• KIEAE Journal
• /
• v.10 no.6
• /
• pp.145-151
• /
• 2010

Bearing wall system was used extensively in most multi-residential apartment buildings in Korea. However, bearing wall apartments have the lack of architectural plan flexibility, remodelling-incompatible, causing serious economic losses in terms of construction waste. Recently, many researchers have studied the use of Rahmen structure as a potential alternative. The beam-column connection in the paper for long-life apartment housing forms connection of a Rahmen structure utilizing the advantages of steel and reinforced concrete. In addition, reduction of cast-in place concrete and construction schedule is expected by using precast concrete. Reduction effect of quantity decreased construction costs and $CO_2$ emission of key construction materials. However, verifying the feasibility of new construction method entails numerous challenges. Accordingly, the purpose of this study is to analyze the construction feasibility of sleeve, coupler, and pressure welding connections for long-life apartment building structure. A 3D modeling software was used to perform the analysis, and a real scale model was created to verify the results of construction feasibility. By verifying the construction feasibility of beam-column connections, this study will contribute to the efficient application of these methods on construction sites.

• Resources Recycling
• /
• v.18 no.3
• /
• pp.3-10
• /
• 2009

This paper will introduce the study which is the solidification and reduction of $CO_2$ green house gas, by using inorganic industrial wastes such like waste cement, steel making slag, incineration ash and so on. These inorganic wastes contain a large quantity of CaO content in common, which is easily reacted with CaO resulting in formation of $CaCO_3$. It will be suggested in this study that the necessary of the reduction and solidification of $CO_2$ gas with using industrial inorganic wastes is for building the Korea carbon storage model in this study.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2009.05b
• /
• pp.113-117
• /
• 2009

Fly ash (called FA hereafter) that results from thermal power plants is a long-term strength improving substance with reactivity to pozzolan and has been used for long. However, large amount of FA shows many advantages such as reduction of hydratio energy, long-term improvement in strength and economic feasibility and also has difficulties from reduction in initial strength and durability. In a preceding study, fine particle cement was applied to test the effects on initial strength. Therefore in this study, the effects of fine particle cement on the quality of FA concrete were reviewed. The results can be summarized as follows. Liquidity was increased by the most at FC substitution ratio of 15%. Air capacity was reduced according to increasing substitution ratio of FA and FC. Compressive strength showed high strength expression at all ages when FC was substituted at 45%. Synthesizing the above results, appropriate mixing of FC in FA concrete can improve liquidity, reduce unit quantity and show improvement in strength. In particular, mixed use of FC seems effective in improving early quality of concrete.

• The Journal of Asian Finance, Economics and Business
• /
• v.9 no.3
• /
• pp.11-22
• /
• 2022

The iron and steel sector is caught between two worlds: "carbon reduction" and "development." The goal of this study is to show that optimizing asset structure to boost intangible assets, particularly brand assets, is a viable strategy to achieve low-carbon development. This study uses panel data from 38 A-share companies in China's iron and steel industry from 2010 to 2020, as well as World Brand Lab data, to create a comprehensive impact index of enterprise value from the standpoint of an asset structure optimization, and to test the impact of intangible assets and brand equity on enterprise value. The findings show that: the asset structure of iron and steel enterprises is closely related to enterprise value, implying that iron and steel industry development necessitates a transformation of quantity control and quality improvement; the proportion of intangible assets in the asset structure of iron and steel enterprises plays a positive and critical role in enterprise value under surplus conditions. The iron and steel industry begins to shift from tangible to intangible assets; there is heterogeneity in the iron and steel industry transformation. Given certain technological levels, the share of brand assets contributes significantly to the increase in enterprise value.

• Korean Journal of Organic Agriculture
• /
• v.31 no.4
• /
• pp.327-341
• /
• 2023

The Ministry of Agriculture, Food and Rural Affairs, Hanwoo Association and Nonghyup have discussed proactive reduction measures for cows in response to concerns about an oversupply of hanwoo to ensure supply stability. This study aims to empirically analyze whether the cow fattening support program is being implemented in line with its objectives. Based on the analysis of beef traceability data, the slaughter age of participating cows was reduced by 7.6 to 14.7 months compared to non-participating cows. And heifer was reduced 1.5 months in their slaughter age. In case of parity, participating cows showed a reduction of 1.4 compared to non-participating cows. Through the SUR model, an analysis was conducted to examine the effect of the cow fattening support program on the suppression of calf production numbers. The analysis results showed that the calf production numbers are positively influenced by the number of fertile cow and the quantity of semen sales. Furthermore, it is estimated that calf production decreased as the fat index increased, and during the period when the cow fattening support program was implemented, an average monthly suppression of 3,558 calves was observed.

• Journal of the Korea Institute of Building Construction
• /
• v.24 no.4
• /
• pp.447-458
• /
• 2024

This study investigates the effectiveness of Building Information Modeling(BIM) software, specifically SketchUp and Revit, in reducing errors during quantity take-off(QTO) for complex building elements. While 3D modeling offers advantages, existing software may not fully account for manufacturing discrepancies, such as variations in concrete cover thickness and reinforcing bar radius. To address this limitation, this research proposes a BIM-based QTO method for high-insulation wall panels with intricate details. The method utilizes a BIM family library, focusing on key parameters like concrete cover thickness and inner radius of shear reinforcement. A case study compared the cross-sectional details of a wall panel modeled in Revit with the actual manufactured specimen. The analysis revealed a 12% reduction in modeled concrete cover thickness and a 1.27 times larger modeled inner radius of the shear bar compared to the real-world values. The proposed method incorporates these manufacturing variations into the Revit model of the high-insulation wall panel. Software like Navisworks facilitates the identification and correction of any material interferences arising from these adjustments. Furthermore, the method employs a unit wall concept(1m²) to account for the volume of various materials, including insulation and splice sleeves at joints. This allows for the identification of a similar existing family within the BIM library(e.g., "Double RC wall with embedded insulation") that reflects the actual material quantities used in the wall panel. By incorporating these manufacturing-induced variations, the proposed method offers a more accurate QTO process for complex high-insulation wall panels. The "Double RC wall with embedded insulation" family within the Revit program serves as a valuable tool for material quantity estimation in such scenarios.

• Journal of Powder Materials
• /
• v.16 no.5
• /
• pp.336-341
• /
• 2009

To produce alloy powders with only Sm$_2$Fe$_{17}$ single phase by reduction-diffusion (R-D) method, the effect of excess samarium oxide on the preparation of Sm-Fe alloy powder during R-D heat treatment was studied. The quantity of samarium oxide was varied from 5% to 50% whereas iron and calcium were taken 0% and 200% in excess of chemical equivalent, respectively. The pellet type mixture of samarium, iron powders and calcium granulars was subjected to heat treatment at 1100$^{\circ}C$ for 5 hours. The R-D treated pellet was moved into deionized water and agitated to separate Sm-Fe alloy powders. After washing them in deionized water several times, the powders were washed with acetic acid to remove the undesired reaction products such as CaO. By these washing and acid cleaning treatment, only 0.03 wt% calcium remained in Sm-Fe alloy powders. It was also confirmed that the content of unreacted $\alpha$-Fe in Sm$_2$Fe$_{17}$ matrix gradually decreased as the percentage of samarium oxide is increased. However, there was no significant change above 40% excess samarium oxide.

• Journal of Food Hygiene and Safety
• /
• v.19 no.3
• /
• pp.119-125
• /
• 2004

This study examined the effects of pearling, simple heating, baking and extrusion in processing of barley contaminated with deoxynivalenol (DON) on the reduction or destruction of DON. The DON contamination level of barley used in the experiment was 2.08 ppm. The DON-forming strain isolated from the barley was Fusarium graminearum, and the DON formation potential of which was 6.3 ppm on the average in Czapek-Dox broth medium. The DON removal efficiency of pearling was 56.5%, simple heating 3.8-32.7%, extrusion 53-59%, and baking 10.4%. As a large quantity of DON still remains after processing, it tis necessary to develop a new method of removing DON comletely.

• Korean Journal of Materials Research
• /
• v.14 no.11
• /
• pp.790-794
• /
• 2004

Ultra-fine Copper particles for a conductive paste in electric-electronic field were prepared using wet-reduction process with hydrazine hydrate ($N_{2}H_4{\cdot}H_{2}O$) as a reductor. The effect of reaction conditions such as the amount of dispersion ($Na_{4}O_{7}P_2{\cdot}10H_{2}O$) and reductor ($N_{2}H_4{\cdot}H_{2}O$) on the particle size and shape for the prepared Cu powders was investigated. The quantity of dispersion and reductor varied from 0 to 0.0025 M and from 5 to 40 ml at a reaction temperature of $70^{\circ}C$, respectively. The particle size, shape, and structure for the obtained Cu particles were characterized by means of XRD, SEM, TEM, EDS and TGA. The aggregation of Cu particles was reduced with relatively increasing of the amount of dispersion at fixed other reaction conditions. The smaller Cu particle with size of approximately 300nm was obtained from 0.032 M $CuSO_4$ with adding of 0.0025 M $Na_{4}O7P_2{\cdot}10H_{2}O$ and 40ml $N_{2}H_4{\cdot}H_{2}O$ at a reaction temperature of $70^{\circ}C$.

• Journal of Nutrition and Health
• /
• v.32 no.8
• /
• pp.957-966
• /
• 1999

Underreporting of dietary intake is common and might distort analysis and interpretation of dietary surveys. This study was designed to investigate the degree of underreporting and characterastics of under-reporting group in Korean college female students. Dietary survey of 1-day 24-hour recall method was conducted on 379 college students in Seoul and Chonan areas. Physical activity and life style were aquired from questionnnaires. Underreporting was defined as energy intake(EI) lower than 0.9BMR(based metabolic rate), since EI<0.98BMR is statistically judged as bias in 1-day 24 hour recall. BMR was calculated from Schofield's equation. Proportion of underreporting was 18.7% and it's not so different from one of American or European women. Intake of nutrients except vitamin A by underreporting group was lower than other groups(p<0.001). Proportions of subjects with nutrient intake level less than 75% of Korean RDA were more than 80% in protein, Ca, Fe, vitamin A, riboflavin, niacin, zinc as well as energy. Dietary quality of underreporting group was also worse than other groups. Proportion of subjects less than 3 food groups among 5 food group was higher in underreporting group. The number of foods eaten by underreporting group were also less than those of other groups. BMI and body weight were the largest in underreporting group(p<0.05) and the trial of weight reduction was shown higher trend(p<0.01). Different in PAC and other characteristics between underreporting group and other group were not significant. Not only dietary quantity but also dietary quality were worse in the underreporting group. Furthermore underreporting in college female students seemed to be affected by body weight and concern for weight reduction.