• The Journal of Internal Korean Medicine
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• v.13 no.1
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• pp.135-142
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• 1992

Pi(Spleen, 脾) corresponds to central earth and is called as the basis of acquired essence as it has the function of transforting and transforming the nutrients, keeping the blood circulating, and nourishing the muscle and limbs. Recently many studies to research the nature and deficiency of Pi are actively carried out. Especially functional deficiency of Pi(脾虛證) which occupies 60 to 70% or 88% in miscell aneous disease is divided into deficiency of Qi(脾氣虛), Yang(脾陽許), and Yin(脾陰虛), and tought to be positive when three or more such symptoms as anorexia, abdominal distension, loose bowels, pale face and weakness are present. Investigating the resent studies on the nature of the deficiency of Pi shows that Pi has the function of digestive system and also should be considered as functional unit of mult system related immune, metabolic, hematic, muscular, rnddocrine and nervus system. Various experiments as ptyaline activity test and xylose absorption test are used as an indication to deficiency of Pi and would be helpful to understand its nature. As deficiency of Pi appears in many disease and has various manifestations, further studies to diagnose the symptom of Pi using various experiments and oriental medical diagnostic method should be ensued.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.143-146
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• 2002

Saponins are glycosidic compounds present in many edible and inedible plants. Structurally, they are composed of a lipid-soluble aglycone consisting of either a sterol or, more commonly, a triterpenoid and water-soluble sugar residues differing in type and amount of sugars ［1］. Because of their amphiphilic nature, they are highly surface-active. Their biological activity is closely related to the chemical structures that determine the polarity, hydrophobicith and acidity of compounds ［1］. (omitted)

• Bulletin of the Korean Chemical Society
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• v.16 no.11
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• pp.1093-1099
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• 1995

The polycondensations of bis(2-hydroxyethyl) naphthalate were kinetically investigated in the presence of various metallic compounds as catalysts at 295 ℃. The effect of the catalyst nature in the polycondensation has been studied. The order of catalytic activity on the formation of poly(ethylene 2,6-naphthalate) was found to be related to the stability constants which are indicated in an index of the catalytic activity.

• Communications of Mathematical Education
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• v.18 no.2 s.19
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• pp.9-33
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• 2004

The purpose of this paper is to contribute to the dialogue about the notion of advanced mathematical thinking by offering an alternative characterization for this idea, namely advancing mathematical activity. We use the term advancing (versus advanced) because we emphasize the progression and evolution of students' reasoning in relation to their previous activity. We also use the term activity, rather than thinking. This shift in language reflects our characterization of progression in mathematical thinking as acts of participation in a variety of different socially or culturally situated mathematical practices. We emphasize for these practices the changing nature of student' mathematical activity and frame the process of progression in terms of multiple layers of horizontal and vertical mathematizing.

• Journal of Korean Institute of Industrial Engineers
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• v.43 no.1
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• pp.1-11
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• 2017

Stochastic resource-constrained project scheduling problem is an extension of resource-constrained project scheduling problem such that activity duration has stochastic nature. In real situation where activity duration is not known until the activity is finished, open-loop based static policies such as activity-based policy and priority-based policy will not well cope with duration variability. Then, a dynamic policy based on closed-loop decision making will be regarded as an alternative toward achievement of minimal makespan. In this study, a dynamic policy designed to select activities to start at each decision time point is illustrated. The performance of static and dynamic policies based on variable neighborhood search is evaluated under the discrete-event simulation environment. Experiments with J120 sets in PSPLIB and several probability distributions of activity duration show that the dynamic policy is superior to static policies. Even when the variability is high, the dynamic policy provides stable and good solutions.

• Journal of Educational Research in Mathematics
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• v.9 no.1
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• pp.151-165
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• 1999

In this study, I consider the meaning of activity as the source of mathematical knowledge. Mind-body dualism of Descartes which understands that knowledge precedes activity is somewhat overcomed by Ryle who understands that knowledge and activity are two sides of the same coin. But his discussion cannot offer the explanation about the foundation of rightness or the development of rules which can be expressed propriety of activity or rationality. Contrary to these views, Piaget solve this problem by the reasonability of 'the whole system of activity'. The theory of Dewey can be evaluated as an origin of activism of Piaget. Piaget considers knowledge as the system of activity itself, whereas Dewey considers knowledge as 'the result of activity'. This view of Dewey is related to the view of pragmatism which considers 'practice' is more important than 'theory'. The nature of 'activity' in this study has to be understanded as the interaction or the relation between the subject and the object. If we understand activity like this, we can explain that the whole structure of activity has the 'wholeness' that cannot be simply restored to the sum total of 'parts' and the new structure is a self-regulative transformation system which includes former structure continuously.

• Journal of the Ergonomics Society of Korea
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• v.29 no.1
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• pp.145-153
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• 2010

Activity of lifting has been a major issue in many research area related in manual materials handling tasks. However, the opposite activity of lifting, lowering, has received much less attention. It is known that 52% of all box-handling tasks were lowering in nature. The difference in stress between lifting and lowering activity is not well understood. A simple assumption that these two activities are very similar has been established and widely used. However, this simple assumption may be questionable. The objective of this study was to compare a lifting activity and a lowering activity based on the three different ergonomic approaches; (1) biomechanical, (2) physiological, (3) psychophysical approach. It was found that the stress of lowering activity was from 65% to 93%, from 87% to 97%, and from 87% to 96% according to the biomechanical, physiological, and psychophysical point of view, respectively. It is concluded from the result of this study that the stress of lowering activity is lower than that of the lifting activity. The maximum compressive force on the lumbro-sacral joint (L5/S1) was 158% and 108% respectively, for lifting and lowering activity of which the work load is the 58% of Action Limit. It is suggested that the NIOSH AL and RWL and biomechanical criteria should be reconsidered especially for the low frequency of lifting activities.

• Microbiology and Biotechnology Letters
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• v.38 no.3
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• pp.278-282
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• 2010

In this study, the antibacterial activity and component analysis of Persicaria perfoliata extracts were investigated. MIC (Minimum Inhibitory Concentration) values of ethyl acetate fraction from P. perfoliata on Escherichia coli, Propionibacterium acnes, and Staphylococcus aureus were 0.25%, equally. The results showed that the antibacterial activity of the ethyl acetate fraction was the highest in the S. aureus and P. acnes. Ethyl acetate fraction from P. perfoliata extracts showed 5 bands in TLC and 8 peaks in HPLC (320nm). In HPLC chromatogram of ethyl acetate fraction, first main peak 2 (24.99%) and peak 3 (22.65%) were identified as quercetin-3-o-glucuronide and isoquercitrin in the order of elution time. Also, in HPLC chromatogram of deglycosylated fraction, main peak 2 (76.93%) was identified as quercetin in the order of elution time. And these components are very effective as antioxidants. Thus, these results indicate that extract/fractions of P. perfoliata can be applicable to new functional cosmetics for antioxidant, antibacterial activity.

• Journal of the Korean Applied Science and Technology
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• v.27 no.4
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• pp.559-567
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• 2010

In this study, the antioxidative effect, cellular protective effect and inhibitory effect on tyrosinase of Cosmos bipinnatus extracts were investigated. The ethyl acetate fraction of Cosmos bipinnatus flower extract ($11.48\;{\mu}g$/mL) showed more excellent free radical (1,1-diphenyl-2-picrylhydrazyl radical, DPPH) scavenging activity (FSC50) than those of leaf and stem extracts ($17.45\;{\mu}g$/mL). Reactive oxygen species (ROS) scavenging activity (OSC50) of Cosmos bipinnatus extracts on ROS generated in $Fe^{3+}$-EDTA/H2O2 system were investigated using the luminol-dependent chemiluminescence assay. The ethyl acetate fraction of Cosmos bipinnatus flower extract ($0.56\;{\mu}g$/mL) showed 3 times more excellent ROS scavenging activity than L-ascorbic acid ($1.50\;{\mu}g$/mL). The protective effects of the ethyl acetate fractions of extracts from different parts of Cosmos bipinnatus on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The ethyl acetate fractions of leaf and stem extract and flower extracts suppressed photohemolysis in a concentration dependent manner ($10\sim50\;{\mu}g$/mL). The inhibitory effect of ethyl acetate fraction of Cosmos bipinnatus flower extract ($62.75\;{\mu}g$/mL) on tyrosinase was investigated to assess the whitening efficacy. The ethyl acetate fraction of Cosmos bipinnatus flower extract showed 3.5 times higher tyrosinase inhibitory effect than arbutin ($226.88\;{\mu}g$/mL) known as an effective whitening agent. These results indicate that fractions of Cosmos bipinnatus extracts can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging $^1O2$ and other ROS, and protect cellular membranes against ROS. Fractions of Cosmos bipinnatus extracts can be applicable to new functional cosmetics for antioxidant and whitening.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.36 no.4
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• pp.303-314
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• 2010

In this study, the antibacterial, antioxidative effect and component analysis of Pinus koraiensis leaf extracts were investigated. MIC values of the ethyl acetate fraction from P. koraiensis leaf extracts on P. acnes, S. aureus, P. ovale, and E. coli were 0.06 %, 0.25 %, 0.13 % and 0.50 %, respectively. The results showed that the antibacterial activity of the ethyl acetate fraction on P. acnes, P. ovale. and S. aureus was more prominent. The aglycone fraction of P. koraiensis leaf extracts ($22.93\;{\mu}g/mL$) showed more higher free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity ($FSC_{50}$). Reactive oxygen species (ROS) scavenging activity ($OSC_{50}$) of P. koraiensis leaf extracts on ROS generated in $Fe^{3+}$-EDTA/$H_2O_2$ system was investigated using the luminol-dependent chemiluminescence assay. The 50 % ethanol extract ($0.70\;{\mu}g/mL$) showed the most prominent ROS scavenging activity. Also the ethyl acetate ($1.04\;{\mu}g/mL$) and the aglycone fraction ($1.43\;{\mu}g/mL$) showed very high antoxidant activity. The protective effects of extract/fractions of P. koraiensis leaf extracts on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The P. koraiensis leaf extracts showed cellular membrane protective effects in a concentration dependent manner ($5{\sim}50\;{\mu}g/mL$). TLC and HPLC chromatogram of the ethyl acetate fraction obtained from hydrolysis of P. koraiensis leaf extracts revealed 2 main bands (PK-4, PK-6) and peaks (peak 1, peak 2), which were identified as kaempferol-3-O-glucoside (PK-6, peak 1) and kaempferol-3-O-arabinoside (PK-4, peak 2) by LC/ESI-MS/MS, respectively. These results indicate that extract/fractions of P. koraiensis can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging ROS, and protect cellular membrane against ROS. Extract/fractions of P. koraiensis can be applicable to new cosmeceuticals for antioxidant, antiaging, and antibacterial activity.