• The Korea Journal of Herbology
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• v.25 no.4
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• pp.95-102
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• 2010

Objectives : Specifications by Processing Methods of Liriope platyphylla (LP) was not established in korea. We carried out method study for manufacture of LP. Above all, LP were purchased and were processed at four kinds. First group had hearts of swelling roots, not cut bodies(LP-A). Second group had not hearts of swelling roots, not cut bodies(LP-B). Third group had hearts of swelling roots, cut bodies(LP-C). Forth group had an aggregate of hearts of swelling roots(LP-D). Methods : We has gained losses on drying, contents of ethanol-soluble extracts, contents of water-soluble extracts and contents of spicatoside A. Results : 1. Losses on drying of all group were less than 18% that is a standard of chinese pharmacopoeia. 2. Contents of ethanol-soluble extracts at LP-C, LP-D were included more than contents of those in the other groups in significance levels. 3. Contents of water-soluble extracts at LP-A, LP-C were included more than contents of those in the other groups in significance levels. 4. Contents of spicatoside A in LP-B were included more than content of spicatoside A in the other groups in significance levels. Resultingly, standards of LP in korea were proposed compatible proposals suggested as below. 1. Losses on drying of LP were less than 15% that is less than that of chinese pharmacopoeia. 2. Form to boil in water must be cutting body with heart of swelling root. 3. Because there is no content of spicatoside A in heart of swelling root, it is not suited to purpose a index component. Conclusions : The subjects of loss on drying and form of LP to boil in water must be contained in korean pharmacopoeia. Moreover, because of much valuable LP in food and medicine, it is urgently required aspect of index component such as spicatoside B, spicatoside C, flavonoid, polysaccharide having medical actions and so on.

• The Korean Journal of Financial Management
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• v.25 no.1
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• pp.23-49
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• 2008

We test the hypothesis that the gradual diffusion of information across asset markets leads to cross-asset return predictability in Korea. And, the aim of this paper is related to forecast the stock market, business cycle index and industrial production by various indicators of economic activities in Korea. For this, our paper sets models and focuses on empirical test. The stock market on this month correlate with industries in Korea. The stock market doesn't lead to industries. The industries and macroeconomic variables have high correlation. We test that gradual diffusion of industrial information will predict stock market in Korea. For this, we analysis on possibility of Granger cause by VAR models between industries and stock market. As a result, 21 portfolios cause to Kospi statistically significance at 5%. Especially, the Beverage portfolio has bilateral Granger causality to Kospi. In case of Internet and Cosmetics portfolio, Kospi has unilateral Granger causality to it. The predictability of specific industries has a relation to Macroeconomic variables. What industrial portfolios predict to Business Coincidence Index? The only 6 industrial portfolios of 36 portfolios have a statistically significance at 10%. And, 9 portfolios have a statistically significance at 5%.

• International Journal of Highway Engineering
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• v.8 no.1 s.27
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• pp.15-23
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• 2006

Criteria of the current asphalt mix design, Marshall method, includes the stability and flow which are not related with field performance of HMA mixture, together with the air void, Void filled with asphalt (VFA) and/or Void of mineral Aggregate(VMA). In addition, the limits of stability and flow are satisfied in most cases, the Optimum asphalt content (OAC) is determined based on volumetric properties, such as the air void and/or VFA and/of VMA. Therefore, many researchers have sought mechanistic properties which can replace the stability and flow, making the designed mixture having potential for better field performance. This study initiated to develope a mix design by introducing two performance-related mechanistic properties, the deformation strengh and fracture energy, in place of the stability and flow of the Marshall method. The deformation strength $(S_D)$ from the Kim Test has a high correlation with rutting property and the fracture energy(FE) from the indirect tensile test represents the fatigue cracking property of asphalt mixture. Four types of asphalt mixture were prepared for examining possibility of using the suggested mix design method in comparison with current methods. The results showed that mechanical properties were reflected in determination of OAC with this suggested mix design, unlike the existing Marshall method.

• Journal of the Mineralogical Society of Korea
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• v.5 no.2
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• pp.102-108
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• 1992

The natural (Ca, Mg)-buserite has been identified from the manganese oxideores of the Janggun mine, Korea, which have been formed by supergene weathering of sedimentary-metamorphic rhodochrosite. It occurs together with rancieite forming one very fine-grained buserite-rancieite flake. This (Ca, Mg)-buserite-rancieite occurs as microcystalline flaky crystals. It precipitated around the fine-grained takanelite aggregate. Electron microprobe analyses give the formula ($Ca_{.08}Mg_{.07}Mn_{.05}^{2+})Mn_{.89}^{4+}O_2{\cdot}1.46H_2O$ for (Ca, Mg)-buserite. The dehydration experiments by relative humidity control and heating as well as rehydration experiment by relative humidity control show that (Ca, Mg)-buserite dehydrates completely at 90$^{\circ}C$ and rehydrates up to 27% of the original state. The dehydration at 26% RH (corresponding to heating to about 40$^{\circ}C$) is characterized by thedecrease in the decrease in the intensity of 9.86${\AA}$ peak with slight shifting to 9.60${\AA}$. It is due to the loss of weakly bound water molecules in the interlayer. The dehydration from 40$^{\circ}C$ to 90$^{\circ}C$ is characterized by the gradual shifting of 001 peak from 9.6${\AA}$ to 7.42${\AA}$. It is due to the loss of weakly bound water molecules in the interlayer.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.6
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• pp.771-781
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• 1994

Monthly measurements made at 15 stations along the axis of the upper Neuse River estuary show a highly variable degree of correlation between concentration of suspended particulate material (SPM) and attenuation coefficient (c) of light as measured by transmissometer. Coefficients of determination along transect lines ranged from $0.12{\sim}0.93$ and calibration slopes ranged from $0.50{\sim}5.63$. When examined on a station-by-station basis, coefficients of determination ranged from $0.21{\sim}0.96$ and calibration slopes ranged from $1.04{\sim}4.94$. Surface calibrations made at individual stations over the full 13-month period were the most consistent of all observations and were considerably better than calibrations made using all of the stations on a given day. Organic content, which can dominate the suspended sediment load during some months, does not appear to explain the variations in reliability of the calibrations. However, an abundance of large aggregates with time-varying size and shape distributions may be partly responsible for variations in optical properties of the sediments, and thus may confound the relationship between SPM and c in the Neuse River estuary Time-varying calibrations to account for non-negligible changes in optical properties may not suffice in complex estuarine environments where the in situ particle dynamics are poorly understood. However, the best use of Beam Transmissometer will continue to be for applications such as detecting water-column events or for use in situations where wide error bars in establishing SPM concentrations are acceptable.

• Journal of the Korea Concrete Institute
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• v.13 no.5
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• pp.484-490
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• 2001

This study focused on the investigation of durability of latex modified concrete in the points of chloride ion permeability and freeze-thaw resistance as latex content variated such as 5%, 10%, 15% and 20%. When latex was mixed in concrete and cured, the concrete consisted of hydrated cement and aggregate interconnected by a film of latex particles. An increasing the amount of latex produced concrete with increased flexural strength, but with slightly lower compressive strength. The increase in flexural strength might be attributed to the latex films between the hydrated cement and aggregates, and the decrease in compressive strength to the flexibility of the latex component named by Butadiene. The rapid chloride permeability test was used to evaluate the relative permeability of latex-modified concretes and conventional concretes. The results showed that the permeability of latex-modified concretes was considerably lower than conventional concretes tested, which might be due to the latex filled in voids and interconnections of hydrated cement and aggregates by a film of latex particles. The freeze-thaw resistance of LMC was quite good comparing to conventional concrete. Air entraining agent has been used in conventional concrete to improve the freeze/thaw resistance, but latex modified concrete does not need additional air entraining agent for freeze-thaw resistance provided adequate cure occurs.

• Magazine of the Korea Concrete Institute
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• v.10 no.6
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• pp.281-289
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• 1998

This study has been performed to test the flowability and filling ability of high flowing concrete as well as distribution of aggregate and pore of core specimen, heat of hydration, compressive strength and core strength of concrete. In addition, the resistance to chloride ion penetration and chemical solutionof concrete was tested in order to evaluate the resistance to sea water of concrete and its application of high flowing concrete using blended low heat cement in the field of Seohae Grand Bridge. The properties of high flowing concrete with blended low heat cement were compared with ordinary 25-240-15 concrete using Type V cement. As the results of this study, the flowability and filling ability of high flowing concrete with blended low heat cement is satisfied without vibration. Though the cement content of high flowing concrete with blended low heat cement was 400kg/m$^2$, the rising temperature of it was relatively lower than that of the ordinary 25-240-15 concrete with Type V cement. Also, the compressive of high flowing concrete with blended low heat cement is similar to that of the ordinary 25-240-15 concrete with Type V cement.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.2
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• pp.91-96
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• 2010

The purpose of this study is to find problems about pedestrian road of tourist resort and to make new type of sidewalk pavement with wood chip and binder using urethane resin on the parks and tourist resort. The wood chip pavement has new economics and durability with comfortable texture. Samples of these pavement materials were tested for tensile strength, permeability and ball rebound value. Also, after immersion for 24 hours, tensile strength, samples' thickness and weight were measured and discussed the strength reduction according to the water immersion. Tensile strength experimentation was examined on dry condition and water immersion. The result of examination on dry condition was 1.06MPa and on water immersion was 0.67MPa. The results showed 36.8% decreasing rate of tensile strength. Permeability experiment test based on field permeability method of pavement were conducted as a result, permeability coefficients were in the range of 0.67~0.78mm/s that all exceeds object permeability coefficient. Elasticity experiment was based on elasticity test method of Japan road association. GB coefficient was 21% and SB coefficient was 10%. GB coefficient and SB coefficient increased if fine aggregate were increased.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.3
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• pp.275-281
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• 2017

This study is to investigate experimentally the effect of refining of fly ash (FA) on the engineering properties of the cement mortar. Five different FAs are used including raw fly ash, refined fly ash, reject ash and their two different combinations. The cement mortars are fabricated with 1:1(binder to fine aggregate), 1 : 3 and 1 : 5 respectively, which are replaced 30% of FA by cement. Test results, indicated that, the flow of Ra showed lower flowability than Rf at all mixing ratios. Also in the case of Rj, it was expected to show low fluidity, but it showed flowability equal to or higher than Rf. Air contents are all formulations except Rf and Rj did not satisfy the target range. Using Ra, the refining process shows an air amount about 41% lower than Rf, in the case of Rj, it showed about 19% higher air content than Rf due to porous foreign matters inside the mortar. Compressive strength was in the early days 3 and 7, the strength was lower than that of Plain's OPC, after 28 days Rf exerts higher strength than other FAs, it was confirmed that higher strength than OPC can be secured at a mixing ratio of 1: 1 and 1: 3. For frost resistance, the use of unrefined FA resulted in decrease of frost resistance sharply due to loss of air content by the use of unrefined FA. Therefore, it is considered that the use of high quality FA through refining process will contribute positively to the economical formulation of concrete and the stability of the structure.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.283-290
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• 2020

Porous asphalt pavement is used widely in advanced countries to reduce traffic accidents and noise. On the other hand, it is not applied widely in Korea due to concerns about its durability. This study aims to find a statistical method to improve the durability of porous asphalt pavement. A Cantabro test was selected to test the durability. The Cantabro test was performed on an asphalt mixture made of a binder and aggregate. This test was repeated three times for each of the four groups to obtain the Cantabro loss rate. The average values of each of the four groups satisfied all the reference values. In addition, through an analysis of variance (ANOVA), it was possible to quantitatively classify test groups with differences in durability, thereby finding problems and improving the durability. Furthermore, the Pay Factor method can lead to voluntary improvements in quality, and the Pay factor can be calculated through statistical analysis of limited data. Through the Pay factor, it is possible to induce definite quality improvement of the contractor and continuously improve the durability of the porous asphalt mixture by evaluating the adequacy of the quality standard.