• Journal of Korean Society of Transportation
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• v.21 no.1
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• pp.41-49
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• 2003

Marine traffic management could be defined as the implementation of managerial technical measures to improve vessel traffic safety. The managerial elements of vessel traffic management for ports and harbours or narrow channels include the total amount of traffic control, the vessel traffic separation scheme, speed restriction, traffic control by signals, the navigation information service and so forth. This research aims to quantify how much the traffic separation schemes(TSS) contribute to the alleviation effect of ship handling difficulty and to propose a design standard when the individual management measure is applied in an actual waterway. Traffic separation schemes have now been established in most of the major routes and congested waters of the world, and the number of collisions and groundings have often been dramatically reduced. In this part, the relationship between the alleviation of ship handling difficulty and the reduction of encounter figures among ships is quantitatively clarified by applying the ES model. As results of simulation analysis, it is recognized that a traffic separation system is most effective in the case of narrow width and heavy traffic volume. The centre buoy installation reduces about 1/4 of the alleviation of ship handling difficulty, TSS establishment 1/3, and design change to one-way traffic from two-way traffic reduces 1/2.

• Journal of Plant Biotechnology
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• v.39 no.3
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• pp.127-132
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• 2012

We analysed the current status of development of GM crops and national biosafety framework including legislation-related agricultural GMO in China to provide the policy for the development of global GM crops in Korea. In China, several GM crops including cotton, petunia, tomato, sweet pepper, poplar, and papaya have been approved for commercialization and they have been cultivated at more than 4 million ha. In addition, GM rice and GM maize have also obtained approval for productive testing in 2009. China will be the first country to approve GM rice for commercialization. Prior to commercialization in China, all GM crops must be approved by government authority for biosafety assessment specified by national legislation including restricted field testing, enlarged field testing, productive testing and safety certificate. According to China's legislation, agricultural GMOs have been classified by research and testing, production and processing. All GMOs must go through 3 steps of field testing (restricted, enlarged and productive). Prior to conducting each field testing, it has to be approved by government authority. It is assumed that at least one to two years will be taken for each step of field testing (total 4 to 8 years to obtain the final safety certificate) along with a large amount of budget.

• Journal of Soil and Groundwater Environment
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• v.12 no.1
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• pp.97-102
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• 2007

An environmental survey from three abandoned metal mine areas was undertaken on to assess the risk of adverse health effects on human exposure to heavy metals influenced by past mining activities. Tailings contained high concentrations of heavy metals may have a impact on soils and waters around the tailing piles. In order to perform the human risk assessment, chemical analysis data of soils, rice grains and waters for As, Cd, Cu and Pb have been used. The HQ values for heavy metals via the rice consumption were significantly higher compared with other exposure pathways in all metal mine areas. The resulting HI values in three mine areas were higher than 9.0, and their toxic risk due to rice ingestion was strong in these mine areas. The cancer risk of being exposed to As by the rice consumption from the A, B and C mine areas was $5.1\;{\times}\;10^{-3}$, $6.8\;{\times}\;10^{-3}$ and $3.1\;{\times}\;10^{-3}$, respectively. The As cancer risk via the exposure pathway of rice ingestion from these mine areas exceeds the acceptable risk of 1 in 10,000 set for regulatory purposes. Thus, the daily intakes of rice by the local residents from these mine areas can pose a potential health threat if exposed by long-term As exposure.

• Journal of the Korean Geotechnical Society
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• v.27 no.12
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• pp.107-116
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• 2011

Rigid soil containers (or rigid boxes) are often used for 1g shaking table tests. The rigid boxes, however, do not accurately simulate the amplification of ground acceleration and phase difference of seismic motion in the model ground due to the confinement of shear deformation and the reflection of seismic wave at the box walls. Laminar soil containers (or laminar shear boxes) can simulate the free field motion at convincingly superior accuracy than the rigid ones. In this study, the soft ground is modeled for both types of boxes and is subjected to seismic loading using a 1g shaking table. The comparison of the results using the two types of soil containers illustrates that, in case of the rigid box, the ground acceleration shows non uniform distribution and the phase synchronization of input motion. Whereas, the dynamic behavior of the laminar shear box shows good agreement with the free field behaviors such as the amplification of ground acceleration and the occurrence of phase difference.

• Korean Journal of Food Science and Technology
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• v.47 no.3
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• pp.306-320
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• 2015

This survey was carried out in 2014 to estimate the pesticide residue levels in commercial environment-friendly agricultural products in Seoul metropolitan area. Pesticide residues in 27 commodities were examined and analyzed using LC-MS/MS, which can simultaneously detect up to 85 pesticides. A total of 441 samples were collected and analyzed. Among the detected samples, the residue levels in 1.2% of organic agricultural products and 2.2% of pesticide-free agricultural products exceeded the maximum residue limits (MRLs); hence, 1.8% of the total samples exceeded the MRLs. The safety of the detected pesticides was assessed by monitoring the acceptable daily intake level (ADI) and acceptable dietary exposure (ADE) to the pesticides via consumption of the commodities. ADI and ADE are found to be 0.07728-9.46530% and 0.00141-0.17210%, respectively, which means that the residual pesticides in the environmental-friendly agricultural products in Korea are below the safe limit and therefore, pose no potential public health risks.

• Korean Journal of Acupuncture
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• v.25 no.3
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• pp.43-51
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• 2008

배경 : 최근까지 이루어진 천식의 침치료 무작위 대조군 연구들에 의한 결과는 뚜렷한 효과를 보여주지 못하고 있다. 이러한 요인의 하나로 적절한 피험자 수를 정하기 위한 예비 임상시험의 부재가 거론되고 있다. 따라서 천식에 대한 침치료의 본 임상시험에 앞서 이의 실행 가능성 및 규모를 예측하는 예비임상시험이 필요한 상황이다. 목적 : 예비임상시험을 통해 서양의학적 치료를 받고 있는 천식환자들에 대한 침치료의 부가적 효과를 검증하기 위한 본 임상시험의 실현 가능성을 예측하기 위함. 방법 : 본 시험은 무작위 단일 맹검 대조군 평행 설계 예비 임상시험이다. 1차 평가변수는 최대 호기량 검사기로 집에서 아침, 저녁으로 매일 측정한 수치로 구해진 최대 호기 유속 일중 변동률의 1주간 평균치 변화이며 2차 평가변수는 의료기관에서 시행하는 폐기능 검사, 기준시점 호흡곤란 지수, 호흡곤란 변화에 대한 지수, 천식환자들의 삶의 질 평가를 위한 설문 등이다. 피험자 수는 총 45명으로 선정 및 제외기준을 통해서 참여하게 되며 1주간의 최대 호기 유속 기저치 평가 기간을 거친 후 진짜침 처치 군, 가짜침 처치 군, 대기군 세 군에 각각 무작위로 15명씩 할당된다. 모든 피험자에게 기존의 천식관련 약물의 사용을 허용하며, 진짜침 처치군 및 가짜침 처치군은 주 3회 4주간 해당 처치를 받고 2주 후에 각 평가 항목에 대하여 추적, 관찰하게 된다. 대기군은 기존의 천식관리를 유지하면서 2주마다 방문하여 총 6주간 평가를 받고 진짜침 처치를 4주간 받게 된다. 고찰 : 본 연구는 국내에서 최초로 이루어지는 천식에 대한 침 무작위 대조군 예비 임상시험으로 향후 적절한 피험자 수와 실행가능성을 예측할 수 있으리라 기대된다.

• Journal of the Korean GEO-environmental Society
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• v.16 no.12
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• pp.5-12
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• 2015

Since blasting noise is impact noise, it will give a sudden shock to the human. In the case, such as the blast vibration, it has given aging buildings and livestock great damage to move the vibration along ground in nearby regions. In this study, the influence of the blasting generated during excavation was analyzed for effects on regional. A couple of field and laboratory surveys about geological were carried out to figure out the geological ratio in the study-performed area. Blast vibration noise was compared to the domestic and abroad case studies and each of the institutions permissible standards established the most appropriate criteria in site condition. The vibration velocity of blasting vibration exploits the values which were measured from test blasting on the ground in order to examine blasting effect. Considering the blasting point as the shortest distance from safety facilities (farms, private houses, etc.), the examination of the influence range, which was derived from the vibration velocity of blasting vibration, was performed to figure out how the point affected the safety facilities. Three-dimensional numerical analysis was performed a time history analysis in order to analyze the behavior of the structure for a dynamic blast load, which was determined in three directions of the blast vibration value. The results of three-dimensional numerical analysis and the blasting effect of blasting vibration estimation equation blasting vibration of impact circle with accompanying test blasting were compared. And the analysis confirmed similar results figures.

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.2
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• pp.95-107
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• 2009

The purpose of this research was to examine the fitness of zirconia cores that were made by different sintering methods; generic electricity furnace and microwave furnace. Firstly, 12 cores for each group were made by using each different sintering process and attached them to a metal die with silicon. The internal and marginal gap of sintered zirconia was measured by using Skyscan 1076 micro-CT, then it was reorganized by CT-An software. To each samples, we extracted B-L image, M-D image of cutting side, and cross-sectional side of tooth long axis and calculated the mean value of marginal, axial, and occlusal gap each side. Results: 1. The mean marginal gap of sintered zirconia was $36.20{\mu}m$ for EVE, $47.67{\mu}m$ for LAV, $52.47{\mu}m$ for DEN, and $54.63{\mu}m$ for CER. 2. For the axial wall, the research showed the largest value of $63.49{\mu}m$ for EVE, but there were no statistical significance. 3. In related to the occlusal internal measurement, DEN showed the smallest value ($77.06{\mu}m$), EVE and CER showed significantly high value. From this study, it is suggested that CAD/CAM zirconia core which was made in the process of microwave sintering has clinically acceptable values in marginal and internal gap.

• Korean journal of applied entomology
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• v.41 no.4
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• pp.293-298
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• 2002

Cadusafos and fosthiazate were applied at the rate of 1.8 g a.i./6$\m^2$ as pre-plant or pre-plant＋post-plant treatments on winter-grown oriental melon in a greenhouse soil infested with Meloidogyne arenaria. Nematicides reduced root-knot nematode population from 35 to 90% compared with control； fosthiazate was better than cadusafos (P ＝ 0.003) and fosthiazate pre-plant＋post-plant application reduced nematode population densities as much as 90%. Nematicides increased yield in an average of 23% (11-38%) in May, 39% (2-65%) in June, and 31% (12-46%) for the total (P ＝ 0.085). The residue in the fruit of oriental melon by post-plant treatment of fosthiazate exceeded maximum residue limit of 0.2ppm, while the Cadusafos residue was below the limit. It is concluded that fosthiazate cannot be used as a post-plant treatment in winer-grown oriental melon with overall consideration, i. e., danger of residue, value of melon, costs of nematicide, consumer demand on safer agricultural products, and effects of fallow.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.5
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• pp.453-460
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• 2017

In the offshore industry, helicopters are mainly used for transportation of goods or operating personnel between offshore sites and onshore facilities. A helideck is a structure that is required for landing and take-off of helicopters on the offshore structure. There are several shapes of helidecks depending on the type of offshore structures or installation location. Among them, cantilever-type helidecks usually provide more space on the topside of offshore structures and it is safer against potential accidents like fire or explosion. In this paper, the cantilever-type helideck is selected for the research object and topology design optimization is applied for lightweight design of the helideck. A finite element model is then created from the optimal layout of truss structures of the helideck, and structural analysis is performed under various landing conditions and wind loads. Based on the analysis results, the detailed section dimensions of structural members are determined so that the maximum stress at each structure member does not exceed the allowable stress of the structural material. Also, the final optimal design shows significant decrease in the total weight of the helideck.