• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.2
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• pp.331-336
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• 2018

In this paper, the life cycle cost of the auxiliary power unit in the conventional 8200 series electric locomotive is evaluated and an effective life cycle cost reduction method is sought. For this, a life cycle cost evaluation model was proposed using IEC 60300-3-3 standard. As a result of analysis, material cost which accounted for a large percentage of preventive maintenance cost, accounted for 64% of total cost, and breakdown maintenance cost was as high as 27%. Except for the cost of preventive maintenance, the breakdown maintenance cost ratio was the highest. In order to reduce the LCC of the auxiliary power unit(APU) of the 8200 series in the future, it is necessary to reduce the material cost in case of development and to secure the high reliability according to the parts manufacturing so as to minimize the maintenance cost.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.12
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• pp.1717-1722
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• 2018

Parts and units of 8200 series electric locomotive are aging, but and source technology is not secured. As a results, maintenance costs are increasing steadily due to using expensive substitute parts. Therefore, various studies have been conducted to reduce maintenance costs. In this paper, the life cycle cost(LCC) of the developed and conventional products were compared and analyzed about main conversion system in 8200 Series electric locomotive. As a result of analysis, the material cost was the highest in the conventional product among the various item costs. On the other hand, it is confirmed that preventive cost was the highest among the costs about the developed product.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.624-631
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• 2022

Highway Rest Areas are envisioned to provide an accessible space for rest and parking for travelers, especially those driving a long distance. In addition, modern highway Rest Areas provide many amenities to highway users, including wifi service, picnic tables, litter barrels, running water, public telephones, and sometimes even free coffee. Various studies were conducted in the domain of Rest Area facility design and their operating costs in different states; however, limited studies were conducted on the maintenance costs of these facilities. Therefore, this study's main objective is to compute the annual maintenance cost of Rest Areas in the state of Nevada. This study also analyzes the main cost categories of the maintenance works. The raw cost data of Nevada Rest Area maintenance from 1990 to 2012 were collected from the Nevada Department of Transportation (NDOT). Results show that the maintenance cost fluctuated over the study period; the maintenance cost decreased from 1991 to 2004 and then increased until 2012. The primary cost categories of maintenance work are labor, equipment, and material costs. Among these, labor cost was the largest category with 56 percent of the total maintenance cost, followed by equipment cost and material cost. The findings of this study may help NDOT and other transportation agencies plan their budget for future Rest Area maintenance activities.

• Journal of Korea Port Economic Association
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• v.21 no.3
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• pp.83-113
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• 2005

In this study, for purpose of searching for measures to lower the logistics costs which is one of the most difficulties for the small-medium sized manufacturers in Pusan and Kimhae, those manufacturers were surveyed with questionnaire about the facts in the export logistics costs, difficulties related to the costs, and measures they thought for lowering the cost. Taking account of findings from the survey, the comprehensive measures of saving the export logistics costs were to be proposed. In the surveyed manufacturers, the problems they thought over export logistics costs lied in short logistics information and transportation-related difficulties in cargo and distribution, insufficient standardization in packaging and the shortage of material handling equipments in unloading. In transportation, frequent non-fulfillment of in-time shipment, cost increase including over consumption of transportation time due to traffic jam, and the biased heavy use of inland transportation were pointed out as problems. In customs clearance, logistics information, and marine insurance, addressed were complexity in custom clearance and bonded transportation procedures, and the shortage of software and hardware to construct logistics information system.

• Journal of the Korea Institute of Building Construction
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• v.12 no.6
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• pp.648-663
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• 2012

With recent attempts to improve quality and productivity, the prefabrication manufacturing system has been occupying an increasing share of the construction area. To minimize site work, material is more frequently being produced and partially assembled at a plant, and then installed at a site. For this reason, the production process is being divided and the materials are being delivered to the site after passing through multiple plants. With these changes in the production process, the materials delivery plan is becoming an important management point. In particular, as road transportation using trucks has a 71 percent share of the domestic transportation market, selecting the proper transportation path is important when delivering materials and equipment to a site. But the management system at the project design phase to calculate the delivery cost by considering the production process of the pre-fab material and the $CO_2$ emission at the material delivery phase is currently lacking. This study suggests a process design model for assembly production of the pre-fab material and transportation logistics based on carbon emission. The suggested model can be helpful to optimize the location of the intermediate plant. It is expected to be utilized as a basic model at the project plan and design phase when subcontractors make decisions on items such as materials procurement, selecting the production method, and choosing the location of the assembly plant.

• Journal of Forest and Environmental Science
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• v.32 no.2
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• pp.173-181
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• 2016

This study designed a model of the efficient production schemes and raw materials transportation optimization of current South Korean's simple and monolithic distribution system of wood to build a SCM (supply chain management) as a basic level to establish a distribution of future by pellet production of raw materials costs and reduce transport costs, and specifically to forest of pallet to contribute to revitalizing the market. The result of each transportation costs after building the best transportation network from raw material supply area to demand area applying transport law was 964,600 thousands Won from 6 supply areas to 7 demand areas. And the result of each model's analysis to get the pellet's efficient production through production cost reduction showed that it reduced from 325,701 Won/t to 240,106 Won/t, results of existing efficient pellet for the production model 8,233 tons over 20,000 tons annual production capacity from the size of the expanded production capacity when the expansion. However, when the production size expanded to 50,000 Tons of the production, the effect was very small even though production cost decreased.

• Journal of the Korean Data and Information Science Society
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• v.21 no.2
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• pp.355-361
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• 2010

This paper addresses a mathematical approach to decision making in a real-world material distribution situation. The problem is characterized by a low-volume and highly-varied mix of products, therefore there is a lot of material movement between the facilities. This study focuses especially on the transportation scheduler with a tool that can be used to quantitatively analyze the volume of material moved, the type of truck to be used, production schedules, and due dates. In this research, we have developed a mixed integer programming problem using the minimum cost, multiperiod, multi-commodity network flow approach that minimizes the overall material movement costs. The results suggest that the optimization approach provides a set of feasible solution routes with the objective of reducing the overall fleet cost.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.17 no.32
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• pp.1-6
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• 1994

Many vehicle routing methods have been suggested, which minimize the routing distances of vehicles to reduce the total transportation cost. In describing a distribution network, we have stated that it is basically a system or a set of locations that, receive or store material plus the routes that connect these locations. Whether the network is spread over some geographic region or is whitin a single facility, the definition remains the same. Implicit in this definition, however, is that both the locations and the transportation between these locations must be considered in any decisions regarding the design of the operation of the overall network. The purpose of this paper is optimal layout using transportation quantity and distance in the total system operation. And we minimize the sum of load-carrier costs and spur costs in this flow network.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1859-1864
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• 2004

An effective methodology is reported for the optimal design of multisite batch production/transportation and storage networks under uncertain demand forecasting. We assume that any given storage unit can store one material type which can be purchased from suppliers, internally produced, internally consumed, transported to or from other plant sites and/or sold to customers. We further assume that a storage unit is connected to all processing and transportation stages that consume/produce or move the material to which that storage unit is dedicated. Each processing stage transforms a set of feedstock materials or intermediates into a set of products with constant conversion factors. A batch transportation process can transfer one material or multiple materials at once between plant sites. The objective for optimization is to minimize the probability averaged total cost composed of raw material procurement, processing setup, transportation setup and inventory holding costs as well as the capital costs of processing stages and storage units. A novel production and inventory analysis formulation, the PSW(Periodic Square Wave) model, provides useful expressions for the upper/lower bounds and average level of the storage inventory. The expressions for the Kuhn-Tucker conditions of the optimization problem can be reduced to two sub-problems. The first yields analytical solutions for determining lot sizes while the second is a separable concave minimization network flow subproblem whose solution yields the average material flow rates through the networks for the given demand forecast scenario. The result of this study will contribute to the optimal design and operation of large-scale supply chain system.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.28 no.4
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• pp.175-178
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• 2018

Copper is a well know material for use as heat sink or heat exchanger. However, copper has a considerable low tensile strength and temperature limit. A material that has a good thermal conductivity, low cost, but also excellent mechanical properties are desired. In order to identify the mechanism for the material properties of cast Cu-Fe alloys, $Cu_{50}-Fe_{50}$ (wt.%) alloy was produced by using a high-frequency induction furnace, a typical metal casting process. The Cu-Fe alloy consists of Cu, ${\alpha}$-Fe, ${\gamma}$-Fe with dendrite structures. The crystal structure and microstructure of the prepared $Cu_{50}-Fe_{50}$ alloy were systematically examined using XRD, FE-SEM, EDS and XRF for electrical devices.