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

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.21-22
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• 2019

This study is designed to apply natural clay replaceable redmud as ceramic material by mixing redmud with the materials used in existing brickmaking in laboratory environment. Therefore, through this study, the redmud is recycled as a raw material for clay bricks and presented as a basic material for the use of redmud in clay bricks.

• Culinary science and hospitality research
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• v.6 no.1
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• pp.103-121
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• 2000

All the food including Korean food is made by boiling preparing raw materials food. and to know how to cook correctly is the basis to cook delicious food. For mankind, finding out fire was the source of enormous change in the development of food culture. I have investigated the difference in cooking Korean style & Western style, by using fire, and known that there is a little difference between two methods except for cooking method by food. Preferably there is a wide difference by combinations of raw materials and cooking method.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.174.6-174
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• 2001

Various raw materials from which iron and steel are made are unloaded from ship and then piled up at the designated yard. The equipment that piles up the raw materials is called Stacker and these materials are then dipped out and sent to unit factories such as blast furnace and cokes using the equipment called Reclaimer. The Reclaimer has an actual size of 16 meter high and 50 meter long and runs back and forth over the rail of about 1.2 km, carrying the materials to each unit factory. Until now, in most cases, Stacker and Reclaimer are manually operated. At POSCO, four workers on a shift basis sit in the operation room as shown in the picture, pile up and dip out the materials, checking them out with their own eyes ...

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.2
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• pp.97-109
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• 2003

This study was conducted to investigate use possibility on waste water sludges of water disposal plant as raw materials of organic compost at Fertilizer Official Regulation of Fertilizer Management Law in 2002. In heavy metal contents, some water service sludges were discovered a little over than the standard levels of raw material regulated in organic compost and most of them were not reached the levels. But they were difficult for using the raw materials of organic compost owing to shortage of the organic content. It was judged that the fiber and leather sludges were much in the heavy metal contents and they couldn't use as the raw materials of organic compost. There was afraid that a little heavy metal contents of cosmetic sludge were less than the levels, but it was possible to use selectively as a raw material.

• Applied Biological Chemistry
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• v.4
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• pp.17-22
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• 1963

Changes of Enzymatic activities and chemical components during Koji preparation of soy sauce with various ratio of soy bean and wheat were studied as first step for checking the current ratio of raw materials for improved soy sauce and determination of proper ratio of them in the respect to its quality and taste, and following results could be obtained. 1. The Protease in the dryed Koji were mainly conmposed of a part which active at the neutral (about pH 6.0) range, while parts which active at acid and alkaline side were inferior. The more amount of wheat increases as raw materials of Koji, the stronger Protease activities of acid and neural side were, while the weaker alkaline side were. 2. Activity of Enzymes were increased rapidly in earlier stage then gradually in later stage or Protease and ${\beta}-Amylase$ rapidly throughout except drying of ${\beta}-Amylase$ during the course of Koji preparation. The more amount of wheat as raw material increases, the stronger Protease and ${\beta}-Amylase$ activity except. ${\beta}-Amylase$ were. 3. Reducing sugar, amino nitrogen, total nitrogen were increased, while total sugar were decreased during the course of Koji preparation. 4. The more amount of wheat increases as raw materials, the more increase reducing sugar, total sugar were, while the total nitrogen were decreased, no noticeable differences were observed in the amino nitrogen among the dryed Kojies.

• Journal of the Korean Wood Science and Technology
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• v.41 no.4
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• pp.346-357
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• 2013

In this study, it was conducted to produce wood pellets using domestic forest thinning residues and examine their quality according to Korean pellet quality standard. Raw materials were composed of larch and mixed broad leaves species. Based on the small-end diameter (6 cm), they were classified into four different types of raw materials such as LM (larch with middle diameter), LS (larch with small diameter), MM (mixed broadleaf with middle diameter), and MS (mixed broadleaf with small diameter). After crushing and drying process, wood pellets were produced by a ring-die type pelletizer using each raw material. Wood pellets made from four different types of raw materials were tested for their quality such as calorific value, moisture content, ash content, inorganic matters and so on. As results of quality analysis, the calorific values of all wood pellets were higher than 198 kcal/kg, and satisfied with the first grade of Korea wood pellet standard. The ash content was slightly increased after pelletizing. Mechanical durability of wood pellets was highly dependent on the types of raw materials. The quality differences among wood pellets were turned out due to different physical and chemical characteristics of raw materials even though the same pelletizing condition was applied.

• Analytical Science and Technology
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• v.20 no.6
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• pp.488-495
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• 2007

A wallpaper having many surfaces in indoor is composed of various raw materials. In this study, TVOC contribution from raw materials of PVC wallpaper was evaluated by using headspace-solid phase microextraction (HS-SPME)-GC/MS. Samples were diluent, resin stabilizer, plasticizer, filler, blowing agent and PVC resin. 9 mL of each sample was put into 22 mL glass vial and they were equilibrated for 1 hour at $100^{\circ}C$. Headspace in vial was absorbed to $75{\mu}m$ Carboxen-PDMS fiber and analyzed by GC/MS. Aromatic compounds like a toluene, ethylbenzene and xylene, ketones compounds like a acetone, methoxyacetone and 2-butanone and alkane compounds like a nonane decane and undecane were identified from raw materials. And alcohol compounds like a ethanol and butanol and aldehydes were detected. TVOC emission of diluent, resin stabilizer, plasticizer, PVC resin, blowing agent and filler were $54.20{\mu}g/g$, $32.88{\mu}g/g$, $0.50{\mu}g/g$, $0.88{\mu}g/g$, $0.22{\mu}g/g$ and $0.11{\mu}g/g$, respectively. Contribution of TVOC emission of diluent, resin stabilizer and PVC resin that were concerned about add ratio were 0.708, 0.129, 0.115, respectively. In conclusion, it's necessary to reduce TVOC emission through improvement of diluent, resin stabilizer and PVC resin. Also, HS-SPME-GC/MS method which was developed in this study will be used for raw materials analysis effectively.

• Korean Journal of Agricultural Science
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• v.49 no.3
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• pp.397-405
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• 2022

Castor oil cake is widely used as a raw material for organic fertilizers (OF) in Korea. Compared to other fertilizer raw materials, it is highly dependent on imports. In terms of replacing raw materials, dehydrated food waste powder (FDP) and castor oil cake have similar nutritional content, and if 30% is replaced, about 20% of the raw material cost can be saved. However, few studies on the effects on crop growth and soil properties when organic fertilizer and dry food waste powder are mixed and applied to the soil have been reported. The effects of an organic fertilizer made by mixing the commercial available organic fertilizer with dehydrated food waste (OF + FDP) on soil properties and the growth of two types of leafy vegetables (lettuce and young radish) were evaluated and compared with the performance of OF. The fresh weights of lettuce and young radish were the highest with OF amendment and stood at 114.3 and 119.0 g·plant^-1, respectively. These were followed by OF + FDP amendment, which produced 103.1 and 109.6 g·plant^-1, respectively. Compared to the control, OF and OF + FDP increased the lettuce fresh weights by about 69% and 52%, respectively, while the fresh weights of the radish were increased by about 223% and 207%, respectively. The soil pH, EC, total carbon content, and organic matter content in OF and OF + FDP increased. The mixture of dehydrated food waste powder and organic fertilizers is expected to improve soil quality and facilitate stable production of crops and contribute to the substitution of imported organic fertilizer raw materials.

• Composites Research
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• v.22 no.4
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• pp.50-53
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• 2009

This paper mainly describes the armor materials, especially the ceramic materials for the personal protection. In the ceramic armor materials, B4C ceramics and SiC ceramics are the most popular materials. The $B_4C$ ceramics which consists of 4 atoms of boron and I atom of carbon is very light and strong. It is usually used to personal protection armor and chair protection in the helicopter. This material must be sintered at very high temperature because it melts at $2400^{\circ}C$. In order to have a good armor property, it must have very high density which is achieved by hot press or subsidiary sintering aid methods such as reducing the particle size of raw materials or mixing the sintering agents to the raw materials.