• Fire Science and Engineering
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• v.20 no.1 s.61
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• pp.28-42
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• 2006

The purpose of this study is to offer the improvement for deployment of fire service force in Korea by settlement patterns on the basis of analysis for the present standard and deployment of fire service force. For the adequate deployment and operation of fire service force by settlement patterns, we carried out the analysis of the present standard calculated with allocation of the authorized strength. We also classified clusters for settlement pattern through the statistical methods. We proposed the standard for deployment of fire service force reflected with environmental and need factors through the introduction of standardized index.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.331-336
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• 2001

Aragonite type of precipitated calcium carbonate was synthesized by the successive reaction with hybridization of waste scallop shells with limestone. In the first step, carbonation was performed by using calcined limestone with low brightness, followed by the additional carbonation using calcined-hydrous scallop shells with high brightness. The temperature and the amount ratio of calcined limestone to calcined-hydrous scallop shells were examined as parameters in the experimental conditions. The products were characterized by XRD, SEM. in addition to measurements of brightness index. the specific surface area, and bulk density. The amount ratio of limestone to scallop shell affected not only the brightness but also morphologies of products. The increase in relative amounts of limestone leads to decrease in brightness and bumpy surface of particles. High temperature reaction produces aragonite particles with longer sizes and higher bulk densities. This study has made an attempt to establish the synthesis of aragonite with high brightness and high strength by utilization of waste scallop shells.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.928-931
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• 2006

Due to their light weight, high stiffness-to-weight and strength-to-weight ratios, and potentially high resistance to environmental degradation, resulting in lower life-cycle costs, polymer composites, are increasingly being considered for use in civil infrastructure applications. Recently, an FRP deck has been installed on a state highway, located in New York State. In this study, a thermal stress analysis was conducted using finite element method to study failure mechanisms of the superstructure. This analysis evaluated small and large temperature gradient effects on the FRP deck considering lightweight of FRP deck and ply orientations at the interface between steel girders and FRP deck Finite element model was verified using the load tests of the bridge deck. Finally, the analytical results shows the possible failure mechanism of FRP deck under various temperature changes and its corresponding index is suddenly varied depending on the rapid change of temperature on the deck plate.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1132-1140
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• 2007

As it recently appears that Life Cycle Cost Analysis may be considered as new methodology for economic valuation of infrastructure many researches have been made to assess LCC(Life Cycle Cost) of each facility based on a reasonable methods. In general, LCC is composed of construction cost and expected maintenance repair cost. And especially, maintenance repair cost must be estimated to enhance the reliability through systematic and reasonable methods. However in Korea, because high speed railway steel bridges are recently constructed no direct statistical data are available for the account of the maintenance cost and then their maintenance characteristics are not linear yet. Therefore, the approach proposed in the paper utilizes a theoretical determination and degradation of the corrosion and fatigue of the bridges based on Rahgozar et al.(2006)'s model on fatigue notch factor considering into the corrosion to incorporate the corrosion effect into the fatigue strength reduction model. And then, the corresponding probability of failure is calculated in terms of the reliability index using S-N curve to formulate the fatigue limit state. Therefore, this paper proposes the minimum Life Cycle Cost through optimum maintenance plan analysis of high-speed railway steel bridges under construction. Finally, this paper reviews the proposed model in oder to confirm the applicability and feasibility by appling it to high speed railway steel bridges under construction

• Explosives and Blasting
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• v.22 no.2
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• pp.33-43
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• 2004

The six grades weathering system is normally used in weathered rock classification. In this study. fresh and weathered rock block of grade I to V were sampled in Jang-soo ana but samples of the grade VI was omitted from this study. The variation quantities of chemical weathering indices with weathering degree are smaller than those of physical and mechanical properties. Increase of Weathering degree is well indicated by physical and mechanical properties such as strength, hardness, ultrasonic velocity and slake durability result. Especially, absorption and porosity ratio is a good indicator. As weathering proceeds. a number of the cracks affect the rock deformation. Therefore, stress-strain curves of weathered rocks in unconfined state are quite different from ones of fresh rocks.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.1
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• pp.41.1-41.1
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• 2017

It is well known that there are good relations of coronal hole (CH) parameters such as the size, location, and magnetic field strength to the solar wind conditions and the geomagnetic storms. Especially in the minimum phase of solar cycle, CHs in mid- or low-latitude are one of major drivers for geomagnetic storms, since they form corotating interaction regions (CIRs). By adopting the method of Vrsnak et al. (2007), the Space Weather Research Center (SWRC) in Korea Astronomy and Space Science Institute (KASI) has done daily forecast of solar wind speed and Dst index from 2010. Through years of experience, we realize that the geomagnetic storms caused by CHs have different characteristics from those by CMEs. Thus, we statistically analyze the characteristics and causality of the geomagnetic storms by the CHs rather than the CMEs with dataset obtained during the solar activity was very low. For this, we examine the CH properties, solar wind parameters as well as geomagnetic storm indices. As the first result, we show the different trends of the solar wind parameters and geomagnetic indices depending on the degree of solar activity represented by CH (quiet) or sunspot number (SSN) in the active region (active) and then we evaluate our forecasts using CH information and suggest several ideas to improve forecasting capability.

• The Korean Journal of Community Living Science
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• v.20 no.2
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• pp.231-237
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• 2009

This study was conducted to investigate the effects of mugwort powder on two types of flour batters, i.e., medium and cake, using the Falling Number test, RVA test, alveogram, and farimogram. The mugwort powder was added at 3% and 5% on the medium and cake flour bases, respectively. The Falling Numbers of the medium and cake flour batters with mugwort powder were increased due to the alteration of the protein in the flour. Analysis of the RVA characteristics showed that the addition of mugwort powder did not have significant effects on the initial pasting temperature. Peak viscosity, holding strength, final viscosity, and set back values of the medium flour batter were not consistent, but those of the cake flour batter were decreased. The characteristics of the alveogram showed that the addition of mugwort powder increased the extensibility and the swelling index. Farinogram demonstrated that the addition of mugwort powder decreased the water absorption and improved the stability of the medium and cake flour batters.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.1
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• pp.1-4
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• 1993

Least square means for egg weight (EW), average shell thickness (ST), shape index (SI), shell surface area (SA) and shell breaking strength (BS) were determined in the Philippine native (PN) and F2 upgrades with New Hampshire (NH-N) and White Leghorn (WL-N) blood, respectively. Eggs of PN were smaller in size but had higher SI while their egg shells were thinner and weaker than those of the two upgrades. Highest EW, SA and BS means were observed in WL-N. Significant (p<0.01) positive correlations of EW and SI with SA and BS were noted.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.2
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• pp.159-164
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• 2005

When an optical pulse propagates through the atmospheric channel, the atmospheric turbulence attenuates and spreads this pulse. This attenuation and broadening of pulse are occurred by the fluctuation in the arrival time of pulse at the optical receiver. This pulse broadening induces the intersymbol interference (ISI) between the adjacent pulses. finally, the adjacent pulses are overlapped and the bit rate and the repeaterless transmission length are limited by the ISI. In digital communication system, therefore, the pulse broadening is more important factor than the attenuation. In this paper, thus, we find the ISI in the atmospheric turbulence as the function of the structure constant for the refractive index fluctuation that presents the strength of turbulence using the temporal momentum function and present it by numerical analysis.

• Korean Journal of Poultry Science
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• v.25 no.2
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• pp.71-77
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• 1998

This study was investigated to study split diets on laying performance and eggshell quality with Hy-Line brown layers 43 weeks old for 12 weeks Layers fed a conventional diet and split diets were divided into morning and afternoon diet. The conventional diet contained 3.4 % Ca was given constant nutrients all day. Hens of the split diets fed morning diets contained 0.5 % Ca constantly and afternoon diets contained 5.9, 8.0, and 10.0 % Ca in T1to T3. Split diets were given morning diets from 04:00 to 15:00 and afternoon diets 15:00 to 21 :00 alternately. Egg production, egg weight, and egg mass were not significantly different among diets. Abnormal eggs decreased in T1 and T2, but no significantly differed(P>0.05). Feed intake decreased in all of split diets compared to control diets (P <0.05). So, feed conversion ratio also improved in split diets(P<0.05). ME and CP intake decreased in T2 and T3, and Ca intake increased in proportion to Ca content of diets(P<0.05). ME and CP requirements per kg eggs decreased in the split diets, and that of Ca increased. Although there were not different significantly, egg shell strength and thickness improved slightly in T2 at 12 week. Yolk color, haugh unit and yolk index were not different among diets. Therefore, we concluded that split diet feeding to layer could improve feed and economic efficiency with normal egg production.