• 한국지하수토양환경학회지:지하수토양환경
• /
• 제17권3호
• /
• pp.59-75
• /
• 2012

It is getting difficult to manage water resources in South Korea because more than half of annual precipitation is concentrated in the summer season and its intensity is getting severe due to global warming and climate change. Artificial recharge schemes can be a useful method to manage water resources in Korea adapting to climate change. Patent analysis enables us to prevent overlapping investment and to find out unoccupied technology. In this study, international patent trends and barriers of artificial recharge technology are analysed for patents of Korea, Japan, the United States and Europe. The four artificial recharge methods such as well recharge, surface infiltration, bank filtration and underground structures are classified as main class and the nine sub-technologies such as water intake, water treatment, injection wells, monitoring of groundwater flow, groundwater pumping, surface infiltration/soil aquifer treatment, radial collection well, iron/manganese treatment, and underground subsurface dam are classified as intermediate class. Water intake techniques are subdivided into five classifications. Total 1,281 of patents, searched by WIPS DB tool and selected after removing noisy patents, are analyzed quantitatively to evaluate application trends by year, applicant, country for each classified technologies and analyzed qualitatively to find out occupied and unoccupied technologies. It is expected that upcoming research and development project could be performed efficiently in that an avoidance plan for the similar patents and differentiation plan for the advancing patents are set up based on the quantitative and qualitative analysis results from this research.

• International Journal of Automotive Technology
• /
• 제6권2호
• /
• pp.95-105
• /
• 2005

Diesel engines have low specific fuel consumption, but high particulate emissions, mainly soot. Diesel soot is suspected to have significant effects on the health of living beings and might also affect global warming. Hence stringent measures have been put in place in a number of countries and will be even stronger in the near future. Diesel engines require either advanced integrated exhaust after treatment systems or modified engine models to meet the statutory norms. Experimental analysis to study the emission characteristics is a time consuming affair. In such situations, the real picture of engine control can be obtained by the modeling of trend prediction. In this article, an effort has been made to predict emissions smoke and NO$_{x}$ using cylinder combustion derived parameters and diesel particulate filter data, with artificial neural network techniques in MATLAB environment. The model is based on three layer neural network with a back propagation learning algorithm. The training and test data of emissions were collected from experimental set up in the laboratory for different loads. The network is trained to predict the values of emission with training values. Regression analysis between test and predicted value from neural network shows least error. This approach helps in the reduction of the experimentation required to determine the smoke and NO$_{x}$ for the catalyst coated filters.

• 한국건축시공학회지
• /
• 제14권3호
• /
• pp.237-243
• /
• 2014

지구온난화 현상으로 인해 환경 문제가 심각하며, 또한, 시멘트의 원료인 석회석과 골재의 무분별한 채취로 인한 환경파괴와 자원고갈의 심각성이 강조되고 있는 상황에서 문제점을 줄이려는 노력이 지속되고 있는 실정이다. 따라서, 본 연구에서는 천연골재 대체재인 폐자기를 혼합하여 적용시켰다. 또한, 시멘트 대체재로써 마그네시아 인산염 복합체와 플라이애시를 혼입하여 그에 따른 인조석재의 특성을 알아보고자 한다. 실험결과, 폐유리 혼합비율 60% 및 폐자기 혼합비율 70%가 인조석재의 전반적인 실험에서 가장 우수한 것으로 판단되며, 인조석재의 기초적인 자료로 활용할 수 있을 것으로 기대된다.

• 한국수자원학회논문집
• /
• 제44권6호
• /
• pp.429-438
• /
• 2011

In order to simulate a free surface flow in a trench channel, a three-dimensional incompressible unsteady Reynolds-averaged Navier-Stokes (RANS) equations are closed with the ${\kappa}-{\epsilon}$ model. The artificial compressibility (AC) method is used. Because the pressure fields can be coupled directly with the velocity fields, the incompressible Navier-Stokes (INS) equations can be solved for the unknown variables such as velocity components and pressure. The governing equations are discretized in a conservation form using a second order accurate finite volume method on non-staggered grids. In order to prevent the oscillatory behavior of computed solutions known as odd-even decoupling, an artificial dissipation using the flux-difference splitting upwind scheme is applied. To enhance the efficiency and robustness of the numerical algorithm, the implicit method of the Beam and Warming method is employed. The treatment of the free surface, so-called interface-tracking method, is proposed using the free surface evolution equation and the kinematic free surface boundary conditions at the free surface instead of the dynamic free surface boundary condition. AC method in this paper can be applied only to the hydrodynamic pressure using the decomposition into hydrostatic pressure and hydrodynamic pressure components. In this study, the boundary-fitted grids are used and advanced each time the free surface moved. The accuracy of our RANS solver is compared with the laboratory experimental and numerical data for a fully turbulent shallow-water trench flow. The algorithm yields practically identical velocity profiles that are in good overall agreement with the laboratory experimental measurement for the turbulent flow.

• 전자통신동향분석
• /
• 제33권4호
• /
• pp.92-102
• /
• 2018

On a global level, the energy problem is a very important policy topic, particularly at a time when the nation relies on imports for more than 95% of its energy demand. The starting point of an energy policy should be in line with the international community's concern and cooperation regarding climate warming, and the logic of the new policy on renewable energy expansion in Korea, the pre-developed energy sector, and policy of deserting coal all support this aspect. In particular, to accommodate the rapid urbanization of mankind, the key words of the 4th Industrial Revolution are linking energy to IoT, artificial intelligence, block chain, cloud, and big data.

• 기술사
• /
• 제39권1호
• /
• pp.37-42
• /
• 2006

The scientific technology which develops day by day is realizing thedream of the human being. As thehumanuse the artificial intelligence computer and the robot. it is to become be convenient daily life and to live long healthy. and will enjoy the space trip as like as the overseas trip in 20years. However, the life of the human being shall be extended. become the older society and the population shall increase. stronger earth-quake and the typhoon shall occur more frequently due to global warming. I think that it will be anational concern that we perceive the age-quake approaches in the close of hand which is more terrible than the earth-quake, and prepare on it.

• 한국태양에너지학회 논문집
• /
• 제27권2호
• /
• pp.95-101
• /
• 2007

The surface changes due to urban expansion and the increase of artificial heat releases have brought significant climate changes such as heat island phenomenon in urban area. Furthermore, these changes also have brought serious problems such as air temperature increase, wind changes, and air pollution in urban area. Comprehensive analytical technologies considering various effects are required to analyse complicated mechanism of climate changes, and review the efficient measures. In this research, the effect of the urban expansion in Tokyo and Bangkok area on urban environment will be discussed. By using CFD, urban development and the mechanism of global warming and wind change are studied in those two cities. As a result of numerical research, the surface changes of city could bring the environmental changes in urban area.

• Current Photovoltaic Research
• /
• 제5권4호
• /
• pp.122-134
• /
• 2017

As a promising solution to global warming and growing energy demand, photocatalytic $CO_2$ conversion to useful fuels is widely studied to enhance the activity and selectivity of the $CO_2$ photoreduction reactions. In this review, an overview of fundamental aspects of the $CO_2$ reduction photocatalysts is provided. The recent development of the photocatalyst is also discussed, focusing on the mechanisms of light harvesting and charge transfer. Besides, this review sets its sight on inspiring new ideas toward a practical $CO_2$ conversion technology.

• 한국환경과학회지
• /
• 제23권11호
• /
• pp.1863-1879
• /
• 2014

This study aims at classifying and interpreting on the shrine forest vegetation located in Jirisan national park affiliated to an ecotone in southern part of Korea, foreseeing a vegetation change based on composition species and dominant species on canopy, and proposing the direction of vegetation management. The shrine forests were classified into the 7 community units as Chamaecyparis obtusa-Cryptomeria japonica afforestation, Pinus densiflora community, Pinus rigida afforestation, Quercus variabilis-Quercus serrata community, Zelkova serrata-Kerria japonica for. japonica community, Phyllostachys bambusoides forest, Camellia japonica community. This research is also expatiated on the analogous results of ordination analysis with phytosociological analysis. The constituents of deciduous broad-leaved forest in the warm temperate zone were appeared in the most vegetations. It emerged less that the constituents of evergreen broad-leaved forest in the warm-temperate zone and deciduous broad-leaved forest in the cold-temperature zone. The life form analyses were made use with the two ways: appearance species in total communities and each community. The species diversity of shrine forests is declined because the high dominances of Sasa borealis and Pseudosasa japonica emerged in the shrub and herb layers. These shrine forests will be succession to Q. variabilis-Q. serrata community as the representative vegetation of deciduous broad-leaved forest in the warm-temperate zone, owing to the temperature rise by global warming, and an evergreen broad-leaved forest will be able to be also formed if a temperate rise will be continued. The one of the artificial management of shrine forests is to consider the introduction of the constituents of evergreen broad-leaved forest in the warm-temperate zone.

• 대한원격탐사학회지
• /
• 제38권6_1호
• /
• pp.1047-1056
• /
• 2022

지구 온난화의 중요한 지시자인 북극의 바다 얼음인 해빙은 기후 시스템, 선박의 항로 안내, 어업 활동 등에서의 중요성으로 인해 다양한 학문 분야에서 관심을 받고 있다. 최근 자동화와 효율적인 미래 예측에 대한 요구가 커지면서 인공지능을 이용한 새로운 해빙 예측 모델들이 전통적인 수치 및 통계 예측 모델을 대체하기 위해 개발되고 있다. 본 연구에서는 북극 해빙의 전역적, 지역적 특징을 학습할 수 있는 two-stream convolutional long- and short-term memory (TS-ConvLSTM) 인공지능 모델의 북극 해빙 면적이 최저를 보이는 9월에 대해 2001년부터 2021년까지 장기적인 성능 검증을 통해 향후 운용 가능한 시스템으로써의 가능성을 살펴보고자 한다. 장기 자료를 통한 검증 결과 TS-ConvLSTM 모델이 훈련자료의 양이 증가하면서 향상된 예측 성능을 보여주고 있지만, 최근 지구 온난화로 인한 단년생 해빙의 감소로 인해 해빙 농도 5-50% 구간에서는 예측력이 저하되고 있음을 보여주었다. 반면 TS-ConvLSTM에 의해 예측된 해빙 면적과 달리 Sea Ice Prediction Network에 제출된 Sea Ice Outlook (SIO)들의 해빙 면적 중간값의 경우 훈련자료가 늘어나더라도 눈에 띄는 향상을 보이지 않았다. 본 연구를 통해 TS-ConvLSTM 모델의 향후 북극 해빙 예측 시스템의 운용 가능 잠재성을 확인하였으나, 향후 연구에서는 예측이 어려운 자연 환경에서 더욱 안정성 있는 예측 시스템 개발을 위해 더 많은 시공간 변화 패턴을 학습할 수 있는 방안을 고려해야 할 것이다.