• Title/Summary/Keyword: global climate

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The Recent Increase in the Heavy Rainfall Events in August over the Korean Peninsula

  • Cha, Eun-Jeong;Kimoto, Masahide;Lee, Eun-Jeong;Jhun, Jong-Ghap
    • Journal of the Korean earth science society
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    • v.28 no.5
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    • pp.585-597
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    • 2007
  • The characteristics of the rainfall events on the Korean peninsula have been investigated by means of regional and global observational data collected from 1954 to 2004 with an emphasis on extreme cases $80\;mm\;day^{-1}$. According to our analysis, long-term annual rainfall anomalies show an increasing trend. This trend is pronounced in the month of August, when both the amount of monthly rainfall and the frequency of extreme events increase significantly. Composite maps on August during the 8 wet years reveal warm SST anomalies over the eastern Philippine Sea which are associated with enhanced convection and vertical motion and intensified positive SLP over central Eurasia during August. The rainfall pattern suggests that the most significant increase in moisture supply over the southern parts of China and Korea in August is associated with positive SLP changes over Eurasia and negative SLP changes over the subtropical western Pacific off the east coast of south China. The frequent generation of typhoons over the warm eastern Philippine Sea and their tracks appear to influence the extreme rainfall events in Korea during the month of August. The typhoons in August mainly passed the western coast of Korea, resulting in the frequent occurrence of extreme rainfall events in this region. Furthermore, anomalous cyclonic circulations over the eastern Philippine Sea also promoted the generation of tropical cyclones. The position of pressure systems - positive SLP over Eurasia and negative SLP over the subtropical Pacific - in turn provided a pathway for typhoons. The moisture is then effectively transported further north toward Korea and east toward the southern parts of China during the extreme rainfall period.

Urban energy transition and energy autonomy in Daegu (대구의 도시 에너지 전환과 에너지 자립)

  • Choi, Byung-Doo
    • Journal of the Economic Geographical Society of Korea
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    • v.16 no.4
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    • pp.647-669
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    • 2013
  • Depletion of fossil fuels and sharp rise of international oil price as well as climate worming and frequent environmental disasters have required to strengthen resource(esp. energy) and environmental policy and discourse. And hence highly influential discourses and policies such as the concept of sustainable development and strategy for carbon regulation have been developed and pursued world-widely. But these concept and strategy have seemed to be subsumed in the process of neoliberalism, so as to have little effective results. This leads us to energy transition and energy autonomy or autarky as alternative strategic and normative concepts. Daegu has shown strong interests in urban energy problems relatively earlier than other cities, and developed the so-call 'Solar City' project. But it could not properly tackled with the problems, while tending to meet with the global imperatives. This paper considers urban energy problems and energy policy of Daegu with its significance and limitations, and suggests 4 principles for urban energy transition and autonomy with some concrete alternative measures; that is, the transition from fossil and nuclear energy to renewable energy, the transition from supply-led policy to demand side focusing policy, the transition from central governing energy system to locally distributed one, and the transition from market-dependent management to citizen-participatory energy governance.

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A Development of Intelligent Pumping Station Operation System Using Deep Reinforcement Learning (심층 강화학습을 이용한 지능형 빗물펌프장 운영 시스템 개발)

  • Kang, Seung-Ho;Park, Jung-Hyun;Joo, Jin-Gul
    • Convergence Security Journal
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    • v.20 no.1
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    • pp.33-40
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    • 2020
  • The rainwater pumping station located near a river prevents river overflow and flood damages by operating several pumps according to the appropriate rules against the reservoir. At the present time, almost all of rainwater pumping stations employ pumping policies based on the simple rules depending only on the water level of reservoir. The ongoing climate change caused by global warming makes it increasingly difficult to predict the amount of rainfall. Therefore, it is difficult to cope with changes in the water level of reservoirs through the simple pumping policy. In this paper, we propose a pump operating method based on deep reinforcement learning which has the ability to select the appropriate number of operating pumps to keep the reservoir to the proper water level using the information of the amount of rainfall, the water volume and current water level of the reservoir. In order to evaluate the performance of the proposed method, the simulations are performed using Storm Water Management Model(SWMM), a dynamic rainfall-runoff-routing simulation model, and the performance of the method is compared with that of a pumping policy being in use in the field.

A Study on the Change of Non-Working Days Based on the Rainfall in Incheon Area Using the Climate Change Scenarios (기후변화 시나리오를 활용한 인천지역 강우에 의한 작업불능일 변화 연구)

  • Jang, Junyoung;Lee, Chansik
    • Korean Journal of Construction Engineering and Management
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    • v.19 no.1
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    • pp.103-113
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    • 2018
  • In this study, Construction work is mainly done outdoors, so earth works, reinforced concrete works, etc. are Non-Working Days to rainfall. In particular, changes in rainfall due to global warming have made air calculation more difficult. Therefore, when establishing the process plan, the change of the rainfall in the area should be identified and Non-Working Days should be calculated. In this study, the time of rainfall change point was identified using the meteorological 'observation' data from 1960 to 2016 in Incheon and RCP 4.5, 'weather forecast' data from 2018 to 2074, Year rainfall and seasonal rainfall. The results showed that rainfall changed point in 1972, 1988, 2013, 2038, 2050 and 2069. In particular, it has been found that non-working days due to rainfall has big changed point as of 2013, 2038 and 2069.

An Analysis of Relationship between Carbon Emission and Urban Spatial Patterns (도시패턴과 탄소배출량의 관계 분석)

  • Kim, In-Hyun;Oh, Kyu-Shik;Jung, Seung-Hyun
    • Spatial Information Research
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    • v.19 no.1
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    • pp.61-72
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    • 2011
  • Greenhouses gas emission due to usage of fossil fuel has been known as one of the main causes of global warming. Fundamentally, greenhouse gas is a by-product of economic activity. Since majority of economic activity happens in an urban setting, a countermeasure in an urban setting is needed. Therefore, an analysis of relationship between carbon dioxide emission and urban form will be investigated for urban planning and management in the future. The purpose of this study is to analyze the relationship between carbon dioxide emission and urban spatial patterns, and suggesting an urban form with low carbon dioxide emission. In order to achieve this, first theoretical analysis was carried out on urban spatial patterns related to physical size, usage rate, and activity level. Secondly, Seoul's dam on electricity, natural gas, local heating, petroleum, and water usage and mapping a carbon dioxide emission map. Thirdly, relationship between carbon dioxide emission and urban spatial patterns are analyzed and urban spatial patterns that affects energy usage in urban setting was elucidated, and elicited implications on future directions on urban planning based on our analyses above.

Renewable and Sustainable Resource Derived Carbon Neutral Adhesive Materials (재생 및 지속사용 가능 자원 유래 탄소 중립형 접착소재)

  • Kim, Baekjin;Kim, Sangyong;Cho, Jin Ku;Lee, Sang-Hyeup;Kim, Hyun-Joong
    • Journal of Adhesion and Interface
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    • v.11 no.2
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    • pp.76-83
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    • 2010
  • The extensive use of fossil resources over the past century resulted in dwindling supply and surging price of oil and it is strongly suspected that irreversible global climate change might be due to carbon dioxide emitted from combustion of fossil carbons. With this regard, much attention is recently paid to renewable and sustainable resources as alternatives to petroleum. In this review, we considered a range of efforts to replace petroleum-derived chemicals, particularly adhesive materials with renewable and sustainable plant-based biomass feedstock.

Influences of Forest Fire on Forest Floor and Litterfall in Bhoramdeo Wildlife Sanctuary (C.G.), India

  • Jhariya, Manoj Kumar
    • Journal of Forest and Environmental Science
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    • v.33 no.4
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    • pp.330-341
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    • 2017
  • Tropical forests play a key role for functioning of the planet and maintenance of life. These forests support more than half of the world's species, serve as regulators of global and regional climate, act as carbon sinks and provide valuable ecosystem services. Forest floor biomass and litterfall dynamics was measured in different sites influenced by fire in a seasonally dry tropical forest of Bhoramdeo wildlife sanctuary of Chhattisgarh, India. The forest floor biomass was collected randomly placed quadrats while the litterfall measured by placing stone-block lined denuded quadrat technique. The seasonal mean total forest floor biomass across the fire regimes varied from $2.00-3.65t\;ha^{-1}$. The total litterfall of the study sites varied from $4.75-7.56t\;ha^{-1}\;yr^{-1}$. Annual turnover of litter varied from 70-74% and the turnover time between 1.35-1.43 years. Monthly pattern of forest floor biomass indicated that partially decayed litter, wood litter and total forest floor were differed significantly. The seasonal variation showed that leaf fall differed significantly in winter season only among the fire regimes while the wood litter was found non significant in all the season. This study shows that significant variation among the site due to the forest fire. Decomposition is one of the ecological processes critical to the functioning of forest ecosystems. The decomposing wood serves as a saving account of nutrients and organic materials in the forest floor. Across the site, high fire zone was facing much of the deleterious effects on forest floor biomass and litter production. Control on such type of wildfire and anthropogenic ignition could allow the natural recovery processes to enhance biological diversity. Chronic disturbances do not provide time for ecosystem recovery; it needs to be reduced for ecosystem health and maintaining of the high floral and faunal biodiversity.

Development of PV-Power-Hardware-In-Loop Simulator with Realtime to Improve the Performance of the Distributed PV Inverter (분산전원형 PV 인버터 성능 개선을 위한 실시간 처리기반의 PV-Power-Hardware-In-Loop 시뮬레이터 개발)

  • Kim, Dae-Jin;Kim, Byungki;Ryu, Kung-Sang;Lee, Gwang-Se;Jang, Moon-Seok;Ko, Hee-Sang
    • Journal of the Korean Solar Energy Society
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    • v.37 no.3
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    • pp.47-59
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    • 2017
  • As the global warming threats to humanity, renewable energy is considered the key solution to overcome the climate change. In this circumstance, distributed PV systems are being expanded significantly its market share in the renewable energy industry. The performance of inverter is the most important component at PV system and numerous researches are focusing on it. In order to improve the inverter, PV simulator is an essential device to experiment under various load and conditions. This paper proposes the PV Power-Hardware-In-Loop simulator (PHILS) with real-time processing converted electrical and mathematical models to improve computation speed. Single-diode PV model is used in MATLAB/SIMULINK for the PV PHILS to boosting computation speed and dynamic model accuracy. In addition, control algorithms for sub-components such as DC amplifier, measurement device and several interface functions are implemented in the model. The proposed PV PHILS is validated by means of experiments with commercial PV module parameters.

A Study on the Development Direction of the Renewable Energy Carbon Certification System: Focused on Analysis of International Trade Policy and the Dispute Cases Related to Environmental Labeling (재생에너지 탄소인증제도의 개발 방향성에 관한 연구 : 국제무역규범 및 환경라벨링 관련 무역 분쟁사례분석을 중심으로)

  • Sang, Min-Kyung;Han, Sung-Ae;Park, Sun-Hyo
    • Journal of the Korean Solar Energy Society
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    • v.39 no.6
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    • pp.1-13
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    • 2019
  • With the adoption of the Paris Agreement, a new climate regime is intensifying the global interest in reducing greenhouse gas emissions. In the meantime, Korea is preparing to introduce a new renewable energy carbon certification system in order to activate the use of renewable energy and to reduce carbon emissions in the entire life cycle of manufacturing and disposal of renewable energy facilities. Therefore, this study aims to identify the implications for the introduction of the carbon certification system and to establish a theoretical basis for the system design by examining the status of overseas carbon certification, international trade norms and trade disputes. As a result, carbon emissions certification is being implemented in developed countries such as EU, UK, France, USA and Japan, but only France, Germany and EU have adopted carbon certification for renewable energy sector. The analysis of the WTO TBT Agreement and GATT also confirmed the possibility of a violation of the international trade rules of the carbon certification system and derived nine international technical standards related to carbon certification. Finally, by examining the case of trade disputes related to environmental labeling, the minimum requirements to be considered at the institutional design stage were drawn to eliminate the possibility of trade disputes.

Delayed Mode Quality Control of Argo Data and Its Verification in the Pacific Ocean (태평양 Argo 자료의 지연모드 품질관리 및 검증연구)

  • Yang, Joon-Yong;Kang, Seong-Yun;Go, Woo-Jin;Suh, Young-Sang;Seo, Jang-Won;Suk, Moon-Sik
    • Journal of Environmental Science International
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    • v.17 no.12
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    • pp.1353-1361
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    • 2008
  • Quality control of Argo(Array for Real-time Geostrophic Oceanography) data is crucial by reason that salinity measurements are liable to experience some drift and offset due to biofouling, contamination of sensor and wash-out of biocide. The automated Argo real-time quality control has a limit of sorting data quality, so that WJO program is adopted as standardized method of Argo delayed mode quality control (DMQc) in the world that is a precise quality control method. We conducted DMQC on pressure, temperature and salinity measured by Argo floats in the Pacific Ocean including expert evaluation. Particularly, salinity data were corrected using WJO program. 4 salinity profiles of Argo delayed mode were compared with nearby in situ CTD data and other Argo data in deep layer where oceanographic conditions are stable in time and space. The differences of both salinities were lower than target accuracy of Argo. As compared with the difference of salinities before DMQC, those after DMQC decreased by 60-80 percent. Quality of delayed mode salinity data seemed to be improved correcting salinity data suggested by WJO program.