• Korean Journal of Ecology and Environment
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• v.56 no.4
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• pp.393-405
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• 2023

This study was conducted to select indicators for assessing national biodiversity. For this purpose, 140 biodiversity-related indicators were identified as a result of inventorying biodiversity-related indicators used in Korea and abroad, and when these indicators were applied to the pressure, status, and response indicator system, it was found that status indicators accounted for the largest number of indicators, with 29 pressure, 59 status, and 44 response. We also categorized the status indicators into genes, species, habitat, function, and quality, and found that species and habitat indicators accounted for the majority. Pressure indicators were categorized into direct exploitation, pollution, alien species, climate change, and habitat change. As a result, it was found that direct exploitation and pollution accounted for most of the pressure indicators. In addition, this study used internationally used indicator selection criteria to establish criteria for selecting domestic biodiversity assessment indicators. Using this list of indicators and indicator selection criteria, we evaluated the prioritization of domestically applicable biodiversity indicators through relevant expert consultations. 1) Vegetation class, 2) Land cover indicators, and 3) Change of protected area ranked highly. In fact, these indicators have been used in many studies due to the availability of assessable data. However, most of the highly scored indicators are based on ecosystem area, and further consideration of ecosystem functions and components(species) is needed.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.5
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• pp.140-147
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• 2001

The solenoid valve in ABS hydraulics, modulator is a two directional on-off valve and is controlled by around 100Hz high speed pulse width modulation. When the inlet valve is switched from open state to closed state, there are braking force degration, noise and vibration due to pressure surge phenomena in the hydraulic line and wheel cylinder. In this study, identifies pressure surge phenomenon in the braking process of a ABS, and investigates the way to reduce the phenomenon. For the purpose theoretical analysis on the pressure surge in the closed state hydraulic line, characteristic curve method based on wave equation was utilized. During this analysis, we could find pressure surge characteristics change due to hydraulic line change and PWM control conditions. In conclusion, by using the results of this study for the pressure surge prediction and reduction method, we could expect braking performance enhancement in Anti-Lock Braking System.

• Journal of the korean Society of Automotive Engineers
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• v.14 no.3
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• pp.102-108
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• 1992

To clarify the structure of a diesel spray, a transient non-evaporating diesel spray injected under different ambient pressure and different injection pressure was studied. Spray tip penet- ration and spray angle were measured by taking the high speed shadowgraph of spray and Sauter mean Diameter(SMD) was also measured by light scattering technique at different positions along the spray axis and at different time from the start of injection. The effects of the operating parameters on the spray shape and SMD were investigated. By increasing the injection pressure, the spray tip penetration and the spray angle increased and the change of the ambient pressure also resulted in the considerable change in the shape of the spray. The analysis of SMD measurement showed that the atomization is a process that continues in sp- ace and time. As the injection pressure increases SMD decreases rapidly and with the increa- se of the ambient pressure the atomization process ends faster than the lower ambient press- ure and at lower pressure the atomization process continues to much farther downstream and far afterward.

• Applied Science and Convergence Technology
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• v.27 no.1
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• pp.19-22
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• 2018

The ion energy and angle distributions (IEADs) in the DC magnetron sputtering systems are investigated for the variation of gas pressure using particle-in-cell simulation. Even for the condition of collisionless ion sheath at low pressure, it is possible to change the IEAD significantly with the change of gas pressure. The bombarding ions to the target with low energy and large incident angle are observed at low pressure when the sheath voltage drop is low. It is because the electron transport is hindered by the magnetic field at low pressure because of few collisions per electron gyromotion while the ions are not magnetized. Therefore, the space charge effect is the most dominant factor for the determination of IEADs in low-pressure magnetron sputtering discharges.

• Applied Science and Convergence Technology
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• v.27 no.2
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• pp.26-29
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• 2018

The ion energy and angle distributions (IEADs) in the DC magnetron sputtering systems are investigated for the variation of gas pressure using particle-in-cell simulation. Even for the condition of collisionless ion sheath at low pressure, it is possible to change the IEAD significantly with the change of gas pressure. The bombarding ions to the target with low energy and large incident angle are observed at low pressure when the sheath voltage drop is low. It is because the electron transport is hindered by the magnetic field at low pressure because of few collisions per electron gyromotion while the ions are not magnetized. Therefore, the space charge effect is the most dominant factor for the determination of IEADs in low-pressure magnetron sputtering discharges.

• Journal of the Korean Society for Railway
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• v.7 no.3
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• pp.200-207
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• 2004

Theoretical study has been conducted to clarify pressure characteristics of KTX (Korea Train eXpress) in tunnel. The severe pressure change in tunnel may give rise to the ear-discomfort for passenger and fatigue for car body. Critical tunnel lengths which are induced by x-t diagram analysis can be applied to the experimental results measured by using the running test with atmospheric pressure sensors and portable data acquisition system in previous study. In this study, the tunnels from 200m to 4000m in length have been chosen for the investigation of tunnel length effects. We found that there are similar patterns of external pressure change for each critical tunnel length. The critical tunnel lengths are governed by train speed, train length and sonic velocity. And, the patterns of pressure wave in tunnel are classified into eight groups.

• Journal of the Korean Geographical Society
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• v.48 no.1
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• pp.19-36
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• 2013

This study aimed to investigate the change of humidity by city size in South Korea. Using daily mean relative humidity and water vapor pressure during the period of 1954~2011 for 14 weather stations in South Korea, the change of humidity by city size was analyzed. The change of relative humidity had a continuous decreasing trend for the period of 1954~2011. The decreasing trend in large city was bigger than these of rural one. The seasonal relative humidity was significantly changed in spring and winter. The change of water vapor pressure was rarely changed significance of the results by city size. It was not shown the result to constant trend by city size. There was a negative correlation between relative humidity and mean temperature. And change of relative humidity was correlated with city size. Moreover, there was not correlation between relative humidity and water vapor pressure by city size. The decreasing trend of relative humidity was similar to increasing trend of temperature by urbanization. However, there was not shown significant result of water vapor pressure.

• Magazine of the Korean Society of Agricultural Engineers
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• v.15 no.2
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• pp.2980-3001
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• 1973

Nozzle is a part of sprayer and is consists of several elements; swirl plate, vortexchamber, cap and body. The travelling distance of sprayed particles is important in the wide reach nozzle. The factors to influence the travelling distance of the sprayed particles may be the helical angle of swirl plate, the distance of vortex hamber, the slope and the size of cap hole. The study was conducted to examine the effects of these factors on the travelling distance. The results of this study are summarized as follows; 1) There was higher positive correlation(+0.96) between the maximum travelling distance for which amount of sprayed particles was 5cc/cm min. and centro-position of the travelling distance. 2) There was a higher positive correlation(+0.85) between total discharge of sprayed particles and the centro-position of the travelling distance. 3) Main effects and interaction effects of helical angle, pressure, vortex chamber distance and cap slope were significantly affected the travelling distance of sprayed particles. 4) Main effects of helical angle, pressure and cap slope were especially highly significant to influence the travelling disance. 5) Helical angle, pressure, vortex chamber distance and cap slope influenced spraying forward velocity of dise hole, among which cap slope and pressure of nozzle was the most important factors. 6) Effect of change of helical angle on the travelling distance of sprayed particles, was generally a quadratic, the least value of the distance being showed about $45^{\circ}$ and the largest at about $15^{\circ}\;and\;55^{\circ}$, the decreasing rate of the change between $15^{\circ};and\;25^{\circ}$ was very small. 7) Effect of change of pressure on the travelling distance sprayed particles was generally a linear, the increasing rate of the charge was about 1.68, which was the most effective compared to the change of the other factors. 8) Effect of change of vortex chamber distance on the spraying distance was also generally a linear, the increasing rate being about 0.16, which was the least effective. 9) Effect of change of cap slope on the travelling distance was also generally a linear, the increasing rate was about 0.61 and its effect was about medium.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.13 no.1
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• pp.237-252
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• 2000

Pressure sore is an area of ulceration and necrosis of the skin and underlying tissues usually occuring over the bony prominences of the body after prolonged or often repeated pressure. We reviewed and summarized the published articles and treatise on the treatment of pressure sore. The results were as follows : 1. Pressure sore occur due to prolonged or often repeated pressure. So it is better than decubitus ulcer that is called pressure sore. 2. The most common lesions of pressure sore are sacrum, ischial tuberosity, greater trochanter. 3. The cause of pressure sore are change of comprehension. urine, moisture, change of the ability of activity and exercise, shearing force. 4. The elements to influence on wound healing are collagen accumulation velocity, nutrition condition, Vitamine C, copper, iron. oxygen pressure, steroids, cell-toxic drug, radiation. 5. Non-operative treatments are managements of skin such as avoiding consistant pressure, dressing, preventing moisture, understanding patient and protecter, preventing spasm, improvement of systemic nutrition condition. 6. Operative treatements are debridement, suture, skin transplantation, muscle flap and musculaocutaneous flap surgery. Recently V-${\Gammer}$ advancement surgery in use of muscle and musculocutaneous flap is generally maded. 7. Complications of post-operation are wound rupture, infection, disappearance of transmitted skin, necrosis of flaps.

• Textile Coloration and Finishing
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• v.8 no.6
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• pp.1-8
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• 1996

The crystal structures of Nylon 6 films with the changes of pressure, temperature, and the processing time were examined. The accompanying physical property changes such as the weight fraction, the crystallinity, the crystal size, the initial modulus, and the thermal properties, gives the following results. When the sample is processed at 16$0^{\circ}C$, the weight fraction is not changed significantly with varying pressure. However, at 18$0^{\circ}C$ a significant change of the weight fraction was found with increasing pressure above 5 ton/in$^{2}$ so as to increase the crysallinity. As long as the ct transition is concerned we found that it begins from 14$0^{\circ}C$ and is completed at 18$0^{\circ}C$ and 9 ton/$in^{2}$ of pressure with the processing time of 120 min. The increase of the initial modulus is believed to be due to the increase of the number of the tie chains and the tension resulting from the change of the crystal size in the direction perpendicular to the direction of the applied pressure. The meltiong point change is due to the pressurized crystallization was not observed.