• Title/Summary/Keyword: Estimation Methodology

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Investigating the future changes of extreme precipitation indices in Asian regions dominated by south Asian summer monsoon

  • Deegala Durage Danushka Prasadi Deegala;Eun-Sung Chung
    • Proceedings of the Korea Water Resources Association Conference
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    • 2023.05a
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    • pp.174-174
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    • 2023
  • The impact of global warming on the south Asian summer monsoon is of critical importance for the large population of this region. This study aims to investigate the future changes of the precipitation extremes during pre-monsoon and monsoon, across this region in a more organized regional structure. The study area is divided into six major divisions based on the Köppen-Geiger's climate structure and 10 sub-divisions considering the geographical locations. The future changes of extreme precipitation indices are analyzed for each zone separately using five indices from ETCCDI (Expert Team on Climate Change Detection and Indices); R10mm, Rx1day, Rx5day, R95pTOT and PRCPTOT. 10 global climate model (GCM) outputs from the latest CMIP6 under four combinations of SSP-RCP scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5) are used. The GCMs are bias corrected using nonparametric quantile transformation based on the smoothing spline method. The future period is divided into near future (2031-2065) and far future (2066-2100) and then the changes are compared based on the historical period (1980-2014). The analysis is carried out separately for pre-monsoon (March, April, May) and monsoon (June, July, August, September). The methodology used to compare the changes is probability distribution functions (PDF). Kernel density estimation is used to plot the PDFs. For this study we did not use a multi-model ensemble output and the changes in each extreme precipitation index are analyzed GCM wise. From the results it can be observed that the performance of the GCMs vary depending on the sub-zone as well as on the precipitation index. Final conclusions are made by removing the poor performing GCMs and by analyzing the overall changes in the PDFs of the remaining GCMs.

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Water footprint estimation of selected crops in Laguna province, Philippines

  • Salvador, Johnviefran Patrick;Ahmad, Mirza Junaid;Choi, Kyung-Sook
    • Proceedings of the Korea Water Resources Association Conference
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    • 2022.05a
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    • pp.294-294
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    • 2022
  • In 2013, the Asian Development Bank classified the Philippines among the countries facing high food security risks. Evidence has suggested that climate change has affected agricultural productivity, and the effect of extreme climatic events notably drought has worsened each year. This had resulted in serious hydrological repercussions by limiting the timely water availability for the agriculture sector. Laguna is the 3rd most populated province in the country, and it serves as one of the food baskets that feed the region and nearby provinces. In addition to climate change, population growth, rapid industrialization, and urban encroachment are also straining the delicate balance between water demand and supply. Studies have projected that the province will experience less rainfall and an increase in temperature, which could simultaneously affect water availability and crop yield. Hence, understanding the composite threat of climate change for crop yield and water consumption is imperative to devise mitigation plans and judicious use of water resources. The water footprint concept elaborates the water used per unit of crop yield production and it can approximate the dual impacts of climate change on water and agricultural production. In this study, the water footprint (WF) of six main crops produced in Laguna were estimated during 2010-2020 by following the methodology proposed by the Water Footprint Network. The result of this work gives importance to WF studies in a local setting which can be used as a comparison between different provinces as well as a piece of vital information to guide policy makers to adopt plans for crop-related use of water and food security in the Philippines.

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Admittance Model-Based Nanodynamic Control of Diamond Turning Machine (어드미턴스 모델을 이용한 다이아몬드 터닝머시인의 초정밀진동제어)

  • Jeong, Sanghwa;Kim, Sangsuk
    • Journal of the Korean Society for Precision Engineering
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    • v.13 no.10
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    • pp.154-160
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    • 1996
  • The control of diamond turning is usually achieved through a laser-interferometer feedback of slide position. The limitation of this control scheme is that the feedback signal does not account for additional dynamics of the tool post and the material removal process. If the tool post is rigid and the material removal process is relatively static, then such a non-collocated position feedback control scheme may surfice. However, as the accuracy requirement gets tighter and desired surface cnotours become more complex, the need for a direct tool-tip sensing becomes inevitable. The physical constraints of the machining process prohibit any reasonable implementation of a tool-tip motion measurement. It is proposed that the measured force normal to the face of the workpiece can be filtered through an appropriate admittance transfer function to result in the estimated dapth of cut. This can be compared to the desired depth of cut to generate the adjustment control action in additn to position feedback control. In this work, the design methodology on the admittance model-based control with a conventional controller is presented. The recursive least-squares algorithm with forgetting factor is proposed to identify the parameters and update the cutting process in real time. The normal cutting forces are measured to identify the cutting dynamics in the real diamond turning process using the precision dynamoneter. Based on the parameter estimation of cutting dynamics and the admitance model-based nanodynamic control scheme, simulation results are shown.

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A Study on Calculation of Interior Construction Area Using 3D Modeling Program (3D 모델링 프로그램을 활용한 인테리어 공사면적 산출에 대한 연구)

  • Ha, Seung-Beom
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.1
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    • pp.531-537
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    • 2023
  • Interior construction is required to estimate the quantity of material and the cost expected from 2D drawing in design phase and look for the reasonable method of work. Therefore, exact estimation for quantity and budgeting are very important processes, as a measure of judging the profitability of interior construction. These processes are mostly based on 2D drawing, so time and experienced staff are required. Error and omission can occur because the experienced staff also calculates the area using 2D based drawing. Interior market is currently based on 3D modeling from planning to final design. Accordingly, estimating quantity based on 3D modeling is emerging as a way of reducing error and omission. This paper will present the methodology on calculating area, the basic element of estimating quantity based on 3D Modeling in interior field.

Directed Graph를 이용한 경제 모형의 접근 - Crandall의 탑승자 사망 모형에 관한 수정- ( Directed Graphical Approach for Economic Modeling : A Revision of Crandall's Occupant Death Model )

  • Roh, J.W.
    • Journal of Korean Port Research
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    • v.12 no.1
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    • pp.55-64
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    • 1998
  • Directed graphic algorithm was applied to an empirical analysis of traffic occupant fatalities based on a model by Crandall. In this paper, Crandall's data on U.S. traffic fatalities for the period 1947-1981 are focused and extended to include 1982-1993. Based on the 1947-1981 annual data, the directed graph algorithms reveal that occupant traffic deaths are directly caused by income, vehicle miles, and safety devices. Vehicle mileage is caused by income and rural driving. The estimation is conducted using three stage least squares regression. Those results show a difference between the traditional regression methodology and causal graphical analysis. It is also found that forecasts from the directed graph based model outperform forecasts from the regression-based models, in terms of mean squared forecasts error. Furthermore, it is demonstrates that there exists some latent variables between all explanatory variables and occupant deaths.

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Development and Application of a Methodology to Build Geotechnical Information System Based on Geo-Knowledge Using GIS Technology (GIS를 이용한 지반-지식 기반 지반 정보화 시스템 구축 기법의 개발 및 적용)

  • Sun Chang-Guk;Chung Choong-Ki
    • Journal of the Korean Geotechnical Society
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    • v.22 no.2
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    • pp.55-68
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    • 2006
  • For the reliable prediction of spatial geotechnical data, a procedure to build the Geotechnical Information System (GTIS) based on geo-knowledge within the frame of GIS technology was developed by introducing a couple of new concepts of the extended area containing the study area and the additional site visit for acquiring surface geological data. To build the GTIS for Gyeongju as the case study of regional model application, intensive site investigations and pre-existing geotechnical data collections were performed and additional site visit was also carried out for acquiring surface geo-layer data in accordance with the developed procedure. Within the GTIS based on geo-knowledge for Gyeongiu area, the spatially distributed geo-layers across the extended area were predicted using the geostatistical kriging method and those for the study area were extracted. Furthermore, the spatial distribution maps for the thickess of geo-layers and the depth to bedrock were constructed for the practical use in geotechnical field. It was evaluated that the GTIS based on geo-knowledge developed in this study is superior to the conventional geotechnical GIS in terms of both the standard deviation and the geological expert judgment.

A Study on Impediments and Suggestion in Developing DHRMIS (국방인사정보체계(DHRMIS) 개발의 문제점과 개선안 연구)

  • Rho, Seung-Dam;Yang, Hae-Sool
    • Journal of the Korea Society of Computer and Information
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    • v.14 no.4
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    • pp.161-169
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    • 2009
  • Republic of Korea is actively adopting IT fusion technologies to achieve the goal of 'Advanced National Defense'. This study is aiming to directly contribute to the ongoing DHRMIS project by analyzing its any discovered and substantial problems as well as suggesting improvements. Current difficulties include the efficient estimation on project cost, the lack of statistics for cross-referencing, the inefficient development methodology, compliance with global quality control standard, and the separated command centers. This study suggests the budget appraisal process prior to the actual execution, the introduce of regulatory business registration system, applying an efficient development methodologies as well as ISO9126 standard for quality control, and a centralized command department. We expect this study would contribute to following researches in advancing our national defense.

Rare Disaster Events, Growth Volatility, and Financial Liberalization: International Evidence

  • Bongseok Choi
    • Journal of Korea Trade
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    • v.27 no.2
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    • pp.96-114
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    • 2023
  • Purpose - This paper elucidates a nexus between the occurrence of rare disaster events and the volatility of economic growth by distinguishing the likelihood of rare events from stochastic volatility. We provide new empirical facts based on a quarterly time series. In particular, we focus on the role of financial liberalization in spreading the economic crisis in developing countries. Design/methodology - We use quarterly data on consumption expenditure (real per capita consumption) from 44 countries, including advanced and developing countries, ending in the fourth quarter of 2020. We estimate the likelihood of rare event occurrences and stochastic volatility for countries using the Bayesian Markov chain Monte Carlo (MCMC) method developed by Barro and Jin (2021). We present our estimation results for the relationship between rare disaster events, stochastic volatility, and growth volatility. Findings - We find the global common disaster event, the COVID-19 pandemic, and thirteen country-specific disaster events. Consumption falls by about 7% on average in the first quarter of a disaster and by 4% in the long run. The occurrence of rare disaster events and the volatility of gross domestic product (GDP) growth are positively correlated (4.8%), whereas the rare events and GDP growth rate are negatively correlated (-12.1%). In particular, financial liberalization has played an important role in exacerbating the adverse impact of both rare disasters and financial market instability on growth volatility. Several case studies, including the case of South Korea, provide insights into the cause of major financial crises in small open developing countries, including the Asian currency crisis of 1998. Originality/value - This paper presents new empirical facts on the relationship between the occurrence of rare disaster events (or stochastic volatility) and growth volatility. Increasing data frequency allows for greater accuracy in assessing a country's specific risk. Our findings suggest that financial market and institutional stability can be vital for buffering against rare disaster shocks. It is necessary to preemptively strengthen the foundation for financial stability in developing countries and increase the quality of the information provided to markets.

A Study on Estimation of Labor Value of Female Fishermen (여성어업인의 노동가치 추정에 관한 연구)

  • Jong-Cheon, Kim;Chang-Soo Lee
    • The Journal of Fisheries Business Administration
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    • v.54 no.2
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    • pp.1-14
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    • 2023
  • The sustainability of fishing villages is threatened by manpower shortages due to population aging and poor settlement conditions. In the reality of poor fishing villages, the importance of women's labor is more emphasized than that of the past because female workers are key workers in fishing labor, processing and sales of marine products. However, policy support for female fishermen is not sufficient. The reason for this is that policy makers did not properly recognize the labor value of female fishermen. In fact, fishing villages have emphasized the importance of female workforce as a slogan, but there has been no attempt to estimate the labor value. There was not even a review of the methodology for estimating the value of labor that was attempted in similar fields. As a result, the policy importance of female fishermen was underestimated for there was no attempt to evaluate their value even though women had been continuously participating in the fishery from the past. Female fishermen's labor is under the dual labor structure of housework and fishing labor. Therefore, in this study, housework and fishing labor were estimated separately and the total labor value was calculated. The basic data necessary for estimating the labor value of female fishermen were obtained through a survey. The method of estimating the labor value of female fishermen was used in combination with the present income method and the total replacement cost method. As a result of the study, the total labor value of female fishermen was about 4.4 trillion won, which is about half of the total fishery production of 9 trillion won in Korea.

A Study on the Effect of Storytelling Marketing on Brand Image and Brand Attitude

  • Kim, Hye-Jin;Park, So-Yeon;Park, Hye-Yoon
    • The Journal of Economics, Marketing and Management
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    • v.6 no.4
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    • pp.1-16
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    • 2018
  • Purpose - This study will investigate and identify the relationship between brand image, brand attitude and intent to purchase based on subjects that have remembered or watched more than one storytelling marketing ad related to airlines. The purpose of the project is to secure market competitiveness by presenting the basis for and use of the marketing strategy using storytelling, which can capture the goodwill of the aerospace competition market in the future. Research, design, data, and methodology - Prior to the research model and hypothesis testing phase, a verification factor analysis was conducted to assess internal consistency among each measurement item and to ensure reliability and validity of the measurement tool. Further, the organization was assessed for validity by calculating the mean variance estimation (AVE) and the construction concept reliability (CCR) through a positive factor analysis. Hypothesis verification was analyzed through a structural equation model, and each concept set in the hypothesis was entered as a potential variable, and each measurement item was entered as an observation variable. Results - Airline's storytelling marketing has a significant impact on the brand image and two emotional and cognitive responses have been shown to influence the brand image. In addition, airline storytelling marketing has a significant impact on brand attitudes and airline storytelling marketing derived from factor analysis has shown two emotional and cognitive responses to brand attitudes. Conclusions - The parts derived based on the research results show that storytelling marketing has a strong influence on the airline's brand image and attitude, and that it is necessary for airlines to have a brand image and attitude. Also, forming a favorable brand image has a significant impact on brand attitudes. We believe that by presenting basic data to the aviation industry in future research on airline storytelling, we will be able to increase understanding and contribution to development of storytelling marketing in aviation.