• Korean Journal of Heritage: History & Science
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• v.49 no.2
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• pp.56-69
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• 2016

Flame resistant treatment has been applied since 1973 for fire prevention in historical wooden buildings, but several problems, such as whitening and discoloration are constantly occurring in some Dancheong, in spite of evaluation criteria. It is supposed that these phenomena are caused by the stability issue of flame retardant, Dancheong production methods, the residue of chemicals, which were applied in the past, building location environments, etc., but no evaluation and cause inspection has been performed. Therefore, this study aims to verify the effect of flame retardant on Dancheong by producing Pseudo-samples and setting spatial and temporal environment conditions. Pseudo-samples of Dancheong were produced using three methods; the method specified in the Standard Specification of Properties; the method, which is generally used in the site and the traditional method. For different environment conditions of pseudo-samples, the areas were classified into a coastal area and an inland area and the places were classified into a sunny place and a wetland. After applying a flame retardant, annual variations were inspected for 12 months and change aspects were observed through scan and regular observation. In annual variation inspection, various variations like whitening, decolorization, dissolution and exfoliation were found and especially, whitening was most dominant. When the effect of flame retardant depending on the production methods was analyzed, whitening occurred in all the three production methods. It is supposed that this is because calcium(Ca) was contained in the coloring material of each production method and it reacted with phosphorous(P) of flame retardant. When the effect of flame retardant depending on the environment conditions was analyzed, whitening occurred more in the coastal area than in the inland area and it reduced in the building in a sunny place, which was constructed using the traditional method. It is supposed that this results from the humidity change and the difference of glue used in each production method. In conclusion, for using a flame retardant containing phosphorous(P), there is a need to check if calcium components including Oyster Shell White were used in Dancheong in advance and to conduct various preliminary studies on place conditions and Dancheong construction conditions.

• Korean Journal of Ecology and Environment
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• v.52 no.3
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• pp.245-265
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• 2019

Biotope, which represents the characteristic habitats of living organisms, need to be identified as essential for the efficient creation and sustainable management of urban ecosystems. This study was carried out to provide the basic information for ecological urban planning by analyzing types and attributes of the biotop established throughout the whole area of the Pohang city, a representative industrial city in Korea. The biotop established in Pohang city is composed of 12 types including forests (coniferous, deciduous, and mixed forests), agricultural fields (rice paddy and upland field), green facilities, river, reservoir, bare ground, residential area, public facilities, commercial area, industrial area, roads, and schools. As a result of analyzing the properties according to biotop types, industrial, commercial and residential areas, which represent urban areas, was dominated by introduced vegetation. Moreover the introduced vegetation is usually composed of exotic plants or modified forms for landscape architecture and horticulture rather than native plants, which reflects ecological property of both region and site. As the distance from the urban center increases, the agricultural field showed a form of typical farmland, whereas the closer it is, the more form of greenhouse farming. Natural green spaces were divided into riparian vegetation established along the stream and forest vegetation. Forest vegetation is consisted of secondary forests (seven communities) and plantations (three communities). The urban landscape of Pohang city is dominated by the industrial area. Among them, the steel industry, which occurs large amounts of heat pollution and carbon dioxide, occupies a large proportion. On the other hand, green space is very insufficient in quantity and inferior in quality. This study proposed several restoration plans and further, a green network, which ties the existing green spaces and the green space to be restored as a strategy to improve the environmental quality in this area.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.4
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• pp.287-294
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• 2021

The objective of this study was conducted to calculate the damage of whole crop maize in accordance with abnormal climate using the forage yield prediction model through machine learning. The forage yield prediction model was developed through 8 machine learning by processing after collecting whole crop maize and climate data, and the experimental area was selected as Gyeonggi-do. The forage yield prediction model was developed using the DeepCrossing (R²=0.5442, RMSE=0.1769) technique of the highest accuracy among machine learning techniques. The damage was calculated as the difference between the predicted dry matter yield of normal and abnormal climate. In normal climate, the predicted dry matter yield varies depending on the region, it was found in the range of 15,003~17,517 kg/ha. In abnormal temperature, precipitation, and wind speed, the predicted dry matter yield differed according to region and abnormal climate level, and ranged from 14,947 to 17,571, 14,986 to 17,525, and 14,920 to 17,557 kg/ha, respectively. In abnormal temperature, precipitation, and wind speed, the damage was in the range of -68 to 89 kg/ha, -17 to 17 kg/ha, and -112 to 121 kg/ha, respectively, which could not be judged as damage. In order to accurately calculate the damage of whole crop maize need to increase the number of abnormal climate data used in the forage yield prediction model.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.6
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• pp.576-585
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• 1991

General procedures of seed preparation as conventional guide had been established in China before most of Korean literature documented them. ‘Chwijongbeob’ (method of seed select) was to select good quality of seeds and to discard the rest. In ‘Seonjongbeob’ (method of seed grading) although China employed only ‘Sooseonbeob’ (method of seed select with water), but seeds were selected in order of selection of seeds by winds, selection of seeds by sieve and selection of seed with water in Korea. As compared with the recent techniques, those methods were perfect techniques for selection of good quality seeds of rice, except for method of seed selection by salt water was developed. The method for measurement of seed moisture, and for measurement of melted snow, spoiled urine and extracted juice by boiling water with the bone of livestock were originated from ancient China. The farming books in Korea were more or less followed the above methods. However, these techniques were complicated and impractical interms of validity and rationality. Also, it is judged that these tchniques are more appropriate in dry areas and alkaline soil of China rather than in Korean conditions. The plowing is a work to begin farming, and is operated for air ventilation between atmosphere and earth. Also, this techniques was adopted in the farming books from the early to the late Chosun dynasty without changes. Fields were deep-plowed in the first, in fall (or in spring) and for cultivation, and were shallow -plowed in the second, in spring (or in summer) and in intertillage. The former was for water reserve and land preparation, and the later was for weed control with intertillage. However, plowing in fall which was different from fallowing in dry areas, was recommended in Korea (Jikseol). but was not practiced in Sejongsilrok. This was changed with time, and plowing for cultivation in Korea was interrelated with use of green manure crops, method of plowing of upseting plough, method of manure practice and sometimes dry plowing. In addition, until the 15th century method of using a kind of plowing-tool made of log as farm tools was created to support reclamation for enlargement of farm land in mountaineous and coastal areas. For desolate farm lands by many internal and external disturbances, one tried to recover yield ability by increasing labor productivity from the 17th or 18th century. To do this, ‘Banjongbeob’ (culture method by upset plowing weed control) and ‘Hwanubeob’(culture method by firing weed control) which were cultural methods of ancient China were readapoted but the results were not clearly informed. Also, the reality of those was reexamined in the end of the Chosun dynasty.

• Journal of Bio-Environment Control
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• v.32 no.2
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• pp.165-171
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• 2023

Potato dry rot is one of the potato storage diseases caused by Fusarium species and is a representative pathological disorder that induced post-harvest loss during storage. Chlorpropham treatment for sprouting inhibition is mainly used for room temperature storage of potatoes for processing. In this study, the inhibitory effect of chlorpropham on Fusarium-induced dry rot of potato 'Dano'. To investigate the mycelial growth rate of the dry rot fungus (Fusarium solani Appel & Wollenw), mycelial growth was investigated in a chlorpropham (5.0, 50.4, 503.8, and 5,038 ppm) and prochloraz (0.1, 1.0, 10.0, and 100.0 ppm) medium containing F. oxysporum mycelia. Mycelia were more inhibited as the concentration of chlorpropham and prochloraz increased during incubation at 20℃, and the inhibition rate was 98.2% and 100% when treated with 503.8 ppm of chlorpropham and 10ppm of prochloraz in 14 days, respectively. Potato Dano tubers inoculated with F. oxysporum were dipped in chlorpropham (5.0, 50.4, and 503.8 ppm) and prochloraz (100 ppm) to investigate the effect of preventing dry rot during cold storage at 20℃ and 4℃ in vivo. The disease diameter of potatoes stored at room temperature (about 20℃) was reduced to 13.0 mm in the prochloraz 100 ppm teatment, and 10.7 mm in the chlorpropham 50.4 ppm treatment compared to 13.7 mm in the control tuber at 70 days of storage. The disease progression in all treatments including control was similar with no statistically significant difference at 4℃ air temperature. From the results of this study, it is considered that treatment with 50.4 ppm of chlorpropham after harvest will be useful for suppressing dry rot of stored potatoes.

• Journal of The Korean Society of Grassland and Forage Science
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• v.43 no.4
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• pp.232-239
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• 2023

This study was to evaluate the values of Korean native sweet sorghum as a new feed crop for ruminants. Sweet sorghum was the Muan native species (Bioenergy Crop Research Center, National Institute of Crop Science), and cultivated from May to October 2021 at Sangji University (Wonju-si, Gangwon-do, Korea). There were a non-treated group (Con), a recommended amount treatment (RD) and a treatment with double the recommended amount (Double RD) by an oil cake fertilizer. Plant height was measured at weekly intervals for 12 weeks after planting sweet sorghum seedlings, and was a significant difference in the order of Double RD, followed by RD and Con in 7 weeks (p<0.05). Feed values and sugar contents were measured in 7, 9, and 11 weeks. Crude protein of Double RD was higher than that of the other treatments in 7 and 9 weeks (p<0.05). Crude fat was higher at Double RD than the other one in 9 weeks (p<0.05). ADF and NDF of Double RD were higher than the other one (p<0.05). When it was compared to corn and sudangrass hybrids grown on farms, Crude protein was lower in sweet sorghum than other crops (p<0.05), and crude fat was higher in sweet sorghum than corn (p<0.05). Crude fiber, ADF and NDF were higher in sweet sorghum compared to corn and sudangrass (p<0.05). The sugar contents of sweet sorghum were 4.07 ± 0.12~7.63 ± 0.21 brix, and showed higher than corn and sudangrass hybrid (p<0.05). The rumen in situ digestibility of sweet sorghum was 30.73~38.13% at the 9th and 11th weeks, and showed higher than that of corn and sudangrass hybrids (p<0.05). Therefore, it is considered that Korean native sweet sorghum has sufficient value as a new forage crop for ruminants, and good value as yield, nutrients and digestibility, when the grass height is 273.33~332.50 cm.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.4
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• pp.359-367
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• 2023

Grapes are one of the most important fruit trees both domestically and globally. Recently, changes in plant phenology and frequent low temperatures due to climate change are increasing the possibility of damage to grape shoots in spring, which is a serious threat to grape production. This study was conducted to investigated the severity of shoots damage and the change of free sugar content in the plant organs by phenological stage, especially, from germination to leafing period. Furthermore, in order to compare the cold hardiness among grape varieties including 'Campbell Early', 'Kyoho' and 'Shine Muscat' widely grown in Korea, lethal temperature (LT₅₀) and free sugar content by grape variety were analyzed. Shoot damage by low temperatures continued to increase as the phenological stage progressed gradually, from the bud burst to the fourth leafing stage. On the other hand, the free sugar content of each organ except leaves continued to decrease, showing pattern to similar to cold hardiness. This indicates a close relationship between free sugar content and cold hardiness. In terms of cold hardiness comparison among grape varieties, 'Shine Muscat' showed the highest cold resistance in the leafing stage with the lowest LT₅₀ and the highest total free sugar content. Next was 'Kyoho' and 'Campbell Early'. There are clear differences in cold hardiness depending on the variety. However, it is not the same at all growth stage. It may change according to phenological stage and influenced by free sugar content at that time.

• Journal of Bio-Environment Control
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• v.32 no.4
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• pp.359-365
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• 2023

Native plants are unique genetic resources that have the potential to be used as ornamental, medical, and food resources. Allium koreanum H.J. Choi & B.U. Oh is one of the native plants distributed in the coastal rocky land of Korea, which has high conservation value due to climate change and reduction of its habitat. This study was conducted to investigate the effects of temperature and hydrogen peroxide on the germination of A. koreanum. The seeds were prepared as untreated (control) or those treated with 1% hydrogen peroxide for 90 minutes (H₂O₂), and the treatments were placed in plant growth chambers set at 15, 20, and 25℃. Regardless of the H₂O₂ treatment, the germination percentage at 15℃, which was 42%, was more than two times higher than that at 20℃ and 25℃, which were 18% and 0%, respectively, 23 days after sowing. The number of days to attain 50% of the final germination percentage (T₅₀) was the shortest at 20℃, but the mean daily germination (MDG) was the highest at 15℃. Therefore, 1% of H₂O₂ treatment did not have a significant effect on the germination percentage of A. koreanum, and a temperature of 15℃ was considered to be optimum to increase the germination percentage of A. koreanum. The results of this study can be used as basic research data for the germination of A. koreanum.

• Journal of Bio-Environment Control
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• v.32 no.4
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• pp.501-512
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• 2023

This study aimed to assess and determine the optimal model for predicting the full bloom date of 'Fuji' apples across South Korea. We evaluated the performance of four distinct models: the Development Rate Model (DVR)1, DVR2, the Chill Days (CD) model, and a sequentially integrated approach that combined the Dynamic model (DM) and the Growing Degree Hours (GDH) model. The full bloom dates and air temperatures were collected over a three-year period from six orchards located in the major apple production regions of South Korea: Pocheon, Hwaseong, Geochang, Cheongsong, Gunwi, and Chungju. Among these models, the one that combined DM for calculating chilling accumulation and the GDH model for estimating heat accumulation in sequence demonstrated the most accurate predictive performance, in contrast to the CD model that exhibited the lowest predictive precision. Furthermore, the DVR1 model exhibited an underestimation error at orchard located in Hwaseong. It projected a faster progression of the full bloom dates than the actual observations. This area is characterized by minimal diurnal temperature ranges, where the daily minimum temperature is high and the daily maximum temperature is relatively low. Therefore, to achieve a comprehensive prediction of the blooming date of 'Fuji' apples across South Korea, it is recommended to integrate a DM model for calculating the necessary chilling accumulation to break dormancy with a GDH model for estimating the requisite heat accumulation for flowering after dormancy release. This results in a combined DM+GDH model recognized as the most effective approach. However, further data collection and evaluation from different regions are needed to further refine its accuracy and applicability.

• Journal of Preventive Medicine and Public Health
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• v.7 no.2
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• pp.349-354
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• 1974

Survey results concerning the general information on health status of 7,050 inhabitants (1,141 households) which have been selected within Keumsan Gun, Chung Choung Nam Do area are as follws: 1. The average family size is $6.18{\pm}2.17$ persons per household. Tertiary sex ratio is 105.5 population composition of Kumsan Gun shown a pyramidal form consisting of 51.6% of the inhabitants under 20 years of age. 2. Rate of illiteracy amounts to 12.1% and only 4.1% of villagers were graduated from high schools, 80% of the inhabitants have some kind of jobs: 46.1% of them are engaged in agriculture, 95.2% of villagers have their own houses, and remaining 4.8% do not have their own. 3. 72% of households made use of health services provided provided by health centre or subcentres during a period of 1 year from April 1, 1973 to March 31, 1974. 26.8% of them visited health centre of sub-centres 2-4 times annually for the following purposes: 1) Vaccination: 35.7% 2) Diagnosis or treatment: 26.7% 3) Family planning: 24.1% 4) Maternal and child health: 10.5% 4. Utilization rate of health facilities is on an average 4.4 times per household and 0.75 times per capita. 5. Birth rate in the area is 1.91% and death rate is 0.75%, indicating the natural increase rate is only 1.16% that is lower than the nationwide rate of 1.8-2.2% in 1970 and 1.5-1.9% in 1973. 6. 37.7% of fertile women (20-40 years old) in the area are still unmarried, Fertility rate is the highest in the age group of 63-40 years old showing a value of 17.1%. 7. The unmarried population in this area amounts to 61.4% : 61.4% in male and 57.6% in female. 8. Number of inhaibtants who practice family planning is 612 persons(22.6%) among the married (2.771). This value consists of 8.3% of married males and 34.8% of married females. Only 16.0% of the people who put family planning in practice undergo permanent contraceptive methods and remaining 84.0% of them do temporary measures. 9. Only 57.7% of the subjects took vaccinations as follows: 1) B.C.G. vaccination: 82.7% 2) D.P.T. vaccination: 76.2% 3) Poliomyelitis vaccination: 67.9% 4) Smallpox vaccination: 62.6% 10. In the utilization of medical facilities in case of sickness drug stores (32.15%) comes first and hospitals or clinics (28.65%), health centre of health sub-centres (17.96%), herb drug stores (7.36%) and herb gerneral practioners (6.31%), etc., in decreasing order. Sickness that people living in this area suffer from are neuralgia, disease digestive troubles, respiratory diseases and skin lesions, etc.