• Title/Summary/Keyword: Inventory Cycle

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Life cycle impact assessment of the environmental infrastructures in operation phase: Case of an industrial waste incineration plant

  • Kim, Hyeong-Woo;Kim, Kyeong-Ho;Park, Hung-Suck
    • Environmental Engineering Research
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    • v.22 no.3
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    • pp.266-276
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    • 2017
  • A life cycle impact assessment was applied in an industrial waste incineration plant to evaluate the direct and indirect environmental impacts based on toxicity and non-toxicity categories. The detailed life cycle inventory of material and energy inputs and emission outputs was compiled based on the realistic data collected from a local industrial waste incineration plant, and the Korean life cycle inventory and ecoinvent database. The functional unit was the treatment of 1 tonne of industrial waste by incineration and the system boundary included the incineration plant and landfilling of ash. The result on the variation of the impact by the unit processes showed that the direct impact was decreased by 79.3, 71.6, and 90.1% for the processes in a semi dry reactor, bag filter, and wet scrubber, respectively. Considering the final impact produced from stack, the toxicity categories comprised 91.7% of the total impact. Among the toxicity impact categories, the impact in the eco-toxicity category was most significant. A separate estimation of the impact due to direct and indirect emissions showed that the direct impact was 97.7% of the total impact. The steam recovered from the waste heat of the incineration plant resulted in a negative environmental burden.

Environmental Impact Evaluation for Glass Bottle Recycle using Life Cycle Assessment (LCA를 이용한 유리병 재활용의 환경영향 평가)

  • Baek, Seung-Hyuk;Kim, Hyung-Jin;Kwon, Young-Shik
    • Journal of Environmental Science International
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    • v.23 no.6
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    • pp.1067-1074
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    • 2014
  • Life Cycle Assessment(LCA) has been carried out to evaluate the environmental impacts of glass bottle recycle. The LCA consists of four stages such as Goal and Scope Definition, Life Cycle Inventory(LCI) Analysis, Life Cycle Impact Assessment(LCIA), and Interpretation. The LCI analysis showed that the major input materials were water, materials, sand, and crude oil, whereas the major output ones were wastewater, $CO_2$, and non-hazardous wastes. The LCIA was conducted for the six impact categories including 'Abiotic Resource Depletion', 'Acidification', 'Eutrophication', 'Global Warming', 'Ozone Depletion', and 'Photochemical Oxidant Creation'. As for Abiotic Resource Depletion, Acidification, and Photochemical Oxidant Creation, Bunker fuel oil C and LNG were major effects. As for Eutrophication, electricity and Bunker fuel oil C were major effects. As for Global Warming, electricity and LNG were major effects. As for Ozone Depletion, plate glasses were major effects. Among the six categories, the biggest impact potential was found to be Global Warming as 97% of total, but the rest could be negligible.

Analysis of Multi-branch Inventory Distribution System for an Item with Low Level of Demand : Lost Sale Model (다지점으로 구성된 재고시스템의 최적화 분석 : 저수요, 유실판매 모형)

  • Yoon Seung Chul;Choi Young Sub
    • Proceedings of the Society of Korea Industrial and System Engineering Conference
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    • 2002.05a
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    • pp.349-357
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    • 2002
  • This research is basically deals with an inventory distribution system with several regional sales branches. Under the continuous review policy, each sales branch places an order to its supplier whenever on hand plus on order inventory falls on the order point, and the order quantity is received after elapsing a certain lead time. This research first shows the method how to apply the product with low lever of demand into the continuous review policy. For the application, we use an order level as the maximum level of inventory during an order cycle. Also we analyze the lost sales case as a customer behavior. Further we use variable demands and variable lead times for more realistic situation. Based on the above circumstances, the research mainly discusses those methods to decide the optimal order level, order point, and order quantity for each sales branch which guarantees the system wide goal level of service, while keeping the minimum level of the system wide total inventory.

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INVENTORY OF DIFFERENTIAL ITEMS SELLING AT TWO SHOPS UNDER SINGLE MANAGEMENT

  • Kar, S.;Bhunia, A.K.;Maiti, M.
    • Journal of applied mathematics & informatics
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    • v.11 no.1_2
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    • pp.291-304
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    • 2003
  • Inventory of differential (both good And defective) items purchased in a lot for two shops under a single management is considered here. In the primary shop, the lot is received and separated, only good units are sold and shortages are allowed which are backlogged from the good units specially purchased at the beginning of the next cycle. The separated defective units are continuously transferred and sold at a reduced price from the secondary shop. This inventory model is formulated and illustrated numerically for three scenarios depending upon the time periods of the shops. Inventory, deterioration, two shops.

Analysis of Multi-branch Inventory Distribution System for an Item with Low Level of Demand and Lost Sale Allowed (다지점으로 구성된 재고시스템의 최적화 분석 : 저수요, 유실판매 모형)

  • 윤승철;최영섭
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.25 no.3
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    • pp.78-84
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    • 2002
  • This research is basically deals with an inventory distribution system with several regional sides branches. Under the continuous review policy, each sales branch places an order to its supplier whenever on hand plus on order inventory falls on the order point, and the order quantity is received after elapsing a certain lead time. This research first shows the method how to apply the product with low lever of demand into the continuous review policy. For the application, we use an order level as the maximum level of inventory during an order cycle. Also we analyze the lost sales case as a customer behavior. Further we use variable demands and variable lead times for more realistic situation. Based on the above circumstances, the research mainly discusses those methods to decide the optimal order level, order point, and order quantity for each sales branch which guarantees the system wide goal level of service, while keeping the minimum level of the system wide total inventory.

Uncertainty Assessment for CAPSS Emission Inventory by DARS (DARS에 의한 CAPSS 배출자료의 불확도 평가)

  • Kim, Jeong;Jang, Young-Kee
    • Journal of Korean Society for Atmospheric Environment
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    • v.30 no.1
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    • pp.26-36
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    • 2014
  • The uncertainty assessment is important to improve the reliability of emission inventory data. The DARS (Data Attribute Rating System) have recommended as the uncertainty assessment technic of emission inventory by U.S. EPA (Environmental Protection Agency) EIIP (Emission Inventory Improvement Program). The DARS score is based on the perceived quality of the emission factor and activity data. Scores are assigned to four attributes; measurement/method, source specificity, spatial congruity and temporal congruity. The resulting emission factor and activity rate scores are combined to arrive at an overall confidence rating for the inventory. So DARS is believed to be a useful tool and may provide more information about inventories than the usual qualitative grading procedures (e.g. A through E). In this study, the uncertainty assessment for 2009 CAPSS (Clean Air Policy Support System) emission inventory is conducted by DARS. According to the result of this uncertainty assessment, the uncertainty for fugitive dust emission data is higher than other sources, the uncertainty of emission factor for surface coating is the highest value, and the uncertainty of activity data for motor cycle is the highest value. Also it is analysed that the improvement of uncertainty for activity data is as much important as the improvement for emission factor to upgrade the reliability of CAPSS emission inventory.

The inventory analysis on exhaust gas from training ships for ship's LCA study (선박 전과정평가를 위한 실습선 배기가스 인벤토리 분석)

  • Im, Nam-Kyun;Jo, Ho-Jin
    • Journal of Navigation and Port Research
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    • v.32 no.1
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    • pp.29-35
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    • 2008
  • As the seriousness of the global environment is gaining our attention recently, studies on application of LCA(Life Cycle Assessment) to ship are being carried dynamically in various industry fields. However domestic study on LCA was not carried out in various fields. This study was carried out to examine the application of LCA to ship and was focused on the ship operation inventory analysis especially in life cycle assessment. Two training ships of Mokpo maritime university were adopted as ship models. Actual voyage data of at last several years was used to analysis the ship's exhaust gas inventory. The analysis shows how many weight of gas being exhaused per 1 gross tonnage and per 1 trainee in the training ships.

Optimal Design of Process-Inventory Network under Cycle Time and Batch Quantity Uncertainties (이중 불확실성하의 공정-저장조 망구조 최적설계)

  • Suh, Kuen-Hack;Yi, Gyeong-Beom
    • Journal of Institute of Control, Robotics and Systems
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    • v.16 no.3
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    • pp.305-312
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    • 2010
  • The aim of this study is to find an analytic solution to the problem of determining the optimal capacity of a batch-storage network to meet demand for finished products in a system undergoing joint random variations of operating time and batch material loss. The superstructure of the plant considered here consists of a network of serially and/or parallel interlinked batch processes and storage units. The production processes transform a set of feedstock materials into another set of products with constant conversion factors. The final product demand flow is susceptible to joint random variations in the cycle time and batch size. The production processes have also joint random variations in cycle time and product quantity. The spoiled materials are treated through regeneration or waste disposal processes. The objective function of the optimization is minimizing the total cost, which is composed of setup and inventory holding costs as well as the capital costs of constructing processes and storage units. A novel production and inventory analysis the PSW (Periodic Square Wave) model, provides a judicious graphical method to find the upper and lower bounds of random flows. The advantage of this model is that it provides a set of simple analytic solutions while also maintaining a realistic description of the random material flows between processes and storage units; as a consequence of these analytic solutions, the computation burden is significantly reduced. The proposed method has the potential to rapidly provide very useful data on which to base investment decisions during the early plant design stage. It should be of particular use when these decisions must be made in a highly uncertain business environment.

VMI with Upper Limit of Inventory for Vendor and Retailer (판매자와 구매자의 재고상한이 존재하는 VMI)

  • Lee, Dongju
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.40 no.4
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    • pp.105-111
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    • 2017
  • Vendor Managed Inventory is a well-known vendor-retailer coordination approach in supply chain management where the vendor manages inventory of the retailer and determines the order interval and order quantity for the retailer. To consider practical situation, the upper limit of inventory for the retailer is set. If the inventory level for the retailer exceeds the upper limit, then the penalty cost is charged to the retailer. Furthermore, maximum allowable inventory level is set for the vendor to prevent the vendor from keeping much inventory. Single-vendor multi-retailer supply chain model with upper limit of inventory for vendor and retailers is studied. All the retailers' are assumed to have the common cycle time, and a vendor manages retailers' inventory and replenishes products. The mathematical formulation is introduced to minimize the total cost including the penalty cost violating the upper limit of inventory for retailers with the constraint of maximum allowable inventory level. The solution procedure based on Karush-Kuhn-Tucker (KKT) conditions is derived. KKT conditions are often applied to find an optimal solution of nonlinear programming problem with constraints. An illustrative example is used to show the application of the proposed solution procedure. Furthermore, sensitivity analysis is done to find out the relationship between maximum allowable inventory level and other values such as order quantity, the number of shipment, vendor's cost, retailer's cost, and total cost. As maximum allowable inventory level decreases, the number of shipment decreases but total cost increases. Order quantity has the trend of decline and is affected by the number of shipment.