• Korean Journal of Remote Sensing
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• v.23 no.1
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• pp.33-42
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• 2007

In this paper, an iterative MAP approach using a Bayesian model based on the lognormal distribution for image intensity and a GRF for image texture is proposed for despeckling the SAR images that are corrupted by multiplicative speckle noise. When the image intensity is logarithmically transformed, the speckle noise is approximately Gaussian additive noise, and it tends to a normal probability much faster than the intensity distribution. MRFs have been used to model spatially correlated and signal-dependent phenomena for SAR speckled images. The MRF is incorporated into digital image analysis by viewing pixel types as slates of molecules in a lattice-like physical system defined on a GRF Because of the MRF-SRF equivalence, the assignment of an energy function to the physical system determines its Gibbs measure, which is used to model molecular interactions. The proposed Point-Jacobian Iterative MAP estimation method was first evaluated using simulation data generated by the Monte Carlo method. The methodology was then applied to data acquired by the ESA's ERS satellite on Nonsan area of Korean Peninsula. In the extensive experiments of this study, The proposed method demonstrated the capability to relax speckle noise and estimate noise-free intensity.

• Journal of Labour Economics
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• v.42 no.3
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• pp.39-74
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• 2019

In this paper, the wage equations of local labor markets for college graduates in Korea are estimated by Dahl(2002)'s methodology to correct for selection bias. The results suggest that the variations of coefficients in wage equations across the local labor markets are mostly remained after correcting for selection bias. The gender wage gap is hardly affected by selection bias. The variations of return to education and the major premium are reduced about 18% and 11% respectively. Meanwhile, the selection bias is negligible in the national capital region, which suggests that college graduates prefer the national capital region regardless of their gender, level of education, and major.

• The Journal of Information Systems
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• v.27 no.4
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• pp.149-165
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• 2018

Purpose As Korean economy has been sluggish in recent years, firms' interest in publicly financed projects has increased due to the relatively increasing proportion in the economy. Since 1999, publicly financed projects in Korea need to undergo preliminary feasibility study to evaluate economic efficiency and policy quality if they are larger than a certain scale. The benefits of public projects are one of the most important factors in the preliminary feasibility study but are difficult to estimate due to their nature. Design/methodology/approach This study estimates the benefits of the agricultural soil information database, a public database in Korea. The method used in the study is the stated preference method which is formally used in Korea's preliminary feasibility study. Data are collected through surveys and a logit model is constructed to be estimated by the maximum likelihood estimation method. Findings As the first study evaluating a public database, this study can be used as a baseline in all public database projects developed in the future. In addition, this study can contribute to improving the understanding of both private companies and public organizations who are interested in the cost-benefit analysis and estimation procedure for the publicly financed projects.

• Journal of the Korean Solar Energy Society
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• v.39 no.5
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• pp.29-40
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• 2019

In response to the rapid climate change, in order to save energy in the field of buildings, the country is planning not only zero energy buildings but also zero energy cities. In the Urban Development Project, the Energy Use Plan Report is prepared and submitted by predicting the amount of energy demand at the planning stage. However, due to the activation of zero-energy buildings and the increase in the supply of new and renewable energy facilities, the energy consumption behavior of buildings in the city is changing from the previous ones. In this study, to estimate urban energy demand of Zero Energy City, building energy demand forecasts based on "Passive plans for use of energy based primary energy consumption", "Actual building energy usage data from Korea Appraisal Board" and "data from Certification of Building Energy Efficiency Rating" as well as demand forecast according to existing "Consultation about Energy Use Plan Code" were calculated and then applied to Multifunctional Administrative City 5-1 zone to compare urban total energy demand forecasts.

• Journal of Korean Society on Water Environment
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• v.27 no.6
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• pp.822-829
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• 2011

The purpose of the present study is to estimate the ecological instream flow for conservation and restoration of fish habitat in running water ecosystem which has very important status for stream environment. Estimation of the ecological instream flow in the present study was carried out by application of a two-dimensional depth averaged model of river hydrodynamics, River2D model. It can model fish habitat in natural streams and rivers and assess the quality of physical habitat accoriding to the species preferences for habitat suitability. Zacco platypus and Zacco temmincki were selected as target fish species in the study area of the Seomjin river. The Habitat Suitability Criteria (HSC) developed by Sung et al. (2005) were used for target fish species, life stages and habitat conditions in the study. Weighted usable area (WUA) was computed by the River2D model considering preferences of target fish species for velocity, depth, and channel substrate. The result revealed that the ecological instream flow of $10.0m^3/s$ is needed to maintain the target fish habitat at each life stage in the river.

• Korean Journal of Remote Sensing
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• v.38 no.1
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• pp.1-20
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• 2022

As unmanned aerial vehicle (UAV) technology grew in popularity over the years, it was introduced for air quality monitoring. This can easily be used to estimate the sidewalk emission concentration by calculating road traffic emission factors of different vehicle types. These calculations require a simulation of the spread of pollutants from one or more sources given for estimation. For this purpose, a Gaussian plume dispersion model was developed based on the US EPA Motor Vehicle Emissions Simulator (MOVES), which provides an accurate estimate of fuel consumption and pollutant emissions from vehicles under a wide range of user-defined conditions. This paper describes a methodology for estimating emission concentration on the sidewalk emitted by different types of vehicles. This line source considers vehicle parameters, wind speed and direction, and pollutant concentration using a UAV equipped with a monocular camera. All were sampled over an hourly interval. In this article, the YOLOv5 deep learning model is developed, vehicle tracking is used through Deep SORT (Simple Online and Realtime Tracking), vehicle localization using a homography transformation matrix to locate each vehicle and calculate the parameters of speed and acceleration, and ultimately a Gaussian plume dispersion model was developed to estimate the CO, NOx concentrations at a sidewalk point. The results demonstrate that these estimated pollutants values are good to give a fast and reasonable indication for any near road receptor point using a cheap UAV without installing air monitoring stations along the road.

• Journal of Distribution Science
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• v.20 no.5
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• pp.119-127
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• 2022

Purpose: The purpose of this study is to analyze the Cost-Effectiveness Analysis (CEA) of wholesale and retail brokerage businesses in Korea. And give managerial implications and contribute to academics. Research design, data and methodology: This research empirically analyzes the relationship between expenses and business performance. As for business performance, this research considered two financial performances; sales and profit. As for antecedent variables, this research measured three cost investment expenses; human resource management (HRM), marketing (MKT) and corporate social responsibility (CSR). This research used frequency analysis, correlation analysis, stepwise regression analysis and curve estimation analysis. Results: The result shows that HRM and CSR positive significant influence on sales yet marketing negatively significant influence on sales. And for profit, HRM and CSR give a positive significant influence. However, marketing's influence was not significant. According to curve estimation analysis, the relation between individual cost and performance, best functional relation was all quadratic functions. Some results show ∩ shape and others show shape. Conclusions: Based on this study result, implications for practical management to Wholesale and Retail Brokerage companies in Korea. And the contribution to academics is expected. Also, based on the limitation of this study, future research is suggested.

• Asia-Pacific Journal of Business
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• v.13 no.3
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• pp.329-341
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• 2022

Purpose - The purpose of this study was to investigate consistency in estimating the number of vacant jobs using the two business labor force survey with two different time points of survey. Design/methodology/approach - We studied the cause of the differences in estimating the number of vacant jobs between the monthly sample and the new sample in business labor force survey. Findings - To summarize our findings, As the size of the company increases, the number of vacant jobs in the company also increases, and the probability that the number of vacant jobs in the company is zero decreases. The monthly sample was assessed to have a higher likelihood that the number of vacant jobs in the company was zero and the number of vacant jobs was considerable compared to the local sample. Research implications or Originality - Because local survey sample companies tend to minimize the number of vacant jobs even when they reply under the same conditions, the estimation result of the number of vacant jobs in the current monthly survey differs significantly from the estimation result of the local survey. Divergent "degrees of knowledge of question items," survey methodologies, or investigators could be the causes of the various response trends.

• Journal of Distribution Science
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• v.21 no.6
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• pp.99-106
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• 2023

Purpose: This study aims to analyze the distribution of the role of adversity quotient in the estimation bias of future earnings. Adversity quotient is a cognitive ability that can be distributed as a reducer of bias effects that occur in profit forecasting or investment decision making. Research design, data and methodology: The study designs a full factorial within-subject 2×3 as a laboratory experiment. The study subjects are 30 accounting students who are proxied as investors. Results: The results show that the estimated earnings made by investors experience anchoring-adjustment heuristic bias which means the initial value becomes a basic belief that influences the decisions taken by investors. However, this study also provides evidence that heuristic bias can be reduced by the presence of adversity quotient. Investors who have high adversity ability are abler to reduce the estimation bias when compared to investors who have medium and low adversity ability so the higher the difficulty ability possessed by investors, the less likely the occurrence of bias in decision making. Conclusion: Thus, the adversity quotient is proven to be distributed as a reducing opportunity from the bias that will occur in estimating future earnings or making investment decisions.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.676-684
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• 2009

Decision making at the early stages of a construction project has a significant impact on the project, and various scenarios created based on the owner's requirements should be considered for the decision making. At the early stages of a construction project, the information regarding the project is usually limited and uncertain. As such, it is difficult to plan and manage the project (especially cost planning). Thus, in this study, a cost model that could be varied according to the owner's requirements was developed. The cost model that was developed in this study is based on the case-based reasoning (CBR) methodology. The model suggests cost estimation with the most similar historical case as a basis for the estimation. In this study, the optimization process was also conducted, using genetic algorithms that reflect the changes in the number of project characteristics and in the database in the model according to the owner's decision making. Two optimization parameters were established: (1) the minimum criteria for scoring attribute similarity (MCAS); and (2) the range of attribute weights (RAW). The cost model proposed in this study can help building owners and managers estimate the project budget at the business planning stage.