• Journal of the Korea Organic Resources Recycling Association
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• v.26 no.4
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• pp.31-43
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• 2018

This study was conducted to investigate the effects of organic farmland soil and nutrient management on soil properties depending on organic (animal manure compost and green manure [hairy vetch]) and chemical fertilization, tillage and no-tillage, and crop rotation (corn-wheat, corn-.hairy vetch). It was found that the application of organic matter such as animal manure compost and hairy vetch, increased the soil organic matter content, the soil microbial density and microbial biomass C content as compared with the chemical fertilizer treatment. It was also confirmed that the functional diversity of soil microbial community was increased. As a result of the comparison with the crop rotation and single cropping, the soil chemistry showed no significant difference between the treatments, but the corn-wheat and corn-hairy vetch rotation treatments tended to have higher microbial biomass C content and shannon's diversity index than the single cropping. Soil chemical properties of tillage and no-tillage treatments showed no significant difference between treatments. There was no statistically significant difference in substrate utilization of soil microbial community between tillage and no-tillage treatment. Correlation analysis between soil chemical properties and soil microbial activity revealed that soil organic matter content and exchangeable potassium content were positively correlated, with statistical significance, with substrate utilization, and substrate richness. To conclude, organic fertilization had positive effects on the short-term improvement of soil chemical properties and diversity of microbial communities.

• Microbiology and Biotechnology Letters
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• v.48 no.3
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• pp.344-357
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• 2020

Strain improvement and bioprocess development were undertaken to enhance hyaluronic acid(HA) production by Streptococcus zooepidemicus cells. Using a high-yielding mutant strain, statistical medium optimization was carried out in shake flask cultures, resulting in 52% increase in HA production (5.38 g/l) at the optimal medium composition relative to the parallel control cultures. For sufficient supply of dissolved oxygen (DO), which turned out to be crucial for enhanced production of HA, agitation system and speed were intensively investigated in 5 L bioreactor cultures. Increase in oxygen mass transfer coefficient (k_La) through increment of agitation speed (rpm) and 35% expansion of diameter of the newly-designed impellers showed significantly positive effects on HA production. By installing an expanded Rushton-turbine impeller for efficient break-down of sparged air, and an extended marine impeller above the Rushton-turbine impeller for efficient mixing of the air-born viscous fermentation broth, maximum amount of HA (9.79 g/l) was obtained at 450 rpm, 1.8 times higher level than that of the corresponding flask culture. Subsequently, the possibility of bioprocess scale-up to a 50 L bioreactor was investigated. Despite almost identical maximum HA production (9.11 vs 9.25 g/l), the average HA volumetric productivity (r_p) of the 50 L culture turned out only 74% compared to the corresponding 5 L culture during the exponential phase, possibly caused by shear damages imposed on the producing cells at the high stirring in the 50 L culture. The scale-up process could be successfully achieved if a scale-up criterion of constant oxygen mass transfer coefficient (k_La) is applied to the 50 L pilot-scale bioreactor system.

• Journal of the Society of Disaster Information
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• v.11 no.2
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• pp.191-202
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• 2015

The purpose of this study was to examine the influence of the disaster perception and satisfaction level of volunteer fire-fighters on the continuity of their volunteering. The 163 subjects in this study were selected from male and female volunteer fire-fighters who resided in urban and rural regions in Gangwon Province. After a this survey was conducted, the collected data were analyzed by a statistical package SPSS WIN 20.0, and frequency analysis, correlation analysis and multiple regression analysis were made. The level of statistical significance was all set at p<.05. The findings of the study were as follows: First, as for the correlation of disaster perception, satisfaction and volunteering continuity, perception of disaster countermeasures, satisfaction and the level of participation were negatively correlated with one another, and there was a positive correlation among disaster training, disaster preparation, regional disaster, the period of volunteering, and will of persistent volunteering. Second, as for perception of disaster, the volunteer fire-fighters were asked a question about disaster countermeasures, and the largest group replied they were partially aware of the countermeasures. Concerning questions about disaster training/education experience and triage, the biggest group replied they underwent the training and knew about triage on the whole. Regarding questions on the emergency contact system and emergency work schedule, they knew about the two in general. As to a question on the occurrence of human disaster, the greatest group answered that they knew about it yet not well. Third, in regard to the impact of satisfaction level on volunteering continuity, the period of volunteering was affected by needs for experience, social contact and social recognition among the subfactors of satisfaction level, and will of persistent volunteering was under the influence of social contact and achievement needs. The level of persistent volunteering was affected only by needs for experience and achievement needs.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.11 no.2
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• pp.126-134
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• 2001

Statistical approaches for analysis of data from the limited number of samples in ship building industry(SBI) collected by an industrial hygienist for checking compliance to an occupational standard were considered. Sampling for compliance usually has been guided by judgment selection, rather than true randomness, resulting in the creation of compliance samples which approximate a censored sample from the upper tail of the exposure distribution. Similar exposure groups(SEGs) including welding and painting process were established to assess representative values in each groups after reviewing the whole production line in SBI. For the convenient statistical approaches, the code has assigned to each SEGs. The descriptive statistics and probability plotting were used to yield the representative values in each SEGs. In the first step, SEGs of 558 were established from 5 ship building companies. The 38 SEGs showed the uncertainty are divided into each 5 companies and assessed the representative values again. The 44 SEGs in each companies was not showed the normal and lognormal distribution was analyzed each data. And also, recommendation was suggested to resolve the uncertainty in each groups.

• The Journal of Korean Academy of Prosthodontics
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• v.36 no.6
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• pp.832-845
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• 1998

The purpose of this study was to compare the marginal fit of all ceramic crowns prepared from alumina slip casting, which is consistent with the conventional In-ceram system, and those fabricated from alumina tapes which is currently under development in an effort to alleviate complexities involved in the forming procedure of the In-ceram crown core. All ceramic crowns, made of In-ceram(slip casting) and alumina tapes(Doctor blade casting), were prepared with $90^{\circ}\;and\;135^{\circ}$ shoulder margins. The crowns were cemented with a glass ionomer cement and embeded in epoxy resin. The embedded crowns were sectioned faciolingually and mesiodistally and marginal discrepancies and marginal gaps were measured under the Measurescope MM II. The measurements were analyzed using Wilcoxon rank sum test and Kruskal-Wallis test and the results were as follows: 1. In the case of $90^{\circ}$ shoulder margin, the combined marginal discrepancies and marginal gaps were $78.3{\mu}m\;and\;44.4{\mu}m$ respectively, for the all ceramic crowns fabricated using the alumina tapes. In comparison, the values were $65{\mu}m\;and\;25.5{\mu}m$ for the In-ceram crowns. For the marginal gaps a statistical difference existed (p<0.05) but no significant difference was observed for the marginal discrepancy (p>0.05). 2. In the case of $135^{\circ}$ shoulder margin, the combined marginal discrepancy and marginal gaps were $82.1{\mu}m\;and\;40.2{\mu}m$ respectively, for the all ceramic crowns formed with the tapes. As compared with the marginal discrepancy and gaps of the $90^{\circ}$ shoulder margin in the fabricated from the alumina tapes, no significant statistical differencies were discerned in both cases (p>0.05). 3. There was no statistically significant difference in the fits among four locations around the margins of the all ceramic crowns fabricated using the alumina tapes. The results obtained in this study showed that the marginal fits of the glass infiltrated alumina cores fabricated from the alumina tapes are slightly higher value than those prepared using the In-ceram but the difference is within a clinically acceptable range.

• The Journal of the Korea Contents Association
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• v.14 no.10
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• pp.562-569
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• 2014

The purpose of this study was to investigate the determinants of total payment for mental and behavioral disorders patients admitted through the emergency room. Study data was selected from the Korean National Health Insurance sample data in 2009. This data was consisted of 753 inpatients who are 331 inpatients with only main sick(F31-F39) and 422 inpatients with main sick codes(F31-F39) and sub sick(F00-F99) admitted through the emergency room. SPSS v.18 was used for the statistical analysis such as descriptive analysis, t-test, ANOVA, and multiple regression analysis. In multiple regression analysis, significant variables affecting total payment of main sick patients were gender(p<.01), treatment result(p<.001), path of the emergency room(p<.001), and length of stay(p<.001). Also, main sick patients with sub sick were gender(p<.01), age(p<.001), treatment result(p<.001), path of the emergency room(p<.001), and length of stay(p<.001). These findings implied that it is necessary to build short, middle, and longterm program and system for high risk mental and behavioral disorders groups.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.3
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• pp.465-479
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• 2020

Regardless of the domestic and foreign governments/companies, SOC (Security Operation Center) has operated 24 hours a day for the entire year to ensure the security for their IT infrastructures. However, almost all SOCs have a critical limitation by nature, caused from heavily depending on the manual analysis of human agents with the text-based monitoring architecture. Even though, in order to overcome the drawback, technologies for a comprehensive visualization against complex cyber threats have been studying, most of them are inappropriate for the security monitoring in large-scale networks. In this paper, to solve the problem, we propose a novel visual approach for intuitive threats monitoring b detecting suspicious IP address, which is an ultimate challenge in cyber security monitoring. The approach particularly makes it possible to detect, trace and analysis of suspicious IPs statistically in real-time manner. As a result, the system implemented by the proposed method is suitably applied and utilized to the real-would environment. Moreover, the usability of the approach is verified by successful detecting and analyzing various attack IPs.

• The Journal of Engineering Geology
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• v.16 no.4 s.50
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• pp.337-349
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• 2006

Seven hundred and fifty one fractures of the rhyolitic tuffaceous rock masses were mapped using 6 scanlines placed on rock slope exposures that were within 8.02 km of Busan-Ulsan highway. These data were analyzed to find the number of fracture sets that exist in the rock slopes and the probability distributions of orientation, spacing, trace length and fracture size in 3-D for each of the fracture sets. All the fracture set orientation distributions exhibit high variability. The Fisher distributions were found to be unsuitable to represent the statistical distribution of orientation for most of the fracture sets. The probability distributions, gamma, exponential and lognormal were found to be highly suitable to represent the distribution of spacing and semi-trace length of fracture sets. In obtain-ing these distributions, corrections were applied for sampling biases associated with spacing and trace length. The generated fracture system in 3-D was used to make predictions of fracture traces for each fracture set on 2-D win-dows. Developed stochastic 3-D fracture network for the rock mass was validated by comparing statistical proper-ties of the observed fracture traces on scanlines with the predicted fracture traces on the scanlines. This exercise fumed out to be successful.

• Journal of the Korean Data Analysis Society
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• v.20 no.6
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• pp.2993-3002
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• 2018

This case study introduces the process of developing the technology rating evaluation model for investment. The technology evaluation rating model for investment is a project that the Financial Services Commission and the Ministry of Commerce, Industry and Energy collaborated to expand the scope of technology finance from loan to investment. The technology evaluation model for investment was developed with the aim of predicting high growth companies. The model consists of a statistical model and an expert model. Here, statistical models were modeled by using logistic regression analysis. Expert models gathered opinions of experts and identified the weight of each evaluation item and set the model. The rating system of the model is composed of 10 grades. The distribution of the model was consistent with KTRS grade distribution. Interestingly, the emphasis is on technology and marketability. In the technology valuation grade model for the goddess, there is a considerable difference from the emphasis on managerial competence or business performance.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.4
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• pp.333-342
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• 2022

This paper has theoretically and practically reviewed the ISO (International Standard Organization) 17123-8 standard not only to raise the appropriateness for introducing performance criteria of GNSS (Global Navigation Satellite Systems) surveying equipment based on RTK (Real-Time Kinematic) accuracy but also to derive its proper test procedure by introducing the international standard. Field experiments have been performed to appreciate the GNSS-RTK accuracy of five selected receivers via the full testing procedure of the ISO standard, which statistically compares the so-called experimental standard deviations with themselves and with the reference accuracy. A series of statistical tests have revealed that the RTK accuracy of the same class receivers is not identical, whereas that of the different classes can be equivalent. Such a result evidences the urgency of adopting an RTK accuracy-based specification of the GNSS equipment to the performance standard, currently referenced to the static observation technique only. It is believed that this transition helps the maximization of a new generation of cost-effective receivers to legal surveying applications. Finally, this study proposes the ISO full test, comparing an experimental standard deviation with its referenced value, for a potential field verification procedure of the new performance standard.