• Journal of Distribution Science
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• v.10 no.4
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• pp.29-36
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• 2012

Research on subjective well-being (SWB) has flourished in recent years. As SWB determines cognitive and motivational processes, including social comparison and cognitive dissonance, it determines how consumers make decisions, including the comparison and evaluation of alternatives. Considering that the comparison and evaluation of alternatives is related to social comparison and cognitive dissonance, the influence of SWB on the comparison and evaluation of alternatives needs to be investigated. This research aims to examine the effect of SWB on the comparison and evaluation of alternatives, especially when people acquire additional information about their chosen or non-chosen alternatives, leading to a change of absolute/relative value of alternatives. The reasonable price of an alternative as evaluated by individuals is used as a measure reflecting the perceived value of an alternative. Putting all of this together, the current study intended to investigate the influence of absolute and relative value on the reasonable price of an alternative depending on SWB. Participants were randomly assigned to one of two experiment groups (deterioration of non-chosen alternative vs. improvement of non-chosen alternative). After reading consumer report ratings of alternatives shown on monitor screens, participants chose one of the alternatives, followed by the change of the consumer report ratings (deterioration of non-chosen alternative vs. improvement of non-chosen alternative). Participants evaluated the reasonable price of their chosen alternative based on the provided price of the non-chosen alternative. Two weeks after the experiment, they were asked to answer survey questionnaire on SWB measures. A regression was performed on the reasonable price with experiment groups, mean-centered SWB, and their interaction. There was a significant simple effect of groups and SWB. More importantly, these effects were qualified by the predicted interaction of groups and SWB. To interpret this interaction further, simple slope tests were performed on the price when SWB was centered at one standard deviation above (i.e., happy people) and below (i.e., unhappy people) the mean. As predicted, happy people rated the reasonable price of the chosen alternative higher in the improvement of non-chosen alternative group than in the deterioration of non-chosen alternative group. Conversely, unhappy people showed no price difference between groups. These results show that happy people pay attention to the absolute value of the alternative, whereas unhappy people give more weight to the relative value as well as to the absolute value of a chosen alternative, indicating that unhappy people are more sensitive to the negative information of a non-chosen alternative compared to happy people. The present research expanded the existing research stream on SWB by showing the influence of SWB on the consumers' evaluation of alternatives. Furthermore, this study adds to previous research on SWB and social comparison by suggesting that unhappy people tend to be more sensitive to negative social comparison information of alternatives even when a target of social comparison is not explicitly present. Moreover, these results yield some managerial implications on how to provide product information based on SWB in order to make products more attractive among the alternatives available to consumers.

• Journal of the Korean GEO-environmental Society
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• v.15 no.5
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• pp.47-56
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• 2014

In winter season, the pore water inside the ground freezes and thaws repetitively due to the cold air temperature. When the freezing-thawing processes are repeated on the ground, the change in soil particle structure occurs and thus the damage of the infrastructure may be following. This study was performed in order to investigate the stiffness change of soils due to the freeze-thaw by using elastic waves. Sand-silt mixtures are prepared with in the silt fraction of 40 %, 60 % and 80 % in weight and in the degree of saturation of 40 %. The specimens are placed into the square freezing-thawing cell by the temping method. For the measurement of the elastic waves, a pair of the bender elements and a pair of piezo disk elements are installed on the cell, and a thermocouple is inserted into soils for the measurement of the temperature. The temperature of the mixtures is decreased from $20^{\circ}C$ to $-10^{\circ}C$ during freezing, is maintained at $-20^{\circ}C$ for 18 hours, is gradually increased up to the room temperature of $20^{\circ}C$ to thaw the specimens. The shear waves, the compressional waves and the temperature are measured during the freeze-thaw process. The experimental result indicates that the shear and the compressional wave velocities after thawing are smaller than those of before freezing. The velocity ratio of after thawing to before freezing of shear wave is smaller than that of the compressional wave. As silt fraction increases from 40 % to 80 %, the shear and compressional wave velocities are gradually increased. This study suggests that the freezing-thawing process in unsaturated soil loosens the soil particle structure, and the shear wave velocity reflects the effect of freezing-thawing more sensitively than the compressional wave velocity.

• Journal of Oral Medicine and Pain
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• v.31 no.3
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• pp.223-229
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• 2006

The objectives of this study was to investigate the amount of tooth ablation and the change of intrapulpal temperature by Er:YAG laser as it relates to pulse energy and pulse repetition rate at the identical power and, thereby, to reveal which of the two parameters strongly relates with ablation efficiency and intrapulpal temperature. Extracted healthy human molar teeth were sectioned into two pieces and each specimen was irradiated within the combination of pulse energy and pulse repetition time at the same power of 3W; $300mJy{\times}10Hz$ group, $200mJy{\times}15Hz$ group, and $150mJy{\times}20Hz$ group. Each specimen comprised ten tooth specimens. A laser beam with conjunction of a water flow rate of 1.6 ml/min was applied over enamel surfaces of the specimens during 3 seconds and the ablation amount was determined by difference in weight before and after irradiation. To investigate the temperature change in the pulp according to the above groups, another five extracted healthy human molar teeth were prepared. Each tooth was embedded into resin block and the temperature-measuring probes were kept on the irradiated and the opposite walls in the dental pulp during lasing. When the power was kept constant at 3W, ablation amount increased with pulse energy rather than pulse repetition rate (p=0.000). Although intrapulpal temperature increased with pulse repetition rate, there were no significant differences among the groups and between the irradiated and the opposite pulpal walls, except at a condition of $150y{\times}20Hz$ (p=0.033). Conclusively, it is suggested that ablation efficacy is influenced by pulse energy rather than pulse repetition rate.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.6
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• pp.848-858
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• 1995

The present study was conducted to investigate the effect of dietary vitamin A on the antioxidant status in ethanol-treated rats. Weaning rats were fed a basal diet until they reached about 160-180g body weight. Thereafter, four experimental groups were fed a liquid diet containing 36% ethanol of total calorie and four pair-fed groups were fed isocaloric sucorse instead of ethanol. Additionally, the liquid diet contained adequate amount of ${\beta}-carotene$, retinyl acetate, or 13-cis-retinoic acid except vitamin A deficient diet. The rats were sacrificed after 7 weeks of feedng periods. Significant decrease in hepatic vitamin E content was found in rats treated with chronic ethanol. However, dietary supplementation of retinyl acetate modified the change to some extent. Total vitamin C content of liver increased in vitamin A-deficient or ${\beta}-carotene$ groups with ethanol feeding. The ratio of reduced/oxidized vitamin C increased in the plasma and liver of ${\beta}-carotene$ group with ethanol feeding. Chronic ethanol intake did not change the total glutathione content of rat liver, but increased reduced glutathione(GSH)/oxidized glutathione(GSSG) ratio. This increase in hepatic GSH after chronic ethanol treatment. The changes of Se content in plasma and liver was not consistant. Fe content of liver increased by ethanol treatment, but this increase reduced in rats fed dietary retinyl acetate or 13-cis-retinoic acid. Fe content of plasma increased in vitamin A-deficient and ${\beta}-carotene$ supplemented groups with ethanol intake.

• Journal of Mushroom
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• v.11 no.3
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• pp.137-144
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• 2013

This study was carried out to investigate storage stability of harvested mushroom in developed varieties of button mushroom through identification of quality change during 35 days. The mushroom harvested up to $2^{nd}$ flush mushroom was stored on different storage temperature(4, 7, $10^{\circ}C$) and weight, length, thickness, color of pileus and stipe in fruit body was tested every 7 days. The morphological trait and color of stipe in fruit body were influenced by harvesting period and storage temperature. On the morphological traits of fruit body, mushroom harvested at $2^{nd}$ flush showed smaller difference than those at $1^{st}$ flush and mushroom stored at $4^{\circ}C$ indicated more difference than ones at the other temperature. Mostly color of pileus in brown button mushroom had lower ${\Delta}E$ (color difference) than white mushroom during storage period. The color of pileus of fruit body in white mushroom had low ${\Delta}E$ at $4^{\circ}C$ whereas that of brown mushroom was low at $10^{\circ}C$. The safe period of storage based on the L value is 7 days under a specified environmental condition. 'Seolgang' was stored for 14 days as good quality of mushroom, 'Saedo' had best quality after harvesting and 'Seojeong' was most stable during storage change in white mushroom varieties.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1306-1313
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• 2011

A liquid fertilizer treated with slurry composting and biofiltration (SCB) process has been applied increasingly on agricultural field but the effects on the soil properties and crop production has not been throughly evaluated. This study was conducted to investigate the effect of the SCB application on soil chemical properties and the growth of radish and corn. SCB liquid fertilizer as a basal fertilization was treated with five levels based on $6kg\;10a^{-1}$ for radish and $10kg\;10a^{-1}$ for corn. The experimental design was the completely randomized block design with five levels and three replicates. Electrical conductivity (EC), $NO_3$-N, Exch. K and Exch. Na increased depending on the treatment levels of SCB. There were no changes in soil organic matter, Avail. $P_2O_5$, Exch. Ca and Exch. Mg. EC, $NO_3$-N and Exch. Na content decreased as precipitation increased. Especially, they decreased up to the initial condition before the treatment after the heavy rainy season in 2008. Although Exch. K decreased at the rainy season, they remained relatively higher content after the experiment on August, 2008. Fresh weight and the amount of N uptake of radish increased due to the levels of SCB, but corn did not present any significant increase. It is recommended that we need to decide the proper amount of SCB as well as the application method on the field to increase the productivity and decrease environmental stress. Additional experiments also need to clarify the effect of the trace element and heavy metal accumulations due to long term application of SCB.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.312-319
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• 2021

This study was conducted to investigate the effect of elevated carbon dioxide on the growth and physiological responses of peach 'Mihong' (Prunus persica). We simulated three different carbon dioxide conditions based on climate change scenarios RCP 8.5 in the sunlight phytotron rooms from April 22 to July 6, 2020; 400 µmol·mol^-1(present condition), 700 µmol·mol^-1 treatment(expecting carbon dioxide concentrations in mid-21st century), 940 µmol·mol^-1 treatment (expecting carbon dioxide concentrations in late 21st century). The average of maximum photosynthesis rate at 700 µmol·mol^-1(16.06 µmol·CO₂·m^-2·s^-1) was higher than those at 400 µmol·mol^-1(14.45 µmol·CO₂·m^-2·s^-1) and 940 µmol·mol^-1(15.96 µmol·CO₂·m^-2·s^-1) from May 22 to July 2. However, stomatal conductances at 700 µmol·mol^-1 and 940 µmol·mol^-1 were lower than those at the control. Also, the carbon dioxide saturation point in all treatments was reduced from 1,200 µmol·mol^-1 in the early stage of growth to 600-800 µmol·mol^-1 in the late stage of growth. The stomatal densities were decreased as carbon dioxide increased. The shoot lengths were decreased while the carbon dioxide was increased, but the increase of trunk diameter and leaf areas, shoot numbers were not statistically different. The fruit weight at 700 µmol·mol^-1(152.5 g) was higher than those at the control(141.8 g) and 940 µmol·mol^-1(147.4 g). The soluble solids were higher at 700 µmol·mol^-1, 940 µmol·mol^-1 compared to the control. These results suggest that a carbon dioxide elevated to 700 µmol·mol^-1 in the future may give a positive effect on the yield and fruit quality of peach 'Mihong' while a carbon dioxide elevated above 940 µmol·mol^-1 may affect negatively such as early senescence and loss of fruit set.

• Journal of the Korean Electrochemical Society
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• v.22 no.1
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• pp.36-42
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• 2019

A macroporous Sn thick film as a high capacity negative electrode for a lithium ion secondary battery was prepared by using a chemical etching method using nitric acid for a Sn film having a thickness of $52{\mu}m$. The porous Sn thick film greatly reduced the over-voltage for the alloying reaction with lithium by the increased reaction area. At the same time. The porous structure of active Sn film plays a part in the buffer and reduces the damage by the volume change during cycles. Since the porous Sn thick film electrode does not require the use of the binder and the conductive carbon black, it has substantially larger energy density. As the concentration of nitric acid in etching solution increased, the degree of the etching increased. The etching of the Sn film effectively proceeded with nitric acid of 3 M concentration or more. The porous Sn film could not be recovered because the most of Sn was eluted within 60 seconds by the rapid etching rate in the 5 M nitric acid. In the case of etching with 4 M nitric acid for 60 seconds, the appropriate porous Sn film was formed with 48.9% of weight loss and 40.3% of thickness change during chemical acid etching process. As the degree of etching of Sn film increased, the electrochemical activity and the reversible capacity for the lithium storage of the Sn film electrode were increased. The highest reversible specific capacity of 650 mAh/g was achieved at the etching condition with 4 M nitric acid. The porous Sn film electrode showed better cycle performance than the conventional electrode using a Sn powder.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.1
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• pp.49-56
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• 2019

This experiment was conducted to select an optimum application rate of blended biochar pellet as slow release fertilizer during cabbage cultivation. The blended biochar pellet made with a combination(4:6) of biochar and pig manure compost with unloading N, P, K solutions for adjusting about 9% of total nitrogen(TN). The treatments were consisted of the control as recommended application rates for cabbage cultivation in National Institute of Agricultural Sciences, N 40%, N 40% and 0.07M MgO and N 60 % of the blended biochar pellet, respectively, based on nitrogen application of recommended rates to cabbage cultivation. Changes of $NH_4-N$, $NO_3-N$, $P_2O_5$ and $K_2O$ concentrations in the soil and growth characteristic and yield components were investigated and observed during the cabbage cultivation. The experimental result shown that contents of $NH_4-N$, $NO_3-N$ and $K_2O$ of soil in the N 40% were significantly difference(p<0.01) with the control. $P_2O_5$ concentrations of soil in the N 40% were highest among the treatments. The fresh weight per cabbage in the N 40% was not significantly different(p>0.05) from the control, but in the N 40% and 0.07M MgO and N 60% was lower than that of the control. It was considered that an optimum blended biochar application rate for cabbage cultivation was 40% of recommended nitrogen application.

• Journal of Life Science
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• v.29 no.1
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• pp.76-83
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• 2019

In this study, the optimal growth and poly(3-hydroxybutyrate) (PHB) biosynthesis of Pseudomonas sp. EML2 were established using waste frying oil (WFO) as a cheap carbon source. The fatty acid composition of WFO and fresh frying oil (FFO) were analyzed by gas chromatography. The unsaturated and saturated fatty acid contents of the FFO were 82.6% and 14.9%, respectively. These contents changed in the WFO. The compositional change in the unsaturated fatty acid content in the WFO was due to a change in its chemical and physical properties resulting from heating, an oxidation reaction, and hydrolysis. The maximum dry cell weight (DCW) and PHB yield (g/l) of the isolated strain Pseudomonas sp. EML2 were confirmed under the following culture conditions: 30 g/l of WFO, 0.5 gl of $NH_4Cl$, pH 7, and $20^{\circ}C$. Based on this, the growth and PHB yield of Pseudomonas sp. EML2 were confirmed by 3 l jar fermentation. After the cells were cultured in 30 g/l of WFO for 96 h, the DCW, PHB content, and PHB yield of Pseudomonas sp. EML2 were 3.6 g/l, 73 wt%, and 2.6 g/l, respectively. Similar results were obtained using 30 g/l of FFO as a carbon source control. Using the FFO, the DCW, PHB content, and PHB yield were 3.4 g/l, 70 wt%, and 2.4 g/l, respectively. Pseudomonas sp. EML2 and WFO may be a new candidate and substrate, respectively, for industrial production of PHB.