• Title/Summary/Keyword: Scenario analysis

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Analysis and estimation of species distribution of Mythimna seperata and Cnaphalocrocis medinalis with land-cover data under climate change scenario using MaxEnt (MaxEnt를 활용한 기후변화와 토지 피복 변화에 따른 멸강나방 및 혹명나방의 한국 내 분포 변화 분석과 예측)

  • Taechul Park;Hojung Jang;SoEun Eom;Kimoon Son;Jung-Joon Park
    • Korean Journal of Environmental Biology
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    • v.40 no.2
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    • pp.214-223
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    • 2022
  • Among migratory insect pests, Mythimna seperata and Cnaphalocrocis medinalis are invasive pests introduced into South Korea through westerlies from southern China. M. seperata and C. medinalis are insect pests that use rice as a host. They injure rice leaves and inhibit rice growth. To understand the distribution of M. seperata and C. medinalis, it is important to understand environmental factors such as temperature and humidity of their habitat. This study predicted current and future habitat suitability models for understanding the distribution of M. seperata and C. medinalis. Occurrence data, SSPs (Shared Socio-economic Pathways) scenario, and RCP (Representative Concentration Pathway) were applied to MaxEnt (Maximum Entropy), a machine learning model among SDM (Species Distribution Model). As a result, M. seperata and C. medinalis are aggregated on the west and south coasts where they have a host after migration from China. As a result of MaxEnt analysis, the contribution was high in the order of Land-cover data and DEM (Digital Elevation Model). In bioclimatic variables, BIO_4 (Temperature seasonality) was high in M. seperata and BIO_2 (Mean Diurnal Range) was found in C. medinalis. The habitat suitability model predicted that M. seperata and C. medinalis could inhabit most rice paddies.

A Study on the Carbon Neutrality Scenario Model for Technology Application in Units of Space (공간 단위 탄소중립 기술적용 시나리오 모형(CATAS) 연구)

  • Park, Shinyoung;Choi, Yuyoung;Lee, Mina
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.43 no.1
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    • pp.63-69
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    • 2023
  • 'Carbon-neutrality Assessment based on Technology Application Scenario (CATAS)' provides an analysis of greenhouse gas (GHG) reduction effectiveness when applying carbon-neutrality technology to areas such as energy conversion, transportation, and buildings at certain spatial levels. As for the development scope of the model, GHG emission sources were analyzed for direct GHG emissions, and the boundary between direct and indirect emissions are set according to the spatial scope. The technical scope included nine technologies and forest sinks in the transition sector that occupies the largest portion of GHG emissions in the 2050 carbon neutral scenario. The carbon neutrality rate evaluation methodology consists of four steps: ① analysis of GHG emissions, ② prediction of energy production according to technology introduction, ③ calculation of GHG reduction, and ④ calculation of carbon neutrality rate. After the web-based CATAS-BASIC was developed, an analysis was conducted by applying the new and renewable energy distribution goals presented in the 「2050 Greenhouse Gas Reduction Promotion Plan」 of the Seoul Metropolitan Government. As a result of applying solar power, hydrogen fuel cell, and hydrothermal, the introduction of technology reduced 0.43 million tCO2eq of 1.49 million tCO2eq, which is the amount of emissions from the conversion sector in Seoul, and the carbon neutrality rate in the conversion sector was analyzed to be 28.94 %.

The Estimation of the Economic Impact of Handset Subsidies Using Input-Output Tables (단말기보조금의 경제적 파급효과에 대한 산업연관분석)

  • Kim, Yongkyu;Kang, Imho
    • Informatization Policy
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    • v.17 no.2
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    • pp.86-103
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    • 2010
  • This paper computes the economic impact of handset subsidies using the recent Input-Output Tables and compares the results with other alternatives which telecommunications companies can choose. The first scenario is that telecommunications companies give handset subsidies to consumers and sales agents. The second is that the companies do not give the subsidies to them, but instead spend the same amount of subsidy on facility investment. The third is that the companies lower the prices of their mobile communications services and consumers spend the saved expenses on other goods and services. The result is that the production, value added, import, job, employment inducement coefficients of the first scenario is larger than those of the second and third scenarios. The reason is as follows. The handset subsidy results in the incentive to consumers for handset purchase or the incentive for sales agents to sell the telecommunication services of the companies. The former has larger production and import inducement effect, and the latter also has larger value-added, job, and employment inducement effect than those of other scenarios.

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Predicting the Design Rainfall for Target Years and Flood Safety Changes by City Type using Non-Stationary Frequency Analysis and Climate Change Scenario (기후변화시나리오와 비정상성 빈도분석을 이용한 도시유형별 목표연도 설계강우량 제시 및 치수안전도 변화 전망)

  • Jeung, Se-Jin;Kang, Dong-Ho;Kim, Byung-Sik
    • Journal of Environmental Science International
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    • v.29 no.9
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    • pp.871-883
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    • 2020
  • Due to recent heavy rain events, there are increasing demands for adapting infrastructure design, including drainage facilities in urban basins. Therefore, a clear definition of urban rainfall must be provided; however, currently, such a definition is unavailable. In this study, urban rainfall is defined as a rainfall event that has the potential to cause water-related disasters such as floods and landslides in urban areas. Moreover, based on design rainfall, these disasters are defined as those that causes excess design flooding due to certain rainfall events. These heavy rain scenarios require that the design of various urban rainfall facilities consider design rainfall in the target years of their life cycle, for disaster prevention. The average frequency of heavy rain in each region, inland and coastal areas, was analyzed through a frequency analysis of the highest annual rainfall in the past year. The potential change in future rainfall intensity changes the service level of the infrastructure related to hand-to-hand construction; therefore, the target year and design rainfall considering the climate change premium were presented. Finally, the change in dimensional safety according to the RCP8.5 climate change scenario was predicted.

A Study on the Relationship Between Moral Cognitive Distortion and Peer Bullying of Children and Adolescents : Physical, Verbal, Relational, and Cyberbullying (아동·청소년의 도덕적 사고 왜곡과 또래괴롭힘 피해/가해경험 간의 관계 : 신체적, 언어적, 관계적 및 사이버 또래괴롭힘을 중심으로)

  • Lee, Seung Eun;Kim, Eun Young;Kim, Jung Min
    • Journal of Families and Better Life
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    • v.32 no.3
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    • pp.99-114
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    • 2014
  • The purpose of this study is to investigate the relationship between moral cognitive distortion and peer bullying of children and adolescents. For this study, questionnaires on moral cognitive distortion and peer bullying were administered to 678 students in the 4th, 5th, 7th, 8th, 10th and 11th grades in elementary, middle and high schools located in the metropolitan area of Seoul. The data were analyzed through frequency analysis, mean and standard deviation, t-test, two-way ANOVA, Pearson's correlation and stepwise multiple regression analysis using SPSS Win 12.0. The main findings of this study are as follows: 1) While grade had a significant influence on the moral cognitive distortion of children and adolescents, gender did not. On bullying perpetration and bullying victimization, both gender and grade had a significant influence. 2) Moral cognitive distortion had a significant influence on peer bullying. More specifically, for elementary school students, the variables affecting bullying victimization and bullying perpetration were found to be worst-case-scenario thinking and other-blame thinking, respectively. For middle school students, victimization was affected most significantly by worst-case-scenario thinking, followed by gender; perpetration was most significantly affected by worst-case-scenario thinking. For high school students, victimization was affected most significantly by other-blame thinking, followed by gender; perpetration was most significantly affected by other-blame thinking.

An Analysis on Supply-Demand Outlook of Korean Omija(Medicinal Plant) (약용작물 오미자의 중장기 수급전망 분석)

  • Choi, Byung-Ok;Kim, Bae-Sung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.5
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    • pp.2689-2694
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    • 2014
  • This study analyze the impact of omija(maximowiczia chinensis) market by Korea-China FTA and review the change of mid and long term supply-demand from 2014 to 2018. A scenario is also imported to simulate and measure the impacts of the Korea-China FTA. The scenario is that tariff rates for Chinese product(omija) will be zero after 5 years from 2014. A partial equilibrium model of Omija is specified to forecast mid and long term supply-demand and prices. Equations in the model were estimated by using econometric techniques. The results based on scenario are compared with the results by the baseline case(maintenance of current situation). Our study show that when the tariff rates for Chinese product(Omija) will be zero after 5 years from 2014, the cultivated area of Omija is forecasted to decline until 3,370ha in 2018, and the consumption is forecasted to increase up to 12,040.8MT in 2018, and also total revenue of about 9.8 billion korean won will be decreased during 5 years(2014-2018).

Analysis of Flood Control Capacity of Agricultural Reservoir Based on SSP Climate Change Scenario (SSP 기후변화 시나리오에 따른 농업용 저수지 홍수조절능력 분석)

  • Kim, Jihye;Kwak, Jihye;Hwang, Soonho;Jun, Sang Min;Lee, Sunghack;Lee, Jae Nam;Kang, Moon Seong
    • Journal of The Korean Society of Agricultural Engineers
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    • v.63 no.5
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    • pp.49-62
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    • 2021
  • The objective of this study was to evaluate the flood control capacity of the agricultural reservoir based on state-of-the-art climate change scenario - SSP (Shared Socioeconomic Pathways). 18 agricultural reservoirs were selected as the study sites, and future rainfall data based on SSP scenario provided by CMIP6 (Coupled Model Intercomparison Project 6) was applied to analyze the impact of climate change. The frequency analysis module, the rainfall-runoff module, the reservoir operation module, and their linkage system were built and applied to simulate probable rainfall, maximum inflow, maximum outflow, and maximum water level of the reservoirs. And the maximum values were compared with the design values, such as design flood of reservoirs, design flood of direct downstream, and top of dam elevation, respectively. According to whether or not the maximum values exceed each design value, cases were divided into eight categories; I-O-H, I-O, I-H, I, O-H, O, H, X. Probable rainfall (200-yr frequency, 12-h duration) for observed data (1973~2020) was a maximum of 445.2 mm and increased to 619.1~1,359.7 mm in the future (2011~2100). For the present, 61.1% of the reservoirs corresponded to I-O, which means the reservoirs have sufficient capacity to discharge large inflow; however, there is a risk of overflowing downstream due to excessive outflow. For the future, six reservoirs (Idong, Baekgok, Yedang, Tapjung, Naju, Jangsung) were changed from I-O to I-O-H, which means inflow increases beyond the discharge capacity due to climate change, and there is a risk of collapse due to dam overflow.

Performance Analysis on Speed Quality of LTE-Maritime Considering Scenario of e-Navigation Service and the Modulation Coding Scheme(MCS) (이내비게이션 서비스 시나리오 및 변조코딩방식(MCS)을 고려한 초고속해상무선통신망(LTE-Maritime)의 전송속도 성능 분석)

  • Kim, Bu-Young;Shim, Woo-Seong
    • Journal of Navigation and Port Research
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    • v.45 no.6
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    • pp.360-365
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    • 2021
  • LTE-maritime, which was built as part of the Korean e-Navigation project, has been providing a service that meets the goal of establishing a network up to 100km from the coast since J anuary 31, 2021. To provide appropriate communication services for LTE-maritime from the perspective of real users, additional performance analysis of LTE-maritime is required considering service implementation, and efficient use of spectrum resources. This paper presents the requirement of transmission speed according to the e-Navigation service scenario, and available transmission speed based on LTE modulation coding scheme (MCS) according to sea-specific ship distribution scenario and frequency resource allocation, and is cross-analyzed with results of the sea test.

An analysis of in-service teachers' perceived interactivity with AI teachers through RPP(Role-Play Presentation) (RPP(Role-Play Presentation)를 통한 교사의 AI 교사와의 지각된 상호작용성 분석)

  • Ko, Ho Kyoung;Huh, Nan;Noh, Jihwa
    • The Mathematical Education
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    • v.60 no.3
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    • pp.321-340
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    • 2021
  • As many changes in the future society represented by the age of artificial intelligence(AI) are expected to come, efforts are being made to draw the shape of the future education and various research methods are being employed to support the attempts. While many research studies use methods for deriving generalized results such as expert survey and trend analysis in along with a review of literature, there are attempts to apply the scenario methodology to explore ideas and information needed within a changing context. A scenario method, one of the experiential learning strategies, aims to seek various and alternative approaches by establishing a plan from the present conditions considering future changes. In this study, in-service teachers' perceptions and expectations of the interactivity between human and AI teachers were visualized by applying the role-play presentation technique that grafted the concept of role-play game to the scenario method. In addition, the mandal-art method was introduced to support in conducting productive discussion during the teachers' collaboration. This method appeared to help to depict teachers' perceptions of AI teachers in the detailed and concrete form, which may flow in the abstract otherwise. Through analyses of the teachers' role-play presentations with the implementation of the madal-art method it was suggested that most teachers would want to collaborate with an AI teacher for improved instruction and individualized student learning while they would take the instructional authority over the AI teacher in the classroom.

Study on the influence of flow blockage in severe accident scenario of CAP1400 reactor

  • Pengcheng Gao;Bin Zhang ;Jishen Li ;Fan Miao ;Shaowei Tang ;Sheng Cao;Hao Yang ;Jianqiang Shan
    • Nuclear Engineering and Technology
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    • v.55 no.3
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    • pp.999-1008
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    • 2023
  • Deformed fuel rods can cause a partial blockage of the flow area in a subchannel. Such flow blockage will influence the core coolant flow and further the core heat transfer during the reflooding phase and subsequent severe accidents. Nevertheless, most of the system analysis codes simulate the accident process based on the assumed flow blockage ratio, resulting in inconsistencies between simulated results and actual conditions. This paper aims to study the influence of flow blockage in severe accident scenario of the CAP1400 reactor. First, the flow blockage model of ISAA code is improved based on the FRTMB module. Then, the ISAA-FRTMB coupling system is adopted to model and calculate the QUENCH-LOCA-0 experiment. The correctness and validity of the flow blockage model are verified by comparing the peak cladding temperature. Finally, the DVI Line-SBLOCA accident is induced to analyze the influence of flow blockage on subsequent CAP1400 reactor core heat transfer and core degradation. From the results of the DVI Line-SBLOCA accident analysis, it can be concluded that the blockage ratio is in the range of 40%-60%, and the position of severe blockage is the same as that of cladding rupture. The blockage reduces the circulation area of the core coolant, which in turn impacts the heat exchange between the core and the coolant, leading to the early failure and collapse of some core assemblies and accelerating the core degradation process.