• Journal of the Korean Society for Precision Engineering
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• v.23 no.9 s.186
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• pp.179-189
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• 2006

Recently the electrostatic 2-axis MEMS stages have been fabricated f3r the purpose of an application to PSD (Probe-based Storage Device). However, all of the components (platform, comb electrodes, springs, anchors, etc.) in those stages are placed in-plane so that they have low areal efficiencies such as a few percentage, which is undesirable as data storage devices. In this paper, we present a novel structure of an electrostatic 2-axis MEMS stage that is characterized by having a large areal efficiency of about 25%. For obtaining large area efficiency, the actuator part consisting of mainly comb electrodes and springs is placed right below the platform. The structure and operational principle of the MEMS stage are described, followed by a design and analysis, the fabrication and measurement results. Experimental results show that the driving ranges of the fabricated stage along the x and y axis were 27$\mu$m, 38$\mu$m at the supplied voltages of 65V, 70V, respectively and the natural frequencies along x and y axis were 180Hz, 310Hz, respectively. The total size of the stage is about 5.9$\times$6.8mm$^2$ and the platform size is about 2.7$\times$3.6mm$^2$.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.157-159
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• 2017

This paper presents a storage reliability evaluation method based on the accelerated degradation test for the engine assembly and parts of the guided missile. The test of the engine assembly is performed at accelerated conditions equivalent to the real storage period, and then the aging condition of parts is checked. For engine parts, performance degradation characteristics are measured periodically at the accelerated conditions and failure times are predicted at each condition. Storage lifetime at normal use conditions is predicted using an accelerated model and failure times at all accelerated conditions.

• Nuclear Engineering and Technology
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• v.45 no.3
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• pp.377-384
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• 2013

During the last three decades, South Korean nuclear power plants have discharged about 5,950 tons of spent fuel and the maximum burn-up reached 55 GWd/MTU in 2002. This study was performed to support the development of Korean dry spent fuel storage alternatives. First, we chose V5H-$17{\times}17$ and KSFA-$16{\times}16$ as representative domestic spent fuels, considering current accumulation and the future generation of the spent fuels. Examination reveals that their average burn-ups have already increased from 33 to 51 GWd/MTU and from 34.8 to 48.5 GWd/MTU, respectively. Evaluation of the fuel characteristics shows that at the average burn-up of 42 GWd/MTU, the oxide thickness, hydrogen content, and hoop stress ranged from $30{\sim}60{\mu}m$, 250 ~ 500 ppm, and 50 ~ 75 MPa, respectively. But when burn-up exceeds 55 GWd/MTU, those characteristics can increase up to 100 ${\mu}m$, 800 ppm, and 120 MPa, respectively, depending on the power history. These results demonstrate that most Korean spent nuclear fuels are expected to remain within safe bounds during long-term dry storage, however, the excessive hoop stress and hydrogen concentration may trigger the degradation of the spent fuel integrity early during the long-term dry storage in the case of high burn-up spent fuels exceeding 45 GWd/MTU.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.12
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• pp.433-442
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• 2014

In this paper, we introduce the client side cache of distributed file system for enhancing read performance by eliminating the network latency and decreasing the back-end storage burden. This performance enhancement can expand the fields of distributed file system to not only cloud storage service but also high performance storage service. This paper shows that the distributed file system with client side SSD cache can satisfy the requirements of VDI(Virtual Desktop Infrastructure) storage. The experimental results show that full-clone is more than 2 times faster and boot time is more than 3 times faster than NFS.

• Food Science of Animal Resources
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• v.20 no.2
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• pp.139-145
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• 2000

This study was conducted to investigate the storage and quality characteristics of vegetable hot dog. The b-value of sausage was increased significantly, but the color of bread was not changed during storage. The hardness, springiness, cohesiveness and chewiness of sausage were not changed, but the gumminess was increased during storage. The hardness, springiness, cohesiveness and gumminess of bread were not changed, but the chewiness was decreased during storage. The moisture content of sausage was not changed, but that of bread was decreased during storage. The pH of vegetable hot dog showed 5.67~5.71 during storage. The TBA of sausage was increased from 0.13 to 0.29mg/kg, the VBN was increased from 4.24 to 5.46mg% during storage. The total plate counts showed $3.5\times$104 CFU/g 8 days of storage. The coliform group, Staphylococcus aureus. Salmonella and Vibrio parahaemolyticus were not detected during storage. The vegetable hot dog was found to be fresh by sensory scores such as taste, aroma, color, texture and palatability, and the appearance of mold and slime was not detected during storage.

• The Korean Journal of Food And Nutrition
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• v.3 no.1
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• pp.13-22
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• 1990

Nangmyun-broth was collected as samples from 25 common restaurants in Bucheon to examine it's sanitary condition. The main course of bacterial contamination was persuited for it's sanitary improvement. Bacterial count in summer sample was not greatly different from that in winter, resulting in total count 1.7$\times$10i1m1, lactic acid bacteria 8.7$\times$106/ml, coliform group 1 2$\times$105/ml, Staphylococcus aureus 6.5$\times$102/ml. Bacterial contamination occurred remarkably with the use of storage barrel in which remnent Nangmyun-broth was still resting, because the remnant Nangmyun-broth contained high level of bacteria Good santary condition in Nangmyun-broth was obtained by the use of clean barrel which had been washed with tap water or sterilizied with steam before filling fresh Nangmyun -broth for cold storage. The growth of Escherichia coli and Staphylococcus aureus was inhibited in the presence of acetic acid(0.01~0.05%) or mustart(0.1~0.5%)

• The Korean Journal of Mycology
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• v.40 no.4
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• pp.210-214
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• 2012

The aim of this study was to determine changes of physicochemical properties and microorganisms of commercial Makgeolli during storage at $10^{\circ}C$ and $25^{\circ}C$ During storage at $10^{\circ}C$ for 11 days, ethanol contents did not increased up to 7.0%, and pH and total acidity were ranged with 3.12-3.99 and 0.22-0.28%, respectively. Makgeolli which was storaged at $25^{\circ}C$ for 11 days showed more than 7.0% of alcohol contents, pH of 3.96-4.17 and total acidity of 0.27-0.30%. Yeast cell counts showed maximal $2.90-16.00{\times}10^7$ CFU/mL at $10^{\circ}C$ for 3 days and $1.12-29.40{\times}10^7$ CFU/mL at $25^{\circ}C$ for 1 day. Lactic acid bacteria and total bacteria cell counts of Makgeolli which was storaged at $25^{\circ}C$ for 11 days were higher than those $10^{\circ}C$ storage. In preference test, Makgeolli from storage at $10^{\circ}C$ for 11 days was showed the level of 4.9-5.2 points however, Makgeolli from storage at $25^{\circ}C$ for one day showed below 5.0 point.

• Korean journal of food and cookery science
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• v.23 no.5
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• pp.720-730
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• 2007

This study was investigated (replaced) the sensory and physicochemical properties of Jeungpyun substituted with 30% or 60% of brown rice and barley flours, respectively. The quality changes of the functional Jeougpyun during the storage periods were analyzed by a texturometer. We found that batter pH was decreased as fermentation progressed, but showed a higher pH resulted after steaming. The brown rice replaced Jeungpyun had higher specific gravity and lower viscosity; however, the barley-replaced Jeungpyun had lower specific gravity and higher viscosity compared to those of the control(0% replace with brown rice or barley flour). The barley-replaced samples showed significantly larger volume indexes than that of the control. The L-value of the for lightness decreased significantly within the replaced samples(p<0.001). All samples had negative a-values, with slight peen colors rather than red. The barley-replaced samples were darker than those of the brown rice sample groups, with less green and yellow color. The brown rice-replaced samples had larger values for adhesiveness, overall, and moistness, and the barley-replaced samples showed intensities greater in cell size, springiness, hardness, and flavor by sensory evaluation. The 30% flour-replaced samples of the comparisons had higher values for overall desirability(p<0.001). The replaced samples showed slow increases in hardness when measured by a texturometer, indicating that, the retrogradation rates decreased as the storage periods increased. The control stored for 72 hr had a hardness value that was 8.0 times harder than that of the control stored for one hour. The 30 and 60% brown rice-replaced samples stored for 72 hr were 5.8 times and 4.7 times harder of their replacement level, respectively, and the 30 and 60% barley-replaced samples stored for 72 hr were 5.7 times and 4.2 times harder of their replacement level, respectively. The adhesiveness and cohesiveness of all samples tended to decrease as the storage period increased. The barley-replaced samples showed significantly the lower adhesiveness and cohesiveness during the storage periods. The springiness of all samples decreased slowly during the storage periods. In conclusion, Jeungpyun that was substituted with brown rice and barley flours demonstrated improved functionality and higher dietary fiber replaced effect. Furthermore, the storage period of was extended as the retrogradation rate was delayed as a result of the dietary fibers.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1511-1517
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• 1999

Effects of washing methods using electrolyzed acid water on lettuce(Lactuca sativa) and quality changes during storage were investigated. The multi-stage immersion treated 3 times in 2 min showed more effective than others to remove microorganisms. Total count of lettuce after immersion in electrolyzed acid water was decreased to 1/100-1/300 of $5.8\;{\times}\;l0^5CFU/g$ of non-immersed lettuce and $2.3\;{\times}\;l0^5CFU/g$ of tap water immersed lettuce. Also coliforms was significantly decreased to 1/3,000 of $3.1\;{\times}\;10^3CFU/g$ after electrolyzed acid water washing. However, microbial levels of electrolyzed acid water treated one became to be similar to those of non-treated lettuce after 3 days of storage at $10^{\circ}C$. The color values of L and b of lettuce treated with electrolyzed acid water were somewhat higher than those of others. Though chlorophyll content of lettuce just after immersion in electrolyzed acid water was 9% lower than those of non-treated one, the content was decreased to the same level of other treatments during storage. Decaying ratio showed the lowest value in lettuce immersed in electrolyzed acid water until 6 days of storage. The sensory tests for overall acceptability and appearance of lettuce immersed in electrolyzed acid water showed higher than those of others until $3{\sim}6$ days of storage.

• KIEAE Journal
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• v.14 no.2
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• pp.87-98
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• 2014

This study is to identify quantitatively the function of carbon dioxide emissions reduction due to temperature and energy reduction according to direct carbon dioxide storage, shade provision, and evaportanspiration of urban park. According to the result of study, landscape tree indicated high carbon dioxide storage effect compare to bush, in which broadleaf tree indicated higher storage function than coniferous tree. It is believed to be the storage of carbon dioxide can be increased by increasing the composition rate of forest plants in the urban park. According to the direct estimation result of carbon dioxide storage in terms of example area, storage of carbon dioxide is estimated to be "seoul a zone" $476,818.8kg{\cdot}CO_2/m^2yr$, "anyang b zone" $186,435.7{\cdot}CO_2/m^2yr$, "daejeon c zone" $262,826{\cdot}CO_2/m^2yr$, "kwangju d zone" $231,657.8{\cdot}CO_2/m^2yr$. The carbon dioxide storage per unit area estimated to be "seoul a zone" $3.4{\cdot}CO_2/m^2yr$, "anyang b zone" $5.0{\cdot}CO_2/m^2yr$, "daejeon c zone" $2.6{\cdot}CO_2/m^2yr$, "kwangju d zone" $5.6{\cdot}CO_2/m^2yr$. The result of indirect carbon dioxide reduction effect estimated to be "seoul a zone" $291,603.4{\cdot}CO_2/m^2yr$, "anyang b zone" $165,462.4{\cdot}CO_2/m^2yr$, "daejeon c zone" $141,719.2{\cdot}CO_2/m^2yr$, "kwangju d zone" $154,803.4{\cdot}CO_2/m^2yr$. Carbon dioxide reduction potential amount through the urban park was increased to 1.6 times to 1.8 times when calculated to the indirect effect.