• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.3
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• pp.41-50
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• 2009

The flash memory has many advantages such as low power consumption, strong shock resistance, fast I/O and non-volatility. And it is increasingly used in the mobile storage device. Many researchers are studying the YAFFS, NAND flash file system, which is widely used in the embedded device. However, the existing YAFFS has two problems. First, it takes long time to mount the YAFFS file system because it scans whole spare areas in all pages. Second, the cleaning policy of the YAFFS does not consider the wear-leveling so that it cannot guarantee the duration of data completely. In order to solve these problems, this paper proposes a new content-based YAFFS that consists of a mounting time reduction technique and a content-cleaning policy by using content-based block management. The proposed method only scans partial spare areas of some special pages and provides the block swapping which enables the wear-leveling of data blocks. We performed experiments to compare the performance of the proposed method with those of the JFFS2 system and YAFFS system. Experimental results show that the proposed method reduces the average mounting time by 82.2% comparing with JFFS2 and 42.9% comparing with YAFFS. Besides, it increases the life time of the flash memory by 35% comparing with the existing YAFFS whereas no overheat is added.

• Journal of Korean Society on Water Environment
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• v.31 no.1
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• pp.12-18
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• 2015

In this research, the hydrologic effects between a pre-existing urban landuse and low impact development (LID) applied conditions were compared and evaluated. The infiltration trench and tree box filter that were utilized in LID represent only 1% of the catchment area that they drain. Storm event monitoring were conducted from July 2010 to July 2014 on a total of 22 storm events in both LID sites. After LID, hydrological improvement was observed as the sites exhibited a delay (lag time) or reduction in the magnitude, frequency and duration of runoff and flow peaks as the rainfall progress. In addition, the maximum irreducible peak flow reduction for infiltration trench was found to be 61% and 33% for the tree box filter when rainfall was 40 mm and 30 mm, respectively. In designing LID, it is recommended to consider the storage capacity and catchment area, as well as the amount of rainfall and runoff on the site.

• Nutrition Research and Practice
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• v.8 no.1
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• pp.27-32
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• 2014

This study investigated the influence of different durations of aerobic exercise on fuel utilization, lactate levels and antioxidative status in trained rats. Forty rats underwent physical training (T, n = 20) or non- training (NT, n = 20) for 6 weeks. For physical training, animals exercised on a treadmill for 30 min 5 days per week. At the end of week 6, the animals in each group were subdivided into BE, DE-0.5, DE-1 and DE-2, which were sacrificed at the end of week 6 without having performed exercise or after exercise on a treadmill for 0.5h, 1h and 2h, respectively, immediately before being sacrificed. The plasma glucose level in DE-2 of the NT group was significantly lower than in the other groups. Muscle and liver glycogen levels were significantly lower in DE-1 and DE-2, but there were no significant differences between DE-1 and DE-2 in the T group. Liver protein in DE-2 of the NT group was significantly lower. Muscle TG levels were decreased in DE-0.5 of the T group, while those of the NT group were decreased in DE-1. FFA levels were increased in DE-0.5 of the T group and in DE-1 of the NT group. Lactate levels were increased in DE-0.5 of the NT group, while they were increased in DE-1 of the T group. Catalase activity of the T group was lower in BE but higher in DE-0.5, DE-1 and DE-2. SOD activities were higher in trained rats, while the GSH/GSSG ratios were higher in BE, DE-0.5 and DE-1 in the T group, and there was no difference in that of DE-2. There were no differences in MDA levels in BE and DE-0.5, but they were significantly lower in DE-1 and DE-2 of the T group. Overall, the results of this study, suggest that training may improve exercise performance by facilitating the mobilization and oxidation of fat and conserving limited carbohydrate storage, and that it may delay the onset of fatigue and enhance the antioxidative defense system, but cannot support two hours of vigorous exercise.

• Korean Journal of Environmental Agriculture
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• v.20 no.2
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• pp.116-121
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• 2001

To observe the stimulating effects of low dose ${\gamma}$ - radiation on the dormancy breaking and physiological activity, potato (Solanum tuberosum L. cv. Dejima) were irradiated at the dose of $0.5{\sim}30$ Gy. Low dose ${\gamma}$ - radiation exhibited promoting effects on the sprouting rate within the range of optimum dose of 1 Gy and 2 Gy and on the sprout length within the range of optimum dose of 2 Gy and 4 Gy. Regardless of storage duration and irradiation doses, the number of sprouts was enhanced. The number of sprouts, which were reserved for 15 days after production (DAP), were significantly increased under 4, 8 and 16 Gy irradiation. The growth of 45 DAP sprouts was extremely stimulated under 4 Gy irradiation accompanying the increase of peroxidase activity in the plantlet. In this study, it was also suggested that the activities of antioxidative enzymes of potato plantlets were not related to the irradiation dose during the plantlet development with the exception of decrease in catalase activity.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.6
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• pp.903-910
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• 2007

In order to make acquire a potential use for Opuntia humifusa as a natural functional food material, this study was performed to determine the quality properties of Jeung-pyun made with added Opuntia humifusa, or prickly pear powder. According to an analysis of its major components, we found that the prickly pear powder consisteds of nitrogen-free extracts (71.85%) and crude fiber (11.20%). Greater additions of prickly pear powder had resulted in significantly lower pH in the of Jeung-pyun. According to measurements on the degree of Jeung-pyun gelatinization, by means of ${\beta}$-amylase, greater additions of prickly pear powder led to the higher levels of isolated maltose, indicating that the gelatinization degree of the Jeung-pyun became higher. Also, samples with higher concentrations of prickly pear powder had a tendency toward lower water content, which allowed us to expect a longer storage duration for the Jeung-pyun. In the textural property tests the Jeung-pyun that had less hardness and greater adhesiveness (p<0.05) than the control group as the content of prickly pear powder became higher. Also, the Jeung-pyunhad lower gumminess and chewiness than the control group as the content of prickly pear powder became higher. Therefore, it is possible to prepare relatively soft Jeung-pyun using prickly pear powder. For the color differences of the Jeung-pyun samples, lower L- values, and higher a- and b -values (p<0.05) presented as the addition level of prickly pear powder became higher. According to SEM observations of the Jeung-pyun, the added prickly pear powder addition groups generally showed a smaller and more inconsistent pore size, but higher porosity, than the control group. According to sensory analyses of the Jeung-pyun, the P2 group scored highest for color item, and the P4 group generated the fermented scent. Higher additions content of prickly pear powder led to the lower score, but higher scores for adhesiveness. Finally, the P2 group achieved the highest score for overall taste.

• Journal of Korea Water Resources Association
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• v.35 no.4 s.129
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• pp.397-410
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• 2002

In order to quantitatively identify historical drought conditions and to evaluate their variability, drought indices commonly used. The calculation method for the drought index based on the principal hydrological factors, such as precipitation and reservoir storage, can estimate the duration and intensity of a drought. In this study the Palmer-type formula for drought index is derived for the Nakdong River basin by analyzing the monthly rainfall and meteorological data at 21 stations. The Palmer Drought Severity Index(PDSI) is used for dry land sectors to evaluate the meteorological anomaly in terms of an index which permits time and space comparisons of drought severity. The Surface Water Supply Index(SWSI) is devised for the use in conjunction with the Palmer index to provide an objective indicator of water supply conditions in Nakdong River basin. The SWSI was designed to quantify surface water supply capability of a watershed which depends on river and reservoir water The Standardized Precipitation Index(SPI) is evaluated for various time periods of 1 to 12 months in Nakdong River basin. For the purpose of comparison between drought indices correlation coefficient was calculated between indices and appropriate SPI time period was selected as 10 months for Nakdong River basin. A comparative study is made to evaluate the relative severity of the significant droughts occurred in Nakdong River basin since 1976. It turned out that $'94{\sim}'97$ drought was the worst drought in it's severity. It is found that drought indices are very useful tools in quantitatively evaluating the severity of a drought over a river basin.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.10 no.3
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• pp.177-184
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• 2016

The purpose of this study was to investigate caretakers' demands and request in electric wheelchairs. The survey included the usability questionnaire (safety, operability, satisfactions) which were selected by opinions of caretakers and specialist of rehabilitation for electric wheelchairs. The survey also included questionnaires consisting of such questions as to demographic information, care experience, care time, and care burden, and demand for folding electric wheelchairs. Participants were fifty caretakers of electric wheelchair users. Caretakers' average age was 54.54years, and the average duration of their care experience was 80.98 months with average care time 9.80 hours per day. In safety and operability, most of participants were mostly satisfied. However, in satisfaction of weight and clean of electric wheelchairs was dissatisfied. They reported that the biggest problem of electric wheelchairs were too heav and difficult to control and that the greatest difficulty in helping electric wheelchair users was helping them with transfer to and from the wheelchair. They also need their prefer to develop folding electric wheelchairs. In this study, caretakers emphasized necessity of development light, easy to storage and clean electric wheelchairs. In conclusion, it is required to develop folding electric wheelchairs to reflect caretaker's opinions.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.782-785
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• 2011

Needs for MG(Microgrid) development are increasing all over the world as a solution to the problems including the depletion problem of energy resources, the growing demand for electric power and the climatic and environmental change. Especially Photovoltaic power is one of the most general renewable energy resources. However there is a problem of the uniformity of power quality because the power generated from solar light is very sensitive to climate fluctuation (variation of insolation and duration of sunshine, etc). As a solution to the above problem, ESS(Energy Storage System) is considered generally, but it has some limitations. To solve this problem this paper suggests a hybrid estimation method of photovoltaic power generation according to two climatic factors, i.e. insolation and sunshine. This result seems to help design the appropriate capacity of ESS and estimate the proper switching time between DC and AC power in the premises power system and thus maintain the uniformity of power quality.

• Journal of Korea Water Resources Association
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• v.51 no.1
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• pp.19-33
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• 2018

This study proposed a rainfall-runoff model for the purpose of real-time flood warning in urban basins. The proposed model was based on the shot noise process, which is expressed as a sum of shot noises determined independently with the peak value, decay parameter and time delay of each sub-basin. The proposed model was different from other rainfall-runoff models from the point that the runoff from each sub-basin reaches the basin outlet independently. The model parameters can be easily determined by the empirical formulas for the concentration time and storage coefficient of a basin and those of the pipe flow. The proposed model was applied to the total of three rainfall events observed at the Jungdong, Guro 1 and Daerim 2 pumping stations to evaluate its applicability. Summarizing the results is as follows. (1) The unit response function of the proposed model, different from other rainfall-runoff models, has the same shape regardless of the rainfall duration. (2) The proposed model shows a convergent shape as the calculation time interval becomes smaller. As the proposed model was proposed to be applied to urban basins, one-minute of calculation time interval would be most appropriate. (3) Application of the one-minute unit response function to the observed rainfall events showed that the simulated runoff hydrographs were very similar to those observed. This result indicates that the proposed model has a good application potential for the rainfall-runoff analysis in urban basins.

• Food Science of Animal Resources
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• v.38 no.6
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• pp.1131-1143
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• 2018

This study aimed to investigate the drying yield, meat quality, oxidation stability and sensory properties of Hanwoo beef loin subjected to different dry-aging conditions. A total of 54 Hanwoo beef loins (bone-in, $6^{th}-13^{th}$ ribs) with fat cover at 2 d postmortem were assigned to four groups and hung in a dry-aging room at a controlled temperature ($2^{\circ}C-4^{\circ}C$), humidity (65%-85%) and air velocity (3 m/s). Four treatment conditions were tested; the respective temperature, humidity and treatment duration are as follows: T1, $2^{\circ}C$, 85%, 60 d; T2, $2^{\circ}C$, 65%, $20d+2^{\circ}C$, 75%, $20d+4^{\circ}C$, 85%, 20 d; T3, $2^{\circ}C$, 75%, $20d+4^{\circ}C$, 85%, 40 d; T4, $4^{\circ}C$, 85%, 60 d. The drying yield, total aerobic counts and fat contents increased, whereas the moisture content, meat color (CIE $L^*$, $a^*$, and $b^*$), and Warner-Bratzler shear force values decreased significantly during the aging period for all treatments (p<0.05). The cooking loss (%) did not change significantly until 40 d, and it was significantly higher in T1 and T4 than in T2 and T3 at 60 d (p<0.05). The water-holding capacity, pH and lipid oxidation [thiobarbituric acid reactive substance (TBARS) values] increased during aging (p<0.05). The sensory scores for tenderness, juiciness, flavor, and overall acceptability of dry-aged loin muscles increased as the aging period increased. T2 and T3 had significantly higher sensory scores and T1 had significantly lower scores for tenderness, juiciness, flavor, and overall acceptability at 20, 40, and 60 d for loin muscles (p<0.05).