• Physical Therapy Korea
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• v.4 no.1
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• pp.48-62
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• 1997

Several studies have evaluated the effects of types of relative frequency and delay interval of knowledge of results(KR) on motor skill learning independently. The purpose of this study was to determine more effective types of KR relative frequency and KR delay interval for motor learning. Forty-six healthy subjects (15 female, 31 male) with no previous experience with this experiment participated. The subjects ranged in age from 20 to 29 years (mean=23.9, SD=0.474). All subjects were assigned to one of four groups: a high-instant group, a high-delay group, a low-instant group, and a low-delay group. During the acquisition phase, subjects practiced movements to a target (400 mm) with either a high (83%) or low (33%) KR relative frequency, and with either an instantaneous or delayed (after 8s) KR. Four groups were evaluated on retention (after 3min and 24hr) and transfer (450 mm) tests. The major findings were as follows: (1) there were no between-group differences in acquisition and short-term retention (p>0.05, (2) a low (33%) KR relative frequency during practice was as effective for learning as measured by both long-tenn retention and transfer tests, compared with high (83%) KR practice conditions (p<0.05), (3) delayed (8s) KR enhanced learning as measured by both long-term retention and transfer tests, compared with instantaneous KR practice conditions (p<0.05), and (4) there were no interactions between KR relative frequency and KR delay interval during acquisition, retention, and transfer phases. The results suggest that relatively less frequent and delayed KR are more effective types for motor learning than more frequent and instantaneous KR.

• Korean Journal of Food Science and Technology
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• v.49 no.6
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• pp.714-716
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• 2017

Rose flower is widely used in the preparation of tea and contains a large variety of phytochemicals, including phenolics such as catechin, quercetin, and rutin. The effects of aging on rose (Rosa hybrida L.) flower extracts (RFE) were examined under conditions of varying temperature and relative humidity. The total phenolic content, antioxidative activity, and catechin levels were measured to evaluate the effects of temperature and relative humidity on the aging process. Performing the aging process at $30^{\circ}C$ under 60% or 90% relative humidity for 24 h significantly increased the total phenolic content and the antioxidant activities of RFE (p<0.05). Additionally, an aging process performed at $30^{\circ}C$ and 60% relative humidity for 24 h maximized the extraction rate of phenolics such as catechin and consequently led to increased antioxidative activity of RFE. In summary, this study indicates that the extraction rate of physiologically active phenolic compounds in rose flower can be increased by performing an aging process under optimized temperature and relative humidity conditions.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.27 no.6
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• pp.424-433
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• 2015

In this study, the wave force distribution acting on a semi-infinite and vertical-type long structure is investigated considering diffraction. An analytical solution of the wave force acting on long structures is also suggested in this study. The wave forces on long structures are evaluated for monochromatic, uni-directional random, and multi-directional random waves. Diffraction effects in front of the breakwater and on the lee side of the breakwater are considered. The wave force on a long structure becomes zero when the relative length of the breakwater (1/L) is zero. The diffraction effects are relatively strong when the relative length of the breakwater is less than 1.0, and the wave forces decrease greatly for long structure when the relative length of the breakwater is larger than 0.5. Therefore, it is necessary to consider diffraction effects when the relative length of the breakwater is less than 1.0, and the relative length of the breakwater must be at least 0.5 in order to obtain a reduction of wave force on long structures.

• 한국노년학
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• v.39 no.3
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• pp.549-567
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• 2019

The present study examined whether the relation between relative handgrip strength and cognitive function varied by paid employment status and participation of social activities among Korean older adults. A total of 3,376 Korean adults aged 65 or older were drawn from the 2016 Korean Longitudinal Study of Ageing (KLoSA). Weighted hierarchical regression analyses were conducted to examine moderating effects of paid employment status and social activities on the relation between relative handgrip strength and cognitive function. After adjusting for covariates, results show that relative handgrip strength has a positive association with cognitive function. Both paid employment status and social activities have positive associations with cognitive function and moderate the relationship between relative handgrip strength and cognitive function. These significant moderating effects show that participating in paid employment and social activities buffer against the effect of lower handgrip strength on cognitive function. Findings from the present study highlight the significant role of active aging in older adults'cognitive function. Implications are discussed in a cultural context.

• Korean Journal of Microbiology
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• v.7 no.4
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• pp.143-152
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• 1969

This investigation was proceeded to define the effects of gibberellic acid on the growth of Chlorella by determining the contents of chlorphyll and changes in various components in Chlorella cells according to the concentration of treated GA. The growth of Chlorella was accelerated with telative low concentrations of GA(10, 40 ppm) and was restrained with relative high concentrations of GA(70, 100, 200 ppm). The synthetic ability of chlorophyll of GA was inhibited generally in proportion to the concentration of treated-GA and the higher the concentration of GA was applied, the longer time was required in the restoration. The contents of RNA, protein and soluble carbohydrate were increased PCA-soluble amino acid and polysacharide were decreased in those cell components between the accelerated and restrained group. Consequently, the effect on accelerated growth in relative low concentrations of GA is considered to be caused by the powerful effet on expansion growth of GA. It is presumed that the effect of restrained growth in relative high concentrations of GA is due to the inhibitory effect on the chlorophyll synthesis.

• Journal of Korea Port Economic Association
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• v.22 no.1
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• pp.125-149
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• 2006

The main purpose of this study is to develop new measurement device of the quality of terminal service, applying the existing research output of service marketing to the specific industrial aspect of container terminal. Especially we tried to help marketing managers present the points of effective marketing strategy with each dimension of service quality. To achieve this aim, we defined the service quality demensions of container port as the following three ones; the internal, the external, and the interactive qualities. The applied measuring instruments could be divided into three dimensions by carrying out factor analysis. Additionally, by analyzing the relative effects of the three dimensions of service quality on customer satisfaction, we found that the relative importance are as follows; interaction quality>internal quality> external quality. We confirmed that the three dimensions of service quality could affect customer loyalty and information, through customer satisfaction.

• Journal of Applied Biological Chemistry
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• v.43 no.4
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• pp.250-253
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• 2000

The effects of high relative humidity (RH) on the physicochemical properties and microbial activity of mature green tomatoes ('Dombito') during refrigerated storage were determined at three temperatures (5, 10, and $15^{\circ}C$) and four different RH levels (91, 94, 97, and 99%). At each temperature, the weight loss rates of tomatoes at different levels of RH were significantly (p<0.05) different from each other. For the samples stored at $10^{\circ}C$, the weight losses were generally higher than those for the samples at $15^{\circ}C$ within the same RH level (i.e., greater vapor pressure deficit). The color change rates ('a' value) showed positive slopes, indicating that the tomato color was changing from green to red. Neither bacteria nor fungi caused visible damages to the samples, and the microbial counts were below 650 colony forming units/$cm^2$ during the test period.

• YAKHAK HOEJI
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• v.43 no.1
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• pp.98-103
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• 1999

Effects of Astragali Radix extract (AG) on the cell mediated-and nonlpecific immunotoxic responses of zinc chloride (Zn) were studied usign ICR mice. Mice were divided into 4 groups (10 mice/group), and Zn was given to the mice 1 hr after i.p. injection with 0.5g/kg of AG by i.p. injection daily for 10 days at a dose of 25 mg/kg. Immune responses on the responses on the relative weight of thymus, delayed-type hypersensitivity to SRBC (DTH), phagocytic activity and circulating leukocytes were evaluated. Zn treatment decreased body weight gain, the relative weight of thymus, DTH and circulating leukocytes compared with those in controls. AG treatment increased DTH, phagocytic activity and circulating leukocytes compared with those in controls. Combination of AG and Zn increased DTH and circulating leukocytes compared with those in controls, but decreased body weight gain and the relative weight of thymus. These findings indicated that AG decreased immunotoxicity of Zn on the DTH and circulating leukocytes.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.183-183
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• 2007

• Bulletin of the Korean Chemical Society
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• v.25 no.10
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• pp.1463-1464
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• 2004