• Journal of Ginseng Research
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• v.33 no.2
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• pp.127-131
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• 2009

The plant protection rate of the marketed microbial products for ginseng cultivation was investigated against Rhizoctoina solani and Pythium sp. in a seedling pot experiment. A significant difference was found among the mean plant protection rates (Pm) of the microbial products, including Tolclofos-methyl (Rhizolex). The best microbial product, C-ISR2, showed a 33% and 33.6% net Pm (total Pm-control Pm) in the two tests against Rhizoctonia solani. In one test with a 58.6% control plot Pm, the total pm was 91.6%, indicating that plant protection can be done only with a microbial product in a well-conditioned field. The net Pm of C-ISR2 against Pythium sp. was 26.4%. The net Pm of a microbial product against a pathogen seems to be fixed. A significant negative linear correlation was found between the Pm and the coefficient of variation (CV) of the protection rate in all the three experiments. This indicates that the protection processes of control, microbial products, and chemical pesticides are in the same system. Pm was only dependent on CV, probably due to each seedling's microenvironment. In the linear correlation equation between the Pm and the CV of the microbial products and the control plot, the intercept of the vertical axis will be the theoretical Pm when CV is zero.

• Korean Journal of Food Science and Technology
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• v.48 no.4
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• pp.301-305
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• 2016

This study was conducted to investigate changes in pH, volatile basic nitrogen (VBN), thiobarbituric acid (TBA), $a^*$ (redness), shearing force, and microbial content (total plate count; TPC) in beef during freezing storage at -1, -5, and $-20^{\circ}C$ for 21 days. TPC as an effective quality indicator was used to identify the decay point by regression analysis. The pH, TBA values, and TPC significantly increased with storage at all tested temperatures (p<0.05). VBN significantly increased and shearing force significantly decreased with storage at -1 and $-5^{\circ}C$ (p<0.05). TPC showed significant correlation with temperature at $-1^{\circ}C\;(R^2=0.891)$, $-5^{\circ}C\;(R^2=0.856)$, and $-20^{\circ}C\;(R^2=0.444)$. The decay points at -1, -5, and $-20^{\circ}C$, were 27, 52, and 84 days, respectively. The results suggest that a freezing temperature of $-5^{\circ}C$ is effective for short-term storage of beef.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.11
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• pp.5939-5946
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• 2013

The bridge approach slabs (BAS) to provide a transitional roadway between a roadway pavement and a bridge structure have not performed adequately due to various factors. The current Korean Roadway Design Guidelines treat the BAS as a simply supported beam with 70% of the span length and do not consider settlement and void development underneath the slab. To investigate the effect of soil settlements on the bending moment of BAS, a beam on elastic support (BAS-ES) was used in the present study. The parameters used in this study were span length, washout length, washout location, and soil modulus. It was shown from the parametric study that washout regions closer to the midspan exhibit maximum moment in the slab. Since voids under the BAS have typically been observed to be closer to bridge abutments, the springs from the abutment were removed to simulate settlement and void development in the model. The design moments based on AASHTO LRFD Bridge Design Specifications were compared to those of Korean Standard Specifications for Highway Bridge and Design Trucks for Highway Bridges. Even if the design moment from BAS-ES was used to incorporate the effect of the potential washout, significant savings could still be achieved compared to the current BAS design.

• Journal of radiological science and technology
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• v.30 no.1
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• pp.53-59
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• 2007

A safety management rule of the diagnosis radiation system which opened a court 2006 February 10th was promulgated for safety of the radiation worker, patients and patients' family members. The purpose of this study is to minimize injury by radiation that can happen to patients and people around a sick ward when managing mobile X-ray system. This study analyzed sickroom environment of mobile X-ray examination and the statistical data of the Konkuk medical Information System(KIS) and the Picture Archiving Communication System(PACS). This study also investigated patient conditions, infection, relation information and related data, when the sickroom mobile X-ray examination is used. Through data analysis, many problems were expected such as restriction of space side, manpower and expense of business side, satisfaction degree decline of patient and protector of operation side. Therefore, we tried to restrict examination of multi bed sickroom, and to use treatment room in each ward to solve problem mentioned. As a result, the whole sickroom mobile X-ray examination rate decreased to near 50%, and mobile X-ray examination rate for inpatients decreased to more than 85%. This study shows that several attempts we did should be helpful for manpower, patients satisfaction and expenses. Also, they should protect patients in sickroom from unnecessary radiation exposure and could minimize inconvenience of patients and their family members from x-ray examination.

• Korean Journal of Plant Tissue Culture
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• v.24 no.2
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• pp.77-81
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• 1997

For the early selection of heat-tolerant clones, the true potato seeds of 750 clones were obtained by several cross combinations : $CIP\;575015\;{\times}\;katahdin,\;CIP\;575015\;{\times}\;B6603-6,\;84\;I\;35-4\;{\times}\;katahdin,\;CIP\;575015\;{\times}\;NookSack,\;and\;CIP575015\;{\times}\;Superior.$ The ratios of in vitro tuberization at 3$0^{\circ}C$ were decreased by 43% in all cross combinations compared with at 2$0^{\circ}C$. In particular, tuberization rate of $CIP575015\;{\times}\;katahdin$ cross at 3$0^{\circ}C$ was only 21%. On the other hand, the rate of tuberization of $CIP575015\;{\times}B6603-6$ cross was 58 % at 3$0^{\circ}C$, so this cross combination was thought to be good heat-tolerant clone. To screen the heat-tolerant clones in lower land during high temperature period, microtubers were cultivated in Kangnung, and the characters of tubers and productivity were examined. Among screened clones, one clone at 2$0^{\circ}C$ and three clones at 3$0^{\circ}C$ were shown to be heat-tolerant. The yield of 89ML75-8 was 88% more than that of Superior, and dry weight rate of 89 ML64-11 was 18.8%. Therefore, 89ML64-11 clone was considered as a good cultivar for processing.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.26 no.2
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• pp.77-83
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• 2020

A series of foamed plastic sheets containing biomass (as HMR container) were developed via different foaming process temperatures, and their density, porosity, WVTR, and pore morphology were evaluated. Thermal stability of samples during re-heating the food in oven, change in morphology, density, porosity, and WVTR were investigated using a simulated thermal shock process according to MIL-STD-883E assay. As such, the pore size of samples was generally increased with increasing temperature of the foaming process. It can be explained that as foaming temperature increased, the viscosity of molten resins and the repulsive force against pore expansion decreased. In addition, an increase in the thermal shock cycle reduced the pore size and WVTR, while density increased because high temperature treatment that softened the sheet matrix was followed by a low temperature incubation, which contracted the matrix, thereby changing the physical and morphological properties of samples. However, an insignificant change in density was observed and WVTR tended to be decreased, indicating that as-prepared foamed plastic sheets could be used as a high thermal stable container for HMR application. Therefore, it found that the properties of newly developed HMR containers containing biomass were dependent on the foaming process temperature. Moreover, to better understanding of these newly developed containers, further investigations dealing with foaming process temperature based on various food items and cooking conditions are needed.

• Korean Journal of Weed Science
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• v.18 no.2
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• pp.106-115
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• 1998

This study was conducted to investigate the effect of oxadiazon, molinate, thiobencarb before seeding on control of red rice and barnyardgrass in water-seeded rice. High application rate plot among oxadiazon treatment plots could observe phytotoxicity symptoms depending on field conditions, but these injury recovered gradually with time. Molinate and thiobencarb application plots at the concentration of 225~400, 210~420g ai/l0a respectively were not observed phytotoxicity. Control of red rice was different according to kinds of herbicides and application rates. Oxadiazon showed higher control performance at the concentration of more than 60g ai/10a. Control effect of molinate and thiobencarb against red rice was enhanced with the increase of application rate, and both herbicides showed satisfactory effect at more than 300g ai/10a. Control of barnyardgrass showed up to 90~100% in all tested herbicides. There was no significant yield reduction by oxadiazon, molinate, and thiobencarb application before seeding in all tested field. In the pot experiment, crop injury, seedling stand, and early growth were more advantageous at time of drainge after one day after seeding than flooding until rooting.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.5
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• pp.69-76
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• 2020

Global warming is a very important problem as it causes rapid climate change and natural disasters. Therefore, researches related to renewable energy are being actively conducted while promoting policies such as reducing carbon dioxide emission and increasing the proportion of renewable energy. Solar power generation is being applied in urban areas like BIPV as well as existing idle areas outside the city. Therefore, in this study, precast concrete blocks developed for paving roadways capable of solar power generation were designed and constructed. For the evaluation of field applicability for 6 months, skid resistance and block settlement were measured. As a result of the experiment, it was found that skid resistance satisfies the standard of general roadway in Korea, but not the standard of highway. The skid resistance tended to decrease as time passed. In addition, the settlement of the block gradually increased slightly, but it is much smaller than the allowable settlement of the roadway. Therefore, it is necessary to establish a maintenance period and method based on the periodic measurement results in the future.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.29 no.1
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• pp.27-33
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• 2023

An optimized design of the transportation insulated box must be considered to control the thermal damage in order to maintain the fresh condition for temperature-sensitive medicine and frozen food safety. The inside temperature of the insulated box is a natural convection enclosure state, thermal stratification naturally occurs as time passes in case of with outside heat load. The latent heat material (LHM) placement inside the box maintains the target temperature of the product for temperature fluctuations during transport, and LHM application is a common and efficient method. In this work, inside temperature stratification in an insulated box depending on the LHM pack position is numerically simulated and experimented. The insulated box is made up of vacuum insulation panel (VIP), and LHM modules are placed over six faces inside the box, with the same weight. The temperature curves for 72 hrs as experiment results clearly show the temperature stratification in the upper, middle, and lower at the LHM melting time region. However, the temperature stratification state is uniformly changed in accordance with the condition of the upper and lower placement weight of the LHM pack. And also, the temperature uniformity by changed placement weight of LHM has an effect on maintaining time for target air temperature inside the box. These results provide information on the optimized design of the insulated box with LHM.

• Magazine of the Korea Concrete Institute
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• v.11 no.2
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• pp.209-220
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• 1999

This paper is aimed to evaluate the effectiveness of flexural toughness of slab panel structures($60{\times}60{\times}10$) reinforced by steel fiber instead of wire mesh. Steel fiber used in this study is double hooked Dramix type fiber. And the fiber length is 60mm, diameter is 0.8mm, Various assessment methods of toughness index are used to estimate the proper effectiveness. In this experimental study, we find that Johnston, JCI-SF4 and EFNARC method are more effective to assess the flexural toughness of slab panels than the others. And the steel fiber is very effective alternative material to reinforce slab panel structures instead of wire mesh. Fiber volume fraction of 0.5~0.75% is more useful than the others in enhancing the post-peak energy absorption and toughness index by Johnston's $I_{5.5}$ assessment method. And the slab panels reinforcing with steel fiber are more resistant to crack propagation than wire mesh reinforcing slabs.