• Journal of the Korea Concrete Institute
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• v.18 no.5 s.95
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• pp.687-693
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• 2006

The Stone Powder Sludge(below SPS) is the by-product from the process that translates stone power of 8mm under as crushed fine aggregate. It is the sludge as like cake that has average particle size of $7{\mu}m$, absorbing water content of 20 to 60%, and $SiO_2$ content of 60% over. Because of high water content of SPS, it is not only difficult to handle, transport, and recycle, but also makes worse the economical efficiency due to high energy consuming to drying. This study is aim to recycle SPS as it is without drying. Target product is the lightweight foamed concrete that is made from the slurry mixed with pulverized mineral compounds and foams through hydro-thermal reaction of CaO and $SiO_2$. Although in the commercial lightweight foamed concrete CaO source is the cement and $SiO_2$ source is high purity silica powder with $SiO_2$ of 90%, we tried to use the SPS as $SiO_2$ source. From the experiments with factors such as foam addition rate and replacement proportion of SPS, we find that the lightweight foamed concrete with SPS shows the same trends as the density and strength of lightweight foamed concrete increases according to decrease of foam addition rate. But in the same condition, the lightweight foamed concrete with SPS is superior strength and density to that with high purity silica. This trends is distinguished according to increase of replacement proportion of SPS, also the analysis of XRF shows that the hydro thermal reaction translates SPS to tobermorite. Although SPS has low $SiO_2$ contents, the lightweight foamed concrete with SPS has superior strength and density, because it reacts well with CaO due to extremely fine particles. We conclude that it is possible to replace the high purity silica as SPS in the lightweight foamed concrete experimentally.

• Preventive Nutrition and Food Science
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• v.17 no.4
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• pp.261-268
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• 2012

Ribes diacanthum Pall (RDP) is a member of the Saxifragaceae family. The plant is traditionally used in Mongolia for the treatment of various ailments associated with kidney and bladder's diseases, cystitis, kidney stone, and edema. This study was aimed to investigate antioxidant activities of different solvent extracts of whole Pall plants, based on ferric-reducing antioxidant potential (FRAP), 2,2'-azinobis(3-ethybenzothiazoline-6-sulfonic acid) ($ABTS{\cdot}+$) radical scavenging activity, 1,1-diphenyl-2-picrydrazyl ($DPPH{\cdot}$), and hydroxyl (${\cdot}OH$) radical scavenging activities. Additionally, total flavonoids and phenolic contents (TPC) were also determined. The ethyl acetate extract of RDP (EARDP) had a remarkable radical scavenging capacity with an $IC_{50}$ value of 0.1482 mg/mL. In addition, EARDP was shown to be higher in total phenolic and flavonoid contents than the methanol extract of RDP (MRDP). Moreover, the EARDP had the predominant antioxidant capacity, DPPH, hydroxyl, and ABTS radical scavenging activities and ferric reducing power. These results suggest a potential for R. diacanthum Pall extract as a functional medicinal material against free-radical-associated oxidative damage.

• Journal of the Korean Institute of Rural Architecture
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• v.11 no.1
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• pp.9-16
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• 2009

This research surveyed the native resources which BiBo(replenishing shortages by helping each other) landscapes have been preserved by aiming at the village settlement spaces of five cities and counties in Gangwon Youngseo province. This research reveals that BiBo landscape patterns of 41 village forests, 23 BiBo symbols, and 6 BiBo ponds were surveyed. The village forests are all 41 places, and were mainly made on the plains in front of villages. BiBo functions of the forests were in the order of the land obstructing the view of the mouth of a river which is the most as 13 places, the land obstructing the view of the mouth of river, situation complements, village protection, and protection against wind. Bibo symbols were all 23 places. Towers, stone towers, menhirs, and Maitreya stones were 12 places, Jangseungs(a signpost raising on the entrance of the village or a temple) were 6 places, Sotdae(a pole raising at the entrance of the village as the symbol of a board or a village protecting deity) was 1 place, and the others were made multiply in 4 places. Bibo symbols were located at 21 places in front of villages. The village protection in Bibo functions was 6 places. 6 Bibo ponds were surveyed. Most Bibo ponds were made for earth power leakage prevention.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.17 no.5
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• pp.223-230
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• 2007

Plasticity of clay bodies containing bottom ashes(BA) and small portion of other wastes was investigated. Plasticity indices of clay bodies using Atterberg limits were measured. It was confirmed that the plasticity indices could be applicable in actual forming process by extrusion. The forming possible compositions were found by changing the contents of water, bottom ash, stone dust, and sewage sludge. The relationship between the plasticity and physical properties of the aggregate green body was also investigated. The compositions for extrusion forming can be expected by measured the plasticity indices and these results were confirmed by real extrusion process. There is also strong relationship between the plasticity indices and the property of aggregate green body.

• Journal of Families and Better Life
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• v.24 no.3 s.81
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• pp.83-94
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• 2006

In order to understand how consumers' buying motivation is formed, that is the starting point of consumer behavior or consumers' decision-making processes, we examined how the interpersonal orientation for consumers is organized to control buying motivation and create a stepping-stone for subjects' behavior in fast varied consumer environments. In addition, we examined what influence this interpersonal orientation has on consumers' buying motivations. The results are shown as follows: First, interpersonal orientation is classified into six categories, according to Cohen's three types, i.e., compliance, detachment I: emotion independence, detachment II: performance independence, detachment III: perception independence, aggressiveness I: competitiveness, aggressiveness II: aggressiveness. Second, based on our inspection of the relation between interpersonal orientation and consumers' buying motivations, for external motivation and internal motivation, the value of R2 in regression seems too low to act as an influencing power on interpersonal orientation, while in case of introjected motivation, identified motivation I: self respect, and identified II: pursuit of harmony, I there seems to be some relationship.

• Journal of Aerospace System Engineering
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• v.8 no.3
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• pp.34-40
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• 2014

Since the global economic crisis in year 2008, the world civil helicopter market has been growing recently. According to the market outlook in the next decade, the demand of civil helicopter will be driven by the demand of Private & Corporate, Oil & Gas, Off-shore and EMS(Emergency Medical Service) usages. On the other side, the demand of military market will be driven by the modification and upgrading for life extension or performance enhancement than the new helicopter development for replacing old models. To summarize these situations, the demand of MRO(Maintenance, Repair & Overhaul) market has also been on the rise because of the demand due to above several usages in civil side and the life-extension in military side. Through the MRO market analysis for characteristics, developmental trends and a supply chain, this paper describes that the potential of MRO business is considerably large as a propulsive power of domestic helicopter industry. And also, it proposes the construction direction of MRO network because the domestic industry must make the developmental awareness and reliability a stepping-stone towards own helicopter.

• Journal of Auto-vehicle Safety Association
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• v.12 no.2
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• pp.47-55
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• 2020

In this case study, the brake line failure of air over hydraulic(AOH) brake system is described. AOH brake system is applied to commercial vehicles between 5 to 8 tons. It consists of a hydraulic system using compressed air and operates the air master to form hydraulic pressure to transfer braking power to the wheels. When the brake lines of the system applied to vehicles with high load capacity are damaged, the braking force of one shaft is lost, and the braking distance increases rapidly, leading to a big accident. Failure of the brake line occurs due to various causes such as road surface fragmentation, corrosion of the line, and aged deterioration of air brake hose. The braking force could be decreased even when a very small break in the form of a pin-hole occurs. However, it is difficult to find a part where the thickness of the line is thin due to stone pecking or corrosion generated in the pin-hole formed on the brake line located under the lower part of the vehicle by the sensory evaluation or the conventional braking force test. Accordingly, it is necessary to analyze the condition and cause of the failure of the brake line more precisely when the accident investigation of the heavy vehicles, and also to examine the necessity of the advanced test for the aged brake line.

• Journal of Drive and Control
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• v.11 no.3
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• pp.47-54
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• 2014

Clutches are an integral part of the automatic transmission for changing gears. Modern automatic transmissions make extensive use of wet multiple-disc clutches employing hydraulic actuation mechanism with electronic control. Although nowadays, highly advanced shifting algorithm implements the superior shift quality and transmission efficiency, its performance should be based on smooth, reliable engagement with a reasonably durable friction material as well as stable clutch piston dynamics. Particularly, clutch filling control is the crucial part of shifting process because only the open-loop control is available due to the lack of measurement. In this paper, the effect of clutch-fill control parameters on clutch piston dynamics is experimentally investigated by using clutch piston test equipment which enables the clutch piston to actuate similar to real shifting conditions. The experimental analysis results can be expected to be utilized for the calibration of proportional solenoid valve as reference current profile data in vehicle test.

• Journal of the Korean Society for Railway
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• v.11 no.1
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• pp.54-60
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• 2008

In the trackbed design using elastic multilayer model, the stress-dependent resilient modulus $(E_R)$ is an important input parameter, that is, reflects substructure performance under repeated traffic loading. However, the evaluation method for resilient modulus using repeated loading triaxial test is not fully developed for practical purpose, because of costly equipment and the significantly fluctuated values depending on the testing equipment and laboratory personnel. The this study, the paper will present an indirect method to estimate the resilient modulus using dynamic properties. The resilient modulus of crushed stone, which is the typical material of sub-ballast, was calculated with the measured dynamic properties and the range of stress level of the sub-ballast, and approximated with the power model combined with bulk and deviatoric stresses. The resilient modulus of coarse grained material decreases with increasing deviatoric stress at a confining pressure, and increases with increasing bulk stress. Sandy soil (SM classified from Unified Soil Classification System) of subgrade was also evaluated and best fitted with the power model of deviatoric stress only.

• Tunnel and Underground Space
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• v.31 no.6
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• pp.534-548
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• 2021

In this paper, the feasibility of generating solar power near an abandoned quarry is examined with the objectives of resolving the essential problems that quarries encounter, such as rockfalls and space usage issues. On an abandoned quarry site in Sadang, Seoul, Republic of Korea, two different PV installation methods were analyzed. The first is attaching PV directly on the quarry slope. Since there are no corresponding safety standards and precedents for installing solar panels directly on slopes, the power generation potential was calculated by using topographic data and reasonable assumptions. The surface area of cut slope section was extracted from the Digital Elevation Model(DEM) via ArcGIS and Python programming to calculate the tilt and power capacity of installable panels. The other approach is installing PV as a rockfall barrier, and the power generation potential was analyzed with the assumption that the panel is installed in the direction of facing solar irradiation. For the derivation of power generation, the renewable energy generation analysis program SAM(System Advisor Model) was used for both methods. According to the result, quarries that have terminated resource extraction and remain devastated have the potential to be transformed into renewable energy generation sites.