• 한국환경복원기술학회지
• /
• 제24권4호
• /
• pp.61-75
• /
• 2021

Roadside greenery in the city is not only a means of reducing fine dust, but also an indispensable element of the city in various aspects such as improvement of urban thermal environment, noise reduction, ecosystem connectivity, and aesthetics. However, in studies dealing with the effect of reducing fine dust through trees in existing urban spaces, microscopic aspects such as the adsorption effect of plants were dealt with, structural changes such as the width of urban buildings and streets, and the presence or absence of trees, Impact studies that reflect the actual form of In this study, the effect of greenery composition applicable to urban space on PM2.5 was simulated through the microclimate epidemiologic model ENVI-met, and field measurements were performed in parallel to verify the results. In addition, by analyzing the results of fine dust background concentration, wind speed, and leaf area index, the sensitivity to major influencing variables was tested. As a result of the study, it was confirmed that the fine dust reduction effect was the highest in the case with a high planting amount, and the reduction effect was the greatest at a low background concentration. Based on this, the cost of planting street green areas and the effect of reducing PM2.5 were compared. The results of this study can contribute as a basis for considering the effect of pedestrian space on air quality when planning and designing street green spaces.

• 한국도로학회논문집
• /
• 제16권6호
• /
• pp.137-147
• /
• 2014

PURPOSES : Daejeon is basically divided into an old downtown and a new downtown, and the recent relocation of the Chungcheongnam-do Provincial Government of Republic of Korea from the old downtown and the opening of governmental buildings in the new downtown as well have made this new downtown only densely populated with industrial and business facilities. Such changes in the downtowns have promoted the conditions of the new downtown while, consequently, dragging down the old downtown. Out of concern for those unbalanced developments of the two downtowns, Daejeon is now carrying out several city projects to revive the old downtown. In the light of that, as a part of the project to promote the old downtown, this study aims to conduct an evaluation on landscape of the culture and arts street in Daeheungdong which was built upon those ideas of a theme street project by Daejeon. METHODS : Based on the findings from the questionnaire not only on the components that would design the streetscape of the culture and arts street but also on the public satisfaction with the streetscape, the study defined how those changes in the components affect emotional factors of the pedestrians. In order to achieve the research goal, the study made changes in D/H ratio of the street structural components as well as the roadside trees. In terms of the questionnaire method, the study used the SD scale, and proceeded with its investigation through the frequency analysis, the principal component analysis (the factor analysis) and the structural equation model. RESULTS : According to the results from the factor analysis and the regression analysis, of those three factors, such as the openness, the comfortable sensation and the safety, the openness followed by the comfortable sensation and the safety was determined to have the most positive influence on the total satisfaction. The structural model analysis reported that the D/H and the structural components of the roadside trees and planting have a positive effect on the emotional image, and this emotional image also appeared to be positively related to the total satisfaction. CONCLUSIONS : This study looked into how the changes in the street structural components of the culture and arts street in Daeheungdong would affect the satisfaction with the streetscape, and finally confirmed that the D/H and the planting are what would have a positive effect on this satisfaction. What has been learned from this study will be the basic data to figure out how to promote and improve the culture and arts street in Daeheung-dong as this data will also help designing and developing of those specialized streets in other regions.

• 인간식물환경학회지
• /
• 제23권4호
• /
• pp.445-453
• /
• 2020

Background and objective: Calcium chloride (CaCl₂) and sodium chloride (NaCl) are commonly used as a deicing agent in South Korea and penetrate the soil on the roadside, causing damage to plants. This study was conducted to investigate the salinity reduction effect of Pennisetum alopecuroides and the chemical characteristics of soil leachate. Methods: The plants were treated with five different concentrations of CaCl₂ (0, 1, 2, 5, and 10g·L^-1) and were grouped into the Cont., C1, C2, C5, and C10 groups. CaCl₂ of 200 m·L^-1 was sprayed to each plant once every two weeks. The growth of P. alopecuroides (plant height, leaf length, leaf width and the number of leaves) was measured. The level of EC and pH, and exchangeable cations (K⁺, Ca²⁺, Na⁺, and Mg²⁺) in the leachate of soil was monitored. Results: The pH of soil leachate decreased as the CaCl₂ concentration increased, and the EC increased significantly. The content of K⁺ did not change significantly until the concentration of CaCl₂ reached 5 g·L^-1, but the content of Ca²⁺, Na⁺, and Mg²⁺ significantly increased. The plant height, leaf length, and leaf width of P. alopecuroides showed the highest value in CaCl₂ 1 g·L^-1 followed by CaCl₂ 2 g·L^-1 and the control group. Root fresh weight was the highest in CaCl₂ 2 g·L^-1. On the other hand, there was no change in the shoot fresh weight, dry weight and root dry weight, and P. alopecuroides growth inhibition at the concentration of 5 g·L^-1 or higher in the plant height and leaf length. Conclusion: P. alopecuroides is relatively highly salt-tolerant and can improve the salt damaged soil by lowering the content of the salt-based exchangeable K⁺ ions.

• 대한전자공학회논문지SP
• /
• 제42권4호
• /
• pp.87-94
• /
• 2005

3차원 영상 모자이크 방법은 도심지의 도로를 따라 움직이는 카메라로부터 취득된 영상을 3차원 다중 투영평면에 투영하여 도심지를 입체적으로 가시화하기 위한 것이다. 카메라가 교차로와 같은 원거리 가시 지점을 통과할 때, 취득된 영상에 대해 3차원 영상 모자이크 방법을 적용 하면, 모자이크 된 영상에서 동일한 대상물의 영상이 반복하여 나타난다. 이 현상을 환영현상(ghost effect)이라고 하는데, 이 환영현상을 줄이기 위해서 원거리 대상물이 있는 곳의 영상 프레임을 찾고, 이 곳에 나타나는 환영현상을 효과적으로 제거하는 알고리즘을 제안하였다. 제안한 알고리즘은 3차원 공간에서 계산된 가상의 초점과 영상 프레임의 초점을 지나는 벡터를 이용하여 영상 프레임들을 3차원 다중평면에 투영 하는 것이다. 이를 위한 가상 초점은 원거리 대상물이 보이기 시작하는 영상 프레임과 원거리 대상물이 사라지기 시작하는 영상 프레임을 이용하여 계산된다. 본 논문에서는 원거리 대상물 지역에 제안한 방법을 적용했을 때, 환영현상이 효과적으로 제거될 수 있음을 실험적으로 보였다

• 환경위생공학
• /
• 제3권2호
• /
• pp.43-60
• /
• 1988

This study was carried out to determine traffic noise level and analyze noise reduction effects of various sound protection facilities in the area of Seoul, Inch'on, Songchoo and Seoul- Busan Expressway from March to Octover, 1987. The results were as follows; 1. As compared with the environmental standards and the traffic noise level in heavy noise areas, traffic noise levels observed were shown in higher than environmental standards. The noise levels in Seoul were determined at 12.8-18.2 dB(A) in daytime and 19.0-26.9 dB (A) in nighttime. And incase of inch'on, it were 6.7-9.6 dB(A) in daytime, 7.9-18.9 dB(A) in nighttime, respectively. 2. The environmental noise level observed in the backside of protection facilities, such as apartment, soundproof barrier and houses, which were constructed in paralled to the road was lower about 3-5 dB(A) than perpendicular to theroad. Noise recuction effect of upper stairs in apartment was higher than lower stairs. 3. The predicted noise level obtained from the equation $({\triangle}L\;=\; -10\;log\;(^{I'1}/Ii)\;was\;\pm\;1dB$ (A) and the correlation coefficient (r) was 0.923. 4. The noise reduction effect in backside of apartment was measured at on sites and predicted by total noise loss equation. The predicted noise level was 60.9 dB(A) and the measured level was 60.6 dB(A), respectively. 5. The narrow width landscape less than 10m width was almost no effect for the protection of traffic noise. According to the synthesis of the above results, the noise level of the road was exceeding mostly the environmental standard in the heavy traffic areas. The counterplan should be set as well. The insulation of noise protection facilities were effective by the location with near distance from the road edge. The reduction effect of double window in apartment was represented so much. The prediction model could be applied to estimate the noise levels in the roadside as well as the effectiveness for the noise protection facilities.

• 한국기계가공학회지
• /
• 제19권4호
• /
• pp.58-64
• /
• 2020

Large-scale flooding due to extreme weather and typhoons causes heavy damage. This is especially true in urban areas where accumulated debris prevents the smooth drainage of rainwater in sewage facilities such as rain gutters installed near roads. In this study, to improve the drainage performance and effectively remove foreign substances by applying the dust screen used in rivers, the rain gutter with Coanda effect was simulated and compared with the experiment. The simulation was performed by setting the parameters to the fillet radius R₁ and R₂ at the top of the screen filter, the fillet radius R₃ at the bottom of the screen filter, and the height H of the gap W from the bottom. W is the gap at the backside of screen filter which is applied to stimulate the Coanda effect. According to the simulation results, the highest drain performance was 87.99% derived from R₁= 30mm, R₂= 5mm, R₃= 85mm, H= 75mm, and W= 2mm. The error rate of simulation results refer to the 4.89%~7.36% compared to the experimental results. In the future, by considering the slope according to the installation environment, the simulation results can be applied to the actual roadside to help prevent flood damage.

• 한국환경복원기술학회지
• /
• 제10권4호
• /
• pp.83-94
• /
• 2007

Test application of revegetation measure was made on the roadside slope damaged by Gimcheon-Eomo national road improvement project in a bid to prevent the soil from being washed out as well as to restore the ecological environment, and the survey for assessing the effect of slope revegetation measures was conducted, beginning Sep 7 through Sep 20, 2006. In the wake of comprehensive reviewing and evaluating the surrounding topographic environment, physical and chemical characteristics of soil, germination of revegetation plants, analysis of bio mass, covering ratio and the plants appeared, revegetation measure C was found to have been most effective and desirable for further application in the area. Viewing the specific applicability by the area, revegetation measure C and C-1 appeared to be appropriate for blasting rock slope and ripping rock slope as they are efficient in preventing the slope from being washed out and in early revegetating. And revegetation measure B deemed to be effective to blasting rock slope or ripping rock slope as an alternative. And for cut slope, vegetation measure C-2 was judged to be more effective than measure D or E, while measure C-3 would be appropriateto embankment slope.

• 한국환경보건학회지
• /
• 제21권4호
• /
• pp.56-62
• /
• 1995

Recently, the traffic noise around residences and schools has become a serious social problem with the increase of the amount of transportation. This study was performed to investigate the sound proof efficiency of windows for traffic noise. The results were as follows 1) The traffic noise in 19 sites among 22 sampling sites was higher value than 65 dB(A) being roadside environment standard level in the daytime when all windows were opened, while the noise in 22 sampling sites was transmitted below standard level when all windows were closed. 2) The transmission loss of sound level at single window and double windows were 10~25 dB(A) and 11~29 dB(A) respectively. 3) The transmission loss of sound level at sampled school with sound proof pannel was 7~8 dB (A), which was lower 2~7 dB(A) than the theoretical value of the influence assessment . 4) The construction cost of double windows was lower 28% even if include the cost of setting up air conditioner for the summer season and the power consuming cost for its operation than that of sound proof pannel for traffic noise. 5) The effect of transmission loss of windows was more influenced by airtight than materials of windows.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제15권2호
• /
• pp.383-403
• /
• 2021

With the development of mobile edge computing (MEC), some late-model application technologies, such as self-driving, augmented reality (AR) and traffic perception, emerge as the times require. Nevertheless, the high-latency and low-reliability of the traditional cloud computing solutions are difficult to meet the requirement of growing smart cars (SCs) with computing-intensive applications. Hence, this paper studies an efficient offloading decision and resource allocation scheme in collaborative vehicular edge computing networks with multiple SCs and multiple MEC servers to reduce latency. To solve this problem with effect, we propose a context-aware offloading strategy based on differential evolution algorithm (DE) by considering vehicle mobility, roadside units (RSUs) coverage, vehicle priority. On this basis, an autoregressive integrated moving average (ARIMA) model is employed to predict idle computing resources according to the base station traffic in different periods. Simulation results demonstrate that the practical performance of the context-aware vehicular task offloading (CAVTO) optimization scheme could reduce the system delay significantly.

• 한국방재학회 논문집
• /
• 제9권3호
• /
• pp.49-57
• /
• 2009

충돌사고시 스마트하이웨이의 정시성과 안전성의 손상정도를 최소화 하도록 스마트하이웨이의 종방향 방호울타리 충돌조건으로 기존의 충돌조건보다 상당히 상향된 충돌조건이 결정되었다. 충돌조건은 충돌차량, 충돌속도, 충돌각도로 구성된다. 가능한 많은 승용차의 탑승자 안전을 고려할 수 있도록 충돌시 피해가 크게 나타나는 작은 차량을 충돌차량으로 선정 하였다. 가능한 많은 사고 충돌속도를 포함하도록 기존의 충돌속도보다 20% 큰 충돌속도가 결정되었다. 충돌각도는 예상되는 사고 충돌각도를 거의 모두 포함하도록 결정되었다. 기존의 국내 최고성능등급의 종방향 방호울타리에 대하여 다양한 충돌조건을 적용한 시뮬레시션을 수행하고 그 결과를 분석하여 제시된 스마트하이웨이 충돌조건이 탑승자 안전에 미치는 영향을 파악하였다. 기존의 국내 최고성능등급의 종방향 방호울타리는 제시된 스마트하이웨이 충돌조건을 만족하지 못하였다. 충돌사고시 스마트하이웨이의 정시성과 안전성의 손상정도를 최소화 하기 위해서 새로운 고성능의 종방향 방호울타리가 필요하다고 판단된다.