scholarly journals A Multiscale Tiered Approach to Quantify Contributions: A Case Study of PM2.5 in South Korea During 2010–2017

Atmosphere ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 141 ◽  
Author(s):  
Minah Bae ◽  
Byeong-Uk Kim ◽  
Hyun Cheol Kim ◽  
Soontae Kim
Keyword(s):  
Air Quality ◽  
South Korea ◽  
Sparse Matrix ◽  
Action Plan ◽  
Weather Research And Forecasting ◽  
Study Results ◽  
Simulation Based ◽  
Operator Kernel

We estimated long-term foreign contributions to the particulate matter of 2.5 μm or less in diameter (PM2.5) concentrations in South Korea with a set of air quality simulations. The Weather Research and Forecasting (WRF)-Sparse Matrix Operator Kernel Emissions (SMOKE)-Community Multiscale Air Quality (CMAQ) modeling system was used to simulate the base and sensitivity case after a 50% reduction of foreign emissions. The effects of horizontal modeling grid resolutions (27- and 9-km) was also investigated. For this study, we chose PM2.5 in South Korea during 2010–2017 for the case study and emissions from China as a representative foreign source. The 9-km simulation results show that the 8-year average contribution of the Chinese emissions in 17 provinces ranged from 40–65%, which is ~4% lower than that from the 27-km simulation for the high-tier government segments (particularly prominent in coastal areas). However, for the same comparison for low-tier government segments (i.e., 250 prefectures), the 9-km simulation presented lowered the foreign contribution by up to 10% compared to that from the 27-km simulation. Based on our study results, we recommend using high-resolution modeling results for regional contribution analyses to develop an air quality action plan as the receptor coverage decreases.

scholarly journals An Observing System Simulation Experiment Framework for Air Quality Forecasts in Northeast Asia: A Case Study Utilizing Virtual Geostationary Environment Monitoring Spectrometer and Surface Monitored Aerosol Data

2022 ◽  
Vol 14 (2) ◽  
pp. 389
Author(s):  
Hyeon-Kook Kim ◽  
Seunghee Lee ◽  
Kang-Ho Bae ◽  
Kwonho Jeon ◽  
Myong-In Lee ◽  
...  
Keyword(s):  
Air Quality ◽  
South Korea ◽  
System Simulation ◽  
Northeast Asia ◽  
Gobi Desert ◽  
Observation Data ◽  
Environment Monitoring ◽  
Study Results ◽  
Current Monitoring

Prior knowledge of the effectiveness of new observation instruments or new data streams for air quality can contribute significantly to shaping the policy and budget planning related to those instruments and data. In view of this, one of the main purposes of the development and application of the Observing System Simulation Experiments (OSSE) is to assess the potential impact of new observations on the quality of the current monitoring or forecasting systems, thereby making this framework valuable. This study introduces the overall OSSE framework established to support air quality forecasting and the details of its individual components. Furthermore, it shows case study results from Northeast Asia and the potential benefits of the new observation data scenarios on the PM2.5 forecasting skills, including the PM data from 200 virtual monitoring sites in the Gobi Desert and North Korean non-forest areas (NEWPM) and the aerosol optical depths (AOD) data from South Korea’s Geostationary Environment Monitoring Spectrometer (GEMS AOD). Performance statistics suggest that the concurrent assimilation of the NEWPM and the PM data from current monitoring sites in China and South Korea can improve the PM2.5 concentration forecasts in South Korea by 66.4% on average for October 2017 and 95.1% on average for February 2018. Assimilating the GEMS AOD improved the performance of the PM2.5 forecasts in South Korea for October 2017 by approximately 68.4% (~78.9% for February 2018). This OSSE framework is expected to be continuously implemented to verify its utilization potential for various air quality observation systems and data scenarios. Hopefully, this kind of application result will aid environmental researchers and decision-makers in performing additional in-depth studies for the improvement of PM air quality forecasts.

scholarly journals The control of anthropogenic emissions contributed to 80 % of the decrease in PM<sub>2.5</sub> concentrations in Beijing from 2013 to 2017

2019 ◽  
Vol 19 (21) ◽  
pp. 13519-13533 ◽  
Author(s):  
Ziyue Chen ◽  
Danlu Chen ◽  
Mei-Po Kwan ◽  
Bin Chen ◽  
Bingbo Gao ◽  
...  
Keyword(s):  
Air Quality ◽  
Emission Reduction ◽  
Action Plan ◽  
Meteorological Conditions ◽  
Weather Research And Forecasting ◽  
Anthropogenic Emissions ◽  
Multi Scale ◽  
Relative Contribution ◽  
Clean Air

Abstract. With the completion of the Beijing Five-year Clean Air Action Plan by the end of 2017, the annual mean PM2.5 concentration in Beijing dropped dramatically to 58.0 µg m−3 in 2017 from 89.5 µg m−3 in 2013. However, controversies exist to argue that favourable meteorological conditions in 2017 were the major driver for such a rapid decrease in PM2.5 concentrations. To comprehensively evaluate this 5-year plan, we employed a Kolmogorov–Zurbenko (KZ) filter and WRF-CMAQ (Weather Research and Forecasting and the Community Multi-scale Air Quality) to quantify the relative contribution of meteorological conditions and the control of anthropogenic emissions to PM2.5 reduction in Beijing from 2013 to 2017. For these 5 years, the relative contribution of emission reduction to the decrease in PM2.5 concentrations calculated by KZ filtering and WRF-CMAQ was 80.6 % and 78.6 % respectively. KZ filtering suggested that short-term variations in meteorological and emission conditions contributed majorly to rapid changes in PM2.5 concentrations in Beijing. WRF-CMAQ revealed that the relative contribution of local and regional emission reduction to the PM2.5 decrease in Beijing was 53.7 % and 24.9 % respectively. For local emission-reduction measures, the regulation of coal boilers, increasing use of clean fuels for residential use and industrial restructuring contributed 20.1 %, 17.4 % and 10.8 % to PM2.5 reduction respectively. Both models suggested that the control of anthropogenic emissions accounted for around 80 % of the PM2.5 reduction in Beijing, indicating that emission reduction was crucial for air quality enhancement in Beijing from 2013 to 2017. Consequently, such a long-term air quality clean plan should be continued in the following years to further reduce PM2.5 concentrations in Beijing.

scholarly journals A Holistic Framework for Evaluating Adaptation Approaches to Coastal Hazards and Sea Level Rise: A Case Study from Imperial Beach, California

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1324
Author(s):  
David Revell ◽  
Phil King ◽  
Jeff Giliam ◽  
Juliano Calil ◽  
Sarah Jenkins ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Public Trust ◽  
Adaptation Strategy ◽  
Public Benefits ◽  
Study Results ◽  
Local Risk ◽  
Over Time

Sea level rise increases community risks from erosion, wave flooding, and tides. Current management typically protects existing development and infrastructure with coastal armoring. These practices ignore long-term impacts to public trust coastal recreation and natural ecosystems. This adaptation framework models physical responses to the public beach and private upland for each adaptation strategy over time, linking physical changes in widths to damages, economic costs, and benefits from beach recreation and nature using low-lying Imperial Beach, California, as a case study. Available coastal hazard models identified community vulnerabilities, and local risk communication engagement prioritized five adaptation approaches—armoring, nourishment, living shorelines, groins, and managed retreat. This framework innovates using replacement cost as a proxy for ecosystem services normally not valued and examines a managed retreat policy approach using a public buyout and rent-back option. Specific methods and economic values used in the analysis need more research and innovation, but the framework provides a scalable methodology to guide coastal adaptation planning everywhere. Case study results suggest that coastal armoring provides the least public benefits over time. Living shoreline approaches show greater public benefits, while managed retreat, implemented sooner, provides the best long-term adaptation strategy to protect community identity and public trust resources.

Comparison of Stopping Modes for Pod-Driven Ships by Simulation Based on Model Testing

2005 ◽  
Vol 219 (2) ◽  
pp. 47-64 ◽  
Author(s):  
M D Woodward ◽  
M Atlar ◽  
D Clarke
Keyword(s):  
Load Condition ◽  
Open Water ◽  
Water Model ◽  
Simulation Algorithm ◽  
Time Domain Simulation ◽  
Dynamic Effects ◽  
Study Results ◽  
Simulation Based ◽  
Fluid Damping

Conventionally, the stopping of a ship is achieved by direct reversal of propeller rotation. However, the introduction of azimuthing pods presents other options. The following study examines the various modes that may be employed to stop a pod-driven ship. A continuous function is derived describing the hydrodynamic forces on both the propeller and the pod body for any load condition and helm angle, including fluid damping and added mass effects. The proposed function is validated through comparison with comprehensive open water model tests. Next, a time domain simulation algorithm is proposed to examine the dynamic effects including the mass inertia on both the propeller shaft and slewing stock. Finally, a simulation study for the proposed stopping modes is performed using a known design as a case study. Results and discussion are presented.

scholarly journals Inventário de Emissões com Alta Resolução para a Região da Grande Vitória Utilizando o Sistema de Modelagem Integrada WRF-SMOKE-CMAQ

2018 ◽  
Vol 33 (3) ◽  
pp. 521-536 ◽  
Author(s):  
Ayres Geraldo Loriato ◽  
Nadir Salvador ◽  
Ayran Ayres Barbosa Loriato ◽  
Anton Sokolov ◽  
Antonio Paula Nascimento ◽  
...  
Keyword(s):  
Air Quality ◽  
Sparse Matrix ◽  
Matrix Operator ◽  
Espírito Santo ◽  
Multi Scale ◽  
Espirito Santo ◽  
Operator Kernel

Resumo A poluição atmosférica proveniente das atividades antropogênicas tem provocado incômodo à população da Região Metropolitana da Grande Vitória (RGV), Espirito Santo, Brasil. Muitos pacientes como asmáticos, alérgicos, químico sensíveis, cardiacos, pessoas com acidente vascular cerebral (AVC), diabetes, grávidas, idosos e crianças são especialmente suscetíveis a uma pobre qualidade do ar. As complexas interações dos poluentes atmosféricos podem ser entendidas usando modelos de transporte químico, os quais necessitam de inventários de emissões para prover a alocação espacial e temporal das emissões. Na RGV, o Instituto Estadual do Meio Ambiente (IEMA) disponibilizou o inventário de emissões da região para o ano de 2010. Nesse artigo foi realizada uma adaptação do inventário de fontes regional para o Sparse Matrix Operator Kernel Emissions (SMOKE) de modo a ser utilizado em modelos de qualidade do ar (MQA) como o Community Multi-scale Air Quality (CMAQ) Modeling System e outros modelos fotoquímicos. Foram obtidos valores simulados elevados referentes às emissões de ressuspensão em vias, apontando uma possível falha do inventário neste tipo de fonte. Utilizando os fatores de emissão médios de Abu-Allaban et al. (2003) para a ressuspensão das vias locais, foram obtidos resultados mais condizentes aos atuais níveis de concentrações de partículas monitorados na RGV.

scholarly journals Freelancing Models for Fostering Innovation and Problem Solving in Software Startups: An Empirical Comparative Study

2020 ◽  
Vol 12 (23) ◽  
pp. 10106 ◽  
Author(s):  
Varun Gupta ◽  
Jose Maria Fernandez-Crehuet ◽  
Chetna Gupta ◽  
Thomas Hanne
Keyword(s):  
Software Development ◽  
Positive Impact ◽  
Empirical Studies ◽  
Competitive Advantages ◽  
Software Development Process ◽  
Model Framework ◽  
Study Results ◽  
Development Tasks

Context: freelancers and startups could provide each other with promising opportunities that lead to mutual growth, by improving software development metrics, such as cost, time, and quality. Niche skills processed by freelancers could help startups reduce uncertainties associated with developments and markets, with the ability to quickly address market issues (and with higher quality). This requires the associations between freelancers and startup to be long-term, based on trust, and promising agreements driven by motivations (leading to the growth of both parties). Freelancers could help startups foster innovations and undertake software development tasks in better ways than conducted in-house, if they are selected using informed decision-making. Objectives: the paper has three objectives, (1) to explore the strategies of startups to outsource software development tasks to freelancers (termed as freelancing association strategies); (2) to identify challenges in such outsourcings; and (3) to identify the impacts of outsourcing tasks to freelancers on overall project metrics. The overall objective is to understand the strategies for involving freelancers in the software development process, throughout the startup lifecycle, and the associated challenges and the impacts that help to foster innovation (to maintain competitive advantages). Method: this paper performs empirical studies through case studies of three software startups located in Italy, France, and India, followed by a survey of 54 freelancers. The results are analyzed and compared in the identification of association models, issues, challenges, and reported results arising because of such associations. The case study results are validated using members checking with the research participants, which shows a higher level of result agreements. Results: the results indicate that the freelancer association strategy is task based, panel based, or a hybrid. The associations are constrained by issues such as deciding pricing, setting deadlines, difficulty in getting good freelancers, quality issues with software artefacts, and efforts to access freelancer work submissions for reward. The associations have a positive impact on software development if there is availability of good freelancers (which lasts long for various tasks). The paper finally provides a freelancing model framework and recommends activities that could result in making the situation beneficial to both parties, and streamline such associations. Fostering innovation in startups is, thus, a trade-off situation, which is limited and supported by many conflicting parameters.

scholarly journals Effects of meteorology and emissions on urban air quality: a quantitative statistical approach to long-term records (1999–2016) in Seoul, South Korea

2018 ◽  
Vol 18 (21) ◽  
pp. 16121-16137 ◽  
Author(s):  
Jihoon Seo ◽  
Doo-Sun R. Park ◽  
Jin Young Kim ◽  
Daeok Youn ◽  
Yong Bin Lim ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
South Korea ◽  
Meteorological Conditions ◽  
Meteorological Variables ◽  
Urban Air ◽  
Short Term ◽  
Long Term Trends ◽  
Local Emissions

Abstract. Together with emissions of air pollutants and precursors, meteorological conditions play important roles in local air quality through accumulation or ventilation, regional transport, and atmospheric chemistry. In this study, we extensively investigated multi-timescale meteorological effects on the urban air pollution using the long-term measurements data of PM10, SO2, NO2, CO, and O3 and meteorological variables over the period of 1999–2016 in Seoul, South Korea. The long-term air quality data were decomposed into trend-free short-term components and long-term trends by the Kolmogorov–Zurbenko filter, and the effects of meteorology and emissions were quantitatively isolated using a multiple linear regression with meteorological variables. In terms of short-term variability, intercorrelations among the pollutants and meteorological variables and composite analysis of synoptic meteorological fields exhibited that the warm and stagnant conditions in the migratory high-pressure system are related to the high PM10 and primary pollutant, while the strong irradiance and low NO2 by high winds at the rear of a cyclone are related to the high O3. In terms of long-term trends, decrease in PM10 (−1.75 µg m−3 yr−1) and increase in O3 (+0.88 ppb yr−1) in Seoul were largely contributed by the meteorology-related trends (−0.94 µg m−3 yr−1 for PM10 and +0.47 ppb yr−1 for O3), which were attributable to the subregional-scale wind speed increase. Comparisons with estimated local emissions and socioeconomic indices like gross domestic product (GDP) growth and fuel consumptions indicate probable influences of the 2008 global economic recession as well as the enforced regulations from the mid-2000s on the emission-related trends of PM10 and other primary pollutants. Change rates of local emissions and the transport term of long-term components calculated by the tracer continuity equation revealed a decrease in contributions of local emissions to the primary pollutants including PM10 and an increase in contributions of local secondary productions to O3. The present results not only reveal an important role of synoptic meteorological conditions on the episodic air pollution events but also give insights into the practical effects of environmental policies and regulations on the long-term air pollution trends. As a complementary approach to the chemical transport modeling, this study will provide a scientific background for developing and improving effective air quality management strategy in Seoul and its metropolitan area.

scholarly journals River Water Quality and its Relation with Air Quality: A Long-Term Case Study in a Remote and Pristine NW Italian Headwater Catchment

2017 ◽  
Vol 5 (1) ◽  
pp. 35-47 ◽  
Author(s):  
Marco Casazza ◽  
Franca Maraga ◽  
Gengyuan Liu ◽  
Massimiliano Lega ◽  
Laura Turconi ◽  
...  
Keyword(s):  
Water Quality ◽  
Air Quality ◽  
River Water ◽  
River Water Quality ◽  
Headwater Catchment

scholarly journals Dropping out – Hungarian experiences at vocational training

2021 ◽  
Vol 12 (33) ◽  
pp. 103-124
Author(s):  
Imola Csehné Papp ◽  
Mária Héder-Rima ◽  
Krisztina Dajnoki
Keyword(s):  
Labour Market ◽  
Action Plan ◽  
School Experiences ◽  
Drop Out ◽  
Dropping Out ◽  
Study Results ◽  
School Drop Out ◽  
Market Status ◽  
Questionnaire Surveys

The proportion of people with low school qualifications remains significant in Hungary, which not only makes it difficult for them to enter the current labour market but may also exclude them in the long term. For the increasing number of people with a low level of education, dropping out seems to be one of the most common reasons. Prevention as a determinative measure can provide answers to this problem. The study focuses on the issue of secondary school drop-out. The study results were based on the methodology of questionnaire surveys and semi-structured conversations. Based on the information obtained from the survey, this study continuously presents the results connected to drop-out conditions and compensatory measures. The study results highlight the significant effects of school and family, including previous school experiences, influence on the place of residence, the labour market status. The conclusions drawn from the results address the topic in a practical way and provide an opportunity to develop a possible action plan to prevent drop-outs.

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