• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.39 no.1
• /
• pp.153-161
• /
• 2016

Semiconductor manufacturing has suffered from the complex process behavior of the technology oriented control in the production line. While the technological processes are in charge of the quality and the yield of the product, the operational management is also critical for the productivity of the manufacturing line. The fabrication line in the semiconductor manufacturing is considered as the most complex part because of various kinds of the equipment, re-entrant process routing and various product devices. The efficiency and the productivity of the fabrication line may give a significant impact on the subsequent processes such as the probe line, the assembly line and final test line. In the management of the re-entrant process such as semiconductor fabrication, it is important to keep balanced fabrication line. The Performance measures in the fabrication line are throughput, cycle time, inventory, shortage, etc. In the fabrication, throughput and cycle time are the conflicting performance measures. It is very difficult to achieve two conflicting goal simultaneously in the manufacturing line. The capacity of equipment is important factor in the production planning and scheduling. The production planning consideration of capacity can make the scheduling more realistic. In this paper, an input and scheduling rule are to achieve the balanced operation in semiconductor fabrication line through equipment capacity and workload are proposed and evaluated. New backward projection and scheduling rule consideration of facility capacity are suggested. Scheduling wafers on the appropriate facilities are controlled by available capacity, which are determined by the workload in terms of the meet the production target.

• Journal of Information Technology Services
• /
• v.21 no.2
• /
• pp.97-107
• /
• 2022

Recently, interest in smart factories is increasing. Investments to improve intelligence/automation are also being made continuously in manufacturing plants. Facility automation based on sensor data collection is now essential. In addition, we are operating our factories based on data generated in all areas of production, including production management, facility operation, and quality management, and an integrated standard information system. When producing LCD polarizer products, it is most important to link trace information between data generated by individual production processes. All systems involved in production must ensure that there is no data loss and data integrity is ensured. The large-capacity data collected from individual systems is composed of key values linked to each other. A real-time quality analysis processing system based on connected integrated system data is required. In this study, large-capacity data collection, storage, integration and loss prevention methods were presented for optimization of LCD polarizer production. The identification Risk model of inspection products can be added, and the applicable product model is designed to be continuously expanded. A quality inspection and analysis system that maximizes the yield rate was designed by using the final inspection image of the product using big data technology. In the case of products that are predefined as analysable products, it is designed to be verified with the big data knn analysis model, and individual analysis results are continuously applied to the actual production site to operate in a virtuous cycle structure. Production Optimization was performed by applying it to the currently produced LCD polarizer production line.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.10 no.4
• /
• pp.304-308
• /
• 2005

The response of IPTG induction was investigated through the monitoring of the alkali consumption rate and buffer capacity during the cultivation of recombinant E. coli BL21 (DE3) harboring the plasmid pRSET-LacZ under the control of lac promoter. The rate of alkali consumption increased along with cell growth, but declined suddenly after approximately 0.2 h of IPTG induction. The buffer capacity also declined after 0.9 h of IPTG induction. The profile of buffer capacity seems to correlate with the level of acetate production. The IPTG response was monitored only when introduced into the mid-exponential phase of bacterial cell growth. The minimum concentration of IPTG for induction, which was found out to be 0.1 mM, can also be monitored on-line and in-situ. Therefore, the on-line monitoring of alkali consumption rate and buffer capacity can be an indicator of the metabolic shift initiated by IPTG supplement, as well as for the physiological state of cell growth.

• Proceedings of the Korea Society for Simulation Conference
• /
• 1999.04a
• /
• pp.105-109
• /
• 1999

Tool shop of the D Heavy Industries Co.(DHI) fabricates engines for a bus, truck, small ship. In order to increase the production capacity of engines, DHI will be established the new tool shop that consists of a block line, head line, assembly line, test line and AS/RS in 1999. In order to assure the production capacity designed of the new tool shop for producing engines and improve the production process of it, it is needed to find a bottleneck process and an optimal way of allocating workloads among machines and workers to maximize the production. In a way to solve this, we model the engine fabrication process of the tool shop and analyze its performance by computer simulation. In this study, we at first identify the bottleneck processes of the engine fabrication process under the designed operation policy. Then, we derive some alternative operating policies applicable to the new tool shop of an engine, and analyze the optimal operation policy by comparing the performance of the tool shop following each alternative policy.

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

• Korean Management Science Review
• /
• v.13 no.3
• /
• pp.143-161
• /
• 1996

For an industry, production capacity is defined as the maximum level of output that plants can maintain within the framework of a realistic work schedule, taking account of normal downtime, and assuming sufficient availability of inputs to operate machinery and equipment in place. Such capacity is one of the important and basic due to measure, manage and evaluate the production performance and ability of any industrial bodies. However, the estimating methods now in use in Korea are seemed far from the definition above. And there are not any standard estimating method suggested even in the same sort of manufacturing and also no applicable theory for objective and exact measurement. Thus, in this paper, a new measuring model is suggested as standard and supporting theories are developed for general measurement purpose to any manufacturing industries.

• Proceedings of the Membrane Society of Korea Conference
• /
• 1995.10a
• /
• pp.74-79
• /
• 1995

In the last 10 years, membrane science and technology in Korea have grown fast in terms of basic research and process applications. Even the first large commercial membrane plant in Korea was an ion-exchange membrane process built in 1975 for the production of table salt with an annual capacity of 150,000 tons of salt, membrane processes could not draw general interests from industry not until 1987 when a reverse osmosis plant for the production of process water with a capacity of 10,000 m$^3$/day was built by Kugdong Petroleum Co. Today, the production of water by RO over the capacity of 140,000 m$^3$/day is in operation or under construction in Korea. Consumption of ultra pure water increases sharply in recent years mainly due to the rapid expansion of semiconductor industry and the introduction of ultra high pressure boilers for power plants.

• Journal of the Korean Regional Science Association
• /
• v.12 no.2
• /
• pp.21-36
• /
• 1996

This thesis focused on the extent of the area-by-area gap of the unit production cost that should be taken into account without exception in supply of the local public goods production cost. With the advent of the local autonomy era, what should be considered in the local governmen's production of the local public goods are the government's fiscal capacity and the environmental difference that shows up in accordance with the area's characteristics. Though with the same level of the fiscal capacity, an occurrence of environmental difference will lead inevitably to the different level of actual supply of the local public goods. The method of analysis used in this thesis was first to bring out implicit price, to combine this with induced expenditure function, to separate demand function parameter and cost function parameter, and then to analyzed the impact of environmental variables on the production cost. The environmental variables were set on the basis of the ones that affected expenditure per person of the public goods. The analysis was conducted in distinction of city areas and county areas. The results showed that, in cases of cities, more production cost of the public goods was in presence in urban areas and in areas where there was sluggish development. In other words, distinction could be drawn between areas where there was a large consumption of production cost resulting from poor environmental sparked by slow development and those where additional costs were required due to population concentration caused by a certain level of accomplished development. In the meantime, in cases of county areas, the results were around the same. However, a comparison between city areas and county ones told that overall difference between city areas was not that big in the production cost while that in county areas was large enough. In times ahead, in implementation of grant-in-aid scheme, production cost index for local public goods could be used as it was written in consideration of environmental characteristics of areas concerned.

• Journal of Biosystems Engineering
• /
• v.29 no.1
• /
• pp.1-8
• /
• 2004

In order to solve the shortage of roughage supply for dairy farm in Korea, winter cereal forage production after harvesting of rice in the fallow paddy field was studied. Two parts are already reported at the previous paper - One was the model development of the mechanized production, and the other was the study of feasibility of the model and its desirable direction in Korea. In this study, the model system is applied for a winter cereal wrap silage production model to practice in Kyungbook National University farm on 3ha scale for 3 years. Results of the research are summarized as follows; It takes 2 or 3 working days to process the wrap silage in middle of May in Daegu region. Also, not much particular problem can be found during the application test of mechanized wrap silage production. Field capacity and field efficiency are estimated to be 0.6-0.85㏊/h and 50-70% in mowing, 1.1∼1.7㏊/h and 52∼80% in tedding and raking, 0.6∼1.1㏊/h and 25∼45％ in baling and 0.5∼0.57㏊/h and 75∼85% in wraping, respectively. Total production cost is estimated to be 1,257won/kg-TDN in oversowing and wrap-silage harvest in 1.6㏊ working area. As a result, large scale field is recommended to produce the wrap silage in order to maximize the field capacity.

• Management Science and Financial Engineering
• /
• v.15 no.1
• /
• pp.33-49
• /
• 2009

We examine the effectiveness of the conventional (Q, r) model in managing production-inventory systems with finite capacity, stochastic demand, and stochastic order processing times. We show that, for systems with finite production capacity, order replenishment lead times are highly sensitive to loading and order quantity. Consequently, the choice of optimal order quantity and optimal reorder point can vary significantly from those obtained under the usual assumption of a load-independent lead time. More importantly, we show that for a given (Q, r) policy the conventional model can grossly under or over-estimate the actual cost of the policy. In cases where a setup time is associated with placing a production order, we show that the optimal (Q, r) policy derived from the conventional model can, in fact, be infeasible.