• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.2
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• pp.218-224
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• 2009

In organic fanning systems, integration of cover crops into cropping system are recommended to improve the soil quality, to prevent soil erosion, and to provide biological control of weeds. The aim of the present study was to evaluate the optimal seeding dates of major cover crops. To know optimal seeding dates, crimson clover, alfalfa, rye and hairy vetch were sown on 20. Sep., 27. Sep., 4. Oct., 11. Oct., 18. Oct., 25. Oct. Rye could germinate and grow well in all the tested sowing dates. Hence, it was concluded that the sowing of rye could be conducted later in fall or more earlier in spring than any other cover crops tested in this study. Growth and ground covering capacity were significantly decreased by late sowing in alfalfa and crimson clover. For safe overwintering, alfalfa and crimson clover should be sown before late September. Similarly, field emergence of hairy vetch was found to be sensitive to soil temperature, however, its growth and ground covering capacity after overwintering was enough to compensate the delay in sowing. Germination tests in laboratory revealed that hairy vetch grew faster at $25^{\circ}C$ compared to $20^{\circ}C$. The result suggested that germination and growth rate of hairy vetch was rapidly decreased at low temperature. Therefore, it is recommended that hairy vetch should be sown as soon as possible in September for improving stand establishment after overwintering.

• Journal of Life Science
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• v.27 no.1
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• pp.32-37
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• 2017

Cyanidin-3-O-glucoside (C3G) shows anti-inflammatory and antioxidant effects; however, its effect on postprandial blood glucose levels remains unknown. Alpha-glucosidase inhibitors regulate post-prandial hyperglycemia by impeding carbohydrate digestion in the small intestine. Here, the effect of C3G on ${\alpha}-glucosidase$ and ${\alpha}-amylase$ inhibition and its ability to ameliorate postprandial hyperglycemia in streptozotocin (STZ)-induced diabetic mice were evaluated. ICR normal and STZ-induced diabetic mice were orally administered soluble starch alone or with C3G or acarbose. The half-maximal inhibitory concentrations of C3G for ${\alpha}-glucosidase$ and ${\alpha}-amylase$ were 13.72 and $7.5{\mu}M$, respectively, suggesting that C3G was more effective than acarbose. The increase in postprandial blood glucose levels was more significantly reduced in the C3G groups than in the control group for both diabetic and normal mice. The area under the curve for the diabetic mice was significantly reduced following C3G administration. C3G may be a potent ${\alpha}-glucosidase$ inhibitor and may delay dietary carbohydrate absorption.

• The Korean Society of Law and Medicine
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• v.9 no.1
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• pp.319-382
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• 2008

As a withdrawing care's study, the purpose of this study is searching about withdrawing care's acceptance and circumstances through Bora-mae hospital case(chapter 1). Withdrawing life-sustaining treatment has various forms. Though the meaning of euthanasia, death with dignity, natural death, physician assisted suicide are duplicated, the meaning of those are different slightly. Firstly, this study looks about the difference of the those meaning and acceptance range(condition) by withdrawing care's forms(chapter 2). Bora-mae hospital case sentenced guilty about physician who discharged incompetent patient who was after surgery by patient's wife determination. This Bora-mae case that sentenced guilty about discharge against medical advise(DAMA) that is regarded to custom has brought intensive confliction of legal, social, medical aspect, Bora-mae hospital case has many legal problems. First, as to criminal law rule 250(murder), the problem is whether discharge and withdrawing life-sustaining treatment is commission or omission. this study concluded omission(district court: omission, appeal, supreme court: commission). Because legal denounce point of discharge and medical treatment withdrawing is omission that physician who is obligatory on patient to cure. If physician's act is regarded omission, it is necessary to determine whether he has guardian status and obligation. Without guardian status and obligation, omission crime can't exist. This study decided that physician had guardian status and obligation and foundation of guardian status was pre-action or acceptance of emergency patient. Physician's medical treatment duty finished when patient(or patient's guardian) demands discharge. But when patient death is foreseen and other possible treatment does not exist, his duty of life prolonging treatment does not finish. This originate from physician's social responsibility and public status that limits patient's private liberty. This study regarded physician's action as accomplice about whether physician's discharging action is accomplice or the principal offender(district court: the principal offender, appeal, supreme court: accomplice). Though the principal offender needs criminal determination and action, there is no this common determination and functional action control of physician in Bora-mae case(chapter 3). Bora-mae hospital case partly originated from deficiency of legal, institutive system including medical security system shortage, the instruction is 1. medical security system strengthening, 2. hospital ethical committee's activity strengthening, 3. institutionalization of withdrawing life-sustaining treatment, 4. acceptance of pre-decision making system, 5. sufficient persuasion of physician for patient and faithful writing of medical paper, 6. respect for patients' self-determination and rights, 7. consciousness's changing for withdrawing life-sustaining treatment and persistent education about medical ethics(chapter 4). Considering Bora-mae case, medical sector is not the dead ground of a criminal punishment. Intervention of criminal law in medical sector give rise to ill effect, that is, excess medical examination and treatment, safeguard treatment, delay of discharge from a hospital. Because sufficient guarantee of life becomes mere empty slogan under situation that impose a burden of heavy cost to family or hospital, public and systematic solution should be given(chapter 5).

• The Transactions of the Korea Information Processing Society
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• v.3 no.4
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• pp.947-960
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• 1996

The primary goal for developing high performance ATM switching systems is to minimized the probability of cell loss, cell delay and deterioration of throughput. ATM switching element that is the most suitable for this purpose is the shared buffer memory switch executed by common random access memory and control logic. Since it is difficult to manufacture VLIS(Very Large Scale Integrated circuit) as the number of input ports increased, the used of switching module method the realizes 32$\times$32, 150 Mb/s switch utilizing 8$\times$8, 600Mb/s os 16$\times$16, 150Mb/s unit switch is latest ATM switching technology for small and large scale. In this paper, buffer capacity satisfying total-memory-reduction effect by buffer sharing in a shared buffer memory switch are analytically evalu ated and simulated by computer with cell loss level at traffic conditions, and also features of switching network utilizing the switching module methods in small and large-capacity ATM switching system is analized. Based on this results, the structure in outline of 32$\times$32(4.9Gb/s throughput), 150Mb/s switches under research in many countries is proposed, and eventually, switching-network structure for ATM switching system of small and large and capacity satisfying with above primary goals is suggested.

• Journal of the Korea Concrete Institute
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• v.24 no.1
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• pp.3-14
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• 2012

This paper describes experimental results on the seismic performance of SHCC (strain-hardening cement composite) infill wall for improving damage tolerance capacity of non-ductile frame. To investigate the effect of tensile strain capacity and cracking behavior of SHCC materials on the shear behavior of SHCC infill wall, three infill walls were fabricated and tested under cyclic loading. The test parameter in this study is a type of cement composites; concrete and SHCCs. The two types of SHCC materials were prepared for infill walls. In order to induce crack damages into the mid-span of the infill wall, each infill wall had two 100-mm-deep-notches on both sides. Test results indicated that SHCC infill walls showed superior crack control capacities and much larger drift ratios at the peak loads than RC (reinforced concrete) infill wall, as expected. In particular, due to the bridging actions of the reinforcing fibers, SHCC matrix used in this study would delay the stiffness degradation of infill wall after the first inclined cracking. Moreover, from the damage classes based on the cracks' maximum width in the infill walls, it was observed that PIW-SHD specimen possessed nearly threefold seismic capacities compared to PIW-SLD specimen. Also, from the results on the strain of diagonal reinforcements, it can be concluded that the SHCC matrix would resist a part of tensile stresses transferred along steel rebar in the infill wall.

• Research in Plant Disease
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• v.19 no.4
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• pp.273-280
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• 2013

Tomato spotted wilt virus (TSWV) was occurred at 8 areas including Naju, Suncheon, Younggwang, Youngam, and Shinan in Jeonnam province and the crops of Younggwang were severely damaged by TSWV. The hot pepper (Capsicum annuum), bell pepper (Capsicum annuum v ar. angulosum) and tomato (Solanum lycopersicon) in greenhouse and hot pepper in open field were infected by TSWV. Especially, hot pepper was severely damaged by TSWV infection. The survey data indicated that 1.1-30% in the nursery field at Naju, Suncheon, and Jangheung were infected by TSWV. Plants were infected by TSWV from early June to August. However, TSWV-infected seedlings from nursery fields showed the disease symptoms from May after transplanting. In pepper greenhouses, Frankliniella occidentalis was more dominant insect vector than Frankliniella intonsa. But in open field, the population of insect vector was opposed to greenhouse. In addition, the removal of weeds was able to delay the incidence of TSWV via side-window of greenhouse in Winter. Taken together, the control of weed and insect vector nearby side-window of greenhouse is important to prevent TSWV infection of plants.

• Horticultural Science & Technology
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• v.28 no.4
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• pp.585-592
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• 2010

This study was conducted to investigate the effect of 1-MCP, an ethylene action inhibitor, and several postharvest treatments including ethylene scrubbing on fruit quality and respiration for keeping marketability in 'Janhowon Hwangdo' peach ($Prunus$ $persica$ Batsch). 1-MCP at the rate of $1.0{\mu}L{\cdot}L^{-1}$ showed best results in maintenance of fruit firmness and external appearance such as skin color. The ethylene production was strongly reduced by 1-MCP treatment at 0.5 or $1.0{\mu}L{\cdot}L^{-1}$ but respiration rate was only suppressed at $1.0{\mu}L{\cdot}L^{-1}$ during 6 days of shelf life at $20^{\circ}C$. Mature fruits (harvested 1 week before full commercial maturity) were much highly responsive to $1.0{\mu}L{\cdot}L^{-1}$ of 1-MCP compared to those of commercial maturity. At the concentration of $0.5{\mu}L{\cdot}L^{-1}$ of 1-MCP did not affect fruit marketability compared to untreated control. Beneficial effects of carbon ceramic as an ethylene scrubber were also found such as delay of firmness loss and deterioration of external appearance at $10^{\circ}C$, but these positive effects on fruit quality remained for only 5 days. The application of ethylene scrubber on the shipping carton boxes was effective on keeping firmness of immature fruit pretreated with 1-MCP when compared with mature fruit.

• Economic and Environmental Geology
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• v.29 no.2
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• pp.215-225
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• 1996

All the radionuclides in high-level nuclear waste will decay to harmless levels eventually but for some radionuclides decay is so slow that their radiation remains dangerous for times on the order of tens or hundreds of thousands of years. At the present time, the most favorite disposal plan for high-level radioactive waste is a mined geological disposal in which canister enclosing stable solid form of radioactive waste is placed in mined cavities locating hundred meters below the surface. The chief hazard in such disposal is dissolution of radionuclides from the waste in the groundwater that will eventually carry the dissolved radionuclides to surface environments. The hazard from possible escape of the radionuclides through groundwater can be delayed by engineered and geologic barriers. The engineered barriers can become useless by unexpected geologic catastrophe such as volcanism, earthquake, and tectonic movement and by fraudulent work such as careless construction, improperly welded canisters within the first few decades or centuries. As a result, dangerously radioactive waste which is still intensively radioactive is directly exposed to attack by moving groundwater. All the more, it is almost impossible to control repositories for times more than 10,000 years. Therefore, naturally controlled geologic, barriers whose properties will not be changed within 10,000 years are important to guarantee the safety of repositories of high-level radioactive waste. In Sweden and France, the suitability of granite for the mined geological disposal of high-level waste has been studied intensively. According to the research in Sweden and France, granites has the following physio-chemical characteristics which can delay the transportation of radionuclide by groundwater. First, the permeabilities of granites decreases as the depth increases and is $10^{-8}{\sim}10^{-12}m/s$ at depth below 300 m. Second, groundwater at depth below 300 m has pH=7-9 and reducing condition (Eh=-0.1~0.4). This geochemical condition is desirable to prevent both canister and solid waste from corrosion. Third most radionuclides are not transported by low solubilities and some radionuclide with high solubility such as Cs and Sr are retarded by absorption of geologic media through which ground water flows. Therefore, if high-level waste is disposed at depth below 300 m in the granite body which has a low permeability and is geologically stable more than 10,000 years, the safety of repositories from the hazard due to radionuclide escape can guaranteed for more than 10,000 years.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.6
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• pp.887-895
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• 2019

Recently, the number of underground road development projects has been increasing to solve traffic problems in the national capital region and metropolitan areas with intensified overcrowding, and there has been a tendency to plan underground roads by applying a double-deck tunnel technology that has advantages in constructability and economical efficiency. The double-deck tunnel has a structure where one excavation section is divided into two parts and used as up and down lines, and is mainly used as a road for small vehicles only due to its low floor height. In addition, due to the small cross-sectional area, it has characteristics different from those of general road tunnels in terms of ventilation and disaster prevention. In this regard, this study proposed an operational plan that applies an oversized exhaust system, which is one of semi-transverse ventilation systems, to small cross-sectional tunnels like double-deck tunnel with low floor height, and a comparative analysis between smoke exhaust characteristics according to the fire occurrence locations and oversized exhaust systems was conducted using the Fire Dynamics Simulator (FDS). The results showed that unlike uniform exhaust, intensive smoke exhaust using the oversized exhaust port maximized the delay effect of smoke diffusion and limited the smoke within 50 m above and below the fire point.

• Magazine of the Korean Society of Agricultural Engineers
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• v.28 no.2
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• pp.31-41
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• 1986

Knowledge of the degree of yield reduction due to water stress at different crop growth stages in rice production is important for rational scheduling of irrigation during periods of insufficient water supply. Previous studies to determine the degree of yield reduction duo to water stress suffered from interruptions by rain during experiment. Also the findings did rot relate the degree of water stress to the soil water potential and water deficit status of rice plants. In this study, two years experiments were conducted using the high yielding rice varieties, an Indica x Japonica (Nampoong) and a Japonica variety(Choochung). These were grown in 1/200$^{\circ}$ plastic pots placed under a rainfall autosensing, sliding clear plastic roof facility to control rainfall interruptions. The results obtained were as follows. 1.The two varieties differed in the growth stage most sensitive to water stress as well as the degree of yield reductions. When rice plants were stressed to the leaf rolling score 4 and soil water potential of about - 20 bar at major crop growth stages which included heading, booting, non-effective tillering, panicle initiation and early tillering stages, the yield reductions in the Indica x Japonica variety were 58%, 34%, 27%, 22%, and 21%, respectively, whereas in the Japonica vairety they were 23%, 36%, 1%, 13% and 22%, respectively. This result show that the recommended drainage during non-effective tillering is valid only for the Japonica variety. Sufficient irrigation at booting, heading and early tillering stages are necessary for both varieties. 2.The two varieties showed visible wilting symptoms when the soil water potential dropped to about - 3.0 bar. The Japonica variety showed more leaf rolling than the Indica X Japonica. However, it had a higher retention of leaf water content and greater stomatal diffusive resistance. When the soil water potential dropped, the Japonica variety showed leaf rolling score (LRS) 1 at 0 soil-5. 0 bar and LRS 2 at 0 soil -6.0 bar while the Indica X Japonica showed LRS 1 at 0 soil - 5.5 bar and LRS 2at 0 Soil - 9.0 bar. The stomatal diffusive resistance was maximum at the second top leaf blade in both varieties at intermediate water stress of 0 soil - 4.5 bar. 3.The number of days that was required for the soil water potential to drop to-3. 0 bar and to - 20.0 bar after drainage of irrigation water from the 20cm deep silty clay loam soil in the pots were 6 and 13 days, respectively for booting stage, and 7 and 11 days, respectively for heading stage, 9 and 12 days, respectively for panicle initiation stage, and 12 and 19 days, respectively for early tillering stage. 4.Water stress during the early tillering stage recorded the longest delay in beading time, the largest reduction in panicle numbers and a substantial yield decrease of 20%. This calls for better water management to ensure the availability of water at this stage, particularly during drought periods. In addition, a reexamination of the conventional inter-drainage practice during the non-effective tillering stage is necessary for the high yielding Indica X Japonica varieties.