• Journal of the Korea Institute of Building Construction
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• v.9 no.1
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• pp.43-47
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• 2009

The most of waste foundry sands(WFS) have been discarded. It is very urgent for our country to make a study on recycling of WFS. The one of recycling method of WFS is using them as fine aggregate for concrete. This study provided the optimum amount of WFS and flyash when WFS and flyash were used together in concrete. The concrete made with 60% WFS fine aggregate replacement showed higher compressive strength, splitting tensile strength and modulus of elasticity than normal concrete. In the case that the flyash and WFS are replaced together, the compressive strength and splitting tensile strength were improved at flyash replacement ratio $10%{\sim}20%$ and WFS replacement ratio $40%{\sim}60%$. The increase of WFS and flyash replacement led lower air content. While the increase of WFS replacement led lower slump, the increase of flyash replacement led higher slump.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.9
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• pp.1241-1245
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• 2004

Two separate trials were conducted to determine effects of dietary level of whole flaxseed (WFS; 0, 10 and 15%) on feed intake, weight gain, and carcass yield and quality of Korean Hanwoo cattle. The daily gains of bulls (Trial 1) were not different among treatment groups, but those of cows (Trial 2) fed WFS 15% were higher (p<0.01) than others. Feed intake of both bulls and cows tended to decrease as dietary level of WFS increased. However, feed conversion ratio (feed/gain) of bulls tended to be improved by dietary inclusion of WFS and was significantly improved (p<0.01) in cows by increasing level of WFS. Neither carcass weight nor dressing percentage were affected by WFS level. Back fat thickness of bulls was decreased (p<0.01) by dietary inclusion of WFS and the same trend was observed in cows without statistical significance. Loin-eye area of bulls was not different among treatment groups but was significantly higher (p<0.01) in cows fed WFS. Carcass yield and quality were not improved by WFS addition. The results indicate that WFS is an acceptable fat source in diets of finishing beef cattle to increase energy density without any adverse effects.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.281-286
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• 2001

The development of automobile, vessel, rail road, and machine industry leads increase of foundry production used as their components, which cause a by-product, waste foundry sand (WFS). The amount of the WFS produced in Korea is over 900,000 ton a year, but most WFS buries itself and only 5~6% WFS is recycled as a material in construction materials. In this study, WFS is used as a fine aggregate for concrete. Five types of concretes aimed at the specified strength of 240$\pm$10 kgf/$cm^{2}$ , air contents of 4.5$\pm$1% and slump of 12$\pm$1.5cm were mixed with washed coarse seashore sand(WFS) in which salt was removed and then optimum mix proportion of concrete was determined. Moreover, basic properties such as setting time, workability, bleeding and slump loss of the fresh concrete with WFS were tested and compared with those of the concrete mixed without WFS. In .addition, both compressive strength of hardened concrete at each ages and tensile strength of it at the age of 28 days were measured and discussed.

• IE interfaces
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• v.13 no.4
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• pp.646-657
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• 2000

We developed an efficient small sized weather condition forecasting system (WFS). A cheap NT-server was utilized for handling a large amount of data, while traditional WFS has conventionally relied on Unix based workstation server. The proposed WFS contains automatic weather observing system (AWS). AWS was designed for collecting weather conditions automatically, and it was linked to WFS in order to provide various weather condition information. The existing two phase scheme and chain code algorithm were used for transforming AWS's data into WFS's data. The WFS's data were mapped into geometric information system using various display techniques. Finally the transformed WFS's data was also converted into JPG (Joint Photographic Group) data type, and the final JPG data could be accessible by others though Internet. The developed system was implemented using WWW environment and has provided weather condition forecasting information. Real case is given to show the presented integrated WFS with detail information.

• Journal of the Korea Concrete Institute
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• v.14 no.3
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• pp.420-429
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• 2002

The amount of $CO_2$-silicate bonded waste foundry sand(WFS) occurred in Korea is over 800,000 ton per year. WFS, as a by-product, is generated through manufacturing process of foundry may affect our environmental contamination, The reason is that WFS has been buried itself not less than 90％ out of total WFS. So, it can give damage on the ground of contamination in soil and underwater. Therefore, it is necessary to establish the method recycling WFS because of being intensified waste management law. In this study, we performed the research with respect to harmful component analysis, the qualities of WFS mortar and concrete mixed with WFS. As the results the specific gravity of WFS is the same as that of natural aggregate while unit weight and percentage of solids of WFS are smaller than those of it. But it is found that WFS can be used by substituting WFS for natural aggregate after control of poor grade of WFS. The flowability of mortar and concrete with WFS is inferior to those of natural aggregate, and the setting time of concrete with WFS is faster than that with only natural aggregate, On the contrary, the bleeding of concrete with WFS is shown good result, and compressive and tensile strength of concrete substituted WFS for 30％ are higher than those with only natural aggregate regardless of elapsed time.

• Journal of the Korea Concrete Institute
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• v.17 no.1 s.85
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• pp.141-147
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• 2005

The development of automobile, vessel, rail road, and machine industry leads an increase of foundry production used as their components, which cause a by-product, waste foundry sand (WFS). The amount of the WFS produced in Korea is over 700,000 tons a year, but most WFS has been buried itself and only $5{\~}6\%$ WFS is recycled as construction materials. Therefore, it is necessary for most WFS to research other ways which can be used in a higher value added product. The study on recycling it as a fine aggregate for concrete or green sand has been in progress in America and Japan since 1970s and 1980s respaectively. In this study, two types of WFS were used as a fine aggregate for concrete. Nine types of concrete aimed at the specified strength of 30 MPa were mixed with washed seashore coarse sand in which salt was removed, and WFS and then appropriate mixture proportion of concrete was determined. Moreover, basic properties such as air contents, setting time, bleeding, workability and slump loss of the fresh concrete with WFS were tested and compared with those of the concrete mixed without WFS. In addition, both compressive strength of hardened concrete at each ages and tensile strength of it at the age of 28 days were measured and discussed.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.9
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• pp.1246-1254
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• 2004

Two separate trials were designed to determine effects of dietary level of whole flaxseed (WFS) on fatty acid composition of serum, and subcutaneous, perirenal, intermuscular, and intramuscular adipose tissues of Korean Hanwoo cattle. Twentyone bulls (trial 1) and 15 cows (trial 2) were assigned to diets containing 0, 10 or 15% WFS. Relative treatment effects were similar between bulls and cows. The proportion of C18:3 in serum and to a lesser extent in adipose tissues were increased by dietary inclusion of WFS, reflecting supplemented lipid composition of WFS that escaped ruminal biohydrogenation. Animals fed WFS had a lower proportion of saturated fatty acids in serum and adipose tissues than animals fed diets without WFS, while the opposite trend was observed in unsaturated fatty acids with little differences between two WFS groups. WFS-fed animals had higher proportions of C18:1, 18:2, 18:3, 20:3, and 22:3 and lower proportions of C12:0, 14:0, 16:0 and 18:0 in intramuscular fat than animals fed diets without WFS. Furthermore, feeding WFS increased proportions of both $\omega$-3 and $\omega$-6 fatty acids but decreased the ratio of $\omega$-6/$\omega$-3 substantially. In conclusion, feeding WFS can be an effective method of increasing absorption of unsaturated fatty acids, and subsequent deposition in adipose tissues.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.8
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• pp.1151-1159
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• 2009

This study was conducted to determine the effects of dietary level of whole flaxseed (WFS; 0, 10 and 15%) on performance, carcass characteristics and fatty acid composition of serum and subcutaneous, perirenal, and intramuscular adipose tissues of Korean Hanwoo cattle. The daily gains were not different among treatments. Dietary inclusion of WFS decreased (p<0.05) feed intake but improved (p<0.05) feed conversion ratio (feed/gain). Backfat thickness and marbling score were increased (p<0.05) by dietary WFS. Carcass weight, dressing percentage, loin-eye area, and carcass yield and quality were not different among treatments. The proportion of C18:3 in serum and, to a lesser extent, in adipose tissues were increased (p<0.01) by dietary WFS, indicating that lipids from WFS escaped ruminal biohydrogenation. Animals fed WFS had lower proportions of saturated fatty acid (SFA; C14:0 and 16:0) and higher proportions of polyunsaturated fatty acids (PUFA; C18:2. 18:3, 20:2, 20:4, 20:5 and 22:6) in perirenal and intramuscular fat than animals fed diets without WFS, resulting in an increased PUFA/SFA ratio. Furthermore, feeding WFS increased (p<0.01) proportions of $\omega$-3 and $\omega$-6 fatty acids in intramuscular fat but decreased (p<0.05) the $\omega$-6/$\omega$-3 ratio. Relative treatment effects were similar between 10 and 15% WFS. Feeding WFS can effectively alter composition of adipose tissues with enhanced feed conversion ratio.

• Computers and Concrete
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• v.33 no.1
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• pp.77-90
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• 2024

Waste foundry sand (WFS) is the waste product that cause environmental hazards. WFS can be used as a partial replacement of cement or fine aggregates in concrete. A database comprising 234 compressive strength tests of concrete fabricated with WFS is used. To construct the machine learning-based prediction models, the water-to-cement ratio, WFS replacement percentage, WFS-to-cement content ratio, and fineness modulus of WFS were considered as the model's inputs, and the compressive strength of concrete is set as the model's output. A base extreme gradient boosting (XGBoost) model together with two hybrid XGBoost models mixed with the tunicate swarm algorithm (TSA) and the salp swarm algorithm (SSA) were applied. The role of TSA and SSA is to identify the optimum values of XGBoost hyperparameters to obtain the higher performance. The results of these hybrid techniques were compared with the results of the base XGBoost model in order to investigate and justify the implementation of optimisation algorithms. The results showed that the hybrid XGBoost models are faster and more accurate compared to the base XGBoost technique. The XGBoost-SSA model shows superior performance compared to previously published works in the literature, offering a reduced system error rate. Although the WFS-to-cement ratio is significant, the WFS replacement percentage has a smaller influence on the compressive strength of concrete. To improve the compressive strength of concrete fabricated with WFS, the simultaneous consideration of the water-to-cement ratio and fineness modulus of WFS is recommended.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.576-580
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• 2001

The amount of the waste foundry sand(WFS) produced in Korea is over 700,000 ton per year, but most WFS buries itself and only 5~6% or total WFS is recycled in the way or mixing as fine aggregate for construction materials. A bY-product, WFS produced from a foundry may affect our environmental contamination if it is discharged without proper waste disposal in Korea. Therefore in this study, we performed the fundamental research about specific gravity, absorption, grading curve, finesse modulus of WFS, different aggregates and the flow and the compressive strength of mortar with WFS replaced as fine aggregate, the workability and compressive strength of concrete with WFS as fine aggregate aimed at the specified strength of 270 kgf/$\textrm{cm}^2$, and then optimum mix proportion of concrete was determined