• Agribusiness and Information Management
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• v.3 no.2
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• pp.43-62
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• 2011

The goal of this study is to determine, based on survey results, the underlying factors that affect the intention of the farmers who have not adopted the Hazard Analysis and Critical Control Points (HACCP) system for the rearing phase of pig production to adopt this system in the future. The research model for this study was con structed based on strategic contingency theory, the theory of the diffusion of innovation, and the technology acceptance model (TAM). Using structural equation modeling with partial least squares (PLS), this study analyzes the effects of the intensity of competition, the environmental uncertainty, the innovativeness and self-efficacy of the individual farmers, and the impact of the credibility of the Agricultural Technology Service Center (ATSC), which acts as the principal agent of technology dissemination and as a leader of change, on the perceived usefulness of technology and the farmers' intention to adopt the system. The results of the analysis are as follows. First, with regard to the underlying factors affecting the intention to adopt the new system, the intensity of competition within the industry and the institutional credibility of the ATSC were inferred to underlie the perceived usefulness. Second, institutional credibility has a positive impact on the perceived usefulness of the system, and the perceived usefulness, in turn, has a positive impact on the intention to adopt. The perceived ease of use also has a positive impact on the intention to adopt. Because the factor that has the biggest impact on the intention of a farm to adopt is the credibility of the ATSC, it is crucial for extension organizations, such as the ATSC, to make greater efforts to promote the expansion of the HACCP system. Because farmers feel that the implementation of the HACCP system is an instrumental strategy for coping with the high intensity of competition within the industry, they attempt to gain a competitive edge through the production of safe livestock products.

• Journal of Korea Water Resources Association
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• v.43 no.2
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• pp.211-220
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• 2010

The objective of this paper presents the application of an "integrated urban flood modeling-runoff model, urban flood model and sewer system model-" in a highly urbanized area of Samcheok where is seriously inundated in 2002 and 2003. For this, we demonstrate how couple a 1-D hydrodynamic model of the river, a 2-D hydrodynamic model of the overland (surface) flow, and a sewer network model including each boundary conditions. In order to make data file for the model, topographic information like elevation and share rate of buildings are directly extracted from DEM or topographical source data without data exchange to avoid uncertainty errors. Furthermore, the research is to assess the impacts of Manning n and buildings influences to inundated depth by changing its share ratio from 10 % to 30 % in low-land urban area. As a results, we found out that the urban inundated depth was decreased by Manning n but increased by buildings ratio. The calculated results of inundation was similar with observed one in 2002 and 2003 flooding. Furthermore, the area was also inundated under not riverbank break case in 2002 flooding.

• Environmental and Resource Economics Review
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• v.23 no.2
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• pp.187-224
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• 2014

We present key issues to consider in estimating damages from price-fixing cases and then apply the procedure addressing those issues to a transportation fuel market. Among the five methods of overcharge calculation, the regression analysis incorporating the yardstick method is the best. If the price equation relates the domestic price to the foreign price and the exchange rate as in the transportation fuel market, the functional form satisfying both logical consistency and modeling flexibility is the log-log functional form. If the data under analysis is of time series in nature, then the ARDL model should be the base model for each market and the regression analysis incorporating the yardstick method combines these ARDL equations to account for inter-market correlation and arrange constant terms and collusion-period dummies across component equations appropriately so as to identify the overcharge parameter. We propose a two-step test for the benchmarked market: (a) conduct market-by-market Spearman or Kendall test for randomness of the individual market price series first and (b) then conduct across-market Friedman test for homogeneity of the market price series. Statistical significance is the minimal requirement to establish the alleged proposition in the world of uncertainty. Between the sensitivity analysis and the model selection process for the best fitting model, the latter is far more important in the economic analysis of damage in price-fixing litigation. We applied our framework to a transportation fuel market and could not reject the null hypothesis of no overcharge.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.5
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• pp.608-616
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• 2015

In this study, we have estimated the storm surge heights using numerical modeling on coastal area, and then evaluated the vulnerability index by applying the vulnerability assessment techniques. Surge modelling for 27 typhoons affected from 2000 to 2014 were simulated by applying the ADCIRC model. The results of validation and verification was in significant agreement as compared with observations for the top 6 ranking typhoons affected. As results, the storm surge heights in Jinhae Bay, Sacheon Bay, Gwangyang Bay, Cheonsu Bay and Gyeonggi Bay were higher than other inner coastal areas, then storm surge vulnerability assessment was performed using a standardization, normalization and gradation of storm surge heights. According to results of storm surge vulnerability assessment, index of Jinhae Bay, Sacheon Bay, Gwangyang Bay etc. are estimated to be vulnerable(4~5) because of the characteristics of storm surge such as inner bay are vulnerable compared with exposed to the open sea areas. However, index in the inner bay of western Jeonnam are not vulnerable(1~3) relatively. It may not appear the typhoons affected significantly for the past 15 years. So, the long-term vulnerability assessment with the sensitivity of geomorphology are necessary to reduce the uncertainty.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.2
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• pp.125-130
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• 2011

Since conventional optimization that is classified as a deterministic method does not consider the uncertainty involved in a modeling or manufacturing process, an optimum design is often determined to be on the boundaries of the feasible region of constraints. Reliability-based design optimization is a method for obtaining a solution by minimizing the objective function while satisfying the reliability constraints. This method includes an optimization process and a reliability analysis that facilitates the quantization of the uncertainties related to design variables. Moment-based reliability analysis is a method for calculating the reliability of a system on the basis of statistical moments. In general, on the basis of these statistical moments, the Pearson system estimates seven types of distributions and determines the reliability of the system. However, it is technically difficult to practically consider the Pearson Type IV distribution. In this study, we propose an enhanced Pearson Type IV distribution based on a kriging model and validate the accuracy of the enhanced Pearson Type IV distribution by comparing it with a Monte Carlo simulation. Finally, reliability-based design optimization is performed for a system with type IV distribution by using the proposed method.

• Journal of Korea Water Resources Association
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• v.51 no.9
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• pp.769-782
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• 2018

Estimation of design floods is typically required for hydrologic design purpose. Design floods are routinely estimated for water resources planning, safety and risk of the existing water-related structures. However, the hydrologic data, especially streamflow data for the design purposes in South Korea are still very limited, and additionally the length of streamflow data is relatively short compared to the rainfall data. Therefore, this study collected a large number design flood data and watershed characteristics (e.g. area, slope and altitude) from the national river database. We further explored to formulate a scaling approach for the estimation of design flood, which is a function of the watershed characteristics. Then, this study adopted a Hierarchical Bayesian model for evaluating both parameters and their uncertainties in the regionalization approach, which models the hydrologic response of ungauged basins using regression relationships between watershed structure and model. The proposed modeling framework was validated through ungauged watersheds. The proposed approach have better performance in terms of correlation coefficient than the existing approach which is solely based on area as a predictor. Moreover, the proposed approach can provide uncertainty associated with the model parameters to better characterize design floods at ungauged watersheds.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.2
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• pp.79-91
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• 2020

Accurate assessment of greenhouse gas emissions is a cornerstone of every climate change response study, and reliable assessment of greenhouse gas emission data is being used as a practical basis for the entire climate change prediction and modeling studies. Essential, fundamental technologies for estimating greenhouse gas emissions include an on-site monitoring technology, an evaluation methodology of uncertainty in emission factors, and a verification technology for reductions. The closed chamber method is being commonly used to measure gas fluxes between soil-vegetation and atmosphere. This method has the advantages of being simple, easily available and economical. This study presented the technical bases of the closed chamber method for measuring methane fluxes from a rice paddy. The methane fluxes from rice paddies occupy the largest portion of a single source of greenhouse gas in the agricultural field. We reviewed the international and the domestic studies on automated chamber monitoring systems that have been developed from manually operated chambers. Based on this review, we discussed scientific concerns on chamber methods with a particular focus on quality control for improving measurement reliability of field data.

• Journal of Distribution Research
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• v.15 no.4
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• pp.87-117
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• 2010

'Entrepreneurship' which means spirit or activity seeking new value by challenging boldly the uncertainty is one of the most important concept in 21st century business environment. Franchise Industry taking a relationship with distribution industry also needs entrepreneurship. As franchise industry consists of small and medium enterprises, the entrepreneurship of franchisor's CEO is important for the franchisor's growth. The purpose of this study is to analyze the factors influencing on the entrepreneurship of franchisor's CEO, and the effect of the CEO's entrepreneurship on franchisor's performance. For this purpose, this study set CEO's psychological characteristics, market characteristics, and social-institutional characteristics as independent variables, CEO's entrepreneurship as parameter variables, and franchisor's performance as dependent variables. And to analyze this study model, this study collected questionnaires from 152 franchisors' CEOs, and uses SEM(Structural Equation Modeling). As the result, 'CEO's Entrepreneurship' influenced on both 'Franchisor's Financial Performance' and 'Franchisor's Non Financial Performance'. The results of this study provide some guides for franchisor's CEO and government policies.

• Journal of Climate Change Research
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• v.9 no.1
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• pp.13-29
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• 2018

This study presented evaluation procedure for selecting appropriate GCMs and downscaling method by focusing on the climate extreme indices suitable for climate change adaptation. The procedure includes six stages of processes as follows: 1) exclusion of unsuitable GCM through raw GCM analysis before bias correction; 2) calculation of the climate extreme indices and selection of downscaling method by evaluating reproducibility for the past and distortion rate for the future period; 3) selection of downscaling method based on evaluation of reproducibility of spatial correlation among weather stations; and 4) MME calculation using weight factors and evaluation of uncertainty range depending on number of GCMs. The presented procedure was applied to 60 weather stations where there are observed data for the past 30 year period on Korea Peninsula. First, 22 GCMs were selected through the evaluation of the spatio-temporal reproducibility of 29 GCMs. Between Simple Quantile Mapping (SQM) and Spatial Disaggregation Quantile Delta Mapping (SDQDM) methods, SQM was selected based on the reproducibility of 27 climate extreme indices for the past and reproducibility evaluation of spatial correlation in precipitation and temperature. Total precipitation (prcptot) and annual 1-day maximum precipitation (rx1day), which is respectively related to water supply and floods, were selected and MME-based future projections were estimated for near-future (2010-2039), the mid-future (2040-2069), and the far-future (2070-2099) based on the weight factors by GCM. The prcptot and rx1day increased as time goes farther from the near-future to the far-future and RCP 8.5 showed a higher rate of increase in both indices compared to RCP 4.5 scenario. It was also found that use of 20 GCM out of 22 explains 80% of the overall variation in all combinations of RCP scenarios and future periods. The result of this study is an example of an application in Korea Peninsula and APCC Integrated Modeling Solution (AIMS) can be utilized in various areas and fields if users want to apply the proposed procedure directly to a target area.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.238-238
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• 2015

There are demands for water environmental analysis of discharge processes in paddy fields, however, it is not fully understood in nutrients discharge process for watershed modeling. As hydrological processes both surface and ground water and agricultural water managements are so complex in paddy fields, the development of lowland paddy fields watershed model is more difficult than upland watershed model. In this research, the improvement of SWAT (Soil and Water Assessment Tool) model for a paddy watershed was conducted. First, modification of surface inundated process was developed in improved pot hole option. Those modification was evaluated by monitoring data. Second, the monitoring data in river and drainage channel in lowland paddy fields from 2012 to 2014 were analyzed to understand discharge characteristics. As a case study, Imbanuma basin, Japan, was chosen as typical land and water use in Asian countries. In this basin, lowland paddy fields are irrigated from river water using small pumps that were located in distribution within the watershed. Daily hydrological fluctuation was too complex to estimate. Then, to understand surface and ground water discharge characteristics in irrigation (Apr-Aug) and non-irrigation (Sep-Mar) period, the water and material balance analysis was conducted. The analysis was composed two parts, watershed and river channel blocks. As results of model simulation, output was satisfactory in NSE, but uncertainty was large. It would be coming from discharge process in return water. The river water and ground water in paddy fields were exchanged each other in 5.7% and 10.8% to river discharge in irrigation and non-irrigation periods, respectively. Through this exchange, nutrient loads were exchanged between river and paddy fields components. It suggested that discharge from paddy fields was not only responded to rainfall but dynamically related with river water table. In general, hydrological models is assumed that a discharge process is one way from watershed to river. However, in lowland paddy fields, discharge process is dynamically changed. This function of paddy fields showed that flood was mitigated and temporally held as storage in ground water. Then, it showed that water quality was changed in mitigated function in the water exchange process in lowland paddy fields. In future, it was expected that hydrological models for lowland paddy fields would be developed with this mitigation function.