• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1995.04a
• /
• pp.476-486
• /
• 1995

In this paper, an attempt has been made to revise Raafat' s(1985) results on an inventory model for decaying raw materials and the finished product at a constant rate which was based on Goyal's integrated inventory model for a single product system. This paper is concerned with scheduling the frequencies of order quantity of several different raw materials on a production inventory model. The purpose of this paper is to present a simple method of deciding the frequencies of order quantity of raw materials, in the sense of minimizing the average total cost of the system. We describe on iterative procedure for directly determining near optimal frequencies of order quantity for the raw materials and the associated fundamental cycle time which can be used for constructing the production duration of the finished product. In cases where feasible schedules cannot be constructed using the values from the iterative procedure, the procedure provides a basis for changing the order quantity frequencies and the fundamental cycle time to obtain feasible schedules. An example is given to illustrate the derived results.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2014.05a
• /
• pp.150-151
• /
• 2014

A mold of free-form concrete segment can be used only one time. Thus, the construction duration and cost are increased. The materials of the mold such as wood and metal have limitations due to the implementation and reuse. The review of the material of the mold for free-form concrete segment is needed to reduce duration and production cost. Phase change material can be used both to implement free-shape by heating and to produce mold after cooling. After using Phase change material can be re-used to mold by heating. The scope of this study is many kind of phase change materials for molding. The aim of this study is to analyze the phase change materials for production of changable mold for free-form concrete segment. In this study, the paraffin wax that is melted at 64℃ was selected by considering both the energy efficiency and the weather of Korea.

• Carbon letters
• /
• v.13 no.1
• /
• pp.48-50
• /
• 2012

Mass production of graphene-based materials, which have high specific surface area, is of importance for industrial applications. Herein, we report on a facile approach to produce thermally modified graphene oxide (TMG) in large quantities. We performed this experiment with a hot plate under environments that have relatively low temperature and no using inert gas. TMG materials showed a high specific surface area (430 $m^2g^{-1}$). Successful reduction was confirmed by elemental analysis, X-ray photoelectron spectroscopy, thermogravimetic analysis, and X-ray diffraction. The resulting materials might be useful for various applications such as in rechargeable batteries, as hydrogen storage materials, as nano-fillers in composites, in ultracapacitors, and in chemical/bio sensors.

• Journal of Powder Materials
• /
• v.19 no.1
• /
• pp.40-48
• /
• 2012

The current situation of the nanopowders production technology based on the process of electrical explosion of wires is described. The advantages and disadvantages of the electroexplosive technology are indicated. The results of studies characterizing the effect of the electrical explosion conditions on the nanopowders properties are presented, including latest results: conditions of nanopowders passivation, conditions of nanopowders production having narrow size distribution, the methods of nanopowders diagnostic and standartization. In addition, the application and area of future research on this technology are proposed.

• Journal of the Korean Society for Library and Information Science
• /
• v.51 no.3
• /
• pp.215-246
• /
• 2017

Alternative materials for the visually disabled are very important factors for accessing and using information, dissolving the knowledge information gap, social participation and integration. Nevertheless, since alternative materials have been produced, until recently, even under the voluntary efforts of the braille library and the financial support of local governments, the scope of the materials is restricted to literary materials and hobby books, duplicated in title, and limited in format. In this study, we investigated and analyzed the cases of domestic and international library and related organizations' alternative material production and the current state and perception of alternative materials by applying the survey method to special libraries for the visually disabled and the visually disabled. Based on these results, we added suggestions for the improvement for alternative material production and utilization.

• Korean Management Science Review
• /
• v.32 no.4
• /
• pp.19-28
• /
• 2015

This study presents a mathematical programming model to develop production planning in the manufacturing processes for photovoltaic silicon ingots and wafers. The model is formulated as a linear programming model that maximizes total growth margin, which is composed of production cost, inventory cost, shortage cost, and sales profit while considering the constraints associated with the production environments of photovoltaic materials. In order to demonstrate the utility of the model for production planning, we run operations for a planning horizon of a year for a case study. When the primary results of this mathematical programming are compared with the historical records, the model could have resulted in the considerable increase of the total growth margin by effectively reducing inventory cost if a decision maker had employed the model as a decision support system with perfect information for sales demand.

• Journal of Korean Institute of Industrial Engineers
• /
• v.19 no.2
• /
• pp.65-74
• /
• 1993

In this paper, a two-echelon production-inventory model is developed which integrates the production scheduling problem of the multi-products produced on a single facility and the inventory problem of the related raw materials. The setup costs of the final products are assumed to be dependent on the production sequence. The aim is to determine simultaneously the production cycle time and the production sequence of the final products, and the procurement cycle times of the raw materials. For the model developed, a solution algorithm is suggested and illustrated with a numerical example. And the result is compared with those obtained by two separate subproblems.

• Transactions of Materials Processing
• /
• v.20 no.8
• /
• pp.534-539
• /
• 2011

The production technology is the basic of manufacturing for various materials and components. This technology can influence the quality and productivity of leading export products such as automobile, ship, and electronic device. Besides, the production technology is very useful to apply to other manufacturing fields and has a great ripple effect. However, it is very difficult to make the production technology into standardization and knowledge-based database because the production technology is dependent in hands-on experience. In this study, the knowledge-sharing platform for the molding & forming technology which is a branch of the production technology is introduced. This platform is web-based system and has the knowledge authoring tool technologies storage, semantic database, and web portal service. Therefore, the molding & forming technology can be shared and spread easily by the knowledge-sharing platform.

• Journal of Powder Materials
• /
• v.17 no.6
• /
• pp.435-442
• /
• 2010

• Journal of Korean Institute of Industrial Engineers
• /
• v.11 no.2
• /
• pp.29-37
• /
• 1985

This paper studies a production-inventory model which unifies the inventory problem of raw materials and the finished product for a single product manufacturing system. The integrated production-inventory model is formulated wth a nonlinear mixed integer programming problem. An algorithm is developed by utilizing the finite explicit enumeration method. The algorithm guarantees to generate an optimal policy for minimizing the total annual variable cost. A mumerical example involving 15 raw materials is given to illustrate the recommended solution procedure.