• Title/Summary/Keyword: uncertainty management

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Stochastic Disaggregation and Aggregation of Localized Uncertainty in Pavement Deterioration Process (포장파손과정의 지역적 불확실성에 대한 확률적 분해와 조합)

  • Han, Daeseok
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.4
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    • pp.1651-1664
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    • 2013
  • Precise analysis on deterioration processes of road pavements is not so simple matter due to severe uncertainty originated from a lot of explanatory variables engaged in. For those reasons, most analytical models for pavement deterioration prediction have often preferred to probabilistic approaches than deterministic models. However, the general probabilistic approaches that treat overall characteristics of population or entire sample would not be suitable for providing detail or localized information on their changing process. Considering the aspects, this paper aimed to suggest a stochastic disaggregation method to analyze the localized deterioration speeds and its variances changed by time and condition states. In addition, life expectancies and their uncertainty were estimated by probabilistic algorithm using the disaggregated stochastic process. For an empirical study, pavement inspection data (crack) accumulated from 2003 to 2010 from Korean national highway network was applied. This study can contribute to securing reliability of life cycle cost analysis, which is one of the primary analyses in road asset management, with much advanced deterioration forecasting functions. In addition, it would be meaningful trials as fundamental research for preventive maintenance strategy that demands essential understanding on changing process of the deterioration speed of pavement.

Real Option Analysis on Ship Investment Valuation

  • Kim, Chi-Yeol;Ryoo, Dong-Keun;Kim, Jae-Kwan
    • Journal of Navigation and Port Research
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    • v.33 no.7
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    • pp.469-476
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    • 2009
  • Recent collapse of shipping market right after unprecedent surge clearly demonstrates that shipping industry is extremely risky. Due to the volatile movements of the freight rates, investors tend to ask higher rate of return; higher required return reduces the total net present value of the investment project. For several decades, the Discounted Cash Flow(DCF hereafter) analysis has been the most frequently used valuation technique. However, the main problem of the DCF analysis is its assumption that the discount rate would stay the same during the project life. In other words, it usually does not address the decisions that managers have after a project has been accepted. The purpose of this study is investigate a new valuation method of investment: the Real Option Analysis(ROA hereafter) on ship investment. By replacing the existing valuation methods with the new one, the research will present a new perspective on investment with uncertainty. While uncertainty increases risk of investment and consequently discounts the value of it in the traditional feasibility analysis, in the ROA, a new valuation method which will be addressed in the research, uncertainty means some additional value of flexibility so that the tool can help investors produce more accurate decisions. Contrary to the DCF analysis, the ROA takes managerial flexibilities into account. In reality, capital budgeting and project management is typically dynamic, rather than static in nature. The ROA finds and assesses the values of managerial flexibilities or real options in the investments. The main structures of the research will be as follows: (1) overview of the ship investment project, (2) evaluation of the project by the Net Present Value analysis, (3) evaluation of the same project by the Real Option Analysis, (4) comparision of the two techniques.

Performance tests and uncertainty analysis of precipitation types (강수량계 종류별 성능시험 및 불확도 분석)

  • Hong, Sungtaek;Park, Byungdon;Kim, Jonglib;Jung, Hoekyung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.22 no.7
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    • pp.935-942
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    • 2018
  • Precipitation has a wide range of applications, such as the management and operation of dams and rivers, supply of dranking water for urban and industrial complex, farming and fishing, forest greening, and safety management. In order to prepare for disasters and to obtain economical effects in case of flood damage, it is necessary to measure accurate precipitation. In this study, we carried out the characteristics tests for various types of rainfall gauge using integrated verification system, which can analyze the performance of collective type rainfall gauge. The uncertainty for tipping bucket rain gauge was 0.0041 mm, where weight type and surface tension type was 0.0045 mm and 0.0039 mm respectively. Therefore, the uncertainty according to the type and characteristics of the precipitation system is not significantly different. The uncertainty is also influenced greatly by the resolution.

The Effect of Mobile Web-Based COVID-19 Isolation Hospitalization Management Training on Patient Uncertainty, Anxiety and Nursing Education Satisfaction (모바일 웹 기반 코로나19 격리 입원관리 교육이 환자의 불확실성, 불안 및 간호교육 만족도에 미치는 효과)

  • Yang, Na Kyung;Seo, Ji Yeong
    • Journal of Korean Clinical Nursing Research
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    • v.28 no.2
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    • pp.112-121
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    • 2022
  • Purpose: This study aims to identify the effects of mobile web-based COVID-19 isolation hospitalization management training on patient's uncertainty, anxiety, and nursing education satisfaction. Methods: Patients hospitalized with COVID-19 isolation rooms from August to October 2021, in Medical Center B which is an infectious disease dedicated hospital located in metropolitan city B were included. The total number of subjects was 142, of which 71 were the experimental group and 71 the control group. As an experimental treatment, a total of 5 minutes and 35 seconds of mobile web-based education were provided to the experimental group three times, including the day of, the first day of, and the second day of hospitalization. Existing training conducted on the control group was provided by the nurses in charge of the ward through oral explanation using printed materials. The data were analysed using the IBM SPSS/WIN 26.0 program. Results: Significant differences were observed between the two groups in pre-and post-assessment of uncertainty scores (t=-22.92, p<.001), anxiety scores (t=-15.03, p<.001) and nursing education satisfaction score (t=11.61, p<.001). Conclusion: As a result of the above, mobile web-based education can be used as an effective educational medium in nursing practice to improve the work efficiency and quality of nursing care and contribute to improving the patient's educational satisfaction.

Factors Affecting Efficiency of Electronic Customs and Firm Performance in Vietnam

  • NGUYEN, Hang Thanh;GRANT, David Bruce;BOVIS, Christopher;NGUYEN, Thuy Thi Le;MAC, Yen Thi Hai
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.2
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    • pp.151-164
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    • 2021
  • The paper identifies the enablers (drivers) and inhibitors (barriers) influencing e-customs implementation in Vietnam (known as a developing country with a lower technological environment) along with determining the impact of e-customs on firm performance. The survey was conducted with the representatives (managers) of firms in five cities and provinces dominating Vietnam's international trade. The data was analyzed using structural equation modeling (SEM). The findings show two significant drivers (enablers) - relative advantages and national culture, while compatibility and ease of use are the barriers. Previous studies showed that cultural dimensions related to 'uncertainty acceptance' and 'individualism' encourage innovation; however, this paper demonstrates that 'uncertainty avoidance' and 'collectivism' promote e-customs deployment in Vietnam. Previously, Vietnamese culture was known for scoring high on cultural dimensions related to 'power distance' and 'short-term orientation'. However, today, as an emerging country, Vietnamese has switched to 'low distance' and 'long-term orientation', especially in terms of e-customs innovation. Additionally, the paper also emphasized that e-customs implementation had a positive influence on firm performance in Vietnam. Based on the results of the paper, policy-makers can devise essential solutions to enhance e-customs implementation as well as managers of firms can set-up strategies to adapt to the modernized environment.

The Influence of Business Environment Factors on the Characteristics of Management Accounting System(MAS) - Focusing on small and mid-sized enterprises (기업의 경영환경요인이 관리회계시스템에 미치는 영향에 관한 연구: 중소기업을 대상으로)

  • Lee, JeongEun;Lee, ChanHo
    • Journal of Korea Society of Industrial Information Systems
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    • v.27 no.3
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    • pp.127-144
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    • 2022
  • This study attempted to analyze the influence of both internal and external business environment factors on the characteristics of the management accounting system (MAS). For this, external business environment factors were divided into environmental uncertainty and market competition while internal factors were classified into management strategy, organizational structure and advanced manufacturing technology. In addition, the characteristics of the MAS were categorized into information scope, timeliness, integration and aggregation. The study results found the followings: Among business environment factors, environmental uncertainty had a relatively significant effect on the scope, integration and aggregation of information while organizational structure revealed the largest influence on timeliness. However, market competition had no particular effect on the characteristics of the MAS.

Factors Influencing Internet Consumer's Purchase Delay Behaviors : Focusing on Situational Factors and Perceived Uncertainty (인터넷 소비자의 구매지연행동에 영향을 미치는 요인 : 상황적 요인과 지각된 불확실성을 중심으로)

  • Kim, Jong-Ouk;Suh, Sang-Hyuk
    • The Journal of the Korea Contents Association
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    • v.14 no.7
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    • pp.407-426
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    • 2014
  • This study analyzed the effects of situational factors and perceived uncertainty on purchase delay behaviors of internet consumers. The survey was conducted from internet consumers in the Seoul Metropolitan areas, and 394 responses were used in the data analysis. The results of this study were as follows. First, the negative experience and avoid regrets of the situational factors had a positive impact on overall purchase delay. The time pressure, changeability about purchase, negative experience and avoid regrets had a positive impact on payment stage delay. Also, the time pressure, negative experience and avoid regrets had a positive impact on shopping cart abandonment. Second, all factors of perceived uncertainty had a positive impact on overall purchase delay and payment stage delay. In addition, the information uncertainty and psychological uncertainty had a positive impact on shopping cart abandonment. Therefore, this study is contributing to the diversification of internet study, and it is provide useful information on the customer management and marketing strategy of internet shopping malls.

Parameter and Modeling Uncertainty Analysis of Semi-Distributed Hydrological Model using Markov-Chain Monte Carlo Technique (Markov-Chain Monte Carlo 기법을 이용한 준 분포형 수문모형의 매개변수 및 모형 불확실성 분석)

  • Choi, Jeonghyeon;Jang, Suhyung;Kim, Sangdan
    • Journal of Korean Society on Water Environment
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    • v.36 no.5
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    • pp.373-384
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    • 2020
  • Hydrological models are based on a combination of parameters that describe the hydrological characteristics and processes within a watershed. For this reason, the model performance and accuracy are highly dependent on the parameters. However, model uncertainties caused by parameters with stochastic characteristics need to be considered. As a follow-up to the study conducted by Choi et al (2020), who developed a relatively simple semi-distributed hydrological model, we propose a tool to estimate the posterior distribution of model parameters using the Metropolis-Hastings algorithm, a type of Markov-Chain Monte Carlo technique, and analyze the uncertainty of model parameters and simulated stream flow. In addition, the uncertainty caused by the parameters of each version is investigated using the lumped and semi-distributed versions of the applied model to the Hapcheon Dam watershed. The results suggest that the uncertainty of the semi-distributed model parameters was relatively higher than that of the lumped model parameters because the spatial variability of input data such as geomorphological and hydrometeorological parameters was inherent to the posterior distribution of the semi-distributed model parameters. Meanwhile, no significant difference existed between the two models in terms of uncertainty of the simulation outputs. The statistical goodness of fit of the simulated stream flows against the observed stream flows showed satisfactory reliability in both the semi-distributed and the lumped models, but the seasonality of the stream flow was reproduced relatively better by the distributed model.

The Uncertainty of Extreme Rainfall in the Near Future and its Frequency Analysis over the Korean Peninsula using CMIP5 GCMs (CMIP5 GCMs의 근 미래 한반도 극치강수 불확실성 전망 및 빈도분석)

  • Yoon, Sun-kwon;Cho, Jaepil
    • Journal of Korea Water Resources Association
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    • v.48 no.10
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    • pp.817-830
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    • 2015
  • This study performed prediction of extreme rainfall uncertainty and its frequency analysis based on climate change scenarios by Coupled Model Intercomparison Project Phase 5 (CMIP5) for the selected nine-General Circulation Models (GCMs) in the near future (2011-2040) over the Korean Peninsula (KP). We analysed uncertainty of scenarios by multiple model ensemble (MME) technique using non-parametric quantile mapping method and bias correction method in the basin scale of the KP. During the near future, the extreme rainfall shows a significant gradually increasing tendency with the annual variability and uncertainty of extreme ainfall in the RCP4.5, and RCP8.5 scenarios. In addition to the probability rainfall frequency (such as 50 and 100-year return periods) has increased by 4.2% to 10.9% during the near future in 2040. Therefore, in the longer-term water resources master plan, based on the various climate change scenarios (such as CMIP5 GCMs) and its uncertainty can be considered for utilizing of the support tool for decision-makers in water-related disasters management.

The Uncertainty as the Healing Function in the Poetry of Robert Frost (프로스트 시에 나타나는 치유적 기능으로서의 불확실성)

  • Kim, Kyoung-Soon
    • Journal of Digital Convergence
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    • v.17 no.12
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    • pp.337-344
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    • 2019
  • The purpose of this study is to explore the uncertainty as the healing function in the poetry of Robert Frost. One of the therapeutic functions in poetry therapy is to make us look into life from a new perspective, which appears in the uncertainty of his poetry. His uncertainty is based on his peculiar poetic theory and philosophy of dualism. This paper reviews these things and deals with aspects of the uncertainty in detail through his poems. The result of this study shows that Frost conveys elements of ambiguity, illogical development and unpredictability in our society and fear, loneliness and anxiety in our daily life, and also offers realistic depictions of complex life as a therapeutic medium for overcoming these problems. So it seems that his poetry provides us with a recovery of psychic health and a possibility of healing and personal growth. Furthermore we need a practical in-depth study on the healing function of English poetry.