• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.657-664
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• 2000

Weak and soft compressible clay deposits are commonly found in natural subgrade soils. These Soils need to be stabilized for using the subbase materials of highway constructions. This paper presents that a chemical treatment using chemical additives comprised of sulfate(SO$_4$) and chloride(Cl) is evaluated for stabilizing soft clay deposits and lime. The physical and mechanical characteristics of soil-lime and additives are described by means of a laboratory study. The study results indicate that the presence of chlorides encouraged the efficiency of lime stabilization, and the use of calcium chloride with quicklime is the best additive for improving soil behavior. The treated soil with lime-calcium chloride can have the adaptability to the subbase materials of highway constructions.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.693-698
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• 2000

Aspects of classical information theory, such as rate distortion theory, investigate how to encode and decode information from an independently identically distributed source so that the asymptotic distortion rate between the source and its quantized representation is minimized. However, in most natural dynamics, the source state is highly corrupted by disturbances, and the measurement contains the noise. In recent coder-estimator sequence is developed for state estimation problem based on observations transmitted with finite communication capacity constraints. Unlike classical estimation problems where the observation is a continuous process corrupted by additive noises, the condition is that the observations must be coded and transmitted over a digital communication channel with finite capacity. However, coder-estimator sequence does not provide such a quantitative analysis as a variance for estimation error. In this paper, under the assumption that the estimation error is Gaussian distribution, a variance for coder-estimation sequence is proposed and its fitness is evaluated through simulations with a simple example.

• Natural Product Sciences
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• v.16 no.3
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• pp.175-179
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• 2010

The present study aimed to assess the antifungal properties of the essential oil fraction from Ligusticum chuanxiong (Umbelliferae) and its components against five clinically important Aspergillus species. The essential oil fraction was extracted from the underground parts of the plant by steam distillation, and its main components, namely, Z-ligustilide, butylidene phthalide, and p-cresol were isolated by column chromatography. The antifungal activities of the essential oils were evaluated by the broth dilution method. Both the total essential oil fraction of L. chuanxiong and its components showed significant anti-Aspergillus activity against all five tested strains with MICs between 62.5 and 250 ${\mu}g$/ml, respectively. In a checkerboard microtiter assay, the combination of antibiotics, itraconazole with the essential oil fraction of L. chuanxiong or its main components exhibited synergistic or additive, and in some cases indifferent, effects against the tested Aspergillus species, resulting in FICIs (fractional inhibiting concentration indices) ranging from 0.12 to 2, while the combination of antibiotics, amphothericin B with L. chuanxiong essential oils mostly showed antagonistic effects.

• Journal of the Korean Applied Science and Technology
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• v.6 no.1
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• pp.15-19
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• 1989

The oxidative stability of palm oil with moisture addition during heationg was investigated and the antioxidant effects of tocopherol, citric acid and sodium polyphosphate were evaluated. The addition of natural tocopherol up to 200 ppm level did not improve the oxidative stability of palm oil with moisture (1m1 $H_2O$ additive to 200g of oil at $180^{\circ}C$). The maximum antioxidant effect was observed at the Concentration of 400 ppm. Addition of citirc acid did not influence the effective concentration of tocopherol. Whereas addition of sodium polyphosphate and citric acid increased the antioxidant effect of tocopherol. The maximum synergistice effect was observed at the concentrations of 50 ppm citric acid and 50 ppm of sodium polyphosphate. Addition of 50 ppm citric acid and 50 ppm sodium polyphosphate to 100 ppm of tocopherol exceeded the antioxidant effect of 400 ppm tocopherol alone.

• Proceedings of the Safety Management and Science Conference
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• 2011.11a
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• pp.315-324
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• 2011

The purpose of this study is to improve for the inhibition of the generating the PCH(Propylene Chlorohydrins) in HPMC(Hydroxypropylmethyl Cellulose) manufacturing process. HPMC is made of cellulose which is natural high polymer. And HPMC is applicable to several industrial areas. Especially it can be used in food industrial as an effective additive. PCH is the by-product which is generated in chemical reaction in HPMC manufacturing process. So it is essential to eliminate PCH for the improvement of product quality. Therefore we have studied to minimize the amount of PCH. It is expected that the application of HPMC could be enlarged as the result of this study.

• Proceedings of the IEEK Conference
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• 2002.06d
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• pp.93-96
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• 2002

This paper presents robust and efficient scene-based video watermarking method using visual rhythm (spatio-temporal slice) in compressed domain. Scene change can be detected easily using visual rhythm and video sequences are conveniently edited at the scene boundaries. Therefore, scene-based watermark embedding Process it a natural choice. Temporal spread spectrum can be achieved by applying spread spectrum methods to visual rhythm. Additive Gaussian noise, low-pass filtering, median filtering and histogram equalization attack are simulated for all frames. Frame sub-sampling is also simulated as a typical video attack Simulation results show that proposed algorithm is robust and efficient in the presence of such kind of attacks.

• Journal of the Korea Safety Management & Science
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• v.13 no.4
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• pp.247-252
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• 2011

The purpose of this study is to minimize the PCH(Propylene CHlorohydrins) as a by-product in HPMC(HydroxyPropyl MethylCellulose) manufacturing process. HPMC is made of cellulose which is natural high polymer. And HPMC is applicable to several industrial areas. Especially it can be used in food industry as an effective additive. PCH is the by-product which is generated in chemical reaction in HPMC manufacturing process. So it is essential to eliminate PCH for the improvement of product quality. Therefore we have studied to minimize the amount of PCH. It is expected that the application of HPMC could be enlarged as the result of this study.

• YAKHAK HOEJI
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• v.56 no.5
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• pp.320-325
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• 2012

To develop a new effective and safe natural antibiotics and antioxidant the essential oil was extracted from the roots of Anthriscus sylvestris by steam distillation. Its composition was analyzed by GC-MS. The activities of the essential oil fraction and its main components were evaluated against antibiotic-susceptible and -resistant strains of some food-born bacteria. In addition the synergism was examined with this oil combined with antibiotic by checkerboard titer test. The antioxidant activities were determined by in 1,1-diphenyl-2-picryl-hydrazil (DPPH) free radical scavenging activity test and reducing power assay. The essential oil fraction of A. sylvestris revealed significant inhibiting activities against antibiotic-susceptible and -resistant species of Vibrio and Shigella with MICs ranged from 1.00~4.00 mg/ml. It showed synergistic or additive effects when it was combined with amphicillin or trimethoprim/sulfamethoxazole (1 : 9). Additionally, the essential oil fraction of A. sylvestris exhibited significant DPPH free radical scavenging activity and the reducing power.

• Natural Product Sciences
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• v.22 no.2
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• pp.134-139
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• 2016

Phytochemicals were isolated from leaves of the fiber crop, ramie (Boehmeria nivea, Bn), using open column chromatography and medium pressure liquid chromatography. Their structures were identified as ${\beta}$-sitosterol, (-)-loliolide, rutin, and pyrimidinedione by MS, $^1H$-, and $^{13}C$-NMR spectroscopic analysis. Among them, (-)-loliolide was isolated for the first time from B. nivea. A content analysis of (-)-loliolide in B. nivea collected from different regions and harvest times was conducted by HPLC. The highest content of (-)-loliolide was found in Bn-23 harvested in September. These results will be helpful to use the plant which harvest in September as a high content phytochemical additive in food, health supplements, and medicinal products.

• Food Science and Biotechnology
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• v.17 no.4
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• pp.692-699
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• 2008

The effects of wasabi stalk on the taste and storage characteristics of baechukimchi were assessed in the final product. Wasabi stalk was added in different ratios: 0, 1, 3, 5, or 7%(w/v) of Chinese cabbage. As the fermentation progressed, the pH of the product dropped. Total acidity increased in all treatments during fermentation. The total vitamin C content increased during the first 8 to 13 days of fermentation. Reducing sugar decreased in all treatment as fermentation continued. The numbers of total cells and lactic acid bacteria increased until they peaked, and then began decreasing as fermentation continued. With regard to acceptability characteristics, the 3% treatment was most favored. With simple regard to the quantitative level of wasabi stalk addition, the 3% treatment was most appropriate under all testing conditions. In conclusion, stalk seems to be an economical and natural additive which has effects on extension of the shelf life of baechukimchi.