• Journal of Chest Surgery
• /
• v.29 no.1
• /
• pp.1-6
• /
• 1996

We developed an experimental model of brain death using dogs. Brain death was induced by increasing the intracranial pressure (ICP) gradually by continuous Infusion of saline through an epidural Foley catheter in 5 mongrel dogs (weight, 18~22kg). Hemodynamic and electrocardiographic changes were evaluated continuously during the process of brain death and obtained the following results. 1. The average volume and time required to induce brain death was 4.8$\pm$1.0ml and 143.0$\pm$30.9minutes respectively. 2. There was a steady rise of the ICP after starting the constant infusion of saline, and ICP rised continuously until the brain death (122.0$\pm$62.5mmHg). After reaching to the maximal value (125.0$\pm$47.7mmHg) at 30 minutes after brain death, the ICP dropped and remained approximately constant at the slightly higher level than the mean arterial pressure (MAP). 3. MAP showed no change until the establishment of brain death and it declined gradually. The peak heart rate reached to 172.6$\pm$35.3/min at 30 minutes after the brain death. 4. Even though the body temperature and all hemodynamic variables, such as cardiac output, mean pulmonary arterial pressure, left ventricular (LV) end-diastolic pressure and LV maximum + dp/dt, were slightly greater than those of basal state, at the point of brain death, there was no statistically significant change during t e process of brain death. 5. There was no remarkable arrhythmias during the experiment except ventricular premature beats which was observed transiently in one dog at the time of brain death. Hemodynamic changes in the brain death model induced by gradual ICP increment were inconspicuous, and arrhythmias were rarely seen. Hyperdynamic state, which was observed at the point of brain death in another brain death model caused by abrupt ICP increase, was not observed.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.5 no.1
• /
• pp.19-24
• /
• 1976

A determination of proper maturity is a significant factor for a good quality and storage. This study is aimed at a determination of optimum harvest date related to a decisive measuring of maturity in Spur Golden Delicious. In this case, respiratory status and other characteristics are taken as a indicator for maturing determination. The results are as follows. 1. Respiratory rate has been decreased through a fruit development and come to its minimized point on Sep. 25. at last. On the contrary its tendency has been increased after Sep. 25. It is also estimated that the former is pre-climacteric, the latter climacteric rise based on dimacteric minimum Sep. 25. 2. A flesh hardness has maintained comparably high value until Sep. 18. But in the point of climacteric minimum, Sep. 25, curve of flesh firmness has rapidly been broken down, and after Sep. 25, tendency has slowly decreased at the sucessive date. 3. Pectin content, optimum acidity are remarkably decreased after Sep. 25, Oct. 2 respectively. 4. When water soluble sugar content shows to be swung from climacteric minimum, any resonable tendency are not found. 5. In this experiment, optimum harvest time is found by Oct. 2, in time of 145 days after flowering.

• Journal of Labour Economics
• /
• v.24 no.1
• /
• pp.207-230
• /
• 2001

This paper uses the Korean Labor Panel data to investigate changes in the employment types of male workers following their job changes with the classification of workers into three categories: regular wage workers, non-regular wage workers, and self-employed workers. It also estimates a competing-risks hazard model to analyze the determinants of employment types of workers. The results show that the type of employment of a worker at an immediate previous job has a critical importance in determining his employment type at a new job and that the types of employment at jobs other than the immediate previous job also play some role in determining the type of employment at a new job, although their impact declines as the number of intervening jobs increases. A job loser, who worked as a non-regular worker at his immediate previous job, for example, is considerably less likely to find a regular job, but more likely to get reemployed at another non-regular job than one who worked as a regular worker at his immediate previous job. Similarly, a worker who quit self-employment is much less likely to find a regular job but more likely to restart his own business than one who worked as a regular worker at his immediate previous job. These findings suggest that it is not easy at all for a worker who worked as either a non-regular worker or self-employed worker to become a regular worker, although it might be premature to assert that non-regular jobs or self-employed jobs are dead-end jobs. Another interesting finding of this analysis is that a high unemployment rate lowers a probability of reemployment at either regular jobs or self-employed jobs, but raises a non-regular job reemployment probability, which strongly implies that as labor market conditions become adverse to workers the proportion of non-regular employment can rise rapidly.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.36 no.1
• /
• pp.97-102
• /
• 2012

A hermetically sealed oil transformer is designed by applying expanding function of the tank due to the volume changes of the insulation oil according to the temperature rises. When the insulation oil expands, an increase in the volume of the corrugated fin prevents a pressure rise of the transformer. For a wind turbine transformer, a vegetable-oil-immersed transformer has the advantages of excellent biodegradation and fire-resistant properties like an exceptionally high fire point. When vegetable oil is substituted for mineral oil, however, the maximum winding temperature rises because of the decrease in the internal circulation flow rate resulting from the variations of the oil's physical characteristics, such as density and viscosity. The purpose of this study is to develop a hermetically sealed vegetable oil transformer that can be applied in a wind turbine and to analyze the thermal stability of the active part of the transformer to deal with pressure variations due to the temperature changes. In addition, thermal tests for the vegetable oil transformer have been performed, and the measured values are compared with the analysis results.

• The Journal of Society for e-Business Studies
• /
• v.26 no.4
• /
• pp.81-93
• /
• 2021

Through processors, wholesale markets, intermediate sellers, and retailers, agricultural products have been distributed in a multi-level customary manner for a long time as they are easy to deteriorate and no not have a standardized system of size and quality. However, with the advancement of Internet networks and logistic services during the 2000s that facilitated the development of offline markets, and the rise of the non-contact purchase preference in direct response to COVID-19, previous offline consumers flowed into the online market to purchase agricultural goods. In other words, the volume of online agricultural transactions exploded since the pandemic. Against this social backdrop, this study focused on the difference in distribution costs as a result of converting from conventional offline distribution channels to online channels, and analyzed the reduced distribution costs through a case study of garlic sales on the online platform "H" shopping mall. The analysis found that considerable economic effects occurred, some of the effects being an approximate 39% decrease in distribution cost when comparing direct online transactions of the online shopping mall with other more traditional means, a reduced distribution cost rate of approximately 28%p, and increased profit for farmers.

• Journal of Navigation and Port Research
• /
• v.48 no.3
• /
• pp.192-199
• /
• 2024

Wave overtopping is a significant natural hazard that occurs in coastal areas, primarily driven by high waves, particularly those generated during typhoons, which can cause coastal flooding. The development of residential and commercial areas along the coast, driven by increasing social and economic demands, has led to a concentration of people and assets in these vulnerable areas. This, coupled with long-term sea level rise and an increase in typhoon frequency, has heightened the risk of coastal hazards. Traditionally, the evaluation of wave overtopping volumes has relied on directly measuring the collected volume of water that exceeds the crest height of structures through hydraulic model experiments. These experiments are averaged over a specific measurement period. However, in this study, we propose a new method for estimating individual wave overtopping volumes. We utilize the temporal variation of wave overtopping heights to develop an observation system that can quantitatively assess wave overtopping volumes in actual coastal areas. To test our method, we conducted hydraulic model experiments on rubble mound breakwaters, which are commonly installed along the Korean coast. We introduce wave overtopping discharge coefficients, assuming that the inundation velocity from the structure's crest is the long-wave velocity. We then predict overtopping volumes based on wave overtopping heights and compare and review the results with experimental data. The findings of our study confirm the feasibility of estimating wave overtopping volumes by applying the overtopping discharge coefficients derived in this study to wave overtopping heights.

• Journal of the Korean GEO-environmental Society
• /
• v.17 no.10
• /
• pp.45-53
• /
• 2016

At present, coffee consumption amount is annually on the rise in Korea, which results in about 0.27 million tons of coffee waste annually. They are mostly classified as food waste and deserted with moisture contained, being a serious environmental issue. Existing slope greening techniques, which are vegetation based soil-media hydroseeding measures, have problems such as lack of coherence, dryness or lack of organic matters. Therefore in order to assess usability of Spent Coffee Ground (SCG), medium-to long-term growth test was conducted under the indoor and outdoor conditions. According to the result of growth test, when SCG was mixed with existing base materials, moisturizing power increased and organic matter content was reinforced, promoting germination and growth in a medium term. Among others, under the condition when supply of water was discontinued, withering rate was lower than existing base materials and diverse phenomena resulting from lack of nutrition decreased. Therefore, SCG as a waste organic matter with abundant nitrogen has the characteristic of inhibiting early growth but was found to have a quality favorable to long-term growth resulting from water containing ability and the supply of organic mater and is judged to be a material to replace or complement existing base materials.

• Korean Journal of Soil Science and Fertilizer
• /
• v.41 no.6
• /
• pp.408-414
• /
• 2008

Importance of climate change and its impact on agriculture and environment has increased with the rise Green House Gases (GHGs) concentration in the atmosphere. To slow down the speed of climate change many efforts have been applied in industrial sectors to reduce GHGs emission and to enhance carbon storage. In agricultural sector, many researches have been performed on GHGs emission reduction, but few on the role of carbon sink. In this study, we investigated carbon balance and soil carbon storage in agricultural field in the barley-red pepper and barley-soybean cropping system. With the system for automatic measuring of carbon dioxide, net ecosystem production(NEP) was estimated to be $6.3ton\;CO_2\;ha-1$ for N-P-K chemical fertilizer treatment plot and $10.6ton\;CO_2\;ha^{-1}$ for N-P-K chemical fertilizer with swine manure treatment plot in the barley-soybean rotation cropping. In the barley-red pepper rotation cropping, it was $12.0ton\;CO_2\;ha^{-1}$ for N-P-K chemical fertilizer treatment plot and $13.2ton\;CO_2\;ha^{-1}$ for N-P-K chemical fertilizer with swine manure treatment plot. Soil carbon storage rate was estimated to be $0.7ton\;C\;ha^{-1}$ for the barley-soybean cropping system and $0.5ton\;C\;ha^{-1}$ for barley-pepper cropping system. In appeared that agricultural lands may contribute to the greenhouse effect as a potential carbon sink preserving carbon into soil.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.19 no.1
• /
• pp.61-67
• /
• 2015

The cooling of hot exhaust gas is an important issue for the construction of combustor test facility. Water spray is an effective method for exhaust gas cooling due to its large latent heat in process of evaporation. In this study, 1-D analysis has been performed based on continuity, energy conservation, and saturated vapor property to understand water spray cooling of combustion gas. In the exhaust duct of combustor test facility, the injected water decreases combustion gas temperature, and evaporates in the combustion gas. However, some of the injected water is collected in the sump due to condensation. The evaporation of water helps combustion gas cooling, but causes pressure increase inside the exhaust duct due to increase of vapor pressure. These phenomena has been analyzed by 1-D modeling in this study. From 1-D analysis, the adequate mass flow rate of water spray to cool combustion gas and to avoid excessive pressure rise inside the exhaust duct has been decided.

• KDI Journal of Economic Policy
• /
• v.34 no.4
• /
• pp.27-68
• /
• 2012

This study outlines measures related to fiscal policies aimed at responding to the financial crisis according to the timing of commencement and then examines impacts of expansionary fiscal policies on macro variables so as to extract policy implications. The size of expansionary fiscal policy to respond to the financial crisis is found to total 59.8 trillion won (6.1% of GDP in 2007), among which a total of 30.5 trillion won was the increased fiscal expenditure made by the 2008 supplementary budget, the 2009 revised budget and the 2009 supplementary budget. In addition, tax reductions are found to be a total of 29.3 trillion won, mainly driven by the tax reforms in 2008 and 2009. Examining dynamic changes in macro variables caused by the temporary increase in fiscal expenditure and the tax reductions reveals that the increase effect of the real GDP growth rate brought by a temporary rise in fiscal expenditure excluding tax reduction effects turned out to be 1.1%p in 2009 and 0.3%p in 2010, compared to the period without the increase in fiscal expenditure. Meanwhile, when taking into account the effect of expansionary fiscal policies including tax reduction effects, the increase effect of real GDP turns out to be much higher. In the case of 2009, the real GDP rose additionally by 1.9%p, in which 1.1%p by the increase in fiscal expenditure and 0.8%p by tax reduction. Based on these results, the expansionary fiscal policy conducted during the financial crisis since the second half of 2008 can be seen to have played a significant role in helping the Korean economy post a higher-than-anticipated recovery pace from the economic slowdown triggered by the crisis.