• Korean Journal of Agricultural Science
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• v.44 no.2
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• pp.188-195
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• 2017

Biotech crops can only be commercialized after they receive safety approvals, which require thorough risk assessments of their release to the environment. Environmental release experiments are indispensable for environmental risk assessments, and each country has been preparing its own regulations for the safety management of experiments on the environmental release of biotech crops in confined fields. In this study, we compared and analyzed the safety management regulations of the environmental release of biotech crops in Korea, USA, Japan, European Union, and China. Each country had safety management regulations for the environmental release of biotech crops, and these regulations were generally not much different from the Korean regulations. However, there was a difference amongst the USA, Japan, and China in regulations for isolation distances to prevent gene diffusion through pollen-flow during environmental release experiments of biotech crops. In order to establish the isolation distance regulation suitable for the Korean environment, relevant data were collected and presented. For setting the isolation distance for environment release of biotech crops, it is suggested to refer to the isolation distance information provided in the Guidance of Seed Management in Korea. The results of this study are expected to help establish the safety management of biotech crops in Korea.

• Journal of the Korean Society of Safety
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• v.32 no.2
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• pp.59-65
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• 2017

Calculation of the damage impact of chemical accidents is an important element in site, and the initial isolation distance and the protective action distances are significant factors in coping the chemical accident. In this study, three major cities that represent each Province were selected, and the safety distances were calculated considering regional climate conditions. The results were compared with the prescribed values in Emergency Response Guidebook. It is concluded that the regional meteorological conditions such as temperature, vapour pressure, relative humidity, wind speed, and cloud cover should be reflected in estimating the initial isolation distance and the protective action distance.

• Journal of Environmental Impact Assessment
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• v.23 no.3
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• pp.169-176
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• 2014

The purpose of this study is to estimate the vibration reduction effect of the borehole which is controlled the vibration propagation in the ground. For this study, we measured the vibration velocity before and after the borehole installation. The results are as follows: The peak particle velocity(PPV) and peak vector sum(PVS) was reduced by the borehole. And also, the deviation of vibration velocity before and after the borehole installation showed large values in longitudinal and vertical component depending on the receive distance, and increased depending on the size of vibration energy. Finally, the vibration isolation efficiency was 25~35 percentage at 1.5m receive distance, and was 4~14 percentage at 3.0m receive distance. It was found that the vibration isolation efficiency was good in small vibration energy, but was not good at long receive distance.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.953-956
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• 2005

Low voltage actuation and high isolation characteristics are key features to be solved in electrostatic RF switch design. Since these parameters in the conventional parallel plate MEMS switch design are in trade-off relation, both requirements cannot be met simultaneously. In vertical comb design, however, the actuation voltage is independent to the vertical separation distance between the contact electrodes. Then, we can design the large separation distance between contact electrodes to get high isolation. We have designed an RF MEMS switch which has -40dB isolation at 5 GHz and 6 V operation voltages. The characteristics of the fabricated switch are being evaluate.

• Geomechanics and Engineering
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• v.31 no.1
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• pp.1-14
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• 2022

Urban deep excavation will affect greatly on the deformation of adjacent existing buildings, especially those with shallow foundations. Isolation piles has been widely used in engineering to control the deformation of buildings adjacent to the excavation, but its applicability is still controversial. Based on a typical engineering, numerical calculation models were established and verified through monitoring data to study the influence characteristics of isolation piles on the deformation of existing shallow foundation buildings. Results reveal that adjacent buildings will increase building settlement δ_v and the deformation of diaphragm walls δ_h, while the isolation piles can effectively decrease these. The surface settlement curve is changed from "groove" type to "double groove" type. Sufficiently long isolation pile can effectively decrease δ_v, while short isolation piles will lead to a negative effect. When the building is within the range of the maximum settlement location P, maximum building rotation θ_m will increase with the pile length L and the relative position between isolation pile and building d/D increase (d is the distance between piles and diaphragm walls, D is the distance between buildings and diaphragm walls), instead, θ_m will decrease for buildings outside the location P, and the optimum was obtained when d/D=0.7.

• Journal of the Korean Institute of Landscape Architecture International Edition
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• no.2
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• pp.1-8
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• 2004

The purpose of this study is to carry out the quantitative and qualitative analysis of an urban park in the landscape ecological view and to provide the important basic data in the urban development process. The results of this study are as follows. First, in the case of disposition distance analysis in quantitative plans, very necessary regions of the children park are turned out to be 24 sites, of the neighboring park are turned out to be 30 sites, and walking park are turned out to be 22 sites. Second, in the case of undevelopment neighborhood park analysis, priority orders are Daebong Park, Suseong Park Third, in the case of area, shape, and isolation in qualitative plans, interior area of Bummul park is larger than that of Chimsan park and isolation of Bummul park higher than that of Chimmsan.

• Journal of the Korean Society of Tobacco Science
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• v.18 no.2
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• pp.126-131
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• 1996

In this study effects of isolation distance, transplanting time of maternal plants, and bagging of flower head with the gauze-cloth bag on the outcrossing of burley tobacco (Nicotiana tabacum L.) were investigated. Also the effect of fertilizer level and control of the number of capsules per plant on seed production and quality were examined. A male sterile line. produced 0.3 to 3.8 capsules Per plant when it was Planted with normally flowering tobacco with the average outcrossing of 7.2 plants, ranging from 2 to 18 out of 20 plants. With the farther the isolation distance between maternal plants and pollen donor plant, the lower the outcrossing occurred. Outcrossing occurred even at the isolation distance of 312 m. When the maternal plants were transplanted 35 days after transplanting the pollen donor ones, the outcrossed plants were not decreased significantly. The bagging of the flower head with the gauze-cloth bas (#0.9∼ 1.0 mm) decreased the outcrossed plants significantly, but couldn't prevent the outcrossing completely. The seed amount per plant was higher in the highly fertilized cultivation. The number of seed capsules per plant affected significantly on seed yield and quality. When the seed capsules was controlled by 30 or 50 capsules per plant, the weight of 1,000 seeds and germination rate were higher than those with 70 or 90 capsules per plant. Key words : Nicotiana tabacum, outcrossing, bagging.

• Journal of Korean Association for Spatial Structures
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• v.20 no.4
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• pp.169-176
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• 2020

When an unexpected excessive seismic load is applied to the base isolation of arch structure, the seismic displacement of the base isolation may be very large beyond the limit displacement of base isolation. These excessive displacement of the base isolation causes a large displacement in the upper structure and large displacement of upper structure causes structural damage. Therefore, in order to limit the seismic displacement response of the base isolation, it is necessary to install an additional device such as an anti-uplift device to the base isolation. In this study, the installation direction of the base isolation and the control performance of the base isolation installed anti-uplift device were investigated. The installation direction of the base isolation of the arch structure is determined by considering the horizontal and vertical reaction forces of the arch structure. In addition, the separation distance of the anti-uplift device is determined in consideration of the design displacement of the base isolation and the displacement of the arch structure.

• Journal of radiological science and technology
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• v.45 no.4
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• pp.347-353
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• 2022

In this study, the radiation dose rate was measured by time and distance and evaluated whether radiation dose rate was suitable for domestic and international discharge criteria. In addition, the radiation dose emitted from the patient was measured with a glass dosimeter to evaluate the exposure dose if the caregiver stays in the isolated ward by placing a humanoid phantom instead of the caregiver at a distance of 1 m from the patient, on the second day of treatment. After 23 hours of isolation, the radiation dose rates at a distance of 1 m were 20.54 ± 6.21 µSv/h at 2.96 GBq administration and 27.94 ± 12.33 µSv/h at 3.70 GBq administration. The radiation dose rates at a distance of 1 m were 25.90 ± 2.21 µSv/h when 2.96 GBq was administered and 34.22 ± 10.06 µSv/h when 3.70 GBq was administered after 18 hours of isolation. However, if the isolation period is short may cause unnecessary radiation exposure to the third person. The reading of the attached dosimeter from the morning of the second day of treatment until removal was 0.01 to 0.95 mSv, which is a surface dose determined by the International Commission on Radiation Units and Measurements. And the depth dose was 0.01 to 0.99 mSv. On the second day of treatment, even if the patient caregivers stayed in the isolation ward, the exposure dose of the patient family did not exceed the effective dose limit of 5 mSv recommended by the ICRP and NCRP.

• Journal of the Earthquake Engineering Society of Korea
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• v.22 no.2
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• pp.45-54
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• 2018

The seismically isolated nuclear power plants shall be designed for design basis earthquake (DBE) and considered to ensure safety against beyond design basis earthquake (BDBE). In order to limit the excessive displacement of the seismic isolation system of the seismically isolated structure, the moat is installed at a certain distance from the upper mat supporting the superstructure. This certain distance is called clearance to stop (CS) and is calculated from the 90th percentile displacement of seismic isolation system subjected to BDBE. For design purposes, the CS can be obtained simply by multiplying the median displacement of the seismic isolation system against DBE by scale factor with a value of 3. The DBE and BDBE used in this study were generated by using 30 sets of artificial earthquakes corresponding to the nuclear standard design spectrum. In addition, latin hyper cube sampling was applied to generate 30 sets of artificial earthquakes corresponding to maximum - minimum spectra. For the DBE, the median displacement and the 99th percentile displacement of the seismic isolation system were calculated. For the BDBE, the suitability of the scale factor was assessed after calculating the 90th percentile displacement of the seismic isolation system.