• Journal of Radiation Protection and Research
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• v.39 no.4
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• pp.199-205
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• 2014

In the field of neutron detections, $^3He$ gas, the so-called "the gold standard," is the most widely used material for neutron detections because of its high efficiency in neutron capturing. However, from variable causes since early 2009, $^3He$ is being depleted, which has maintained an upward pressure on its cost. For this reason, the demands for $^3He$ replacements are rising sharply. Research into neutron converting materials, which has not been used well due to a neutron detection efficiency lower than the efficiency of $^3He$, although it can be chosen for use in a neutron detector, has been highlighted again. $^{10}B$, which is one of the $^3He$ replacements, such as $BF_3$, $^6Li$, $^{10}B$, $Gd_2O_2S$, is being researched by various detector development groups owing to a number of advantages such as easy gamma-ray discrimination, non-toxicity, low cost, etc. One of the possible techniques for the detection is an indirect neutron detection method measuring secondary radiation generated by interactions between neutrons and $^{10}B$. Because of the mean free path of alpha particle from interactions that are very short in a solid material, the thickness of $^{10}B$ should be thin. Therefore, to increase the neutron detection efficiency, it is important to make a $^{10}B$ thin film. In this study, we fabricated a $^{10}B$ thin film that is about 60 um in thickness for neutron detection using well-known technology for the manufacturing of a thin electrode for use in lithium ion batteries. In addition, by performing simple physical tests on the conductivity, dispersion, adhesion, and flexibility, we confirmed that the physical characteristics of the fabricated $^{10}B$ thin film are good. Using the fabricated $^{10}B$ thin film, we made a proportional counter for neutron monitoring and measured the neutron pulse height spectrum at a neutron facility at KAERI. Furthermore, we calculated using the Monte Carlo simulation the change of neutron detection efficiency according to the number of thin film layers. In conclusion, we suggest a fabrication method of a $^{10}B$ thin film using the technology used in making a thin electrode of lithium ion batteries and made the $^{10}B$ thin film for neutron detection using suggested method.

• Korean journal of applied entomology
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• v.58 no.4
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• pp.291-297
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• 2019

Since Metcalfa pruinosa was first reported in Koera, it has continually caused damage to sweet persimmon orchard in southern part of Korea. Metcafa pruinosa exist not only in farmland but also in forest areas, and are difficult to control due to the influx of individuals from near forest. M. pruinosa has been occurred in orchard and its surroundings because of various host range. Thus, it has been difficult to decide spatial range and control time for efficient management. In this study, occurrence and dispersal pattern of M. pruinosa in persimmon orchard were surveyed using clear sticky traps, and spatial patterns were analyzed with SADIE(Spatial Analysis by Distance IndicEs), based on location information at sticky traps. Spatial association between survey time was also analyzed to identify when the spatial pattern changed. In sweet persimmon orchard, M. pruinosa mainly dispersed in mid to late May, when the first instar hatches, and in August, emerging season of adult. The first instar nymphs hatched in mid-May were randomly distributed in orchard, but distribution was changed to aggregative pattern after dispersed surroundings of orchard. Adults showed random distribution pattern after immigration to orchard again. These tendency was also observed in density change at orchard and its surroundings, and matched to actual density of M. pruinosa in sweet persimmon trees.

• Korean journal of food and cookery science
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• v.27 no.5
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• pp.589-597
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• 2011

This study was performed to evaluate the physiological and sensory properties of breads with different ratios of persimmon peel. Moisture activation of the bread loaf decreased as storage period increased with a smaller range of decrease in the persimmon peel added group. The amount of weight increased, and volume fell to some degree. Adding persimmon peel increased the RVA temperature, whereas maximum decreased. The color change during storage was due to the addition of control and 4% in group a values except there was no significant difference. As the result of measurements using a texture analyzer, hardness, springiness, cohesiveness, gumminess, and chewiness properties decreased. The sensory test results revealed that the 4% and 6% added persimmon peel bread was the best.

• Applied Biological Chemistry
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• v.51 no.1
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• pp.84-87
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• 2008

In this research, we screened for glucosyltransferase (GTase) inhibitors that effectively prevent the dental caries from 420 kinds of boiled water extracts of herbs and wild plants and searched for GTase inhibitory activities. Among them, 13 kinds of hot water extracts had high GTase inhibitory activities and especially, we focused on Foeniculum vulgare which showed the highest inhibitory activity on GTase. The boiled water extract of F. vulgare was stable at high temperature and showed as a mixed type of competitive and uncompetitive inhibition kinetic behavior. It did not have antibacterial effect on Streptococcus mutans and had inhibitory activity on GTase. Specially, in the clinical trial, the group treated by boiled water extract of F. vulgare showed more decrease of plague index at 4.8 point than untreated group. These results suggested that boiled water extract of F. vulgare can effectively suppress the plague formation as it inhibits the GTase activity.

• Journal of Korea Water Resources Association
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• v.46 no.5
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• pp.531-545
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• 2013

This paper was considered on the applicability of EFDC KUNSAN_SEDTRAN MODEL (2012) to calculate Gunsan Port sediment deposition height efficiently and to use for grasping its aspects quantitatively and providing its prevention measures reasonably based on well-known 3-dimensional EFDC sediment transport module. This model was calibrated and verified with various measured field data of A Report of Hydrological Variation on Kum River Estuary (2004). Due to the model calibration and relevant literature investigation for cohesive sediment parameters, settling velocity (WS), critical deposition stress (TD), reference surface erosion rate (RSE), critical erosion stress (TE) were identified as 2.2E-04m/s, 0.20 $N/m^2$, 0.003 $g/s{\cdot}m^2$, 0.40 $N/m^2$ respectivly on this model. In order to examine the applicability and precision of the model computation, the calculated model data of sediment deposition height at 13 stations for 71 days and suspended-sediment concentration at 2 stations, inner port and outer port for 15 days were compared and analyzed with the measured field data. As a result, the model applicability for sediment deposition height simulation was evaluated as NSE coefficient 0.86 and the precision for suspended-sediment concentration computation was evaluated as time averaged relative error (RE) 23%.

• Journal of the Korean Geotechnical Society
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• v.35 no.5
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• pp.31-41
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• 2019

This paper demonstrates safety factor for effective planning at initial stage by utilizing results on changes of safety factor according to various conditions of slop and examines impacts of factors that affect slope safety factors as well. Firstly, it describes shear strength which satisfies minimum allowable safety factor: 1.20 depending on height and slope. As the height increases by 5.0 m, the safety factors decrease by 0.04 while it tends to consistently reduce by approximately 20%, 30% and 40% after height goes to 10.0 m. As slope reduces by about 0.3, the safety factors increases by 0.4, which shows the rate of safety factors on slope grows by about 10%, 20% and 30% on lowering slope. When cohesion goes up by 10.0 kPa the safety factors increases by around 40% respectably while the angle of internal friction grows by $5^{\circ}$, it increases by about 8%. The rate of safety factors is identified as $Fs=3.86H^{-0.59}$, Fs = 0.43 s, Fs = 0.04 c, $Fs=0.02{\phi}$ depending on height, slope and shear strength. The safety factor with rainfall infiltration tends to increase by 18% compared to the condition of saturated surface on earth.

• Journal of the Korean GEO-environmental Society
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• v.12 no.7
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• pp.57-65
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• 2011

Numerical simulations by three-dimensional Particle Flow Code($PFC^{3D}$, Itasca) considering distinct element method (DEM) were carried out for prediction of triaxial compression test with sand material. The effect of scale conditions for numerical model and distinct material on final prediction results was analyzed by numerical models under various scale conditions, and following observations were made from the numerical experiments. It is very useful to model the initial material condition without any porosity conversion from 2-D to 3-D DEM. Numerical experiments have shown that in all cases considered, 3D distinct element modeling could provide good agreement on stress-strain behavior, volume change and strength properties with laboratory testing results. It was important thing to assess reasonable scale ratio of numerical model and distinct elements for saving calculation time and securing calculation efficiency under condition with accuracy and appropriateness as numerical laboratory. As results of DEM simulations under various scale conditions, most of results show that shear strength properties as cohesion and internal friction angle are similar in condition of $D_{mod}/D_{gmax}$ < 10. It shows that 3-D distinct element method could be used as efficient tool to assess strength properties by numerical laboratory technique.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.1
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• pp.7-11
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• 1983

The purpose of this study was to prepare low methoxyl pectins (LMPs) by pectinesterase (PE) using waste tangerine peels and to compare the chemical, physical and gelling properties of the prepared pectins with the commercial LMP. The LMPs were prepared by treating albedo with 0.25M $Na_2CO_3$ to activate the PE. PE was then inactivated by heating. The sample was centrifuged and the supernatant was collected. LMP was obtained as precipitate by adding alcohol to the collected supernatant. The amounts of extractible pectins in albedo were 12.71~12.98% on a dry weight basis. Methoxyl contents of LMPs prepared by treating albedo with PE at pH 7.5 for 10min, at pH 8.5 for 10min, 20min and 30min were 5.12%, 4.27%, 3.08%, 1.85% respectively, demonstrating that the methoxyl contents of the preparations decreased as the degree of treatment albedo with PE increased. The acetyl contents of the preparations ranged from 0.09% to 0.12%, the values of which do not interfere with gel formation. The anhydrouronic acid contents of the prepared pectins were in the range of 94.2%~94.8%. The values of viscosity and molecular weights of the prepared LMPs tent to decrease as the degree of PE action on albedo increased. The textural value of the prepared LMP gels determined by Consistometer, Ridgelimeter and Instron denonstrated that the excess treatment of albedo with PE significantly impaired the gelling properties of the preparations.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.8
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• pp.1232-1238
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• 2005

The purpose of this study was to find the optimum addition amount of astringent persimmon paste to glutinous rice flour in the preparation of Gaminjeolmi (persimmon glutinous rice cake). The moisture contents of Gaminjeolmi with added astringent persimmon paste were 57$\∼$59$ \% $. With increasing addition of astringent persimmon paste, the L- and b-value were decreased. The a-value was the highest at the 8$\%$ level. In the mechanical evaluation of Gaminjeolmi, the hardness was the highest in the 0$\%$ astringent persimmon paste-lnjeolmi but the 0$\%$ level was decomposed after 2 day of storage. The adhesiveness and cohesiveness were the lowest at the 0$\%$ and 16$\%$ levels. The springiness did not differ significantly with the addition of astringent persimmon paste for 2 days of storage. The gumminess was the highest at the 0$\%$ level for 1 day of storage, significantly. In the sensory evaluation of Gaminjeolmi, the acceptance of the softness characteristics was the best at the 8$\%$ level. Addition of astringent persimmon paste improve preservation of Injeolmi and the addition of 8$\%$ of astringent persimmon paste to glutinous rice flour was found to be the best recipe in terms of the sensory qualities of softness and overall acceptability.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.8B
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• pp.691-700
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• 2006

Based on the destination IP address of incoming packets, the Internet routers determine next hops and forward packets toward final destinations through If address lookup. The bandwidth of communication links increases exponentially fast as well as the routing table size grows significant as the number of single host networks attached to the Internet increases. Since packets should be processed at wire-speed, the increased link speed reduces the processing time of a packet in routers, and hence more efficient and fast IP address lookup algorithms and architectures are required in the next generation routers. Most of the previous IP lookup schemes compare routing prefixes of shorter length first with a given input IP address. Since IP address lookup needs to find the most specific route of the given input, search continues until the longest matched prefix is found while it keeps remembering the current test matching prefix. In this paper, based on binary search on prefix length, we proposed a new IP address lookup algorithm which compares longer prefixes first. The proposed scheme is consisted of multiple tries with prefixes on leaves only. The trie composed of the longest prefixes is primarily searched whether there is a match with the given input. This processing is repeated for the trio of the next longer prefixes until there finds a match. Hence the proposed algorithm provides the fast search speed. The proposed algorithm also provides the incremental update of prefixes while the previous binary search on length scheme does not provide the incremental update because of pre-processing requirement. In this paper, we performed extensive simulations and showed the performance comparisons with related works.