• Current Research on Agriculture and Life Sciences
• /
• v.10
• /
• pp.41-47
• /
• 1992

In general, the behavior of moisture transmission is estimated by vapor permeability or vapor transmission resistance, but its values obtained by experiments do not have great adaptability for practical situations because of changes in the experimental conditions. This fact is why only theoretical discussions have advanced. Thus, the fundamental study of the moisture transmission phenomenon has been treated lightly. Here, as the first step toward the basic research of moisture transmission, the amount of moisture transmission and the moisture distribution in specimens were investigated. The experiment was conducted in a steady state, and the moisture distribution was measured by slicing and weighing the specimens. From the examination of the vapor transmission resistance, the phenomenon of moisture transmission was dealt with devide the moisture transfer on the wood surface and moisture diffusion in wood. The following results were obtained. 1) The phenomenon of moisture transmission should be approached by its division into moisture transfer on the wood surface and moisture diffusion in the wood because the positive values of vapor transmission resistance exist in the extrapolation of thickness 0mm. 2) The distribution of moisture in wood can be illustrated by two straight lines intersecting at the point of nine percent moisture content : namely, diffusion coefficients have two constant values at moisture contents below and above nine percent. The shape of the distribution curve of moisture content is similar irrespective of the wood thickness. On the other hand, when the moisture contents on both sides was more than nine percent, the distribution of the moisture content could be illustrated by one straight lines. 3) The amount of moisture movement is determined by the moisture gradient in wood. 4) Coefficients of the moisture transfer depend on the thickness of the specimens.

• Journal of Korean Society of Environmental Engineers
• /
• v.30 no.1
• /
• pp.97-105
• /
• 2008

Nitrogen budgets in Korea in 2005 were estimated using a mass balance approach. Major nitrogen fluxes were divided into three sections: cities, agricultural area, and forest. Nitrogen inputs were chemical and biological fixation, dry and wet deposition, imported food and feed, while crop uptake, volatilization, denitrification, leaching, runoff, and forest consumption were nitrogen outputs. Non-point source(NPS) pollution budgets were also estimated by mass balance approach. Annual total nitrogen inputs budgets were 1,442,254 ton$\cdot$yr$^{-1}$, and outputs were 814,415 ton$\cdot$yr$^{-1}$. Approximately 19.4% of nitrogen input leaked to river and seawater as NPS pollution. It contains nitrogen input 21 percent more than the previous research in 2002. Especially the change of government plans affect nitrogen budget. As a result, in the output field, the whole nitrogen amount due to landfill reduce from 20 percent to less than 1 percent.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.268-268
• /
• 2017

Common sowing method of italian ryegrass (IRG) has been using the backpack seed sprayer (BSS) in Korea. It has weak point including a hard work and a little sowing area. This study was conducted to find out the effects of sowing IRG using unmanned helicopter (UH) under the established rice field. We checked the labour saving of sowing IRG and the growth and yield of rice after using IRG as forage crop. Two sowing implements(using by UH and backpack seed sprayer (BSS)) were tested for the ability of sowing IRG. For proper pretreatment of IRG seeds for aerial sowing using with UH, we tested one-day soaking seeds, iron-coated seeds, coated seeds sold in stores and untreated seeds. Aerial sowing of IRG seeds using UH was tested under the speed 10 km/h and flying altitude 3~4m. We tried to confirm the effects on rice growth in a paddy field after IRG had been used as forage in mid May. In 6 hours of seeding per day, UH had a seeding area of 21.8 hectares, three times wider than BSS. UH had a decrease of about 63 percent of sowing-seed cost in comparison with BSS. In the IRG aerial sowing using UH, coating seeds had the wider sowing width of 5~6 meter than 3~4 meter untreated seeds. Residual dry matter of IRG after using forage had 4.5 ton per hectare and 20 percent of top dry matter. The amount of nitrogen remaining in residual IRG in the soil was 12 kg per hectare, and the other nutrients such as calcium and potassium was incorporated into the soil with less than 10 kg/ha. The rice yield after the harvesting IRG was 5 percent higher than that of rice single cropping. Consequently, IRG sowing using UH was effective in reducing sowing time and sowing cost compared with conventional methods and, it is considered that there is a positive effect on the rice cultivation compared to rice single cropping.

• The Journal of the Korea Contents Association
• /
• v.11 no.11
• /
• pp.231-240
• /
• 2011

This study of the elderly in the future expansion of long-term care insurance as a priority landing at the introduction of physical therapy services aim to provide baseline data and long-term care insurance for him, the elderly that provides physical therapy services under the elderly property of a physical therapist recognition system for the investigation was conducted. As a result, the perception of the elderly long-term care insurance was higher by 88.1% of the higher needs, but also the absolute need for more than 40 years of age the response was higher with 60.3 percent. In addition, the number of visits that care should be priced higher relative to the 59.7 percent was the highest opinion. Visit of physical therapy services include the most important therapeutic approach to life and 40% was the highest forum, visit the Nursing Center as a service principal points that you need to visit the rehab center, accounting for 69.4 percent opinion. The expected effect of physical therapy visits conducted in a 50-point scale showed an overall average 41.44 points and 42.48 points, especially over the age of 40 appear in the overall expected effect was higher.

• Journal of Nutrition and Health
• /
• v.41 no.8
• /
• pp.809-817
• /
• 2008

This study was conducted to provide basic information snack intake frequency, eating patterns and current dental caries in high school students. A total of 626 students (333 males, 293 females) in Gimhae city participated in this study. The survey conducted by using a self-administered questionnaire in January, 2008. Dental caries-related information was obtained during the students' physical examination at the designated clinical hospital in 2007. The results were as follows. Sixty three point nine percent of the students were shown to have dental caries, which includes a sealant. The average number of dental caries was 3.1, which was greater in female than in male students (p < 0.001). Eighty six percent of the students were shown to maintain correct toothbrushing habits to prevent dental caries. Twenty percent of the participants brushed there teeth ‘instantly’ a meal or snack, and 27.3% of the participants brushed there teeth, gum and tongue, and 58.9% of the participants received toothbrushing education. In snack intake frequency, participants with no dental caries had preference to white milk whereas those with dental caries had preference to snacks such as chewing gums and carbonated beverages. Female students were shown to have more dental caries maybe because of their higher snack intake frequency in chocolate, cookies and chips, yoghurt and ice-cream. Dental caries did not affect eating behaviors. This study suggests that more education for correct toothbrushing and cariogenic and detergent foods are needed for better dental hygiene.

• Journal of the Korean Chemical Society
• /
• v.59 no.5
• /
• pp.454-465
• /
• 2015

The goal of this study is to investigate pre-service chemistry teachers’ understanding of the boiling process of a liquid mixture. We surveyed 65 students in the chemistry program of the College of Education about the boiling point of a 50%(by mole) ethanol aqueous solution and the temperature changes during heating. We then interviewed 9 of these students. According to the survey results, the percent of the pre-service teachers who thought that the boiling point of the ethanol solution would be ‘between the boiling points of ethanol and water (78-100 ℃)’ and ‘the same as that of ethanol’ were 52.3% and 35.4%, respectively. The majority of those who stated the former explained that the boiling point of the ethanol solution increased due to the effects of attraction or blocking by water molecules. Most of those who believed the latter explained that physical properties such as the boiling point would not be changed by the addition of water. With regard to the temperature change during heating, 69.2% of the teachers thought that the temperature would increase gradually while boiling, which some thought resulted from the increasing amount of water in the solution as the ethanol boiled off. Others thought that two temperature plateaus would be observed as each component of the liquid mixture underwent phase transition at its specific boiling point. When asked about the particle model of the gas phase during the boiling and evaporation process, some students drew both ethanol and water during evaporation but only ethanol when boiling. We discussed several alternative concepts of pre-service chemistry teachers about the boiling process of liquid mixtures and ways to improve their understanding.

• Journal of Biosystems Engineering
• /
• v.1 no.1
• /
• pp.1-6
• /
• 1976

This paper is the third one of the study on balanced type oscillating mole-drainer, the first one was presented in No 9. Gyeongsang College Report and the second one in Vol. 17, No.4 of the KSAE. In the first part of this study, the characteristics of traction forces between the nonoscillating earth working equipments and oscillating ones was compared. A model of the balanced type oscillating mole-drainer, which composed of a mechanism that may reduce the machine vibration, was designed following the dimensional analysis and similitude technique. The model test was carried out to clarify the balancing mechanism of the oscillating parts and other parts of the machine. In the light of the results from the model tests, a prototype machine was made for experimental purpose. Results from the field test by a reported in the near future. In the second report, the model tests were carried out under the same soil conditions, i.e, . oscillating frequency, running velocity, and oscillating amplitude, etc. It was clear that use of balanced type oscillating model could substantially reduce the vibration of the whole system of the machine, when compared with the nonoscillating type model. In this paper(the third report), results of investigation on the traction force, power requirement, and moment. etc, is presented. Analysis of variance technique was used for analyzing the effect of the frequency, amplitude, and running velocity on the draft force, torque, power requirements, and moments. The results obtained from the model tests are as follows, 1) By practicing a balanced-type oscillating mole-drainer, it was possible to reduce the traction resistance by 55.1-61. 2 percent of traction resistance, however, was 1.75 - 1.95 times greater than the value of resistance which was induced by use of a mole-drainer with single bullet. The resistance of rear shank against soil was considered as a main causing factor of the above results. 2) As the oscillation frequency was increased, the traction resistance was decreased. Considering on the effect of oscillation the greater the amplitude, and the slower the running velocity was, the greater the reduction ratio of traction resistance was. 3) The ratio of the traction resistance of oscillating mole-drainer to that of non-oscillating one could be represented as a function of dimensionless variable (V/$Af$). The results from the tests were well agreed with the reported results from the experim ents on oscillation plow or hoe. 4) By taking a lower value of (V/$Af$), reducing the traction resistance was possible. This fact meant, however, that the efficiency of mole drain practice would be lower. 5) It was experimentally confirmed under the same condition of soil that the variable (R/$rD1^3$) could be represented as a function of a variable($V^2/gD$) when a non\ulcornerocillating mole-drainer was used. 6) When a oscillating mole-drainer was used, the variable(R/$rD_1^{3}$) could be represented as a function of two variables ($v^2/gD_1$) and (V^2/gD_1$). 7) The torque was not affected by a change of frequency. However, a relation of proportionality existed between torque and amplitude, running velocity, and ratio of bullet diameter. When a balanced type oscillating mole-drainer with two bullets was used, torque was increased by 52.8-78. 4 percent and total power requirement was also increased. 8) Total power requirement was increased linearly in accordance with the increasing frequency, 41.96 percent of total power was used for oscillating action. The magnitude of total power requirement was 1. 8-9. 4 times greater than that of a non-oscillating mechanism. In the view point of power requirement, it was not advisable to increase the frequency, amplitude, running velocity, and ratio of bullet diameter at the same time. 9) Only the positive moment occured in the rear shank. Change of the diameter of a rear bullet, could not affect the balancing against the soil resistance. It was necessary for rear bullet to have a large resistance against soil only when the rear bullet was in backward motion. 10) Within an extent of the experimental base, optimum limits for several design factors were A=0.5cm, $f$=22.5Hz, V=O. 05m/sec, and $\lambda$=1.0 By adapting these values traction resistance was reduced by 40 percent and vibration acceleration wa s reduced by 60 percent. Even though the total , power requirements for operating a balanced type oscillation mechanism was greater ~than that of non-oscillating one, using a oscillating mechanism would be more effective. Because a balanced type oscillating mechanism is used, tractive resistance will be reduced and then the lighter . tractive equipment could be used.

• Health Policy and Management
• /
• v.23 no.2
• /
• pp.124-131
• /
• 2013

Background: This study aimed to measure the opportunity income by identifying the economic length of stay (ELOS) which is the intersection point of daily revenue and cost on appendectomy and pneumonia cases. Methods: The research subjects were 460 patients of appendectomy and 606 patients of pneumonia, discharged from a general hospital between July 1, 2009 and June 30, 2010. ELOS calculated with both of total revenue on diagnosis-related group (DRG) and fee-for service (FFS). The cost is calculated by activity-based costing system of the hospital. Results: Average length of stay (ALOS) of appendectomy was 4.48 days and its average revenue per case were 1,710,215 (1,989,105) won by DRG (FFS). The variable cost was 491,262 won which was 28.7% (24.7%) of DRG (FFS) total revenue. And 97.2% of the total variable cost was incurred within 2 days from admission. The ELOS was 4 (5) days in DRG (FFS). Shortening three days (two days) would increase opportunity income 52.0% (82.2%) in DRG (FFS). ALOS of pneumonia case was 4.86 days and its average revenue per case were 489,448 (761,426) won by DRG (FFS). The variable cost was 27,230 won which was 5.6% (3.6%) of DRG (FFS) total revenue. Thirty-eight point nine percent of the daily variable cost was incurred in discharge date. The ELOS was 2 (4) days in DRS (FFS). Shortening three days (one day) would increase opportunity income 27.6% (37.2%) in DRG (FFS). Conclusion: The ELOS would be used by strategic index for achieving minimum profit and developing the ways to get there. But we also should not pass over that the opportunity income obtained by the reducing ALOS may cause some problem of quality.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.15 no.2
• /
• pp.83-94
• /
• 1979

It is more than half a century since anchovy boat seine has been introduced in Korean fishery to catch anchovies, but the study on it was began in 1970's by the authors. In 1971, the authors carried out an experiment about the net formation of the traditional gear in tow by using model net, and in 1978, about the patti net gear, commercially used in Japan. Now, the authors investigated the new model net, model 79, expecting to be suitable for commercial fishery in Korea, with the strong point of those two gears kept and the weak point of them corrected. The experimental gear was constructed attached the long net pendants to the fore end of extension wing by shortening its length in two-third of the traditional gear. Inside wing was improved so as to show high opening in tow. Rubber bobbins and hanging rings are used to prevent the heavy friction of bosom ground rope against the sea bed. The gear was used to catch anchovies in the commercial fishing ground in the south-eastern coastal waters of Korea, from May to October in 1979. From the experiment, the following results are found. 1. In opening height, the experimented gear was 30 percent greater than the traditional one. 2. It took 3 to 5 minutes for the bosom ground rope to sink from the surface to the sea bed, while 10 to 15 minutes for the traditional gear to do. 3. Ground rope never scooped mud, even in the muddy sea bed. 4. The gear showed better catchability than the traditional gear.

• Journal of Distribution Science
• /
• v.14 no.10
• /
• pp.127-136
• /
• 2016

Purpose - This study investigated the effects of lectures in the English medium (EML) on understanding and learning outcomes. Sixty percent of EML lectures in Korea also use Korean for further support. Thus, this situation needs to clearly distinguish the specific impacts of the EML classes on learning outcomes. Here, we use the same English materials, including PowerPoint slides and video content, given in the Korean and English lectures. The difference between the lectures becomes only whether the lecture is delivered in Korean or English. Thus, we can clearly identify whether the language difference makes any difference in learning outcomes. Research design, data, and methodology - Our sample consisted of 91 students taking an international business course the spring of 2015. All course materials, including textbooks, PowerPoint slides, exams, video, and support content, were presented in English. Survey data and exam results were used. Students filled out their student identification number and name, so we could match the surveys against the exam results. Results - First, results show that whether the lecture was delivered in English or Korean was an important factor when students chose the class. Second, English proficiency related to international business and general English levels were higher in the English class than in the Korean class. However, the understanding of key concepts and reading abilities of international business newspapers were the same for students in both classes. Third, teaching materials and lectures were the most important material for the understanding of key concepts in the business major. Fourth, the exam results showed no difference in performance of the students in the English versus the Korean class. This shows that EML classes were not necessarily detrimental to the understanding of major concepts of the lecture. Thus, it is important that researchers carefully design empirical settings to study the effectiveness of EML. Conclusions - The English lecture can be as helpful for enhancing knowledge in the business major as the Korean lecture. For further research, various English lecture forms can be considered to distinguish the effects of the English lecture.