• Journal of Environmental Health Sciences
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• v.24 no.2
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• pp.68-73
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• 1998

This is a study on the risk assessment of drinking water using mutagenicity testing. The tests have been carried with the raw water, treated water, and drinking water (tap water) in Kwangju and Mokpo areas. The Ames preincubation test was carried concentrating samples using by Sep-Pak PLUS cartriges in Salmonella typhimurium TA100 and TA98. The samples were tested with several chemical water quality analysis. The THMs have not been measured in raw water, but measured treated water and tap water at a value of 7.135-12.473 $\mu$g/l. It was observed that the number of revertants colonies increased in treated water and tap water on TA100 without S9 and showed weak mutagenicity on TA98 without S9. Indirect mutation was not seen in TA100 and TA98 with S9. The results indicated that formed substances of treatment process's of water that increased mutagenicity.

• Journal of environmental and Sanitary engineering
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• v.9 no.2
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• pp.32-40
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• 1994

The concentration of ozone in 5 major cities in Korea( Seoul, Pusan, Taegu, Kwangjoo, Incheon ) has been shown increasing trend after 1984, while decreasing trend in Hsan. According to the data from 12 monitoring stations in 9 cities of metropolitan area from January 1994 to August 1994, ozone concentration exceeded short term standard 99 times and 87%(861imes) of those was occurred during July and Augusta while the maximum ozone concentration was appeared mainly between 14: 00 and 17: 00 daily. As the result of epidemiological survey, main substances which irritate eyes were identified to be PAN and formaldehyde rather than ozone while ozone was identified to be reachable to deep part of respiratory system main target organ of ozone.

• Journal of the Korean Society for Heat Treatment
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• v.11 no.1
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• pp.54-61
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• 1998

Since Cr-Mo-V steel has excellent fracture and creep properties at elevated temperature, they are extensively used as steam turbine components such as the turbine rotor. However, the turbine rotor steel used to suffer material degradation during long term service. Therefore, the assessment of the safety and residual life of the turbine rotor is periodically required during service. One of the most convenient techniques for that is the hardness method mainly due to its simplicity and nondestructive characteristics. In this research, six specimens with different aging times of turbine rotor steel were artificially prepared by an isothermal heat treatment at $630^{\circ}C$. The micro Vickers hardnesses of specimens were measured at room temperature. The relationships between the fracture properties and the hardness ratio were investigated. And also an indirect method to evaluate the residual life of degraded turbine rotor was proposed based on the micro Vickers hardness measurement.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.21 no.1
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• pp.13-16
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• 2010

Diagnosis of a patient with dysphonia begins with a thorough history and physical examination. Larynx can be visualized either indirectly or directly with a rigid or flexible laryngoscope. One notable limitation of simple indirect laryngoscopy is that the examination dose not yields a recordable and reproducible image of the larynx and vocal tract. And unaided human eye is unable to visualize the vibratory patterns of the true vocal cord during phonantion. When available, stroboscopy provides useful information regarding vocal told closure, vibration, and mucosal wave which is useful to decide between microsurgery, vocal reeducation or a combined treatment Even there are some limitations, recognition of the advantages and disadvantages of stroboscopy allows for optimal appreciation and stroboscopy remains an essential diagnostic tool in the assessment of dysphonia.

• Proceedings of the KIEE Conference
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• 2001.07a
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• pp.168-170
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• 2001

This paper presents the strategy of reactive power compensation which directly improves voltage stability. Voltage stability index that serves as an indirect assessment of voltage stability margin is derived from M.G.C.F. (Modified Generalized Curve Fit) algorithm incorporating load model. Weak buses are ranked by this stability index, and amounts of reactive power compensation are determined by function of reactive power and stability index. Using the proposed strategy, all load buses can be prevented from voltage collapse gradually. A simple illustrative example is given as well as simulation results obtained on 5 bus test system and 19 bus real power system.

• Smart Structures and Systems
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• v.15 no.5
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• pp.1203-1214
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• 2015

This paper deals with the experimental validation of the use of PVDF Patches for the assessment of spatial derivatives of displacement field. It focuses more exactly on the shear Force Identification by using Specific forms of PVDF patcHes (FISH) on beams. An overview of the theoretical approach is exposed. The principle is based on the use of the weak form of the equation of motion of the beam which allows the shear forces to be extracted at one edge of the sensor when this last has a specific form. The experimental validation is carried out with a cantilever steel beam, excited by a shaker at its free boundary. The validation consists in comparing the shear force measured by the designed sensor glued at the free edge and the directly measured force applied by the shaker. The sensor is made of two patches, called the "stiffness" patch and the "mass" patch. The use of both patches allows one to identify correctly the shear force on a large frequency domain. The use of only the stiffness patch is valid in the low frequency domain and has the advantage to have a frequency-independent gain that allows its use in real time.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1350-1358
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• 2008

Recently the study related to life cycle cost analysis of railway structure consisted of a complex is proceeded covering several range, which is considering the methodology of efficiency and rationalization for maintenance and analysing long-time behavior of the structure of looking at standpoint from asset management and safety. But LCCA(life cycle cost analysis) of railway structure was almost impossible as there were not anything datum for maintenance plan, such as maintenance periods related to each of components(painting and corrosion of steel, and cracking of elements, etc)and maintenance proportion, despite of its 100-year history. According, for collecting data related to railway truss bridge, bridge record cards and testing safety papers, and researching question, etc are surveyed and classified for LCC Analysis. Especially, LCC assessment on the side of assets-maintenance considering about initial cost, maintenance cost, and indirect cost is constructed. Maintenance period and complementary measure rate are very important in maintenance. To decide maintenance period, Baysian updating method is applied.

• The Korean Journal of Physiology
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• v.6 no.1
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• pp.39-42
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• 1972

This study was carried out on the energy expenditure and physical capacity of 504 persons from 17 occupations. The energy expenditure was measured by indirect calorimetry using a Douglas' bag and Scholander's gas analyser. The physical capacity was determined by the Harvard's step test and the maximum oxygen consumption using a treadmill. The assessment of the daily energy expenditure for each subject was made by the factorial method using a record of the activies throughout 24 hours of every survey day. The total daily energy expenditure is the sum of all energy expenditure. This was calculated by multiplying the caloric value of the metabolic rate by the time spent on each activity. Most of the occupations involved moderate or heavy work.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.9
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• pp.1125-1140
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• 2018

This paper analyzes robotic technology developed for live-line electricity distribution and its applicability to domestic environment. In doing so, available robotic systems developed for the live-line work are thoroughly investigated and compared in terms of from robotic functionality to economic feasibility. To assess the technology readiness for domestic live-line robot, the rubber gloves based direct live-line engineering methods have been also analyzed and mapped into robotic technology requisites. The results are expected as a fundamental data to help with solving the safety and economics issues when considering development and introduction of compact live-line robot for complex domestic electricity distribution environment.

• Journal of Dental Anesthesia and Pain Medicine
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• v.19 no.6
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• pp.323-341
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• 2019

Background: Local anesthetics alone or in combination with adjuncts, such as oral medications, have routinely been used for pain control during endodontic treatment. The best clinical choice amongst the vast numbers of agents and techniques available for pain control for irreversible pulpitis is unclear. This network meta-analysis combined the available evidence on agents and techniques for pulpal anesthesia in the maxilla and mandible, in order to identify the best amongst these approaches statistically, as a basis for future clinical trials. Methods: Randomized trials in MEDLINE, DARE, and COCHRANE databases were screened based on inclusion criteria and data were extracted. Heterogeneity was assessed and odds ratios were used to estimate effects. Inconsistencies between direct and indirect pooled estimates were evaluated by H-statistics. The Grading of Recommendation, Assessment, Development, and Evaluation working group approach was used to assess evidence quality. Results: Sixty-two studies (nine studies in the maxilla and 53 studies in the mandible) were included in the meta-analysis. Increased mandibular pulpal anesthesia success was observed on premedication with aceclofenac + paracetamol or supplemental 4% articaine buccal infiltration or ibuprofen+paracetamol premedication, all the above mentioned with 2% lignocaine inferior alveolar nerve block (IANB). No significant difference was noted for any of the agents investigated in terms of the success rate of maxillary pulpal anesthesia. Conclusion: Direct and indirect comparisons indicated that some combinations of IANB with premedication and/or supplemental infiltration had a greater chance of producing successful mandibular pulpal anesthesia. No ideal technique for maxillary anesthesia emerged. Randomized clinical trials with increased sample size may be needed to provide more conclusive data. Our findings suggest that further high-quality studies are required in order to provide definitive direction to clinicians regarding the best agents and techniques to use for mandibular and maxillary anesthesia for irreversible pulpitis.