• Journal of Korean Society of Coastal and Ocean Engineers
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• v.17 no.3
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• pp.188-201
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• 2005

This is the first part of a two-part paper which describes comparison of reliability design methods by application to Donghae Harbor Breakwaters. This paper, Part 1, is restricted to stability of armor blocks, while Part 2 deals with sliding of caissons. Reliability design methods have been developed fur breakwater designs since the mid-1980s. The reliability design method is classified into three categories depending on the level of probabilistic concepts being employed. In the Level 1 method, partial safety factors are used, which are predetermined depending on the allowable probability of failure. In the Level 2 method, the probability of failure is evaluated with the reliability index, which is calculated using the means and standard deviations of the load and resistance. The load and resistance are assumed to distribute normally. In the Level 3 method, the cumulative quantity of failure (e.g. cumulative damage of armor blocks) during the lifetime of the breakwater is calculated without assumptions of normal distribution of load and resistance. Each method calculates different design parameters, but they can be expressed in terms of probability of failure so that tile difference can be compared among the different methods. In this study, we applied the reliability design methods to the stability of armor blocks of the breakwaters of Donghae Harbor, which was constructed by traditional deterministic design methods to be damaged in 1987. Analyses are made for the breakwaters before the damage and after reinforcement. The probability of failure before the damage is much higher than the target probability of failure while that for the reinforced breakwater is much lower than the target value, indicating that the breakwaters before damage and after reinforcement were under- and over-designed, respectively. On the other hand, the results of the different reliability design methods were in fairly good agreement, confirming that there is not much difference among different methods.

• Korean Chemical Engineering Research
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• v.50 no.4
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• pp.684-689
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• 2012

Poly(acrylic acid) (PAA) microspheres is one of the widely-used polymeric materials for the bio-field application and the electric materials. For the synthesis of PAA microspheres, the polymerization technique using surfactants is applied. After the synthesis, the purification and separation processes are required for the removal of surfactant. When general organic solvents were used, many problems, such as huge amount of waste solvent, additional separation processes, and the possibility of residual media, were occurred. Thus, High-pressure Soxhlet extraction using liquid $CO_2$ was developed to solve these problems. In this study, High-pressure Soxhlet extraction of the synthesized PAA microspheres using liquid $CO_2$ was conducted for the removal of Monasil PCA which is used for the dispersion polymerization of acrylic acid in compressed liquid Dimethyl ether (DME). The morphology of the extracted PAA particles was checked by field emission scanning electron microscopy (FE-SEM) and the residual concentration of Monasil PCA was analyzed by inductively coupled plasma - Optical Emission Spectrometer (ICP-OES). For studying the effect of the solvent effect, Soxhlet extraction was conducted using n-hexane, liquid DME, and liquid $CO_2$. In case of n-hexane, some extracted PAA microspheres were produced. However, deformation was also occurred due to the high thermal energy of n-hexane vapor. Liquid DME could not remove Monasil PCA. When using liquid $CO_2$, the extracted PAA microspheres which were free for the residual solvent were produced without deformation. For finding the optimum operating condition, high-pressure Soxhlet extraction was conducted for 8 hours with changing the temperature of reboiler and condenser. When the extractor temperature is $19.6{\pm}0.2^{\circ}C$ and the pressure is $51.5{\pm}0.5$ bar, the best removal efficiency was obtained.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.9
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• pp.917-925
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• 2006

The aim of our research was to apply experimental design methodology in the optimization of photocatalytic degradation of azo dye(Reactive orange 16). The reactions were mathematically described as a function of parameters amount of $TiO_2(x_1)$, and dye concentration($x_2$) being modeled by the use of the Box-Behnken method. The results show that the responses of color removal(%)($Y_1$) in photocatalysis of dyes were significantly affected by the synergistic effect of linear term of $TiO_2(x_1)$ and dye concentration($x_2$). Significant factors and synergistic effects for the $COD_{Cr}$, removal(%)($Y_2$) were the linear term of $TiO_2(x_1)$ and dye concentration($x_2$). However, the quadratic term of $TiO_2(x_1^2)$ and dye concentration($x_2^2$) had an antagonistic effect on $Y_1$ and $Y_2$ responses. Canonical analysis indicates that the stationary point was a saddle point for $Y_1$ and $Y_2$, respectively. The estimated ridge of maximum responses and optimal conditions for $Y_1:(X_1,\;X_2)$=(1.11 g/L, 51.2 mg/L) and $Y_2:(X_1,\;X_2)$=(1.42 g/L, 72.83 mg/L) using canonical analysis was 93% and 73%, respectively.

• Journal of Life Science
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• v.18 no.10
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• pp.1442-1446
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• 2008

Seven populations of 586 Hanwoo have been characterized by using 10 microsatellite DNA markers. Size of microsatellite markers decided using GeneMapper Software (v.4.0) after analyze in kinds of ABI machine of name of 3130. Frequencies of microsatellites markers were used to estimate heterozygosities and genetic distances. Genetic distancesbetween populations were obtained using Ne's DA distance method. Expected heterozygosity between each population was estimated very analogously. Genetic distances (0.0413) between Kangwan (KW) and Gyonggi (GG), Jeonpuk (JP) were nearest than distances between other populations by 0.021. Genetic distances between Gyonggi (GG) and Kyongpuk (KP) showed far distance than other populations by 0.032. In the UPGMA tree that is made based on DA distance matrix. Each individuals were not ramified to different group and were spread evenly in phylogenetic dendrogram about all Hanwoo of each regional area populations. But Hanwoo proven population was ramified to different group.

• Journal of Life Science
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• v.26 no.11
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• pp.1313-1319
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• 2016

Cancer is a complex disease heterogeneously composed of various types of cells including cancer stem-like cells responsible for relapse and chemoresistance in the tumor microenvironment. The conventional two-dimensional cell culture-based platform has critical limitations for representing the heterogeneity of cancer cells in the three-dimensional tumor niche in vivo. To overcome this insufficiency, three-dimensional cell culture methods in a scaffold-dependent or -free physical environment have been developed. In this study, we improved and simplified the HCT-8 colon cancer cell-based spheroid culture protocol and evaluated the relationship between cancer stemness and responses of chemosensitivity to 5- Fluorouracil (5-FU), a representative anticancer agent against colon cancer. Supplementation with defined growth factors in the medium and the culture dish of the regular surface with low attachment were required for the formation of constant-sized spheroids containing $CD44^+$ and $CD133^+$ colon cancer stem cells. The chemo-sensitivities of $CD44^+$ cancer stem cells in the spheroids were much lower than those of $CD44^-$ non-stem-like cancer cells, indicating that the chemoresistance to 5-FU is due to the stemness of colon cancer cells. Taken together, the inflammation and oncogenic gut environment-sensitive HCT-8 cell-based colon cancer spheroid culture and comparative evaluation using the simplified model would be an efficient and applicable way to estimate colon cancer stemness and pharmaceutical response to anticancer drugs in the realistic tumor niche.

• Information Systems Review
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• v.7 no.2
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• pp.229-255
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• 2005

The Korea Development Bank promoted a total outsourcing for IT operation in 1999 for the first time in the banking industry. The Korea Development Bank became the center of public attention because the most banks were unwilling to take an outsourcing with external sources for the reason of financial operation accidents, securities, and threats of strikes. After the introduction of the total IT outsourcing, the Korea Development Bank has continuously diagnosed the problems of the IT outsourcing and adopted various proper complements for the enhancement of the IT outsourcing. As the result of the enhancement, the IT outsourcing of the Korea Development Bank marched into the joint liability operation period after going through the outsourcing operation period and the co-operation period. The joint liability operation which is the most leading outsourcing system which is adopted by the Korea Development Bank for the first time in the banking industry. Through the joint liability operation, the Korea Development Bank could accept the most up-to-date IT, concentrate internal manpower on the core capability, and secure flexibility of manpower. Also, the bank changed the relationship between the bank and the external sources from the one-sided relationship between a producers and a consumer to the joint liability relationship on which both sides are responsible for the operation, and could integrate the internal capacity with the professional know-how of the external IT outsourcing company. In this paper, we testified the soundness and validity for the worries of banks about the total IT outsourcing with external sources. And, we arranged the advantages and outcomes of the total IT outsourcing with external sources compared to the IT outsourcing with internal sources. Moreover, we expect that we can improve the closed financial IT outsourcing industry structure and raise the world competitive power of domestic IT outsourcing companies by correcting wrong ideas on the IT outsourcing with external sources.

• Korean journal of food and cookery science
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• v.26 no.1
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• pp.18-25
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• 2010

This study was carried out to investigate the total polyphenol and flavonoid contents and antioxidative activities of enzymatic digests from dried Citrus unshiu and C. grandis peels. The yields of digests from dried C. unshiu and C. grandis peels were high in viscozyme (a carbohydrase) and kojizyme (a protease), and enzymatic digests from dried C. grandis peels appeared highly comparable to those of C. unshiu. Total polyphenol contents were high in ultaflo (a carbohydrase) and alcalase and flavourzyme (proteases), and the digests from dried C. unshiu peels appeared high in comparison to C. grandis. Total flavonoid contents were high in ultaflo, alcalase, and water extract. DPPH radical scavenging activities appeared very high in digests from dried C. grandis peels in comparison to C. unshiu, and was the highest in viscozyme and kojizyme. The viscozyme digest displayed particularly high activity. Hydrogen peroxide scavenging activities increased somewhat with increasing amounts of digests, but displayed very high activity, more than 91%, except kojizyme the digest from dried C. unshiu peel, at 2.0 mg/mL. Alkyl radical scavenging activities increased rapidly with increasing amounts of digest, and all enzyme digests from dried C. unshiu and C. grandis peels displayed very high activities at more than 0.5 mg/mL. Hydroxyl radical scavenging activities increased rapidly with increasing amounts of digests, and all enzymatic digests from dried C. unshiu and C. grandis peels displayed relatively low activities in comparison to other activated oxygen species.

• Korean journal of food and cookery science
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• v.26 no.1
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• pp.88-94
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• 2010

This study was carried out to investigate the total polyphenol and flavonoid contents and antioxidative activities of the methanol extracts of Citrus sunki, C. unshiu and C. natsudaidai peels before and after drying. Total polyphenolic content was high in the citrus peels before drying compared to the dried peels, and highest in the order of C. sunki, C. natsudaidai and C. unchiu. On the other hand, flavonoid content was high in the dried citrus peels than in the citrus peels before drying, and was highest in the order of C. unshiu, C. natsudaidai, C. sunki, but in dried peels it was highest in the order of C. natsudaidai, C. unshiu, C. sunki. DPPH radical scavenging activity was highest in the order of C. natsudaidai, C. unchiu, C. sunki, and that in the citrus peels before drying was higher than in the dried peels. Inparticular, C. natsudaidai peels before drying showed higher activity than vitamin C in 0.5 or 1.0 mg/100 g. Hydrogen peroxide scavenging activity was highest in the order of C. unshiu, C. natsudaidai, and C. sunki in the citrus peels before drying. The dried peels were highest in the order of C. unshiu, C. natsudaidai, C. sunki at 0.5 mg/100 g, but high in order of C. natsudaidai, C. unshiu and C. sunki at more than 1.0 mg/100 g. Inparticular, all C. natsudaidai peels displayed high activity more than 87% at 2.0 mg/100 g. Clear patterns in alkyl radical scavenging activity could not be confirmed in Citrus species whether before or after drying of peels. Hydroxyl radical scavenging activity was highest in the order of C. natsudaidai, C. unshiu and C. sunki but was relatively low compared to the scavenging activity of other activated oxygen species.

• The Korean Journal of Mycology
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• v.25 no.1 s.80
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• pp.35-45
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• 1997

The yellow fungal isolates inhabiting at the cereals (Hwang-Kuk, HK-fungi) were widely collected from the mejus and nuluks in Korea; the meju is a raw material for Korean traditional foods for soysauce and soypaste, and the nuluk is a raw material for Korean traditional rice wine. These isolates, well known as an Aspergillus oryzae producing amylase for Korean rice wine or producing protease for soybeans, were compared with Aspergillus species known. All isolates were microscopically observed to be a species of A. oryzae or its related, but to be difficult to be identified. Thus, RAPD-DNA techniques were applied for these isolates and analyzed with nummerical values using NT-system, or Ecological programs or Factorial analyses. Several common bands of RAPD-DNA in the 28 isolates were synthesized with the different OPD primers and speculated to be used for identification of HK fungi. The HK-fungi isolated were revealed to belong to the group of A. flavus previously defined. Particularly, the isolates collected from mejus were analyzed to be more closed to A. flavus, The species of A. flavus, A. oryzae and A. sojae were grouped at the values lower than those indicating the diversity of species. In other words, these three fungal species were not distinguishable and all isolates known as a HK-fungus were very closed to A. flavus, All isolates were not diversified at groupings of RAPD-DNA, and considered to be not the natural flora at the mejus or nuluks. The meju or nuluk having the above fungi as the fungal flora were speculated to be not termed "Korean traditional foodstuffs".The yellow fungal isolates inhabiting at the cereals (Hwang-Kuk, HK-fungi) were widely collected from the mejus and nuluks in Korea; the meju is a raw material for Korean traditional foods for soysauce and soypaste, and the nuluk is a raw material for Korean traditional rice wine. These isolates, well known as an Aspergillus oryzae producing amylase for Korean rice wine or producing protease for soybeans, were compared with Aspergillus species known. All isolates were microscopically observed to be a species of A. oryzae or its related, but to be difficult to be identified. Thus, RAPD-DNA techniques were applied for these isolates and analyzed with nummerical values using NT-system, or Ecological programs or Factorial analyses. Several common bands of RAPD-DNA in the 28 isolates were synthesized with the different OPD primers and speculated to be used for identification of HK fungi. The HK-fungi isolated were revealed to belong to the group of A. flavus previously defined. Particularly, the isolates collected from mejus were analyzed to be more closed to A. flavus, The species of A. flavus, A. oryzae and A. sojae were grouped at the values lower than those indicating the diversity of species. In other words, these three fungal species were not distinguishable and all isolates known as a HK-fungus were very closed to A. flavus. All isolates were not diversified at groupings of RAPD-DNA, and considered to be not the natural flora at the mejus or nuluks. The meju or nuluk having the above fungi as the fungal flora were speculated to be not termed 'Korean traditional foodstuffs'.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.12
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• pp.1898-1902
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• 2010

This study was designed to evaluate antioxidant activity of low-quality Codonopsis lanceolata treated by fermentation process followed by hydraulic high pressure extraction. C. lanceolata was subjected to 5,000 bar for 30 min at $25^{\circ}C$. The highest phenolics content was observed in the combined treatment of fermentation and high pressure extraction (35.11 mg/100 g), followed by high pressure extraction alone (14.78 mg/100 g) and conventional extraction (14.56 mg/100 g). The content of flavonoids followed the similar pattern as that of total phenolics, showing 280.86 mg/100 g of C. lanceolata treated by the combined fermentation with high pressure extraction whereas 193.05 mg/100 g of C. lanceolata treated by the conventional extraction. The DPPH scavenging activity was 69.32% at 0.6 mg/mL of C. lanceolata treated by the combined process, while the DPPH scavenging activities of C. lanceolata treated by high pressure extraction alone and the conventional extraction were 60.35% and 30.92%, respectively. The highest reducing power of C. lanceolata extract (1.0 mg/mL) was observed at the combined treatment (0.926), followed by high pressure extraction alone (0.881) and the conventional extraction (0.733). The combination of fermentation with high pressure extraction significantly increased the contents of phenolics and flavonoids and also enhanced the antioxidant activity. Therefore, the combined application of fermentation and high pressure extraction can be an alternative technique for the extraction of C. lanceolata. These results provide useful information for enhancing biological properties of low-quality C. lanceolata.