• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.1
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• pp.51-62
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• 2020

This study was conducted to develop a method for depth assessment of embedded sources using gamma-spectrum ratio and for the evaluation of field applicability. To this end, Peak to Compton and Peak to valley ratio changes were evaluated according to ¹³⁷Cs, ⁶⁰Co, ¹⁵²Eu point source depth using HPGe detector and MCNP simulation. The effects of measurement distance of PTV and PTC methods were evaluated. Using the results, the source depth assessment equation using the PTC and PTV methods was derived based on the detection distance of 50 cm. In addition, the sensitivity of detection distance changes was assessed when using PTV and PTC methods, and error increased by 3 to 4 cm when detection distance decreased by 20 cm based on 50 cm. However, it was confirmed that if the detection distance was increased to 100 cm, the effects of detection distance were small. And PTV and PTC methods were compared with the two distance measurement method which evaluates the depth of source by the change of net peak counting rate according to the detection distance. As a result of source depth assessment, the PTV and PTC showed a maximum error of 1.87 cm and the two distance measurement method showed maximum error of 2.69 cm. The results of the experiment confirmed that the accuracy of the PTV and PTC methods was higher than two distance measurement. In addition, Sensitivity evaluation by horizontal position error of source has maximum error of less than 25.59 cm for the two distance measurement method. On the other hand, PTV and PTC method showed high accuracy with maximum error of less than 8.04 cm. In addition, the PTC method has lowest standard deviation for the same time measurement, which is expected to enable rapid measurement.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.485-496
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• 2022

Modern agriculture is being transformed into smart agriculture to maximize production efficiency along with changes in the 4th industrial revolution. However, rural areas in Korea are facing challenges of aging, low fertility, and population outflow, making it difficult to transition to smart agriculture. Among ICT technologies, simulation allows users to observe or experience the results of their choices through imitation or reproduction of reality. The combination of the three-dimension (3D) model and the greenhouse simulator enable a 3D experience by virtual greenhouse for fruits and vegetable cultivation. At the same time, it is possible to visualize the greenhouse under various cultivation or climate conditions. The objective of this study is to apply the greenhouse climate management model for simulation development that can visually see the state of the greenhouse environment under various micrometeorological properties. The numerical solution with the mathematical model provided a dynamic change in the greenhouse environment for a particular greenhouse design. Light intensity, crop transpiration, heating load, ventilation rate, the optimal amount of CO₂ enrichment, and daily light integral were calculated with the simulation. The results of this study are being built so that users can be linked through a web page, and software will be designed to reflect the characteristics of cladding materials and greenhouses, cultivation types, and the condition of environmental control facilities for customized environmental control. In addition, environmental information obtained from external meteorological data, as well as recommended standards and set points for each growth stage based on experiments and research, will be provided as optimal environmental factors. This simulation can help growers, students, and researchers to understand the ICT technologies and the changes in the greenhouse microclimate according to the growing conditions.

• Information Systems Review
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• v.20 no.2
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• pp.39-62
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• 2018

Thanks to the growth of computing power and the recent development of data analytics, researchers have started to work on the data produced by users through the Internet or social media. This study is in line with these recent research trends and attempts to adopt data analytical techniques. We focus on the impact of "internal marketing" factors on firm performance, which is typically studied through survey methodologies. We looked into the job review platform Jobplanet (www.jobplanet.co.kr), which is a website where employees and former employees anonymously review companies and their management. With web crawling processes, we collected over 40K data points and performed morphological analysis to classify employees' reviews for internal marketing data. We then implemented econometric analysis to see the relationship between internal marketing and market capitalization. Contrary to the findings of extant survey studies, internal marketing is positively related to a firm's market capitalization only within a limited area. In most of the areas, the relationships are negative. Particularly, female-friendly environment and human resource development (HRD) are the areas exhibiting positive relations with market capitalization in the manufacturing industry. In the service industry, most of the areas, such as employ welfare and work-life balance, are negatively related with market capitalization. When firm size is small (or the history is short), female-friendly environment positively affect firm performance. On the contrary, when firm size is big (or the history is long), most of the internal marketing factors are either negative or insignificant. We explain the theoretical contributions and managerial implications with these results.

• Applied Chemistry for Engineering
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• v.9 no.3
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• pp.457-461
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• 1998

The vesicle system of DPPC(dipalmitoylphosphaticylcholine)/Chol(Cholesterol) has been modified by incorporating various mole fractions of flourinated surfactant($C_8F_{17}(CH_2)_2OCO-CH_2CH(SO_3Na)COO(CH_2)_2C_8F_{17}$. Sodium bis(1H,1H,2H,2H-heptadecaflurododecyl)-2-sulfosuccinate, FS)/fluorinated fatty acid salt ($C_7F_{15}COONH_4$, ammoniumpentadecaflurooctyrate, FFS), and their physicochemical properties have been investigated in an attempt to enhance the stability of phospholipid vesicle system. The ${\zeta}$-potential measurement by use of Zetamaster sub-micron Particle Electrophoresis Analyzer (Malvern Co.) showed that a charged homogeneous DPPC/Chol/FS vesicle has been formed owing to the incorporated FFS effect on the membrane, playing a role as a cosurfactant in the bilayer between DPPC and FS components. With increase in the concentration of FFS, it was found that the particle size and also surface charge of the DPPC/Chol/FS vesicle decreased. The stability of DPPC/Chol/FS/FFS liposome was found to be enhanced significantly compared to that of DPPC/Chol/FS according to the dispersity change as a function of time. The release rate of dye molecule of Methylene Blue from the DPPC/Chol/FS/FFS vesicle was determined to be slower than that of DPPC/Chol/FS system, and it may be attributed to the increase in microviscosity of the hydrophobic region in the bilayer. The affinfinity of DPPC/Chol/FS/FFS vesicles to albumin was found to be slightly lowered compared to that of DPPC/Chol/FS. Based on these findings, it was confirmed that a more stable and homogeneous vesicle system of DPPC/Chol/FS could be prepared by addition of FFS, acting as a cosurfactant in the aggregate formation.

• Journal of Mushroom
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• v.11 no.4
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• pp.254-260
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• 2013

The objective of this study was to evaluate antioxidant effect and tyrosinase inhibitory activity of methanol extracts from Hypsizygus marmoreus. The Hypsizygus marmoreus was divided into two parts (pileus and stipe) and extracted with methanol. Total polyphenolics and flavonoids in the methanol extracts were measured by spectrophotometric methods and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities have been determined for antioxidant activities. The total polyphenolics and flavonoids contents of methanol extract of the pileus were higher than methanol extract of the stipes. The total polyphenolics contents in methanol extracts of the pileus and stipes were 8.7 ug/mg and 5.6 ug/mg, respectively. The total flavonoids contents in methanol extracts of the pileus and stipes were 2.8 ug/mg and 1.4 ug/mg, respectively. The tyrosinase inhibitory activity was proportional to concentration of methanol extract. The tyrosinase inhibitory activity of the methanol extract (200 mg/ml) of pileus (66.9%) and stipe (57.97%) was lower than those of positive control 2% arbutin. The DPPH radical scavenging activity of the methanol extract (20 mg/ml) of pileus and stipes was 52.55% and 30.35%, respectively. Moreover, the effects of methanol extarcts on cell proliferation of B16BL6 mouse melanoma cells were investigated using WST-1 assay (4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulphonate) and B16BL6 mouse melanoma cells treated with methanol extract of 200-2,000 ug/ml were higher proliferation rate than those of 0.04% adenosine.

• Korean Journal of Microbiology
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• v.49 no.2
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• pp.172-178
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• 2013

The strains were added to the feed in the concentration of $10^3$, $10^5$, and $10^7$ CFU/kg and 2% of fishes were given the feed twice a day (8 AM and 5 PM) for 12 weeks. In result of the nonspecific immune response study to examine Respiratory burst activity, Lysozyme activity and Phagocytosis activity every two weeks until the end of the study, all test samples showed greater activities than control samples and improved immune activity with Bacillus sp. IS-2. The mortality test performed by artificial infection using Streptococcus iniae, a pathogenic bacterium, after the completion of this study also showed over 55% greater survival rate in all test samples. In result of performing PCR using the universal primer to verify that the probiotic stays in the intestines of the fishes, all test samples showed PCR product of 1,465 bp. Based on the above findings, it was concluded that Bacillus sp. IS-2 in the feed improved farmed flatfish's immune system and resistance against diseases as the probiotics. Also, the physiological indicators discovered by this study would be useful for identifying the mechanisms of probiotics.

• Food Science of Animal Resources
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• v.25 no.1
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• pp.20-25
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• 2005

This study was conducted to evaluate the effects of Zizyphus vulgaris supplementation on growth performance, blood cortisol and meat quality characteristics in finishing pigs. The total of thirty-six [Duroc${\times}$Yorkshir${\times}$Landrace] pigs ($91{\pm}2.11$ kg average initial body weight) were used in a 30-days assay. Dietary treatments included 1) CON (basal diet), 2) T1 (basal diet for 15 days and 0.1 % Zizyphus vulgaris for 15 days) and 3) T2 (0.1 % Zizyphus vulgaris for 30 days). The ADG (Average daily gain), ADFI (Average daily feed intake) and ADG/ADFI during the feeding period were not significantly differences among the treatments (p>0.05). Backfat thickness of pigs fed CON was higher than those of T1 and T2 (p<0.05). The appearance rate of A or B carcass grade was in T1 (74%) and T2 (84%) was significantly higher than that in CON (58%) (p<0.05). Pigs fed Zizyphus vulgaris 0.1 % for 30 days tended to decrease on blood cortisol compared with pigs fed CON and T1. But, there was not significantly difference among the treatments (p>0.05). The Hunter's L/sup */ (lightness) value of loin in the pork fed CON was higher than that of loin in the pork fed T1 and T2 (p<0.05). After 7 days, the L/sup */ value of loin in the pigs fed T2 was higher increased than that of pigs fed T1 and CON (p<0.05). However, a/sup */ and b/sup */ values were not affected by dietary Zizyphus vulgaris (p>0.05). There were not found remarkable differences in sensory properties (marbling, firmness and color) among the treatments. The results from the present study suggest that Zizyphus vulgaris could be a effective feed additive to improve meat quality of pigs. However, further research is needed to investigate effects of carcass characteristics.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.349-355
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• 2018

This study was aimed at predicting the yield of paprika (Capsicum annuum L.) through analyzing the growth characteristics, yield pattern and greenhouse environment. In the greenhouse of the Gyeongnam area (667 m above sea level), the red paprika 'Cupra' and the yellow paprika 'Fiesta' were grown from July 5, 2016 to July 15, 2017. The planting density was $3.66plants/m^2$ and attracted 2 stems. During the cultivation period, the average external radiation of the glasshouse was $14.36MJ/m^2/day$ and the internal average temperature was controlled as $20.1^{\circ}C$. After 42 weeks of planting, the growth rate of 'Cupra' was 7.3 cm/week and that of 'Fiesta' was 6.9 cm/week. The first fruit setting of 'Cupra' appeared at 1.0th node and 'Fiesta' at 2.7th node. The first harvest of 'Fiesta' was 11 weeks after planting and 'Fiesta' was 14 weeks. Comparing the yield per 10 a until the end of the cultivation in July, 'Fiesta' was 19,307 kg, which was 2.4% higher than that of 'Cupra'. And the fruit weight ratio of over 200 g of 'Cupra' was 27.7% which was 7.7% higher than that of 'Fiesta'. The average required days to harvest after fruit setting of 'Cupra' was 72.6 days and 'Fiesta' was 63.8 days. According to the relationship between the average required days to harvest and the cumulative radiation (during from fruit setting to harvest), the more radiation increases the less required days to harvest increases after February. In terms of yield, 'Cupra' increased in yield as the cumulative radiation increased, while 'Fiesta' showed an irregular pattern. Cumulative radiation from fruit setting to harvest was negatively correlated with required days to harvest after February in both cultivars. But in relation to yield, there were difference between 'Cupra' and 'Fiesta'.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.34 no.4
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• pp.109-116
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• 2024

β-Ga₂O₃ is a representative ultra-wide bandgap (UWBG) semiconductor that has attracted much attention for power device applications due to its wide-bandgap of 4.9 eV and high-breakdown voltage of 8 MV/cm. In addition, because solution growth is possible, it has advantages such as fast growth rate and lower production cost compared to SiC and GaN [1-2]. In this study, we have successfully grown Si-doped 10 mm thick Si-doped β-Ga₂O₃ single crystals by the EFG (Edge-defined Film-fed Growth) method. The growth direction and growth principal plane were set to [010] / (010), respectively, and the growth speed was 7~20 mm/h. The as-grown β-Ga₂O₃ single crystal was cut into various crystal planes (001, 100, ${\bar{2}}01$) and off-angles (1^o, 3^o, 4^o), and then surface processed. After processed, the homoepitaxial layer was grown on the epi-ready substrate using the HVPE (Halide vapor phase epitaxy) method. The processed samples and the epi-layer grown samples were analyzed by XRD, AFM, OM, and Etching to compare the surface properties according to the crystal plane and off-angle.

• Journal of Animal Science and Technology
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• v.55 no.1
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• pp.51-59
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• 2013

This study was conducted to investigate the dietary effect of total mixed rations (TMR) containing brewers grain, soybean curd and rice straw, respectively, on growth performance and carcass characteristics of Hanwoo steers. Twenty four Hanwoo steers (average body weight 168 kg) in 6 months age were randomly allocated to 4 experimental groups, which contained 6 animals per group during 22-months feeding trial. The treatment was composed of the group fed concentrate and rice straw separately (T1), the group fed TMR containing brewers grain (T2), the group fed TMR containing soybean curd (T3) and the group fed TMR containing rice straw (T4). Body weight (BW) was not different among treatment groups during the growing and middle fattening period. However, it was significantly greater in T4 group than in T2 group on the final BW (p<0.05). Average daily gain was significantly greater in TMR groups compared to T1 group on the growing and late fattening (p<0.05). However, it was not different in total average. Dry matter intake tended to be increased in TMR groups. The feed conversion ratio was significantly lower in T4 group compare to T2 group (p<0.05). According to the yield traits, carcass weight of T1, T2, T3 and T4 were 389.0, 368.4, 387.5 and 384.3 kg, respectively. The back fat thickness, rib-eye area, and yield index were not different among the groups. Meat color, fat color, texture and maturity were not significantly different among groups. However, marbling score and appearance rate of meat quality grade of over $1^+$ were greater in T2 and T3 groups compare to other groups. Therefore, these results indicated that TMR with brewers grain and soybean curd may be ameliorated the growth performance and carcass characteristics of Hanwoo steers.