• Journal of the Korea Institute of Military Science and Technology
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• v.6 no.4
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• pp.56-62
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• 2003

In order to actively cope with international changes such as cessation of the Cold War in the twentieth century, the government has been proceeding the unification project between military and commercial specification leading to cost reduction of military supplies as well as to high effectiveness. Among these efforts, the study on raw materials specifications, which seems to have been widely used for military or commercial fields, has been performed. As the result of these studies, we have reformed military standards through surveying and summarizing military, KS and international specifications on raw materials. Consequently, the reduction of costs for the procurement of military supplies and the maintenance of current military specifications is to be expected.

• Journal of the Korea Institute of Military Science and Technology
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• v.4 no.2
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• pp.130-137
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• 2001

In order to actively cope with international changes such as cessation of the Cold War in the twentieth century, the government has been proceeding the unification project between military and commercial specification leading to cost reduction of military supplies as well as to high effectiveness. Among these efforts, the study on raw materials specifications, which seems to have been widely used for military or commercial fields, has been performed. As the result of these studies, we have reformed military standards through surveying and summarizing military, KS and international specifications on raw materials. Consequently, the reduction of costs for the procurement of military supplies and the maintenance of current military specifications is to be expected.

• Journal of the Korean Ceramic Society
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• v.52 no.6
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• pp.423-428
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• 2015

The machinability of materials is an important factor in engineering applications. Many ceramic components that have complex shapes require machining, typically using diamond tools, which leads to high production cost. Machinable ceramics containing h-BN have recently been developed, but these materials are very expensive because of high cost of raw materials and machining. Therefore the development of low-cost machinable ceramics is desirable. In this study, mullite-$ZrO_2$ ceramics were prepared additions of $Al_2TiO_5$. $ZrSiO_4$, $Al_2O_3$, and $Al_2TiO_5$ powders mixed at various molar ratios with sintering at 1400, 1500, and $1600^{\circ}C$ for 1 hr. Phase formation and microstructure of the sintered ceramics were observed by XRD and SEM, respectively. The machinability of each specimen was tested using the micro-hole machining method. The machinability results show that the ceramics sintered at temperatures over $1500^{\circ}C$ can be used as good low-cost machinable mullite-$ZrO_2-Al_2TiO_5$ ceramics.

• Journal of Electrochemical Science and Technology
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• v.12 no.4
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• pp.398-405
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• 2021

To fabricate a full-scale pilot model of the cost-effective Na-(Ni,Fe)Cl₂ cell, a Na-beta-alumina solid electrolyte (BASE) was developed by applying a one-step synthesis cum sintering process as an alternative to the conventional solid-state reaction process. Also, Fe metal powder, which is cheaper than Ni, was mixed with Ni metal powder, and was used for cathode material to reduce the cost of raw material. As a result, we then developed a prototype Na-(Ni,Fe)Cl₂ cell. Consequently, the Ni content in the Na-(Ni,Fe)Cl₂ cell is decreased to approximately (20 to 50) wt.%. The #1 prototype cell (dimensions: 34 mm × 34 mm × 235 mm) showed a cell capacity of 15.9 Ah, and 160.3 mAh g^-1 (per the Ni-Fe composite), while the #2 prototype cell (dimensions: 50 mm × 50 mm × 335 mm) showed a cell capacity of 49.4 Ah, and 153.2 mAh g^-1 at the 2^nd cycle.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.36 no.4 s.107
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• pp.1-8
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• 2004

Linerboards and corrugating mediums are being produced using recycled old corrugated containers (OCC) as major raw materials. The utilization rate of recycled fibers is ex­pected to increase further in the future to reduce raw material cost. Use of recycled fibers as raw materials for linerboard, however, causes many problems for papermakers. As the utilization rate of recycled fiber and number of recycling of fibers increases, quality and process problems including strength reduction and deterioration of machine runn­ability will increase. To overcome the problem of strength reduction associated with the use of recycled fibrous materials for producing quality linerboards, diverse extensive research efforts and new technological approaches have been taken. In this study, disintegration characteristics of aee was evaluated by determining the unslushed contents. The amount of unslushed content of KOCC was lower than AOCC. But contaminants content of KOCC was higher than AOCC. As the consistency in disintegration increased, the amount of unslushed fiber content decreased.

• Korean Journal of Construction Engineering and Management
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• v.24 no.6
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• pp.66-73
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• 2023

The construction industry suffers losses due to failures in demand forecasting due to price fluctuations in construction raw materials, increased user costs due to project cost changes, and lack of forecasting system. Accordingly, it is necessary to improve the accuracy of construction raw material price forecasting. This study aims to predict the price of construction raw materials and verify applicability through the improvement of the Data Refactor technique. In order to improve the accuracy of price prediction of construction raw materials, the existing data refactor classification of low and high frequency and ARIMAX utilization method was improved to frequency-oriented and ARIMA method utilization, so that short-term (3 months in the future) six items such as construction raw materials lumber and cement were improved. ), mid-term (6 months in the future), and long-term (12 months in the future) price forecasts. As a result of the analysis, the predicted value based on the improved Data Refactor technique reduced the error and expanded the variability. Therefore, it is expected that the budget can be managed effectively by predicting the price of construction raw materials more accurately through the Data Refactor technique proposed in this study.

• Journal of the Korea Safety Management & Science
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• v.6 no.2
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• pp.155-165
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• 2004

It is needed to develop on-line real time management and RFID-PPS(Radio Frequency Identification-Pallet Pool System) by putting information technology. Additionally, it is possible to figure out the flow of all the materials loaded on the RFID pallet; product, material, raw material immediately, so that epoch-making management is possible and it contributes to the reduction of logistics cost because there are little loss or outflow of pallet. The materials flow is getting speedy and inventory is decreasing in the logistics process, and also bad inventory and loss problems are prevented. As a result, not only logistics cost of company but also national logistics cost is decreased. Thus it contributes to the strength of national competitiveness.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.6
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• pp.753-760
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• 2007

For protection of the cylinder wall of the ball mill for grinding raw ore. the inner side of the cylinder is covered with rubber liner. The rubber is easily worn down because the rubber relatively soft compared with raw ore. So the rubber liner in the ball mill cylinder must be replaced almost every year and the cost for replacing rubber liner formidable. In this paper, for reducing or excluding the cost of replacing rubber liner the basalt liner is designed. The basalt materials are generally harder than raw ore and the basalt liner in the ball mill does not wear down and so it can be used almost permanently. The concave surfaces are made on the liner of the ball mill and the liner in the cylinder wall plays also the role of raising the steel balls mixed in the raw ore. The section profiles of the concave surface have an important effect on the performance of the ball mill. The deep concave grooves raise the steel balls to high levels and give the large potential energy to the steel balls impacting to the raw ore. But if the concave grooves are too deep. the steel balls raised too high by the concave grooves fly along the parabolic path and reach to the other side of cylinder wall and so the steel balls do not play the roles of grinding the raw ore. The forces acting to a steel ball in a concave groove of the cylinder liner are also analyzed in this paper. The formulas calculating the height and the impact point of the steel ball are introduced and presented. Based to these formulas, the optimum section profiles of the basalt liner are presented.

• 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.

• Journal of the Korean institute of surface engineering
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• v.33 no.2
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• pp.107-114
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• 2000

In this study, we investigated the possibility of the application of the EzROBO system to direct shaping techniques which can make arbitrary shapes without any specific mold. We formed arbitrary shapes using raw materials of EH-260D (Epoxy＋Binder) with the conditions of $250\mu\textrm{m}$ layer thickness, 0.2MPa working pressure, 20mm/sec working velocity, and 1.8mm needle thickness. The developed Spatial Printing Technique showed enhanced working velocity and lower cost than existing 3DP process, and is expected to replace the existing process through the process optimization in the future.