• International Journal of Oral Biology
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• v.44 no.4
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• pp.152-159
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• 2019

The oral care probiotic strain Weissella cibaria CMU (oraCMU) inhibits volatile sulphur compounds associated with halitosis, presumably by inhibiting the growth of associated oral pathogens. In the present study, we investigated whether oraCMU inhibits the production of these compounds by suppressing the expression of mgl. This gene encodes L-methionine-α-deamino-γ-mercaptomethane-lyase (METase) and is involved in the production of methyl mercaptan (CH₃SH) by Porphyromonas gingivalis. Therefore, we specifically investigated the effects of oraCMU on the growth, CH₃SH production, METase activity, and mgl expression of P. gingivalis. The minimum inhibitory concentrations of cell-free supernatant and secreted proteins from oraCMU were 125 mg/mL and 800 ㎍/mL, respectively. At sub-minimum inhibitory concentration levels, these metabolites inhibited CH₃SH production, but they also reduced P. gingivalis viability. Only heat-killed oraCMU decreased CH₃SH production without affecting P. gingivalis viability. Heat-killed oraCMU also inhibited METase activity toward L-methionine and mgl mRNA expression (p < 0.05). In summary, we demonstrated the inhibition of volatile sulphur compounds via the antimicrobial action of oraCMU and, for the first time, the inhibition of such compounds by heat-killed oraCMU, which occurred at the molecular level.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.3
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• pp.286-291
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• 2011

Purpose: The purpose of this study was to evaluate the use of OraQuick tests in previously reported articles. Methods: The literature was searched using Pubmed Medline with keywords, such as "OraQuick" or "rapid HIV test". Articles that included the specificity and sensitivity of this device were reviewed. Results: A total of 11 journal articles including 3 domestic articles were reviewed. The sensitivity of the OraQuick Test was reported to be 97.8 to 100% and its specificity was 98.8 to 100%. Conclusion: The results indicated that the simple OraQuick assay has proven to be accurate and it can be used to detect patients with HIV and to prevent the spread of HIV on test screens.

• International Journal of Oral Biology
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• v.43 no.4
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• pp.193-200
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• 2018

The purpose of this study is to determine if natural extracts could be used as an additive in oral health food made with Weissella cibaria CMU (oraCMU). Natural extracts of green tea, mulberry leaf, licorice, and propolis, which are reported to have antimicrobial activities, were selected and used in this study. The minimum inhibitory concentrations (MIC) of extracts on periodontal pathogens such as Fusobacterium nucleatum and Porphyromonas gingivalis and their synergy effects with oraCMU by the fractional inhibitory concentrations methods were measured. From the results obtained, all the extracts showed no effect on the growth of oraCMU. Green tea extract showed the best antibacterial activity with MIC of 1.8 mg/ml against both F. nucleatum and P. gingivalis. In addition, green tea extract had a synergistic effect with oraCMU against F. nucleatum. Therefore, these results suggested that green tea extract is available as an additive in oral health food made with oraCMU.

• Journal of Environmental Health Sciences
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• v.44 no.3
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• pp.217-226
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• 2018

Objectives: Despite the positive effects of Off-site risk assessment (ORA) system such as prevention of chemical accidents, some problems have been constantly raised. The purpose of this study is to analyze the problems that have occurred through the implementation of the ORA system for the past three years and to suggest reasonable directions for improvement in the future. Methods: In order to identify the problems with the methodology and procedure of ORA system, we analyzed statutes, administrative rules and documents related to the ORA system. A survey of ORA reviewers in National Institute of Chemical Safety was conducted to investigate the weight of determinants considered when judging the level of total risk in ORA. Results: In this study, we found out the uncertainty of the estimation of the number of people in the impact range in the procedure of the risk assessment of individual handling facilities, the lack of quantitative risk analysis methods for environmental receptors, and the ambiguity of the criteria for the total risk. In addition to suggesting solutions to the problems mentioned above, we also, suggested a decision tree for total risk in ORA. Conclusion: We anticipate that the solutions including the systematic decision tree for total risk suggested will contribute to the smooth operation of the ORA system.

• KIEE International Transactions on Power Engineering
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• v.4A no.2
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• pp.58-68
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• 2004

This paper presents an optimal routing algorithm (ORA) for maximizing voltage stability as well as for minimizing power loss in radial power systems. In the proposed ORA, a novel voltage stability index (VSI) for real-time assessment is newly introduced based on the conventional critical transmission path framework. In addition, the suggested algorithm can automatically detect the critical transmission paths resulting in voltage collapse when additional real or reactive loads are added. To implement an effective ORA, we have developed an improved branch exchange (IBE) method based on a loss calculation index and tie-branch power flow equations, which are suggested for real-time applications. The proposed algorithm has been tested with IEEE test systems as well as a large-scale power system in Korea to demonstrate its effectiveness and efficiency.

• The Optical Journal
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• s.122
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• pp.22-24
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• 2009

광학설계 프로그램 CODE V를 국내에 공급하고 있는 (주)모던하이테크(대표 김명중, www.okdomern.com)이 인하대학교 광기술교육센터 및 미Optical Research Associates(이하 ORA)와 함께 지난 6월 18일 서울 교육문화회관에서 '2009 CODE V User 컨퍼런스'를 개최하였다. CODE V 최신 버전 소개 및 특별강연이 진행된 이 행사에는 ORA사의 조지 베이스 사장이 참석하여 직접 비전을 소개하고 향후 국내 유저들을 위해 적극적인 서비스 지원을 약속했다.

• Journal of Environmental Impact Assessment
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• v.29 no.4
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• pp.239-251
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• 2020

The Off-site Risk Assessment (ORA) for preventing chemical accidents estimates the chemical accident risk at chemical plants. The method of estimating the risk is made by multiplying the number of residents within the effect area of the chemical accident and the frequency of accidents at a chemical plant. At present, the ORA does not quantitatively consider environmental receptors when the damage types within the scope of the accident are environmental receptors. In order to solve this problem, this study proposes a method of estimating the risk considering resident and environmental receptors. Through these studies, it was confirmed that the ORA impact for the prevention of chemical accidents requires risk analysis considering environmental receptors in the medium and long term.

• Ocean and Polar Research
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• v.43 no.1
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• pp.15-30
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• 2021

In this study, using 16 ORA-IP (Ocean Reanalysis Intercomparison Project) data, we investigated spatial and temporal changes of net surface heat flux in the East Asian seas and presented a new ensemble net surface heat flux index. The ensemble net surface heat flux index is produced considering the data distribution and the standard deviation of each ORA-IP. From the correlation analysis with air temperature averaged over the Korean Peninsula, ensemble net heat flux around the Korea Strait shows the highest correlation (0.731) with a 3 month time lag. For the correlation study regarding precipitation over the Korean Peninsula, it also shows significant correlation especially in winter and spring seasons. Similar results are also found in comparison with climate indices (AO, PDO, and NINO3.4), but ensemble net surface heat flux data in winter season reveals the strongest correlation patterns especially with winter temperature and spring precipitation.

• International Journal of Highway Engineering
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• v.9 no.4
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• pp.215-226
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• 2007

To verify the performance of roadside barriers, occupant risk indices are calculated from acceleration and angular velocity data of vehicle crash tests. The occupant risk indices to be computed include THIV(Theoretical Head Impact Velocity), PHD(Post-impact Head Deceleration), ASI(Acceleration Severity Index), OIV(Occupant Impact Velocity) and ORA(Occupant Ridedown Acceleration). There is a confusion due to different values of occupant risk indices produced for the same test data because various computational procedures and data processing methods can be applied to compute them. To slove this problem the effects of various numerical procedures and data processing methods on occupant risk indices were investigated. If the sampling rate specified in the guidelines is used for full-scale vehicle crash tests, an interpolation of impact time and numerical integration methods do not result in an appreciable change of THIV and OIV. The way to determine 10msec moving average for PHD and zero offset of data processing should be specified in the guidelines because 10msec moving average and zero offset methods have a significant influence on occupant risk indices.

• Journal of the Korean Society of Safety
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• v.32 no.6
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• pp.46-53
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• 2017

The risk is expressed as consequence of damage multiplied by likelihood of failure. The installation of a protective system reduces the risk by reducing the likelihood of failure at the facility. Also, the protective system has different effects on the likelihood of failure according to the proof test cycle. However, when assessing risks in the Off-site Risk Assessment (ORA) system, the variation in risk was not reflected according to the proof test cycle of protective system. This study was conducted to examine the need for proof test and the importance of cycle setting by applying periodic proof test of the protective system to ORA. The results showed that the likelihood of failure and the risk increased with longer proof test cycle. The risk of a two-yearly proof test was eight times greater than that of a three-month cycle. From the results, the protective system needs periodic proof test. Untested protective system for a long term cannot be reliable because it is more likely to be failed state when it is called upon to operate. In order to reduce the risk to an acceptable level, it is effective to differently set the proof test cycle according to the priority. This study suggested a more systematic and accurate risk analysis standard than ORA. This standard is expected to enable an acceptable level of risk management by systematically setting the priority and proof test cycle of the protective system. It is also expected to contribute to securing the safety of chemical facilities and at the same time, will lead to the development of the ORA system.