. In the edge area of the middle-flow in Singal reservoir, the density of chironomids was 1,208 ind. m^-2 in April when the water level was high, but it increased to 1,401 ind. m^-2 in July when the water level was low. Similarly, the density of chironomids at the outflow of Yedang lake was high (1,990 ind. m^-2) in July when the water level was low. The density of chironomids also decreased along with the increasing water level at all edge areas of Juam lake. These results indicated that it will be necessary to consider the water level when studying macroinvertebrate communities in the lake.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.24 no.3
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• pp.21-25
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• 1979

To evaluate the possibility of hardening of rice seedlings to chilling injury by low temperature conditioning for improvement of nursery temperature management a chilling sensitive new variety Tongil from Indica \times Japonica cross and a chilling tolerant Japonica variety Jinheung were reared by the 3rd leaf-stage in a day $30^{\circ}C/night\; 20^{\circ}C$ growth chamber, and were subjected to temperature conditioning for hardening against chilling injury for 6 days. Then the seedlings conditioned and unconditioned were chilled in a day and night $8^{\circ}C$ chamber for 2, 4, 6, or 8 days long and returned to the day and night $30^{\circ}C/night\; 20^{\circ}C$ condition for development of chilling injuries. Survival rate after chilling injury development of the variety Tongil showed distinct effect of hardening, i. e. the unhardened-25 % survival, the hardened by a gradual drop of temperature regime $(30^{\circ}C/20^{\circ}C\rightarrow24^{\circ}C/14^{\circ}C\rightarrow18^{\circ}C/12^{\circ}C\rightarrow8^{\circ}C)4 -59% survival and the hardened. by repeated brief exposure (4hrs. to 6hrs.) to $8^{\circ}C$ shock-89% survival against chilling of $8^{\circ}C$ for 4 days long. The variety Jinheung survived even against 8 days chilling at $8^{\circ}C$ C, but the discoloration rate of leaves due to chilling showed noticeably the hardening effect as repeated shock was much better than the gradually lowering temperatures.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.4
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• pp.249-257
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• 2022

This study was conducted to comparison analysis growth characteristics, yield and forage quality of 18silage corn varieties grown in paddy and upland fields. In this condition, days to silking of Sinhwangok was the shortest with 78 days and Kangdaok the longest with 92 days. Moreover it was confirmed that the difference of days to silking at this condition greatly occurred in the late species than in the precocious species. The height and ear height ratio of corn grown in paddy decreased by 5~10% and increase by 10~15% compared to upland, respectively. It was confirmed that the ear ratio of corn which enhances the forage quality was highest in Sinhwangok at paddy and upland and most of the varieties decreased by 10~30% at paddy rather than upland. The length of ear was also reduced by 10~25%. In fresh yield, Dacheongok showed the highest yield at 65,750 kg/ha in upland and 38,830 kg/ha in paddy. Similar to the fresh yield, dry and TDN yield in Dacheongok also showed the highest yield at 36,910 kg/ha, 18,040 kg/ha in upland and 21,670 kg/ha, 14,390 kg/ha in paddy, respectively. As a result of analyzing crude protein and starch from seeds to evaluate the feed value of corn for silage, there was no difference between cultivars grown in this condition. In addition, as a result of analyzing the contents of ADF and NDF using leaves, stems and seeds, the contents of leaves and stems were lower in P3394 and P1543 at the upland and lower in Singwangok and Daanok when cultivated at paddy. Moreover ADF and NDF contents were decreased in some varieties in paddy rather than upland. Therefore, there is no significant difference in the feed value of corn varieties grown in this condition, it is possible to cultivate corn in paddy if normal growth is achieved through drainage management.

• Journal of Nutrition and Health
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• v.56 no.1
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• pp.97-111
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• 2023

Purpose: Childhood obesity has become a social problem due to the social distancing necessitated by the coronavirus disease 2019 pandemic. This study aimed to identify the dietary problems of obese children through various dietary assessment methods and to confirm the usefulness of each method. Methods: The subjects were 88 students in the 4th to 6th grade of elementary school who participated in the nutrition camp organised by the Busan Metropolitan Office of Education, 2020. To evaluate dietary problems and assess diet quality, 24-hour meal records, monthly food intake frequency, and Dietary Screening Test (DST) data were analyzed. Results: Of the subjects, 15.7%, 30.3%, and 53.9% were normal weight, overweight, and obese, respectively. The average age was 11.77 ± 0.77 years and the average body mass index was 23.96 ± 3.01 kg/m². It was observed from the 24-hour meal record method that the overweight and obese subject groups consumed fewer green vegetables (p < 0.001) and white vegetables (p < 0.01) than the normal weight group. In the monthly food intake frequency method, the consumption of ramen (p < 0.01), snacks (p < 0.05), and sausages (p < 0.05) were high in the obese group, and that of anchovies, broccoli, and sweet pumpkin was high in the normal group (p < 0.05). The comparative data from the DST revealed that the overweight and obese groups had less vegetable intake than the normal weight group (p < 0.01) and had higher intakes of dairy products, fast food, and sweet snacks (p < 0.05). Conclusion: The usefulness of each method in the dietary evaluation of obese children was confirmed. To address the problem of obesity, it is necessary to evaluate the dietary problem and approach it with a customized solution tailor-made for the individual subject.