• Journal of Korean society of Dental Hygiene
• /
• v.20 no.5
• /
• pp.707-716
• /
• 2020

Objectives: This study aims to provide basic data for high-quality dental services. In addition, we will promote the operation of preventive dentistry that implements preventive measures. It was conducted to study the change of patient's treatment behavior and treatment cost due to the discontinuation of preventive dentistry in university dental hospitals. Methods: This study collected data using the integrated medical information system of the C University Dental Hospital. From September 1, 2017 to August 31, 2019, data were analyzed using frequency, percentage, mean, standard deviation, chi-square test using SPSS version 24.0 statistical program, and T-test. Results: There was a significant difference in the number of preventive dental treatment cases from 58.3% of preventive dental operation periods to 41.7% of preventive dental operation periods. As a result of comparing the medical expenses, the total medical expenses during the preventive dental operation period decreased from 521,308,872 won to 379,724,995 won during the discontinuation period, 141,583,877 won. The number of medical treatments by treatment behavior decreased 3,835 (28.4%) from a total of 13,520 preventive dental operation periods to 9,685. Conclusions: This study is meaningful as the first study to confirm the change in the treatment behavior and the change in the cost of treatment due to the discontinuation of the operation of preventive dentistry at university dental hospitals. In conclusion, it is thought that there is a possibility of the lack of accessibility and the limitation of professional preventive care due to the discontinuation of preventive dentistry.

• Proceedings of the KIEE Conference
• /
• 1989.11a
• /
• pp.332-336
• /
• 1989

This paper describes the nonlinear analysis and effectual operation methods of thermal power plant turbine control system. When the turbine control governor system has dead-zone characteristic, the effectual frequency development control is difficult, because turbine output does not correspond to frequency deviation in dead-zone. Therefore to obtain effectual correspondance, the turbine dead-zone characteristic must be analyzed by proper method. This paper proposes this nonlinear analysis and effectual plant operating load.

• 제어로봇시스템학회:학술대회논문집
• /
• 1986.10a
• /
• pp.648-651
• /
• 1986

Sometimes, there are conditions when rapid control of the hypertension needed such as malignant hypertension, and the preoperative pereparation of the hypertensive patient requiring emergency operation, etc. Using the adaptive control algorithm, the mean arterial pressure reduction is achived rapidly and safely in hypertensive rabbit. Among the adaptive control algorithms the pole assignment self tuning control algorithm is superial to the one step ahead minium variance control algorithm. The convergence time is less than 600 sec, and the standard deviation of experimental data are less than 4 mmHg.

• Proceedings of the IEEK Conference
• /
• 2002.06d
• /
• pp.171-174
• /
• 2002

This paper presents an implementation method of phasor measurement device, which is based on the FPGA implementation of the sliding-DFT The design is verified by the timing simulation of its operation. The error effect of coefficient approximation and frequency deviation in the recursive implementation of the sliding-DFT is analytically derived and verified with the computer simulations.

• Journal of the Korean Society for Precision Engineering
• /
• v.17 no.4
• /
• pp.240-246
• /
• 2000

An in-process estimation of the ground surface roughness is a bottle-neck and an essential field in conventional grinding operation. We defined the dimensionless average roughness factor (D.A.R.F) that exhibits a roughness characteristics of ground surface. The D.A.R.F was composed easily of the absolute average and the standard deviation values which were the analytic parameters of the acoustic emission (AE) signal generated during the machining process. The theoretical equation between the surface roughness and the D.A.R.F has been derived from the linear regressive analysis and verified its availability through the experimentation on the surface grinding machine.

• Journal of Energy Engineering
• /
• v.15 no.1 s.45
• /
• pp.67-73
• /
• 2006

A calculation method on performance impact of the controllable operations parameter such as GT inlet filter ${\Delta}P$, compressor efficiency, and condenser pressure was devised to achieve best performance of combined cycle power plant with the on-line performance monitoring system. This method calculates the performance impact on the deviation between 'Expected' values and 'Actual' values. Controllable parameter targets are determined based on achievable performance given existing equipments and control conditions.

• Journal of the Korean Ceramic Society
• /
• v.35 no.2
• /
• pp.201-207
• /
• 1998

A tube-type filter dam(or baffle with holes) for ferrous melt refining is applied to the tundish operation for molten steel having low carbon and ultra-low carbon. The changes in the total oxygen content insoluble aluminum content and the distribution of inclusion size in molten steel during tundish operation were in-vestigated at the pouring part strand and mold of tundish. Removal mechanism of inclusions is considered to be caused by buoyancy action of the filter dam better than filtration action and the size range of in-clusions filtrated by the filter dam was for 30-50$\mu\textrm{m}$. Decrease in deviation of inclusion content in molten steel was confirmed for appling the filter dam in comparison with using conventional dam and weir. Also the filter dam had the advantage of baffle with holes at lower part in the efficiency of inclusions removal.

• Proceedings of the KOSOMBE Conference
• /
• v.1997 no.05
• /
• pp.366-369
• /
• 1997

In this study, we measured upper right, lower right, upper left region to find the optimal region which represent liver function. We found that the upper right region is optimal because of high accuracy and low standard deviation. For normal subjects all the calculated HEFs were greater than 100% and all those of abnormal ones were less than 80%. Thus HEF can be assumed to discriminate abnormal livers from normal ones. It was found that the patients with surgical operation would survive if both the pre-and the post-operative HEFs are greater than 50%. Therefore HEF method can be a good estimator for surgeon to determine the surgical operation and to evaluate remaining hepatic function after surgery as well as it is reliable and simple.

• Proceedings of the KIEE Conference
• /
• 2003.07a
• /
• pp.396-398
• /
• 2003

This paper presents the scheme for load model based dispersed generation system (DGs) installation and operation in unbalanced distribution systems. Groups of each individual load model consist of residential, industrial, commercial, official and agricultural load. The main idea of solving fuzzy nonlinear goal programming is to transform the original objective function and constraints into the equivalent multiple objective functions with fuzzy sets to evaluate their imprecise nature for the criterion of power loss minimization, the number or total capacity of DGs and the bus voltage deviation, and then solve the problem using genetic algorithms. The method proposed was applied to IEEE 13 bus test systems to demonstrate its effectiveness.

• The Journal of the Korean dental association
• /
• v.22 no.4 s.179
• /
• pp.333-338
• /
• 1984

This is to report a case of traumatic bone cyst which occurred in the left condylar head of the mandible. It is a very rare case and the prognosis after operation seems to be fair, therefore we report as follows. 1. The pt, a 49 year-old female, has been suffering from difficulties of mastication with disfiguration of face due to deviation of mandible to the right side for 20 years. 2. Histopathologic findings showed the figure of multilocular bony cysts contained with fibrous tissue, osteoid tissue and many hematopoietic cells 3. Roentgenographic features showed well circumscribed radiolucent lesion with some radiopaque area. 4. After clinical evaluation, condylectomy was done to remove the lesion. 5. After the operation, the esthetic problem and masticatory functions were improved.