• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.831-842
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• 2021

Accurate measurements of feed energy values have a positive effect on the control of feed intake for animals, the formation of prices, and on economic profits. However, few studies have attempted to measure the energy values of domestic roughages and to validate an energy value prediction model. The purpose of this study is to build a database through measurements of the nutrient digestibility and digestible energy results of roughages used in Korea and to evaluate the domestic applicability of the National Research Council (NRC) estimation model. Oat hay, annual ryegrass, tall fescue, barnyard millet, and concentrates for beef cattle were used in the test. As a result of an in vivo digestibility trial, the total digestible nutrients (TDN) of oat hay, annual ryegrass, tall fescue, and barnyard millet were found to be 68.73, 55.02, 55.71, and 52.89%, respectively. As a result of comparing the estimated values using the NRC equation with the in vivo results, there was a difference of 3.55 to 6.84%P in the TDN. Inferred from this result, it is considered that TDN calculations using the NRC equation can be reasonable for the test feeds used in this study. These results can be utilized when revising the Korean Standard Tables of Feed Composition, which provides a comprehensive overview of Korean feed.

• Nuclear Engineering and Technology
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• v.55 no.6
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• pp.2112-2124
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• 2023

With the rise of economic and safety standards for nuclear reactors, new concepts of Gen-IV reactors and modular reactors showed more complex designs that challenge current tools for reactor physics analysis. A Monte Carlo (MC) two-step method was proposed in this work. This calculation scheme uses the continuous-energy MC method to generate multi-group cross-sections from heterogeneous models. The multi-group MC method, which can adapt locally-heterogeneous models, is used in the core calculation step. This calculation scheme is verified using a Gen-IV modular lead-based fast reactor (LFR) benchmark case. The influence of homogenized patterns, scatter approximations, flux separable approximation, and local heterogeneity in core calculation on simulation results are investigated. Results showed that the cross-sections generated using the 3D assembly model with a locally heterogeneous representation of control rods lead to an accurate estimation with less than 270 pcm bias in core reactivity, 0.5% bias in control rod worth, and 1.5% bias on power distribution. The study verified the applicability of multi-group cross-sections generated with the MC method for LFR analysis. The study also proved the feasibility of multi-group MC in core calculation with local heterogeneity, which saves 85% time compared to the continuous-energy MC.

• Structural Engineering and Mechanics
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• v.86 no.6
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• pp.715-730
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• 2023

Broad studies have addressed the issue of structural element damage identification, however, rubber bearing, as a key component of load transmission between the superstructure and substructure, is essential to the operational safety of a bridge, which should be paid more attention to its health condition. However, regarding the limitations of the traditional bearing damage detection methods as well as few studies have been conducted on this topic, in this paper, inspired by the model updating-based structural damage identification, a two-stage bearing damage identification method has been proposed. In the first stage, we deduce a novel bearing damage localization indicator, called element relative MSE, to accurately determine the bearing damage location. In the second one, the prior knowledge of bearing damage localization is combined with sailfish optimization (SFO) to perform the bearing damage estimation. In order to validate the feasibility, a numerical example of a 5-span continuous beam is introduced, also the noise robustness has been investigated. Meanwhile, the effectiveness and engineering applicability are further verified based on an experimental simply supported beam and actual engineering of the I-40 Bridge. The obtained results are good, which indicate that the proposed method is not only suitable for simple structures but also can accurately locate the bearing damage site and identify its severity for complex structure. To summarize, the proposed method provides a good guideline for the issue of bridge bearing detection, which could be used to reduce the difficulty of the traditional bearing failure detection approach, further saving labor costs and economic expenses.

• 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.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.6
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• pp.66-76
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• 2023

The government recently implemented policies to improve transportation for the disabled passengers. On the other hand, metropolitan public transport still lacks adequate services for these individuals. Many new cities lack urban rail lines and focus on high-floor buses for expansion. Wheelchair users can only access to double-decker low-floor seat express buses for intercity travel. This study examined the necessity and rationale for introducing low-floor seat buses by estimating the user's willingness to pay through a contingent valuation method. Two methods for eliciting the willingness to pay were adopted: open-ended and dichotomous choice questions. The binomial logit model was used to estimate the willingness to pay. The results indicated that the general public is willing to pay an additional 126.7 Korean won, while the disabled passengers are willing to pay an additional 117.5 Korean won. When translated into annual economic benefits, this amounts to approximately 35 billion Korean won.

• Journal of Forest and Environmental Science
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• v.40 no.1
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• pp.1-8
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• 2024

Recently, intensive research has been conducted to develop innovative methods for diagnosing plant diseases based on hyperspectral technologies. Hyperspectral analysis is a new subject that combines optical spectroscopy and image analysis methods, which makes it possible to simultaneously evaluate both physiological and morphological parameters. Among the physiological and morphological parameters are classifying healthy and diseased plants, assessing the severity of the disease, differentiating the types of pathogens, and identifying the symptoms of biotic stresses at early stages, including during the incubation period, when the symptoms are not visible to the human eye. Plant diseases cause significant economic losses in agriculture around the world as the symptoms of diseases usually appear when the plants are infected severely. Early detection, quantification, and identification of plant diseases are crucial for the targeted application of plant protection measures in crop production. Hence, this can be done by possible applications of hyperspectral sensors and platforms on different scales for disease diagnosis. Further, the main areas of application of hyperspectral sensors in the diagnosis of plant diseases are considered, such as detection, differentiation, and identification of diseases, estimation of disease severity, and phenotyping of disease resistance of genotypes. This review provides a deeper understanding, of basic principles and implementation of hyperspectral sensors that can measure pathogen-induced changes in plant physiology. Hence, it brings together critically assessed reports and evaluations of researchers who have adopted the use of this application. This review concluded with an overview that hyperspectral sensors, as a non-invasive system of measurement can be adopted in early detection, identification, and possible solutions to farmers as it would empower prior intervention to help moderate against decrease in yield and/or total crop loss.

• Journal of Korean Society of Water and Wastewater
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• v.37 no.6
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• pp.335-345
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• 2023

In Korea, as part of the Green New Deal project toward a carbon-neutral society, it is necessary to build a climate-resilient urban environment to green the city, space, and living infrastructure. To this end, SWMM-ING was improved and the model was modified to analyze the carbon reduction effect. In addition, I plan to select target watersheds where urbanization is rapidly progressing and evaluate runoff, non-point pollution, and carbon reduction effects to conduct cost estimation and optimal design review for domestic rainwater circulation green infrastructure. In this study, green infrastructure facilities were selected using SWMM-ING. Various scenarios were presented considering the surface area and annual cost of each green infrastructure facility, and The results show that the scenario derived through the APL2 method was selected as the optimal scenario. In this optimal scenario, a total facility area of 190,517.5 m² was applied to 7 out of 30 subwatersheds to achieve the target reduction. The target reduction amount was calculated a 23.50 % reduction in runoff and a 26.99 % reduction in pollutant load. Additionally, the annual carbon absorption was analyzed and found to be 385,521 kg/year. I aim to achieve additional carbon reduction effects by achieving the goal of reducing runoff and non-point pollution sources and analyzing annual carbon absorption. Moreover, considering the scale-up of these interventions across the basin, it is believed that an objective assessment of economic viability can be conducted.

• Economic and Environmental Geology
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• v.52 no.5
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• pp.499-508
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• 2019

Based on the preliminary surveys for the occurrences of the Muwellut chrome-nickel mineralized zone ($800km^2$) in northwestern Myanmar, Bophivum area was selected as the detailed exploration area after considering data source, geological potential, metallogenic province, necessity of resource development on target mineral, exploration activity, grade, ore deposit type, nearby operating mine, infrastructure and exploration prediction effect. From 2013 to 2016, KIGAM and DGSE carried out geological and geochemical survey with 1:1,000 scale, magnetic survey(areal extent, $1.672km^2$), trench survey(19 trench, total length 392 m), pitting survey(18 pit, total depth 42.6m), exploration drilling(6holes 600m, 2015; 13holes 617.4m). We analyzed Cr and Ni contents of 77 drill cores with specific gravity in Yangon DGSE analytical center. Considering surface geological survey, geochemical exploration, magnetic survey, trench survey and drilling data, we divided Bophivum area into 8 blocks. Resource estimation are divided into measured and indicated resources. Measured resource is about 9,790t and indicated resource is about 12,080t with the average grade of Cr 11.8% and Ni 0.34%. In case of Bophivum area, if we develop by tying up Webula chrome mineralized zone in the south, it will be possible to upgrade the medium-scale mine. Geologically, the ophiolite belt are distributed in the western and eastern part in Myanmar. So, the exploration technology obtained from exploation in Bophivum area will be helpful to discover the hidden chromitite ore body in Myanmar ophiolite belt in the future.

• Korean Journal of Poultry Science
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• v.18 no.3
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• pp.197-208
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• 1991

This study was conducted to estimated the genetic and phenotypic correlations between economic traits and certain other traits in Korean Native Ogol fowl The data analysis were the record of 450 pullets bred from 150 dams and 20 sires of Korean Native Ogol fowl at Chungnam National University from June 18, 1987 to April 6, 1989. The results obtained are summarized as follows ： 1 The genetic correlation coefficients of the economic traits and body shape components were as follows ： between body weight and shank length, breast width. breast girth, tibia length were 0.210~0.788, 0.231~0.826, 0.610~0.995 and 0.096~0.503 between age at first egg and shank length, breast width, breast girth, tibia length were 0.555~0.626, 0.149~0.270, 0.370~0.445 and 0.014-0.124. between number of egg production and shank length, breast girth, tibia length were -0.446~-0.167, -0.162~-0.320, 0.076~0.336 and 0.203~0.312 ： between egg weight and shank length, breast width, breast girth, tibia length were 0.132~0.498, 0.236~0.410, 0.148~0.775 and -0.019~0.593, respectively. 2. The genetic correlation coefficients of the economic traits and egg components were as follows ： between body weight and albumen weight, yolk weight, shell weight were 0.083~0.591, 0 110~0.541 and 0.336~0.782 between age at the first egg and albumen weight, yolk weight, shell weight were 0.476-0.692, 0.265~0.631 and 0.420~0.519 between number of egg Production and albumen weight, yolk weight, shell weight were -0.578~-0.240, -0.255~-0.060, -0.477~-0.313. between egg weight and albumen weight, yolk weight, shell weight were 0.825~0.939, 0.382~0.564, 0.374~0.337, respectively. 3. The genetic correlation coefficients of the economic traits and egg qualifies were as follows ： between body weight and egg shape index, shell thickness, albumen height, Haugh units were 0.215~0.367, 0.248~0.650, 0.161~0.624, 0.157~0.449. between number of egg production and egg shape index, shell thickness, albumen height, Haugh units were -0.384~-0.207, -0.557~-0.306, -0.555~-0.198, -0.582~-0.074 between egg weight and egg shape index, shell thickness, albumen height, Haugh units were 0.276~0.697, 0.290~0.627, 0.238~0.538, -0.207-0.020, respectively. 4. The genetic correlation coefficients of egg compositions and egg qualities were as follows ： between albumen weight and egg shape index, shell thickness, albumen height and Haugh units were 0.110~0.584, -0.380~-0.002, 0.239~0.887 and -0.195~0.279 ： between yolk weight and egg shape index, shell thickness, albumen height and Haugh units were -0.204~0.160, 0.294~0.133, -0.049~0.133 and -0.196~-0 136 ： between shell weight and egg shape index, shell thickness, albumen height and Haugh units were 0.127~0.503, 0.127~0.476, 0.140~0.273 and -0.172~0.233, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.2
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• pp.143-152
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• 2008

In order to share the understanding agricultural multifunctionality with people, we carried out quantification and monetary evaluation for controlling flood and fostering water resources function in paddy and upland farming in Korea. The amount of water controlling flood and fostering water resources function in paddy farming was much greater than that in upland. The quantification of flood control function could be estimated by sum of the height of dike and water infiltrated during the flooding periods in paddy farming, and water excepting runoff water from precipitation at flooding time in upland farming. As results of estimation of flood control function, the amounts of water controlling flood have been evaluated as $294mm\;year^{-1}$ in paddy farming and $72.6mm\;year^{-1}$ upland farming, and was calculated 3.71 billion MT on a nation basis in 2006. When it was carried out monetary estimation as the cost of dam construction and the depreciation expense by using replacement cost method, flood control functions in paddy and upland were evaluated as 44,338.9 and 7,221.5 billion won, respectively. Comparing with previous reports, monetary value was analyzed much to increase because of rising price cost recently. Fostering water resource functions were also quantified in paddy and upland farming as the amount of water keeping and infiltrating water during the cultivation. In the basis of estimation model, it was showed that paddy and upland farming had been estimated to have $414.28mm\;year^{-1}$, $18.7mm\;year^{-1}$, respectively. They were also calculated to 4.49 and 0.137 billion MT on a nation basis in 2006, respectively. The economic values of fostering water resources function in paddy and upland farming were also estimated to 1,769.4 and 52.8 billion won, respectively, as replacing the amount of water to the cost of drinking water in 2006. There were differences by much to the amounts of controlling flood function and fostering water resource between paddy and upland farming. It means that paddy farming more play an important role in environment than upland farming in Korea.