• Journal of Korean Institute of Industrial Engineers
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• v.42 no.4
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• pp.270-279
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• 2016

A glass product manufacturing company transports a large number of flat glass products from a manufacturing firm to a building construction site. The products are transported using specially designed racks, which assure fewer glass breakages during the deliveries. This study determines the sizes of the racks which minimize the total logistics cost including costs for rack purchasing, handling, transportation, and inventory costs. The determination of the rack size should consider tradeoff relationships between the amount of glasses piled in a rack and the number of racks loaded on a truck, and affects the required number of racks and the truck operational cost. A truck loading algorithm is proposed to maximize a high truck utilization, and an enumeration method is proposed to determine the optimal combination of rack sizes considering the total logistics cost. The numerical example is solved by using a real data.

• Journal of Advanced Navigation Technology
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• v.10 no.3
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• pp.226-234
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• 2006

Aids to Navigation is one of the most important facility for safety at sea. However, in terms of position there always exists discrepancy in inventory by media and/or organizational body who maintains the facility which may result in incredibility for navigator's position fixing or hazard avoidance. This paper suggests two major factors as the causes of the position error when they design, install and survey the aids to navigation. One is the function of direction of tide and water depth which makes swinging circle. The other is a variable value by time resulting from multiple coordination of satellites in contact. This paper aims to minimize inaccuracy by verifying its reason through numerical analysis over inherent position error.

• Journal of Distribution Science
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• v.19 no.8
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• pp.5-12
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• 2021

Purpose: The purpose of this paper is to analyze and examine the issues that are directly associated with the United States COVID-19 vaccine distribution and its strategies so that other countries may learn from it and develop sound distribution strategies. Research design, data and methodology: This paper has applied both historical and narrative models to review, identify, and analyze existing literatures to assess the United States' vaccine distribution strategy. Results: Distribution strategy developed by the United States seems to have focused heavily on the basic tenets of physical distribution, i.e., transportation, warehousing, inventory, and large-venue mass-vaccination sites, and the strategy seems to have been successful when looking only at the physical tenets of distribution. However, the analysis indicates that the distribution strategy has not either focused on or included the major activities of distribution, such as inward and outward communication, information, and customer satisfaction. Conclusions: The countries that are currently developing or implementing COVID-19 vaccine distribution strategy should review and learn from the United States' vaccine distribution strategy and its implementation. The countries should include and address all the activities of distribution, including inward and outward communication, information, and customer satisfaction to achieve their vaccination goals, minimize confusion, reduce wasting of doses and vaccine desserts, and improve vaccination rates.

• Journal of the Korea Society for Simulation
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• v.29 no.4
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• pp.95-109
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• 2020

In this paper, an optimal manufacturing system design problem in an automotive body assembly lines is introduced when various costs such as equipment investment costs are considered. Meta-model methodology based on simulation results has been used for estimating the performances of the system such as production rate and work-in-process levels. The objective function is minimizing total cost which satisfies the target production rate. The investment costs such as robots, buffers, transportation equipment, and the inventory holding cost of work-in-process have been included in the objective function. Harmony search method has been used for optimization.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.508-512
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• 2015

Carbon emission calculation guidelines provided by the Korean Ministry of Land, Infrastructure and Transportation (MOLIT) and existing environmental load assessment studies have suggested a method for estimating based on the volume determined after the design development. Therefore they are not being helpful in the decision making of the environmental economics of road facilities in the planning stage in which specific information on construction output volume is lacking. Based on literature analysis of existing studies and consultation from a group of construction environmental professionals, 12 types of property information considered to be related to environmental load were selected from an inventory of information that will be available in the road planning stage. In addition, multiple regression analysis was performed based on the environmental load computed through the life cycle assessment (LCA) of 40 national highway project cases of Korea to deduce five impact factors of environmental load in the road facilities planning stage.

• Geomechanics and Engineering
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• v.37 no.2
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• pp.135-147
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• 2024

A GIS-based landslide susceptibility mapping (LSM) was carried out using frequency ratio (FR), modified frequency ratio (M-FR), analytic hierarchy process (AHP), and modified analytic hierarchy process (M-AHP) methods to identify and delineate the potential failure zones along the Halong - Vandon expressway. The thematic layers of various landslide causative factors were generated for modeling in GIS, including geology, rainfall, distance to fault, distance to road, slope, aspect, landuse, density of landslide, vertical relief, and horizontal relief. In addition, a landslide inventory along the road network was prepared using data provided by the management department during the course of construction and operation from 2017 to 2019, when many landslides were documented. The validation results showed that the M-FR method had the highest AUC value (AUC = 0.971), which was followed by the FR method with AUC = 0.961. The AUC values were 0.939 and 0.892 for the M-AHP and AHP methods, respectively. The generated LSM obtained from M-FR method classified the study area into five susceptibility classes: very low (0), low (0-1), moderate (1-2), high (2-3), and very high (3-4) classes, which could be useful for various stakeholders like planners, engineers, designers, and local public for future construction and maintenance in the study area.

• Journal of Energy Engineering
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• v.23 no.3
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• pp.72-81
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• 2014

Intergovernmental Panel on Climate Change(IPCC) suggested the three methodology, Tier 1/2/3, considering with the accuracy and difficulty of greenhouse gas emission statistics according to the report determined as the international criterion. In Korea, the existing inventory building was made by the Top-down approach applying with the emission factors for transportation in the entire energy consumption, the emission factors were investigated under the domestic traffic situation which did not reflect by the continuing increase of vehicle and the change of road section. From the suggestion of IPCC, which it is estimated that the emission estimation of $CO_2$ in greenhouse gas emission could be calculated more accurate by the carbon content according to the fuel, the establishment of measures to respond to climate change from the latest greenhouse gas emissions statistics will be able to improve the accuracy of national statistics using monthly or seasonally the analysis of carbon content about the transportation fuels.

• Journal of Korean Society of Transportation
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• v.19 no.4
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• pp.35-47
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• 2001

Traffic represents one of the largest sources of primary air pollutants in urban area. As a consequence. numerous abatement strategies are being pursued to decrease the ambient concentration of pollutants. A characteristic of most of the these strategies is a requirement for accurate data on both the quantity and spatial distribution of emissions to air in the form of an atmospheric emission inventory database. In the case of traffic pollution, such an inventory must be compiled using activity statistics and emission factors for vehicle types. The majority of inventories are compiled using passive data from either surveys or transportation models and by their very nature tend to be out-of-date by the time they are compiled. The study of current trends are towards integrating urban traffic control systems and assessments of the environmental effects of motor vehicles. In this study, a methodology of motor vehicle emission calculation by using real-time traffic data was studied. A methodology for estimating emissions of CO at a test area in Seoul. Traffic data, which are required on a street-by-street basis, is obtained from induction loops of traffic control system. It was calculated speed-related mass of CO emission from traffic tail pipe of data from traffic system, and parameters are considered, volume, composition, average velocity, link length. And, the result was compared with that of a method of emission calculation by VKT(Vehicle Kilometer Travelled) of vehicles of category.

• Journal of the Korean Wood Science and Technology
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• v.44 no.3
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• pp.449-456
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• 2016

This study was aimed to quantify the amount of carbon dioxide emissions and to suggest suitable plans which consider the carbon emission reduction in the manufacturing process of the domestic structural glued laminated timber. Field investigation on two glued laminated timber manufacturers was conducted to find out material flow input values such as raw materials, transportation, manufacturing process, and energy consumption during manufacturing process. Based on the collected data and the relevant literatures about life cycle inventory (LCI), the amount of carbon dioxide emission per unit volume was quantified. Results show that the carbon dioxide emissions for sawing, drying and laminating process are 31.0, 109.0, 94.2 kg $CO_2eq./m^3$, respectively. These results show 13% lesser amount of total carbon dioxide emissions compared with the imported glued laminated timber in Korea. Furthermore, it was decreased about 37% when the fossil fuel would be replaced with biomass fuel in drying process. Findings from this study is effectively used as the basic data on the life cycle assessment of wooden building.

• Korean Journal of Environmental Biology
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• v.38 no.1
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• pp.71-81
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• 2020

In Korea, more than 70% of the ammonia(NH₃) released into the atmosphere is known to originate from livestock manure. The total emission (kg year^-1) is calculated by multiplying the emission factor (kg head^-1 yr^-1) and the activity data (head). To improve the accuracy and reliability of the NH₃ emission estimation process, an accurate account of livestock manure production, calculation of NH₃ conversion and generation during the composting and liquefaction of manure, estimation of NH₃ generation in the storage and transportation of manure and compost, and a comparative study of NH₃ emission during the soil spreading process must be performed. Compared to the US and EU-28, in particular, the domestic emission factor is relatively even and the spatial/temporal scale is not broken down sufficiently to reflect the domestic situation. As a way to improve the accuracy and expertise of estimating NH₃ emission factors, a 'dynamic chamber-capture system' can be utilized, which allows complex considerations of compost, liquid manure, soil, and climate characteristics. By reviewing and comparing the data related to domestic and foreign NH₃ emission, we identified shortcomings in the current domestic system and the directions to be taken and suggested a chamber system that could estimate NH₃ emission flux. It is also necessary to establish a methodology for mesocosm systems in the field, in addition to indoor chamber systems, to be linked with practical policies, such as the calculation of new emission factors for missing sources.