• Korean Management Science Review
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• v.32 no.4
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• pp.135-153
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• 2015

In this paper, we intend to understand distinguishable SNS technology contributions for B2C commerce. In order to theorize this, we draw upon Technology-to-Performance chain (TPC) theory to develop the model that could explain how the technology value of the SNS could be realizable. For the purpose of capturing SNS technology effect to B2C channel effectiveness, on the basis of TPC theory, personal productivity is selected as a performance variable instead of satisfaction from SNS usage. Accordingly, as the antecedents of personal productivity, two variables of locatability and timeliness are extracted to reflect Task-technology-fit (TTF) dimension of performance precursors. For the utilization dimension of TPC framework, convenience and recreation tendency of the personal traits in shopping are included as the precursors of SNS utilization in the sense of reflecting utilitarian and hedonic value of SNS adoption. Empirical validation is conducted with reference to promotion and sales event on Facebook, which is chosen as the typical SNS based B2C commerce scenario. The data analysis result provide useful insights to further investigate the firm's SNS usage potentials for business applications.

• The KIPS Transactions:PartD
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• v.13D no.2 s.105
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• pp.183-190
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• 2006

Database workloads may show different resource usages for database applications. Database administrators can enhance the DBMS performances through resource management that reflects workload characteristics. We provide a method that can identify tunable resources from analyzing the relationship between performance indicators and resources. First, we select which performance indicators increase or decrease by expanding resources using a correlation coefficient and a significance level test. Next, we identify resources that can affect the DBMS Performances by using increasing or decreasing performance indicators. We evaluated our method in the TPC-C and TPC-W environments.

• Current Research on Agriculture and Life Sciences
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• v.32 no.2
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• pp.67-73
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• 2014

Mulberry fruits were semi-dried using hot air ($60-100^{\circ}C$) or cool air ($20-40^{\circ}C$), and the effects of the drying temperature and processing time on the quality of the final dried mulberry fruits were investigated. Response surface methodology was employed to establish a statistical model and predict the conditions resulting in minimal loss of the total phenolic content (TPC) and ascorbic acid. Thus, using overlapped contour plots, the optimal conditions for producing semi-dried mulberry fruits, which reduced the moisture residue to 45% and minimized the nutrient losses of TPC and ascorbic acid, were determined for the hot-air process ($60.7^{\circ}C$ for 5.4 h) and cool-air process ($34.8^{\circ}C$ for 23.3 h). Plus, a higher drying temperature was found to lead to a faster loss of moisture and ascorbic acid, while the TPC was significantly decreased in the cool-air dried mulberry fruits due to the higher activity of polyphenol oxidase between 30 and $40^{\circ}C$.

• Polymer(Korea)
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• v.32 no.4
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• pp.305-312
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• 2008

A novel TPC-PEG-TPC with active end-groups was obtained from the end-groups of polyethylene glycol (PEG) modified by terephthaloyl chloride (TPC). These active end-groups can link up with a rare earth ion, which is a luminescent center of a rare earth fluorescent complex. Complexes of Eu-PEG with novel ligands (TPC-PEG-PTC) were synthesized by the coordination of the active reactant (as the first ligand) and phenanthroline (as the second ligand) with $Eu^{3+}$.IR, $^1H$-NMR, element analysis, DSC, WAXD, fluorescent spectroscopy, TGA, and SEM were used to characterize the structure and properties of these complexes. The results showed that this type of complex is a heat storage material with the phase change character of polyethylene glycol (PEG) and the luminescent properties of europium. There was no thermal decomposition of the complex of Eu-PEG until $300^{\circ}C$. SEM showed that the complex of Eu-PEG can be dispersed in PE.

• Food Science and Preservation
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• v.24 no.3
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• pp.361-366
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• 2017

This study investigated quality change of ginseng depending on far-infrared (FIR) drying methods. The ginseng was cut into 2 mm slices and measured moisture content (MC), color, total polyphenol content (TPC), total flavonoid content (TFC) and DPPH radical scavenging activity (DPPH). The color values (L, a, and b) were decreased after far-infrared (FIR) drying. As increase in drying time, color was changed. Considering quality parameters including MC, TPC, TFC, and DPPH, the optimum condition for drying was set at $65^{\circ}C$ for 60 min. Furthermore, we compared color and functional compounds depending on drying process including FIR, freeze-, vacuum, and hot-air drying. The color values of ginseng were decreased when dried using vacuum and hot-air. While the color values of ginseng were increased after freeze drying. Comparison with another drying method, FIR drying presented the highest color difference. FIR and vacuum-dried ginseng indicate higher contents of TPC and TFC than freeze- and hot air-dried ginseng. And hot-air-dried ginseng present the highest DPPH when compared to another drying methods. On the other hand, freeze dried ginseng show the lowest TPC, TFC, and DPPH.

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.278-284
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• 2016

Commercial Korean domestic and foreign intermediate food materials (IFMs) of blueberry, Aronia, oat, sweet pumpkin, and ginger were purchased to compare their functional properties, including total phenolic content (TPC), total flavonoid content (TFC), total anthocyanin content (TAC), and antioxidant capacity. Each IFM was extracted using 80% (v/v) methanol for the analyses. The TPC (mg gallic acid equivalent/100 g dried sample) and TFC (mg catechin equivalent/100 g dried sample) levels in domestic blueberry (TPC, 2,916 ± 200; TFC, 1,327 ± 31) and sweet pumpkin (TPC, 476 ± 20; TFC, 23 ± 32) IFMs were significantly higher than those in the foreign IFMs. In the case of TAC (mg cyanidin-3-glucoside/100 g dried sample), the level in domestic blueberry IFM (949 ± 57) was significantly higher than that in the foreign product. Among the domestic IFMs, the antioxidant capacities (mg vitamin C equivalent/100 g dried sample) of blueberry, sweet pumpkin, and ginger were 7,057 ± 321, 311 ± 8, and 3,321 ± 109, respectively, being significantly higher than those of their foreign counterparts, based on the ABTS radical scavenging assay. In the DPPH radical scavenging assay, foreign Aronia (12,667 ± 437) and ginger (2,067 ± 99) IFMs showed significantly higher levels of free radical scavenging activity than did the domestic IFMs. These results provide basic information regarding the functional properties of Korean domestic IFMs, compared with their foreign counterparts.

• The Journal of the Korea Contents Association
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• v.10 no.4
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• pp.84-90
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• 2010

DBMS is used for a range of applications from data warehousing through on-line transaction processing. As a result of this demand, DBMS has continued to grow in terms of its size. This growth invokes the most important issue of manually tuning the performance of DBMS. The DBMS tuning should be adaptive to the type of the workload put upon it. But, identifying workloads in mixed database applications might be quite difficult. Therefore, a method is necessary for identifying workloads in the mixed database environment. In this paper, we propose a SVM workload classifier to automatically identify a DBMS workload. Database workloads are collected in TPC-C and TPC-W benchmark while changing the resource parameters. Parameters for SVM workload classifier, C and kernel parameter, were chosen experimentally. The experiments revealed that the accuracy of the proposed SVM workload classifier is about 9% higher than that of Decision tree, Naive Bayes, Multilayer perceptron and K-NN classifier.

• Preventive Nutrition and Food Science
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• v.21 no.3
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• pp.271-280
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• 2016

The effects of $CO_2$ injection and barrel temperatures on the physiochemical and antioxidant properties of extruded cereals (sorghum, barley, oats, and millet) were studied. Extrusion was carried out using a twin-screw extruder at different barrel temperatures (80, 110, and $140^{\circ}C$), $CO_2$ injection (0 and 500 mL/min), screw speed of 200 rpm, and moisture content of 25%. Extrusion significantly increased the total flavonoid content (TFC) of extruded oats, and ${\beta}$-glucan and protein digestibility (PD) of extruded barley and oats. In contrast, there were significant reductions in 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, PD of extruded sorghum and millet, as well as resistant starch (RS) of extruded sorghum and barley, and total phenolic content (TPC) of all extrudates, except extruded millet. At a barrel temperature of $140^{\circ}C$, TPC in extruded barley was significantly increased, and there was also an increase in DPPH and PD in extruded millet with or without $CO_2$ injection. In contrast, at a barrel temperature of $140^{\circ}C$, the TPC of extruded sorghum decreased, TFC of extruded oats decreased, and at a barrel temperature of $110^{\circ}C$, PD of extruded sorghum without $CO_2$ decreased. Some physical properties [expansion ratio (ER), specific length, piece density, color, and water absorption index] of the extrudates were significantly affected by the increase in barrel temperature. The $CO_2$ injection significantly affected some physical properties (ER, specific length, piece density, water solubility index, and water absorption index), TPC, DPPH, ${\beta}$-glucan, and PD. In conclusion, extruded barley and millet had higher potential for making value added cereal-based foods than the other cereals.

• Korean Chemical Engineering Research
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• v.54 no.3
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• pp.315-319
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• 2016

This study examined the optimization of hot-water extraction conditions for maximizing the total polyphenol compounds (TPC) extracted from amaranth leaf. The effects of three independent variables, including extraction temperature, extraction time and ethanol concentration on TPC were investigated using central composite design (CCD). The concentration of TPC increased with increased levels of extraction temperature and time. The extraction temperature and the ethanol concentration showed the significant effect on TPC production (p<0.05). The predicted values at the optimized condition were acceptable when compared to the experimental values ($R^2=0.9566$). The optimum extraction conditions were as follows: temperature of $90.1^{\circ}C$, time of 50 min and ethanol concentration of 61.6% (v/v) for the maximum TPC of 12.6 mg GAE/g DM.

• The Korean Journal of Food And Nutrition
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• v.30 no.4
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• pp.771-779
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• 2017

The purpose of this study was to investigate and analyze the total phenolic content (TPC), antioxidant activities (FRAP, ABTS, and DPPH), and antibacterial properties of lotus (Nelumbo nucifera) extracts. Lotus leaves, stems, and seed pods were extracted with deionized water at $95^{\circ}C$, and with 70.5% ethanol at $85^{\circ}C$. The TPC ranged from 8.12 to 215.12 GAE mg/g. The ethanol extract of the seed pod had the highest TPC, and the TPC of the corresponding deionized water extract was 161.45 mg/g. FRAP values ranged from 104.03 to $3,546.39TEAC\;{\mu}mol/g$, ABTS radical cation scavenging activities ranged from 105.11 to $3,956.94TEAC\;{\mu}mol/g$, and DPPH radical scavenging activities ranged from 37.29 to $2,549.46TEAC\;{\mu}mol/g$. $EC_{50}$ values ranged from 0.26 to 9.63 mg/mL, and 0.31 to 21.21 mg/mL for ABTS and DPPH, respectively. The ethanol and deionized water extracts of the seed pod showed higher TPC and stronger antioxidant properties (FRAP, ABTS, and DPPH) than those of characteristic of the leaf extracts. The ethanol and deionized water extracts of the seed pod showed antimicrobial activity against Bacillus subtilis, Staphylococcus aureus, and Pseudomonas aeruginosa with inhibition zones of 9.0 to 14.0 mm, and the ethanol extract of the leaf showed antimicrobial activity against B. subtilis and S. aureus with inhibition zones of 9.0 and 10.0 mm, respectively. Thus, the lotus seed pod could be used to produce novel teas, and could be a potential source of therapeutic ingredients for food and medicine.