• Korean Journal of Remote Sensing
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• v.37 no.2
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• pp.321-335
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• 2021

Particulate matter (PM10 and PM2.5 with a diameter less than 10 and 2.5 ㎛, respectively) can be absorbed by the human body and adversely affect human health. Although most of the PM monitoring are based on ground-based observations, they are limited to point-based measurement sites, which leads to uncertainty in PM estimation for regions without observation sites. It is possible to overcome their spatial limitation by using satellite data. In this study, we developed machine learning-based retrieval algorithm for ground-level PM10 and PM2.5 concentrations using aerosol parameters from Geostationary Ocean Color Imager (GOCI) satellite and various meteorological parameters from a numerical weather prediction model during January to December of 2019. Gradient Boosted Regression Trees (GBRT) and Light Gradient Boosting Machine (LightGBM) were used to estimate PM concentrations. The model performances were examined for two types of feature sets-all input parameters (Feature set 1) and a subset of input parameters without meteorological and land-cover parameters (Feature set 2). Both models showed higher accuracy (about 10 % higher in R2) by using the Feature set 1 than the Feature set 2. The GBRT model using Feature set 1 was chosen as the final model for further analysis(PM10: R2 = 0.82, nRMSE = 34.9 %, PM2.5: R2 = 0.75, nRMSE = 35.6 %). The spatial distribution of the seasonal and annual-averaged PM concentrations was similar with in-situ observations, except for the northeastern part of China with bright surface reflectance. Their spatial distribution and seasonal changes were well matched with in-situ measurements.

• Korean Journal of Heritage: History & Science
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• v.44 no.3
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• pp.18-43
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• 2011

The results of study on planting and cultivate of Hong Man-Seon(1643~1715)'s 'Salimkyungjae(The Economy of Forest)' the first summative textbook of agricultural skill of South Korea, are as follows. First, 'Salimkyungjae' suggests that one can enrich oneself, eat fruits in fall, enjoy the shade of trees in summer, and enjoy flowers in spring if one plants tree with 10 year plan with knowledge of ecology. Second, the number of plants had increased continuously from the early Chosun Dynasty to the mid Chosun Dynasty. The 52 plants in the book are classified into 31 trees, 8 shrubs, 3 others, and 10 herbs, and 28 of them are fruit trees. Hence, we can see that the book is for the promotion of welfare. Third, planting(transplantation) is the best on January of the lunar calendar, and the second on February, and fertile soil should be added much. Trees must be planted as deep as once it was planted, and buttressed. It will sprout well if it is planted at the depth of one inch, and planting a cutting should be carried out at the early March with 5 inch and finger-thick branches. Grafting is the best when it begins to sprout. Fruit trees will bear many fruits if they are grafted at the direction of South, and fruits will be greater if the trees' branches are cutting off on January. Especially, January was selected for the best season of planting traditionally. Fourth, flower trees are planted or sowed with manure around January and February of the lunar calendar, and it is recommended to replant them into flowerpots with manure when having flower buds around March and April of the lunar calendar. It would bloom earlier when using water mixed with stable manure, and sulfur smoke can be used in order to change the flower color from red to white. Flowerpots would be placed at half shaded lot with being supported by bricks. Pomegranate, gardenia, camellia and four-season flower should be planted after flowers fallen. When flower trees are beside walls, they need to be rotated frequently since their branches all point toward house. Seeds need to be preserved in a sunny hut, where its entrance and ventilating openings would be at south because it is convenient to manage pots. Fifth, insects hidden at fruit trees would be destroyed by torch smoke when roosters cry on New year's day of the lunar calendar. Insects would be decoyed into straw hanged at dawn of Cheongmyeongday(淸明日). Insects on fruit trees would be controlled using sulfur powder to close up holes or sulfur smoke to fumigate. Particularly, it suggests that utilization of fertile soil would be the best solution for growing health plants and preventing pest.

• Journal of the Korean Society of Radiology
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• v.13 no.4
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• pp.653-659
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• 2019

The purpose of this study is to measure the (air dose rate of radiation dose) the discharged patient who was administrated high dose $^{131}I$ treatment, and to predict exposure radiation dose in public person. The dosimetric evaluation was performed according to the distance and angle using three copper rings in 30 patients who were treated with over 200mCi high dose Iodine therapy. The two observer were measured using a GM surverymeter with 8 point azimuth angle and three difference distance 50, 100, 150cm for precise radion dose measurement. We set up three predictive simulations to calculate the exposure dose based on this data. The most highest radiation dose rate was showed measuring angle $0^{\circ}$ at the height of 1m. The each distance average dose rate was used the azimuth angle average value of radiation dose rate. The maximum values of the external radiation dose rate depending on the distance were $214{\pm}16.5$, $59{\pm}9.1$ and $38{\pm}5.8{\mu}Sv/h$ at 50, 100, 150cm, respectively. If high dose Iodine treatment patient moves 5 hours using public transportation, an unspecified person in a side seat at 50cm is exposed 1.14 mSv radiation dose. A person who cares for 4days at a distance of 1 meter from a patient wearing a urine bag receives a maximum radiation dose of 6.5mSv. The maximum dose of radiation that a guardian can receive is 1.08mSv at a distance of 1.5m for 7days. The annual radiation dose limit is exceeded in a short time when applied the our developed radiation dose predictive modeling on the general public person who was around the patients with Iodine therapy. This study can be helpful in suggesting a reasonable guideline of the general public person protection system after discharge of high dose Iodine administered patients.

• Journal of Nutrition and Health
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• v.54 no.4
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• pp.398-411
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• 2021

Purpose: The objective of this study was to investigate food and nutrition information utilization practices of adults aged between 20 and 30 years to provide the basic data for developing customized content. Methods: Statistical analyses were performed using the SPSS program (ver. 24.0) for the 𝛘²-test, t-test, one-way analysis of variance, and Duncan's multiple range test. Results: Of the 570 subjects surveyed, 45.4% were men, 54.6% were women, 66.3% were in their 20s, 33.7% were in their 30s, 41.4% were single-person households, and 58.6% lived with their families. On average, 14.2% of televisions (TVs), 26.0% of personal computers (PCs), and 63.7% of smartphones were used for more than three hours per day. 30.9% of respondents searched for food and nutrition information more than once a week. 70.0% of the respondents had then applied the information in real life and 54.7% of the respondents said they would share information with others. Information retrieval rate was in the order of 'restaurant (64.8%)', 'diet (57.5%)', and 'food recipes (55.7%)'. Overall satisfaction with food and nutrition information averaged 3.33 on a five-point scale. Satisfaction score was in the order of 'enough description and easy to understand (3.43)', 'matching title and content (3.35)', and 'providing new and novel information (3.22)'. Satisfaction scores were significantly higher in the group that searched for information (p < 0.001), the group that used the retrieved information in real life (p < 0.001), and the group that conveyed this information to others (p < 0.001). Conclusion: To improve information user satisfaction, it is necessary to provide customized information that fits the characteristics of information users. For this purpose, it is necessary to continuously conduct surveys and satisfaction evaluations for each target group.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.3
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• pp.333-344
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• 2022

The quarrying and utilization of natural building stones such as granite and marble are rapidly emerging in developing countries. A huge amount of wastes is being generated during the processing, cutting and sizing of these stones to make them useable. These wastes are disposed of in the open environment and the toxic nature of these wastes negatively affects the environment and human health. The growth trend in the world stone industry was confirmed in output for 2019, increasing more than one percent and reaching a new peak of some 155 million tons, excluding quarry discards. Per-capita stone use rose to 268 square meters per thousand persons (m²/1,000 inh), from 266 the previous year and 177 in 2001. However, we have to take into consideration that the world's gross quarrying production was about 316 million tons (100%) in 2019; about 53% of that amount, however, is regarded as quarrying waste. With regards to the stone processing stage, we have noticed that the world production has reached 91.15 million tons (29%), and consequently this means that 63.35 million tons of stone-processing scraps is produced. Therefore, we can say that, on a global level, if the quantity of material extracted in the quarry is 100%, the total percentage of waste is about 71%. This raises a substantial problem from the environmental, economical and social point of view. There are essentially three ways of dealing with inorganic waste, namely, reuse, recycling, or disposal in landfills. Reuse and recycling are the preferred waste management methods that consider environmental sustainability and the opportunity to generate important economic returns. Although there are many possible applications for stone waste, they can be summarized into three main general applications, namely, fillers for binders, ceramic formulations, and environmental applications. The use of residual sludge for substrate production seems to be highly promising: the substrate can be used for quarry rehabilitation and in the rehabilitation of industrial sites. This new product (artificial soil) could be included in the list of the materials to use in addition to topsoil for civil works, railway embankments roundabouts and stone sludge wastes could be used for the neutralization of acidic soil to increase the yield. Stone waste is also possible to find several examples of studies for the recovery of mineral residues, including the extraction of metallic elements, and mineral components, the production of construction raw materials, power generation, building materials, and gas and water treatment.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.16 no.6
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• pp.17-29
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• 2021

Recently, as social distancing have been raised due to the re-spread of COVID-19, the number of serial entrepreneurs who are closing their business is rapidly increasing. Learning from failure is a source of success, but business failure can result in psychological and economic losses and negative emotions of the serial entrepreneur. At this point, it is very important to find a way to recover the negative emotions caused by business failures of serial entrepreneurs. Recently, a strategic model has emerged to deal with the negative emotions of grief caused by business failures of serial entrepreneurs. This study identified the recovery factors from the grief of business failures of serial entrepreneurs and analyzed Shepherd's(2003) three areas: loss orientation, restoration orientation, and dual process. To this end, individual in-depth interviews were conducted with 12 small business serial entrepreneurs who challenged re-startup to identify the attributes of recovery factors that were not identified with quantitative data. As a result of the study, first, recovery factors were investigated in three areas: individual orientation, family orientation, and network orientation. It was found to help improve recovery in nine categories: self-esteem, persistence, personal competence, hobbies, self-confidence, family support, networks, religion, and social support. Second, recovery obstacle factors were investigated in three areas: psychological, economic, and environmental factors. Nine categories including family, health, social network, business partner, competitor, partner, fund, external environment, and government policy were found to persist negative emotions. Third, the emotional processing process for grief was investigated in three areas: loss orientation, restoration orientation, and dual process. Ten categories such as family, partner support, social member support, government support, hobbies, networks, change of business field, moving, third-party perspective, and meditation were confirmed to enhance rapid recovery in the emotional processing process for grief. The implications of this study are as follows. The process of recovering from the grief caused by business failures of serial entrepreneurs was attempted by a qualitative study. By extending the theory of Shepherd(2003), This study can be applied to help with recovery research. In addition, conceptual models and propositions for future empirical research were presented, which can be discussed in carious academic ways.

• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.3
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• pp.318-333
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• 2023

The purpose of this study is to analyze changes in dental trauma in children under the age of 12 during the period of Coronavirus Disease 2019 (COVID-19). March 2020, when COVID-19 was officially declared a pandemic by the World Health Organization, was set as the starting point for COVID-19. From March 2018 to February 2020, subjects in the pre-COVID-19 period were classified as the Pre-COVID-19 group, and from March 2020 to March 2022, subjects in the post-COVID-19 period were classified as the COVID-19 group. Information related to trauma was collected through electronic medical records. The number of trauma patients before and after the outbreak of COVID-19 decreased significantly. During the COVID-19 period, there was no significant difference in the male-female ratio or the distribution order of age groups. In the COVID-19 group of permanent teeth, the ratio of trauma caused by personal mobility was higher than trauma caused by sports. In the COVID-19 group of permanent teeth, the ratio of crown fracture with pulp involvement was significantly higher than the ratio of crown fracture without pulp involvement. Changes in trauma patterns caused by COVID-19 were observed more clearly in school-aged children than in preschool children. In a pandemic situation such as COVID-19, it is expected to be used as a good educational basis for knowing that frequent diagnoses can change due to changes in the environment.

• Journal of the Korean Society of Radiology
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• v.16 no.4
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• pp.427-434
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• 2022

Atrial fibrillation treatment includes 3D RFCA and Cryo-balloon ablation. Both procedures have in common that they enter after understanding the structure of the heart using angiography equipment. Therefore, there is a disadvantage that the effect of exposure according to the procedure time can be a threat to both the patient and the operator, so this study aims to confirm the relationship between the total ablation time and the effect of radiation exposure. We used follow-up data (retrospective) from 41 patients who underwent coronary angiography and arrhythmia at the same time from March 2019 to July 2022. The range for total ablation time was based on the recorded data from the start to the end of the total ablation. The end point of 3D RFCA was when the ablation was completed for 4 pulmonary veins, and in the case of Cryo-balloon ablation, the data that succeeded in electrical insulation were included. As a result of analyzing the total ablation time, the time taken for Cryo-balloon ablation was 1037.29±103.66 s, which was 2448.61 s faster than 3D RFCA using 3485.9±405.71 s, and was statistically significant. (p<0.05) As a result of analyzing the total fluoroscopy time, the exposure time for 3D RFCA was 2573.75±239.08 s, which was less by 1717.15 s than the exposure time for Cryo-balloon ablation, 4290.9±420.42 s, and was statistically significant. In the case of total area dose product, 3D RFCA was 59.04±13.1 uGy/m², which was lower than Cryo-balloon ablation 980.6±658.07 uGy/m² by 921.56 uGy/m², which was statistically significant. As the insulation time of the Cryo-balloon ablation is shorter than that of the 3D RFCA, the method using the Cryo-balloon ablation is considered to be effective when the patient's condition is not good and a quick procedure is required. However, in patients with permanent Atrial fibrillation, there is a high probability of structural changes in the heart, so it is considered that 3D RFCA is better than Cryo-balloon ablation, which is difficult to manipulate.

• Journal of Venture Innovation
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• v.4 no.2
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• pp.97-108
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• 2021

Labor contracts appear in form as an exchange relationship between labor products and wages, but since they transcend the level of simple barter, they can be economically identified as "trading" and can be identified as "rental." From a legal point of view, a legal device that legally supports and imposes binding force on commodity exchange relations is a contract. Such a labor contract led to a relationship in which wages were received and a certain amount of time was placed under the direction and supervision of the employer as a counter benefit to the receipt of wages. Since working hours are subordinate hours with one's labor under the disposition authority of the employer, long hours of work can be done for the health and safety of workers and furthermore, it can be an act that violates the value to enjoy as a human being. The reduction of working hours needs to be shortened in terms of productivity and enjoyment of workers' culture so that they can expand and reproduce, but users' corporate management labor and production activities should also be compatible compared to those pursued by capitalist countries. Working hours can be seen as individual time and time in society as a whole, and long hours of work at the individual level are reduced, which is undesirable at the individual level, but an increase in products due to an increase in production time at the social level can help social development. It is necessary to consider working hours in terms of finding the balance between these individual and social levels. If the regulation method of working hours was to regulate the total amount of working hours, flexibility and elasticity of working hours are a qualitative regulation method that allows companies to flexibly allocate and organize working hours within a certain range of up to 52 hours per week. Accordingly, it is necessary to shorten working hours, but expand and implement the flexible working hours system according to the situation of the company. To this end, it is necessary to flexibly operate the flexible working hours system, which is currently limited to six months, handle the selective working hours by agreement between employers and workers, and expand the target work of discretionary working hours according to the development of information and communication technology and new types based on the 4th industrial revolution.

• Journal of Life Science
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• v.33 no.10
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• pp.828-834
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• 2023

The cDNA that encodes transmembrane protein 258 (Tmem258) was cloned from Gryllus bimaculatus and named GbTmem258. This protein comprises 80 amino acids, has no N-glycosylation site, and contains five potential phosphorylation sites at two serines, two threonines, and one tyrosine. The predicted molecular mass of GbTmem258 is 9.06 kDa, and its theoretical isoelectric point is 5.5. The tertiary structure of GbTmem258 was predicted using the available secondary structure information, which suggests the presence of alpha helices (52.5%), random coils (22.5%), extended strands (16.25%), and beta turns (8.75%). Homology analysis revealed that GbTmem258 exhibits high similarity at the amino-acid level to Tmem258 found in other species. The effect of starvation and refeeding on GbTmem258 mRNA expression was also examined in this study. It was found that GbTmem258 mRNA expression in the hindgut progressively increased throughout the starvation period, peaking at almost 1.5 times the control level after six days of starvation. However, refeeding for one to two days after the six-day starvation period restored GbTmem258 mRNA expression to the control level. In fat body, GbTmem258 mRNA expression was almost 3-fold higher during starvation compared to the control level. Refeeding for one to two days after the six-day fast resulted in a decline in the expression to about a 2.5-fold increase over the control level. Throughout the starving and refeeding periods, no other tissues showed any discernible alterations in GbTmem258 mRNA expression.