• Korean Journal of Digital Imaging in Medicine
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• v.13 no.1
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• pp.49-53
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• 2011

Dynamic range on the digital detector can be a representation to the ratio of maximum and minimum of pixel value. Wide dynamic range and post processing ability of the digital detector made difficult to recognize visually to high or low dose images. We were evaluated a change of mean pixel value on the original and processed image, when we controlled the kVp, mA, exposure time on the digital detector. On the kVp of a constant condition, we were acquired an original and processed image by changes of mA, exposure time. According to the thickness of the subject under the same conditions, to determine a relation of pixel value and X-ray intensity, we used an aluminum step wedge. When mA and exposure times were changed under the kVp of a constant condition, the X-ray intensity was decreased by the reduction of the mean pixel value. In addition when kVp was increased in a constant condition of mAs, the mean pixel value was increased according to the increment of the X-ray intensity. Therefore, low kVp, high mA and short exposure time were a way to reduce a patient dose.

• The Journal of the Korea Contents Association
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• v.21 no.4
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• pp.414-423
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• 2021

This study establishes a conceptual model that can clarify the causal relationship between self-efficacy, expected value and perceived risk, and trust for hydrogen Electric vehicles, which are expected to play an important role in activating hydrogen electric vehicles, and verify this through empirical research. As a specific research goal, first, the concepts of self-efficacy, perceived value, perceived risk, and trust were defined conceptually and operationally, centering on prior research. Second, a research model was presented and verified through an empirical analysis in order to confirm the influence relationship between the self-efficacy, perceived value, perceived risk, and trust derived through prior research. As a result of the study, it was found that self-efficacy had a significant effect on perceived value and trust. Also, perceived value and perceived risk were found to have a significant effect on perceived trust.

• The Journal of the Korea Contents Association
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• v.22 no.8
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• pp.307-317
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• 2022

This study aims to analyze relationship between effect on social value realization efforts and company performances, focusing on the mediating effect of external-support environment. Data for the analysis is collected from open data source from Social Enterprise Promotion Agency. The results of the analysis are, first the social value realization efforts has positive effect on both social and economic outcome of the social enterprises. External-support environment has influence on both social performance and social value realization efforts. Additional analysis to test mediation effect of external-support environment were carried out by statistical software package, Process for SPSS4.0. Mediation effect could be found between social realization efforts and social performances, however, no evidence could be found on economic performance. The result indicates that social value realization efforts as a social capital has influence on social performance mediated by external-support environment.

• Korean Journal of Microbiology
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• v.41 no.1
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• pp.60-66
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• 2005

To select the rapid and efficient molecular subtyping method for epidemiologic monitoring of Staphylococcus aureus (S. aureus) strains at clinical laboratory levels, a total 116 of S. aureus and MRSA (methicillin-resistant S. aureus) strains from diverse animal species [Korean cattle, goat, pig, dog, chicken, mouse] and also humans were analyzed. To evaluate the discriminatory ability (DA) of individual PCR methods, random amplified polymorphic of DNA [RAPD; 4M & RA primer], repetitive extragenic palindromic sequences PCR (REP-PCR), and enterobacterial repetitive intergenic consensus sequences PCR (ERIC-PCR) methods were conducted and then compared on their Simpson's index of diversity (SID) values based on the dendrogram patterns, which was produced by software program (BiolD2+ & GelCompar II). In first, RAPD using the 4M primer (SID 0.915) was expressed more higher SID value than that of RA primer (SID 0.874). 4M primer was expressed more powerful DA than RA. Both REP-PCR (SID 0.930) and ERIC-PCR (SID 0.929) methods showed much more higher DA than that of RAPD. According to the present results, both REP-PCR and ERIC-PCR among the tested analysis methods were found as the most reliable and discriminative molecular subtyping method, because they expressed the highest DA for the present S. aureus and MRSA strains.

• Journal of the Korean Society for Precision Engineering
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• v.3 no.2
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• pp.62-75
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• 1986

An experimental investigation of the machining characteristics such as cutt- ing resistance, surface roughness and tool wear in turning the test pieces of SM45C steel with both coated and uncoated carbide tool tips under various cutting conditions was conducted. Also a specially designed simple vibration damping device was experimentally evaluated for its effectiveness on machined surface roughness and a vibration test was conducted to confirm its ability to reduce the amplitude. Based on these tests finding, the following conclusions are made; 1. The cutting resistance($\textrm{p}_{1}$) increases as the depth of cut(d) increases at fixed feed rate(f) over the cutting speed(v) range of 43-226 m/min and p decreses about 18% average when V is increased for fixed d and f. At V= 226m/min, $\textrm{p}_{1}$/for A, C tips are about the same level but $\textrm{p}_{1}$ for B tip is 15% less than A, C tips. 2. The specific cutting resistance(Ks) at V=226 m/min was derived for A, B, C tips respectively and the value of Ks for B rip is about 20% less than A, C tips. 3. The surface roughness(Ra) improves significantly as the cutting speed(V) is increased and this effect was greater when V>100 m/min. On the other hand, Ra deteriorates as the feed rate(f) is increased and this trend was accelerated when f>0.3 mm/rev. With regard to the difference of Ra values among A, B, C tips, at V=226m/min, d=0.4mm, and f=0.31-0.61mm/rev, Ra values for B.C tips are about 17% less than tip A. 4. The experimental tool wear equations were derived for A, B, C tips and from these equations, the tool life($\textrm{T}_{\textrm{L}}$) baced on the I.S.O. criteria was calculated to be $\textrm{T}_{\textrm{L}}$<$\textrm{T}_{\textrm{LB}}$<$\textrm{T}_{\textrm{LC}}$ for both flank wear($\textrm{V}_{\textrm{B}}$) and boundary wear($\textrm{V}_{\textrm{N}}$). Hence, the coated tips are superior to the uncoated tip and tip C is considered to be the best. 5. The cutting resistance may be slightly reduced and the surface rounghness improved when the damper is used especially when V>100 m/min. Therefore this damping device is considered to be effective and practical. The experimental surface roughness equations were also derived. Based on the vibration test, it is established that the surface roughness improvement was the result of amplitude reduction made possible by the damper.

• Journal of Korean Theatre Studies Association
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• no.48
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• pp.85-125
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• 2012

Geun Hyung Park is one of the playwrights who consistently pursues his unique world of play. One of the characteristics that is constantly discovered in Park's plays is the motif of 'family.' Park chooses family as the motif in most of his work. Park particularly emphasizes 'family life' rather than 'individual life' to focus on the internal problems of families. Therefore, the motif of family in Park's plays takes a very important position in the content and theme. The Korean society imposes unique value on families and possesses a strictly obstinate family ideology. Park observes distorted family relations or individuals who cannot be happy within their families to identify the problems related to the family ideology that is deeply rooted in the Korean society. This is one of the important backgrounds for which Park is constantly dealing with 'family life.' This study selected five of Park's most famous plays to specifically examine Park's critical understanding of family ideology. First, his criticizes extreme family egoism by depicting a family that cannibalizes people to keep the family full. Park chooses 'absurd time and space' and the extreme subject of 'human flesh' to warn his audiences about the awful consequences of family egoism. His , which is the only piece that deals with family history among the five pieces selected, criticizes Korea's unique family-centered ideology by humorously depicting the history of the Cho family that is all about maintaining and worshipping the its clan. He reveals the unethical and hypocritical attitudes of the Cho family for the audiences to reconsider the family-centered ideology of the Korean society. In , he talks about the son and the father who lose his ethical authority and fail to perform his paternal responsibilities to criticize the traditional family ideology of patriarchism and suggests the pessimistic future of patriarchism. contrasts a blood-related family with an irresponsible father and a quasi-family to criticize the identity of blood-related families. In , Park depicts a 'smelly house' of a family in agonizing relations to deny the family myth and the maternal myth. He clearly shows how the ideals of family myth and maternal myth are distant from the reality. In result of this study, Park's criticism of family ideology appears in various forms. He comprehensively criticizes both the general family problems and the unique family issues of Korea. The family ideology of Korea is currently undergoing a radical change. It has been long since the traditional family ideologies have exposed problems to show the signs of crisis. Also, there have emerged various forms of families, including single-parent families, one-person families, adoption families, and multi-cultural families. In this respect, Park's critical understanding of family ideologies allows you to see the obvious family forms from a new perspective and greatly contributes to awakening the essential questions about families. Park's work is noticeable among the various artistic and literature pieces that deal with family issues because of his extraordinary skills to capture the key issues inherent in the problems of family ideologies.

• Nuclear Engineering and Technology
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• v.56 no.6
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• pp.2182-2189
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• 2024

The high-purity germanium gamma-ray spectrometer was used to measure the radioisotope in surface water of lakes in a Chinee petroleum industrial area. 92 samples were collected from surface water of three lakes. Activity concentrations of ²³²Th, ²²⁶Ra and ⁴⁰K in three lakes were measured, distributed in the range of 101.8-209.4, 192.1-224.9 and 335.0-548.9 mBq/L, respectively. Results were all within the limits of WHO and China. Potential environmental and health risks were assessed by calculating some radiation hazard indicators, radium equivalent index, annual effective dose, excess lifetime cancer risk, absorbed dose rate, external hazard index, internal hazard index, annual gonadal dose equivalent, activity utilization index and representative gamma index, which ranged 0.38-0.54 Bq/L, 0.06-0.08 mSv/y, 0.23 × 10^-3-0.31 × 10^-3, 0.17-0.24 nGy/h, 1.01 × 10^-3-1.46 × 10^-3, 1.55 × 10^-3-2.02 × 10^-3, 1.16-1.66 μSv/y, 3.13 × 10^-3-4.45 × 10^-3 and 2.60 × 10^-3-3.77 × 10^-3. The results were all at acceptable levels, meaning no impact on human health. The relationship between the electrical conductivity of surface water and the activity concentration of ²³²Th, ²²⁶Ra and ⁴⁰K was evaluated. The electrical conductivity value was 0.241-0.369 mS/cm, showing a significant correlation coefficient between ²²⁶Ra and ⁴⁰K and electrical conductivity. Multivariate statistical methods were used to determine the relationship between the activity concentrations of ²³²Th, ²²⁶Ra, and ⁴⁰K, radiation hazard indicators and electrical conductivity.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.5
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• pp.631-640
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• 2014

In this study, manufactured a cream soup by varying addition of Hericium erinaceus and decided its recipe, and conducted particle size analysis, calorimetry, sensory test for investigating physicochemical characteristics and quality characteristics (salinity, sugar content, color value, pH, viscosity), antioxidant activities of soup, and mechanical sensory test for objectivity. This study found that moisture content in Hericium erinaceus powder was 6.16%, crude protein 26.87%, crude fat 4.62% and crude ash was 10.75% respectively. No significant differences were found in salinity, sugar content, pH according to addition of Hericium erinaceus. As for color value of cream soup manufactured by adding Hericium erinaceus, L value decreased with increase in addition of Hericium erinaceus, whereas a value and b value increased. The more the addition of Hericium erinaceus, the higher the viscosity, which increases concentration of soup. As result of analysis on antioxidant activities of Hericium erinaceus cream soup, antioxidant activities increased with increase in addition of Hericium erinaceus. Particle size analysis showed results similar to that of viscometry, which means that the smaller the particle size, the higher the viscosity, whereas viscosity lowered vice versa. Calorie of cream soup showed no significant difference notwithstanding the amount of addition. As a result of sensory test, S5 with 5% of Hericium erinaceus powder was highest rated in color, flavor, taste, umami taste and overall preference. As a result of mechanical sensory test, umami taste increased with increase in addition of Hericium erinaceus powder, whereas bitterness taste lowered significantly (p<0.05) with addition of Hericium erinaceus. As for salty taste, both control group and experimental group that added Hericium erinaceus powder showed no significant difference. Accordingly, experimental group with 5% of Hericium erinaceus powder was proved to be the most desirable.

• Economic and Environmental Geology
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• v.35 no.6
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• pp.523-532
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• 2002

The rare earth elements (REE) and Nd, Sr and noble gas isotopic compositions eHer'He, 4$^{\circ}$Arp6Ar) for the Quaternary alkali basaltic rocks and mantle xenoliths in the basaltic rocks from the Baegryongdo were investigated to decipher the origin of alkali basaltic magma and xenolith beneath the Sino-Korean craton. Analytical results are summarized as follows; (1) The alkali volcanic rocks with voluminous xenoliths which are represented by the Mg-olivine and clinopyroxene dominant spinel-lherzolite in the Baegryongdo consist mainly of the basalt-mugearite and basaltic andesite. (2) The REE pattern of alkali basaltic rocks characterized by high HREE is similar to that of oceanic island basalt (OlB). Relatively concordant REE patterns of the basaltic rocks suggest that the alkali basaltic magma be formed by the identical source materials. (3) The Nd-Sr isotopic data of the alkali basaltic rocks suggest that the alkali basaltic magma be originated from the depleted mantle source with a little contamination of the continental crustal materials. (4) The $^3$He/ $^4$He ratios in olivines of xenoliths ranging from 5.0${\pm}$1.lRa to 6.7${\pm}$1.3Ra are lower than that of MORB (ca. 8.0Ra). It suggest that the xenolith be derived from the subcontinental lithospheric mantle. However, the high $^3$Her'He value of 16.8${\pm}$3.IRa at 1800$^{\circ}$C fraction (sample no OL-7) might be resulted from the post-eruptive cosmogenic $^3$He. The 4OAr/ 36 Ar ratios in olivines of mantle xenoliths are comparable to that of atmospheric argon, and are much lower than that of the MORB type mantle. These facts can lead to conclusion that the olivine of the xenolith in the Baegryongdo is affected by the post-eruptive atmospheric contamination during the slow degassing process.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.1
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• pp.41-46
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• 2003

In order to evaluate the sufficient etching time for successful bonding and also minimizing unnecessary mineral loss, the enamel surface roughness analysis was performed using confocal laser scanning microscopy. Sixty extracted sound human molar teeth were imbedded in the center of acrylic cylinder using self-curing clear resin exposing buccal surface, and then polished with series of SiC paper(220, 500, 800, 1000, 2000, 4000 grit). Each specimen was randomly assigned to six groups(N=10). 37% phosphoric acid was applied to the polished tooth surface for 10, 20, 30, 40, 50, 60 seconds respectively and washed with copious water. After the surface roughness analysis, five roughness parameters(Sa, Sq, Sz, Sdr, Ra) were statistically analysed by ANOVA and Duncan post hoc test. We found that the all five parameters had higher roughness value in 30 seconds etching time, especially parameter Sz showed the lowest value in 10 seconds etching time and the highest value in 30 seconds etching time compared with the other etching times(p<0.05).