• The Journal of the Korean dental association
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• v.38 no.2 s.369
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• pp.124-129
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• 2000

1800년대에 유럽에서 가철식 교정장치가 개발되면서 처음으로 교정치료가 시작되었다. 그 후 1900년대에 들어서면서 Edward H.Angle에 의해 미국의 독특한 형태인 고정식 교정장치가 개발되었다. 그 동안 수 많은 선학들에 의해 다양한 재료와 치료방법들이 고안되면서 아름다워지고자 하는 현대인의 욕구와 맞물려 임상교정학 분야는 꾸준히 발전하여 왔다. 국내에서는 1940년대 이후부터 외국의 가철식 교정장치와 고정식 교정장치를 그대로 받아들여 수 많은 부정교합 환자의 치료에 응용하고 있다. 그러나 조금만 더 세밀하게 들여다 보면 가철식 교정장치를 개발한 유럽의 교정의들은 지나치게 가철식 교정장치에만 의존하는 경향이 있고, 고정식 교정장치를 개발한 미국의 교정의들은 지나치게 고정식 교정장치에만 의존하면서 가철식 교정장치의 사용을 아예 금기시하는 경우도 있다. 그러나 이 두가지의 경우 모두 바람직하지 않다. 수혜자의 위치에 있는 우리가 할 수 있는 최선의 방법은 아무련 편견없이 가철식 교정장치와 고정식 교정장치를 적절하게 병행하여 사용하는 것이 바람직하다. 두 장치 모두 확실한 장ㆍ단점을 가지고 있기 때문에 시기와 방법을 적절하게 적용한다면 성공적인 교정치료를 위한 지름길이 될 수 있다.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.3
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• pp.18-30
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• 2020

This study deals an estimation method of thrust measurement uncertainty in solid rocket motors. Guidelines of the force measurement uncertainty estimation have been provided by ISO, domestic and international organizations. However, all of them are described by focusing on the force calibration machines and force transducers with a conceptually-driven way. Thus the guidelines cannot be directly applicable to uncertainty estimation of calibration equation and its linear approximation, which are critical error sources in the thrust measurement. In this paper, the equations taking into account effects of both error sources are derived based on fundamental concepts of measurement uncertainty. These are applied to the real thrust measurement system where a relatively simple estimation method for the thrust measurement uncertainty is proposed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.411-414
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• 2016

K-water institute is a calibration and test institute accredited by international standard calibration center for water-level meters. Due to the absence of on-site calibration system and procedure for Float Water Level Meter, the calibration was performed only in the standard calibration laboratory. In this study, mobile calibration system and procedure were developed to calibrate Float Water Level Meter on site using scale bar and camera. It is possible to obtain reliable water-level data and achieve consistent data management.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.10
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• pp.1964-1972
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• 2017

K-water have been operating as an International accredited calibration organization for ISO 17025 regarding float, ultrasonic and radar type since 2008. Due to the absence of on-site calibration system, water level meter could only be calibrated from a laboratory. Therefore K-water institute developed an mobile calibration system for water-level meter in 2015 to calibrate the water-level meter on site. The mobile calibration system was certificated by KOLAS(Korea Laboratory Accreditation Scheme) in 2016. In this paper a mobile calibration system, which is a method to calibrate float type water level meter on site, is established. A mathematical equation was derived by reviewing characteristics of standard equipment and measurement. By developing the mobile calibration system, it is possible to achieve reliability of data through scientific system operation on hydrological data.

• Annual Conference on Human and Language Technology
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• 1993.10a
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• pp.271-283
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• 1993

본 논문은 온라인 한글인식 시스템에서 오인식된 단어를 교정하는 알고리즘이다. 교정 기법으로는 N-gram 한글사전을 이용하였다. 오인식된 단어는 후보키의 선정과 선정된 후보문자중 가장 유사한 단어로 대체된다. 오인식 단어는 사전에 수록된 단어의 형태소 정보 즉, 사전의 표제어, 이의 품사 및 접속 규칙을 활용하여 교정된다. 본 논문은 오인식 교정에서 필요한 한글의 형태소 분석기에 관한 선행연구를 전제한다.

• The korean journal of orthodontics
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• v.30 no.3 s.80
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• pp.335-342
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• 2000

The authors observed the long term effects of chlorhexidine varnish treatment on microbial change of dental plaque in orthodontic patients with fixed appliances. The initial sample was 100 patients who were arranged to be treated with fixed orthodontic appliances. The final sample consisted of 21 patients who could be traced for 32 weeks after application of fixed orthodontic appliances. They were classified into the experimental group (12 patients) and the control group (9 patients). The experimental group was treated with chlorhexidine varnish once a week for 4 weeks before application of fixed orthodontic appliance. The control group was not treated with chlorhexidine varnish before application of fixed orthodontic appliance. The experimental group was treated once more after 20 weeks. The microbial changes of dental plaque were analysed by indirect immunofluorescence technique at pre-treatment, post-treatment 4, 8, 20, and 32 weeks. The results were as follows. 1. In the experimental group, streptococus mutans was significantly suppressed during experimental period. (p<0.01) But, in the control group, streptococcus mutans was significantly increased after placement of fixed orthodontic appliances during experiment period. (p<0.05) 2. Streptococcus sanguis, Streptococcus mitis, Actinomyces viscosus, md Actinomyces naeslundii did not show significant change between the experimental and the control group during experiment period. So, if we treat the orthodontic patients with chlorhexidine varnish before application of fixed appliances, we may suppress the major cariogenic bacteria, Streptococcus mutans, selectively for long period.

• Journal of Radiation Protection and Research
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• v.22 no.4
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• pp.289-298
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• 1997

Time-consuming experiments have been required in the development of neutron moisture gauge to induce a relation between the water content in soil and the neutron counts. Applying a monte carlo computer code to simulate the experiments of neutron moisture gauging may contribute to reduce time and efforts for experiments and produce a calibration equation which is more applicable to soil in general. In this study MCNP4A, a monte carlo computer code, was employed to simulate soil experiments and the simulated results were compared with experimental ones. The comparative study showed that MCNP4A is applicable to simulate the experiments and calibration equation can be obtained through simulations. Effects of dry density changes were also studied.

• Journal of the Korean Chemical Society
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• v.47 no.1
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• pp.31-37
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• 2003

The expanded uncertainties calculated by the application of GUM -approximation and Monte-Carlo simulation were compared about the model equation of one-point calibration which is widely used for the measurements and chemical analysis. For the comparisons, we assumed a set of artificial data at the various level of concentration and dispersion of t or normal distribution. Mistakes of more then 50 % was revealed at the values calculated by GUM-approximation in comparison with those of Monte-Carlo simulation because of the excess dispersion from t-distribution and non-linearity by division in the equation. In contrary, the mistake of calculation due to non-linearity of the equation was not observed in the level of detection limits with the equation of one-point calibration, because of the relatively large values of uncertainty in response.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.3
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• pp.121-124
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• 2007

Ablation depth of cornea in refractive keratectomy was calculated by Munnerlyn formula. The calculations were preformed for various optical diameter (4 mm~8 mm) and various amount of corrections (-1 Dptr ~ -12 Dptr). The results to be compared with the Munnerlyn approximated formula had little effect within lower corrections, but in higher corrections > 6 Dptr can be occurred the error of 1 Dptr. Although ablation depth were evaluated, the results were only calculated by mathematical model of geometric assumptions. Because ablation depth can vary with operation conditions, the correction factor should be considered not only ablation depth by Munnerlyn formula but also surgeon-specific factor.

• The korean journal of orthodontics
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• v.39 no.6
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• pp.383-392
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• 2009

Objective: The purpose of this study was to evaluate the efficacy of a slim bristled toothbrush compared with a V-shaped orthodontic toothbrush in patients with fixed orthodontic appliances. Methods: Thirty four orthodontic patients receiving edgewise treatment were randomly assigned to two groups, a slim bristled toothbrush (Nano silver slim care) and a V-shaped toothbrush (Oral-B). Plaque index, gingival index and bleeding index were recorded at the beginning of the study (baseline), 2 weeks, 4 weeks and 6 weeks after new toothbrushes were supplied and the results were analyzed statistically. Results: No statistically significant differences were found for plaque index, gingival index and bleeding index between toothbrush groups during the 6 weeks. Plaque and gingival indices were decreased at 2 weeks and 4 weeks but increased at 6 weeks in both toothbrush groups. Bleeding index in the V-shaped toothbrush group showed the lowest value at 2 weeks then increased at 4 weeks and 6 weeks but in the slim bristled toothbrush group decreased from 2 weeks through 6 weeks to under baseline levels. Patients in their twenties had significantly lower values than teenagers in the slim bristled toothbrush group (p < 0.013). Conclusions: The results would suggest that both of the toothbrushes are equally effective but the use of a slim bristled toothbrush may be of benefit in promoting gingival health for fixed orthodontic appliance patients in their twenties and over.