• Journal of Practical Agriculture & Fisheries Research
• /
• v.24 no.2
• /
• pp.12-22
• /
• 2022

The purpose of this study is to design a farming model for Hanwoo start-up farmers. I prepared a Hanwoo production plan model according to the growth cycle of Hanwoo using EXCEL. The Hanwoo production plan model was simulated in two model: Model 1 (a model that only purchases Hanwoo calf) and Model 2 (a model that purchases both Hanwoo cow and Hanwoo calf). Next, I reviewed the profits and costs of two Hanwoo simulation models. As a result of the analysis, Model 2 has the following characteristics compared to Model 1. First, Model 2 requires a lot of initial investment. Second, Model 2 is advantageous in terms of farm cash balance because imports occur every year. Third, Model 2 can efficiently use facilities and machines.

• Journal of the Korea Convergence Society
• /
• v.12 no.5
• /
• pp.191-196
• /
• 2021

This paper proposes to strengthen the technological capabilities of small and medium enterprises on the establishment of a component standardization system and the localization of parts, which is the basis of the marine wind industry. The wind industry is a natural energy industry that countries around the world are paying attention to, and continues to invest and research and development. In particular, most companies are focusing on research and investment in component development, the smallest unit. Therefore, it is believed that we should focus on the three most fundamental and underlying wind industry, an eco-friendly energy industry that could determine the fate of the nation in the future. First, an understanding of the roadmap for standardization should be prioritized. Second, it is necessary to establish a domestic standardization of international standards according to domestic conditions. Third, localization of high value-added single products and components should be achieved by lowering dependence on overseas imports. In the future, it is hoped that the wind industry, centered on small and medium-sized enterprises, will become a solid-based national industry and be completed as a national infrastructure leading the global wind market.

• Korean Journal of Environmental Biology
• /
• v.41 no.1
• /
• pp.31-40
• /
• 2023

In 2022, the Korean Ministry of Environment designated Parthenium hysterophorus as an ecosystem-disturbing plant. The purpose of this study was to present a management plan for P. hysterophorus considering its distribution, morphological, physiological, and ecological characteristics, and to introduce various control techniques. P. hysterophorus is native to Central America and occurs in about 45 countries worldwide. However, in Korea, it only grows in some areas of Tongyeong and Changwon, Gyeongsangnam Province. P. hysterophorus is an annual plant and spreads by seeds, moves between countries in the process of importing and/or exporting agricultural seeds, and spreads by agricultural machinery and vehicles after introduction. P. hysterophorus releases parthenin, an allelochemical that suppresses the occurrence of the surrounding vegetation, from its stems and roots. In addition, P. hysterophorus causes damage to humans and livestock through various allergens. P. hysterophorus can be controlled by physical methods, such as cutting its stems or pulling roots, and by treatment with non-selective herbicides, such as glyphosate. Many biological control research studies have been conducted and, unfortunately, there is no a practical solution so far.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2022.05a
• /
• pp.15-17
• /
• 2022

In the aftermath of the avian influenza that occurred from the second half of 2020 to the beginning of 2021, 17.8 million laying hens were slaughtered. Although the government invested more than 100 billion won for egg imports as a measure to stabilize prices, the effort was not that easy. The sharp volatility of egg prices negatively affected both consumers and poultry farmers, so measures were needed to stabilize egg prices. To this end, the egg prices were successfully predicted in this study by using the analysis algorithm of a machine learning regression. For price prediction, a total of 8 independent variables, including monthly broiler chicken production statistics for 2012-2021 of the Korean Poultry Association and the slaughter performance of the national statistics portal (kosis), have been selected to be used. The Root Mean Square Error (RMSE), which indicates the difference between the predicted price and the actual price, is at the level of 103 (won), which can be interpreted as explaining the egg prices relatively well predicted. Accurate prediction of egg prices lead to flexible adjustment of egg production weeks for laying hens, which can help decision-making about stocking of laying hens. This result is expected to help secure egg price stability.

• Journal of Chest Surgery
• /
• v.43 no.6
• /
• pp.602-613
• /
• 2010

Background: As life expectancy has been increased, the cardiac valve disease has been increased. In past, mechanical valve for valve replacement surgery was used widely, but it has many weaknesses, such as hemorrhage, teratogenic effect caused by warfarin, acute mechanical failure, taking warfarin during life, etc. So, the tissue valve is used widely and researches for durability of tissue valve are in progress. Tissue valves being used are all imported in Korea, and there is a lack of information on its geometry and design. So, we studied the geometry of porcine aortic and pulmonary valve, and tried to suggest theoretical basis for making the aortic and pulmonary valve. Material and Method: We harvested aortic and pulmonary valves of 25 pigs and measured the geometry of valve at fresh and glutaraldehyde (GA) fixed state. In each group, we measured the diameter of the base, diameter of commissure, valve height, commissural height, etc. Also, for making implantable porcine and bovine pericardial valve, we designed the valve stent form, thickness, height, and leaflet size, form, thickness by different size of valve. Result: The aortic and pulmonary valve geometry and ratio were measured in each group. The right coronary cusp of aortic valve and right facing cusp of pulmonary valve was bigger than other cusps and non coronary cusp was smaller than others (RCC: NCC : LCC=1 : 0.88 : 1). Valve height was correlated to the leaflet size. We designed the outer diameter of stented porcine aortic valve from 19 mm to 33 mm and designed stent height and width, using previous measured ratio of each structure, stent thickness, working thickness (for making valve). Also, we designed the size of stent and form for stented bovine pericardial valve, considering diameter of valve, leaflet length, height and leaflet minimum coaptation area. Conclusion: By measuring of 25 pig's aortic and pulmonary valve geometry and ratio, we can make theoretical basis for making implantable stented porcine valve and bovine pericardial valve in various size. After making implantable valve using these data, it is necessary to do in vivo and in vitro researches, furthermore.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.42 no.2
• /
• pp.127-136
• /
• 2022

This study was conducted to estimate the damage of Whole Crop Maize (WCM) according to abnormal climate using machine learning and present the damage through mapping. The collected WCM data was 3,232. The climate data was collected from the Korea Meteorological Administration's meteorological data open portal. Deep Crossing is used for the machine learning model. The damage was calculated using climate data from the Automated Synoptic Observing System (95 sites) by machine learning. The damage was calculated by difference between the Dry matter yield (DMY)_normal and DMY_abnormal. The normal climate was set as the 40-year of climate data according to the year of WCM data (1978~2017). The level of abnormal climate was set as a multiple of the standard deviation applying the World Meteorological Organization(WMO) standard. The DMY_normal was ranged from 13,845~19,347 kg/ha. The damage of WCM was differed according to region and level of abnormal climate and ranged from -305 to 310, -54 to 89, and -610 to 813 kg/ha bnormal temperature, precipitation, and wind speed, respectively. The maximum damage was 310 kg/ha when the abnormal temperature was +2 level (+1.42 ℃), 89 kg/ha when the abnormal precipitation was -2 level (-0.12 mm) and 813 kg/ha when the abnormal wind speed was -2 level (-1.60 m/s). The damage calculated through the WMO method was presented as an mapping using QGIS. When calculating the damage of WCM due to abnormal climate, there was some blank area because there was no data. In order to calculate the damage of blank area, it would be possible to use the automatic weather system (AWS), which provides data from more sites than the automated synoptic observing system (ASOS).

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.43 no.1
• /
• pp.11-21
• /
• 2023

This study was conducted to estimate the damage of Whole Crop Corn (WCC; Zea Mays L.) according to abnormal climate using machine learning as the Representative Concentration Pathway (RCP) 4.5 and present the damage through mapping. The collected WCC data was 3,232. The climate data was collected from the Korea Meteorological Administration's meteorological data open portal. The machine learning model used DeepCrossing. The damage was calculated using climate data from the automated synoptic observing system (ASOS, 95 sites) by machine learning. The calculation of damage was the difference between the dry matter yield (DMY)_normal and DMY_abnormal. The normal climate was set as the 40-year of climate data according to the year of WCC data (1978-2017). The level of abnormal climate by temperature and precipitation was set as RCP 4.5 standard. The DMY_normal ranged from 13,845-19,347 kg/ha. The damage of WCC which was differed depending on the region and level of abnormal climate where abnormal temperature and precipitation occurred. The damage of abnormal temperature in 2050 and 2100 ranged from -263 to 360 and -1,023 to 92 kg/ha, respectively. The damage of abnormal precipitation in 2050 and 2100 was ranged from -17 to 2 and -12 to 2 kg/ha, respectively. The maximum damage was 360 kg/ha that the abnormal temperature in 2050. As the average monthly temperature increases, the DMY of WCC tends to increase. The damage calculated through the RCP 4.5 standard was presented as a mapping using QGIS. Although this study applied the scenario in which greenhouse gas reduction was carried out, additional research needs to be conducted applying an RCP scenario in which greenhouse gas reduction is not performed.

• Journal of Biosystems Engineering
• /
• v.6 no.2
• /
• pp.65-76
• /
• 1982

This survey was conducted to investigate the status of repair and maintenance of 4 wheel tractor for a basic reference to the improvement of quality and proper utilization of tractors. Thirty two counties from eight provinces, except Jeju, were covered in this study in order to investigate annual break-down and repair of tractor in 1980. The analyzed results are summarized as follows; 1. The average number of break-down of large size tractors(47ps) was 5.0 times in a year and it was about twice of that of small size tractors(19-23ps). The break-down frequency per 100 hours of use was 1.11 times in the large size and 0.65 times in the small size tractors. 2. 75.6 percent of total break-down was occured in main body of tractor and 24.4 percent in attachments. In particular, the break-down of plow and rotavator was more than 80 percent of total break-down of the small size tractor attachments. 3. The large size tractors which were occured more than one times of break-down a year was 75 percent and its rate of the small size tractor was 62 percent. But 9 percent of tractor surveyed had more than ten times of break-down in a year 4. The frequency of break-down had a peak in May, and it was directly proportional to the hours of use. 5. The causes of break-down were poor maintenance and operation by 29.8 precent, old parts by 30.2 percent, poor quality of parts by 20.6 percent, poor field condition by 16.3 percent and others by 3.1 percent. 6. Annual number of repair was 5.5 times and among them 55.6 percent was done by shop and 44.4 percent by operator. 7. Total required repair time was 30.6 hours a year in the large size tractor and 19.9 hours in the small size tractor. Average repair time was 3.62 hours a time. 8. Annual repair cost was 278 thousand won in the large size tractor and 70 thousand won in the small size tractor. The repair cost per hour of use was 621 won in the large size and 198 won in the small size tractor. 9. The repair cost rate of tractor(Y) was regulated with tractor age (X) as follow; Y=0.752X In case of the service life of tractor was 10 years, the total repair cost rate was 64 percent.

• Journal of dental hygiene science
• /
• v.6 no.4
• /
• pp.277-284
• /
• 2006

The purpose of this study was to examine the perception of dental hygiene freshmen about their major and their occupational consciousness. The subjects in this study were 361 dental hygiene freshmen at three different colleges in Gyeonggi province. After a survey was conducted, the collected data were analyzed with SPSS WIN 11.5 program. The findings of the study were as follows: 1. As for their view of occupation, the students made a well-paying job a priority(M = 2.97), and looked upon an occupation as a means of living(M = 1.60). Regarding the use of the profits of dental hospitals and clinics, they believed that they should reinvest their profits in a purchase of machinery, an expansion of facilities or technical development(M = 2.00). 2. Concerning relations between their motivation of college entrance and their satisfaction with their major, 96.6 percent of those who found their major satisfactory or quite satisfactory considered it to right up with their alley. 82.6 percent of them chose their major to get a stable job, and 62.8 percent of them did it through the advice of their families, relatives or regular teachers. 59.1 percent of them did it in consideration of their college entrance examination scores. Every student who were pressed for economic reasons to choose their major were unsatisfied with it. Thus, their motivation of college entrance made a statistically significantly wide difference to their satisfaction with major(p < 0.01). 3. They got a mean of 3.10 in occupational consciousness. By sub- category, they scored highest in interpersonal and work ethics(3.19 respectively). They got a mean of 3.04 in academic ethics, and got a mean of 2.99 in professional ethics, which was the lowest mark. 4. As to connections between their general characteristics and occupational consciousness, their occupational awareness was significantly different according to their motivation of college entrance and information they acquired at the time of college entrance(p < 0.05). In regard to the relationship of their satisfaction with major to their occupational awareness, their occupational consciousness statistically significantly varied with their department, their willingness of staying as a dental hygienist, the future prospect of dental hygienist (p < 0.01).

• Journal of Food Hygiene and Safety
• /
• v.24 no.1
• /
• pp.69-77
• /
• 2009

This study was performed to investigate the effect of dried powder of chestnut on lipid metabolism, anti-thrombotic effect in rats. Thirty 5-week-old male Sprague Dawley (SD) rats were randomly allocated into five groups and used for experiment. We examined the lipid metabolism and antithrombotic capacity of SD rats administered for 5 weeks with 0.16 g/kg, 0.5 g/kg chestnut flesh powder and 0.16 g/kg, 0.5 g/kg chestnut inner shell and flesh powder mixture, respectively. Food intake, body weight gain and food efficiency ratio were also checked. The levels of serum triglyceride and tree fatty acid were not statistically significant between the all experimental groups. However, the antithrombotic capacity and total lipid levels of the treatment groups were significantly lower than those of the negative control group. These results suggest that the supplementation of chestnut on diet lower the total lipid level in SD rats.