• Archives of Plastic Surgery
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• v.49 no.4
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• pp.510-516
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• 2022

Background Surgical correction of bilateral cleft lip deformities remains one of the most challenging areas in facial plastic surgery. Many surgical techniques and conservative devices have been offered for the early management of bilateral cleft lip in infants. The purpose of this study was to evaluate the effect of lip adhesion on the lip and nose of patients with bilateral cleft lip. Methods A retrospective review of 13 patients with bilateral cleft lip was performed and compared with age-matched noncleft children. Patients underwent lip adhesion at a mean age of 2.8 months, and cheiloplasty at 6.6 months of age using a modification the Mulliken method. Secondary rhinoplasty was performed at the age of 6 in 13 patients. The surgical results were analyzed using photographic records obtained at the age of 1 and 7 years. Twelve length measurements and one angle measurement were obtained. Results All measurements were not statistically different from those of the noncleft age-matched control group at the age of 1. At 7 years of age, upper lip height and vermilion mucosal height were shorter (p < 0.05) than in the control group. Nasal tip protrusion and the nasolabial angle were greater (p < 0.05) than in the control group. Conclusion Lip adhesion followed by secondary rhinoplasty resulted in an acceptable lip and nasal appearance. Although nasoalveolar molding is now widely used, lip adhesion can be an appropriate alternative if an orthodontist is not available due to geographical or economic constraints.

• Journal of ILASS-Korea
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• v.27 no.2
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• pp.57-65
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• 2022

The purpose of this study is to use machine learning to build a model capable of predicting the flash boiling spray characteristics. In this study, the flash boiling spray was visualized using Shadowgraph visualization technology, and then the spray image was processed with MATLAB to obtain quantitative data of spray characteristics. The experimental conditions were used as input, and the spray characteristics were used as output to train the machine learning model. For the machine learning model, the XGB (extreme gradient boosting) algorithm was used. Finally, the performance of machine learning model was evaluated using R² and RMSE (root mean square error). In order to have enough data to train the machine learning model, this study used 12 injectors with different design parameters, and set various fuel temperatures and ambient pressures, resulting in about 12,000 data. By comparing the performance of the model with different amounts of training data, it was found that the number of training data must reach at least 7,000 before the model can show optimal performance. The model showed different prediction performances for different spray characteristics. Compared with the upstream spray angle and the downstream spray angle, the model had the best prediction performance for the spray tip penetration. In addition, the prediction performance of the model showed a relatively poor trend in the initial stage of injection and the final stage of injection. The model performance is expired to be further enhanced by optimizing the hyper-parameters input into the model.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.1
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• pp.95-101
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• 2022

This paper proposes a method to process the shape of an optical transmission road and attempts to determine the most suitable single processing method for an acrylic plate optical transmission road. In addition, by manufacturing an automatic pattern processing device to generate certain shapes on the acrylic plate at regular intervals, and measuring the illuminance of the patterned acrylic plate optical transmission road, the measured illuminance was confirmed to fall under the KS illuminance values presented in Table 1. In conclusion, when an incident light of approximately 20,000 lx is applied, the transmission illumination is approximately 200 lx, which represents a transmission rate of approximately 1% for incident light and corresponds to the KS illumination criterion F. Additionally, the right-angle triangular pyramid base size (A) processed at a temperature of 350 ℃ for one second was 2 mm, exhibiting the largest transmission illumination of 280 lx. When the transparent acrylic plate was set to a constant size of 1.6 mm at the bottom of the right-angle triangular pyramid, the fastest response occurred at a processing tip temperature of 350 ℃ (0.04 s). On the other hand, it took 10 s to process the size of the bottom of the right-angled triangular pyramid at a temperature of 200 ℃ to 1.6 mm, and it was confirmed that the optical transmission efficiency was significantly reduced because of the burr that occurred at this time.

• Journal of Dental Anesthesia and Pain Medicine
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• v.23 no.5
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• pp.281-285
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• 2023

Background: Dentists bend needles prior to certain injections; however, there are concerns regarding needle fracture, lumen occlusion, and sharps handling. A previous study found that a 30-gauge needle fractures after four to nine 90° bends. This fatigue life study evaluated how many 90° bends a 30-gauge dental needle will sustain before fracture when bent using a needle guide. Methods: Two operators at Element Materials Technology, an independent testing, inspection, and certification company tested 48 30-gauge needles. After applying the needle guide, the operators bent the needle to a 90° angle and expressed the anesthetic from the tip. The needle was then bent back to a 0° angle, and the functionality was tested again. This process was repeated until the anesthetic failed to pass through the end of the needle due to fracture or obstruction. Each operator tested 24 needles (12 needles from each lot), and the number of sustained bends before the needle fracture was recorded. Results: The average number of sustained bends before needle failure was 40.33 (95% confidence interval = 37.41-43.26), with a minimum of 20, median of 40, and a maximum of 54. In each trial, the lumen remained patent until the needle fractured. The difference between the operators was statistically significant (P < 0.001). No significant differences in performance between needle lots were observed (P = 0.504). Conclusion: Our results suggest that using a needle guide increases the number of sustained bends before needle fracture (P < 0.000001) than those reported in previous studies. Future studies should further evaluate the use of needle guides with other needle types across a variety of operators. Furthermore, additional opportunities lie in exploring workplace safety considerations and clinical applications of anesthetic delivery using a bent needle.

• The Journal of Korean Society for Radiation Therapy
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• v.15 no.1
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• pp.29-33
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• 2003

I. Purpose Brachytherapy is the main component in treatment of patients with uterine cervical cancer. The reproducibility of applicator position in the same patient at repeated treatments was very important for accurate dose delivery. It was aimed to evaluate the change of applicator location between each high dose rate(HDR) brachytherapy insertion in the patients with uterine cervical cancer. II. Materials and Methods From January 1999 to October 2001, total 52 patients were treated with external beam radiotherapy and HDR brachytherapy (Microselectron, Nucletron). During six to seven times of brachytherapy, all patients had three treatment plans. From the orthogonal radiographs, we measured the following variables; height from upper border of pubic bone to os (HPO), distance from sacral promontory to tip of tandem (DST), distance from coccyx to os (DCO), distance from tip of right ovoid to os (DRO), distance from tip of left ovoid to os (DLO), and distance from center of the first tandem source to ovoid (DTO). To evaluate the reproducibility of applicator position, it was calculated the standard deviation of differences between three insertions for the 7 parameters in each patient. III. Results The ranges of standard deviations of interfractional differences for the variables were as follows. 1)HPO : $0{\sim}0.79cm$ 2)DST : $0{\sim}0.9cm$ 3)DCO : $0.06{\sim}0.76cm$ 4)DRO : $0{\sim}0.53cm$ 5)DLO : $0{\sim}0.45cm$ 6) DTO $0{\sim}0.36cm$ IV. Conclusions There was some change in applicator position on repeated implants in our study. But variation of the interfractional differences was minimal; in all parameters, there were less than 1 cm. We are continued to try for reducing the geometric variation between each procedure.

• The KSFM Journal of Fluid Machinery
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• v.11 no.5
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• pp.15-21
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• 2008

In modem wind power system of large capacity above 1MW, horizontal axis wind turbine(HAWT) is a common type. And, the optimum design of wind turbine to guarantee excellent power performance and its reliability in structure and longevity is a key technology in wind Industry. In this study, mathematical expressions based upon the conventional BEMT(blade element momentum theory) applying to basic 1MW wind turbine blade configuration design. Power coefficient and related flow parameters, such as Prandtl's tip loss coefficient, tangential and axial flow induction factors of the wind turbine analyzed systematically. X-FOIL was used to acquire lift and drag coefficients of the 2-D airfoils and we use Viterna-Corrigan formula to interpolate the aerodynamic characteristics in post-stall region. In order to predict the performance characteristics of the blade, a performance analysis carried out by BEMT method. As a results, axial and tangential flow factors, angle of attack, power coefficient investigated in this study.

• Agricultural and Biosystems Engineering
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• v.3 no.1
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• pp.29-34
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• 2002

Two charging methods of electrostatic nozzle, i.e. induction and ionized field corona charging, were designed and evaluated for orchard sprayer application. An artificial (metallic) target was constructed and used in this experiment. The charge-to-mass ratio for the induction electrode was measured by using the Faraday cage. Two conventional pressure-swirl nozzles have been employed with different orifice diameters under the same experimental operating conditions. A commercial pressure-swirl nozzle with orifice diameter of 1.0 was used for the conventional spray. The diameter of the electrostatic was 0.59 mm. The experiment was carried out for individual nozzle sprays at $0^{\circ}$, $20^{\circ}$ and $50^{\circ}$ oriented angles and three nozzles, sprayed simultaneously at a distance of 1.0 and 2.0 m from the nozzle tip to the target. The nozzles were mounted on a carriage with constant speed of 1.26 km/h with a blower attached. The weighing method was employed to evaluate for the spray deposition, ground loss and estimated drift. The results show more promising for the induction charging method, especially at $20^{\circ}$oriented angle at a distance of 1.0 m from the target for a single nozzle and when all three nozzles were operated simultaneously for spray deposition. The results of the induction charging method show promising with the developed electrostatic technique.

• Structural Engineering and Mechanics
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• v.75 no.3
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• pp.339-356
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• 2020

In this article, a developed bond-based peridynamic model for functionally graded materials (FGMs) is proposed to simulate the dynamic fracture behaviors in FGMs. In the developed bond-based peridynamic model for FGMs, bonds are categorized into three different types, including transverse directionally peridynamic bond, gradient directionally peridynamic bond and arbitrary directionally peridynamic bond, according to the geometrical relationship between directions of peridynamic bonds and gradient bonds in FGMs. The peridynamic micromodulus in the gradient directionally and arbitrary directionally peridynamic bonds can be determined using the weighted projection method. Firstly, the standard bond-based peridynamic simulations of crack propagation and branching in the homogeneous PMMA plate are performed for validations, and the results are in good agreement with the previous experimental observations and the previous phase-field numerical results. Then, the numerical study of crack initiation, propagation and branching in FGMs are conducted using the developed bond-based peridynamic model, and the influence of gradient direction on the dynamic fracture behaviors, such as crack patterns and crack tip propagation speed, in FGMs is systematically studied. Finally, numerical results reveal that crack branching in FGMs under dynamic loading conditions is easier to occur as the gradient angle decreases, which is measured by the gradient direction and direction of the initial crack.

• The korean journal of orthodontics
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• v.21 no.2 s.34
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• pp.367-397
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• 1991

This study was aimed to investigate the occlusal plane inclination in relation to the skeletal and dental assessment measurements in order to provide a reference in orthodontic treatment planning as the occlusal plane should be reconstructed orthodontically or gnathologically. The sample consisted of 73 normal occlusions and 113 malocclusions of adults. The computerized statistical analysis of 38 occlusal plane's and 29 skeletal and dental measurements were carried out with SPSS. The conclusions were as follows; 1 In normal occlusion, COP-NaPog was average $83.63^{\circ}$ (2.44) and occlusal plane inclination had a strong negative correlation with SNB and FH-NaPog. 2. In normal occlusion, ArANS plane was nearly parallel to the occlusal plane. 3. In malocclusion, the larger the mandibular plane angle and the shorter the ramus height was, the more downward the occlusal plane had a tendency to tip anteriorly. 4. Occlusal plane was more horizontal in deep bite group, while it was steeper in openbite group. 5. The curve of Spee was severe in deep bite group but in openbite group mandibular occlusal plane showed average reverse curvature, where it was found that the configuration of the occlusal plane contributed to the excess or deficiency of anterior overbite.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.690-695
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• 2001

The three-dimensional spatial structures of impeller flow created by a six bladed Rushton turbine have identified based on the volumetric velocity information from multi-plane stereoscopic PIV measurements. A total of 10 planes with 2 mm space with a 50 mm by 64 mm size of the field of view were targeted. To reduce the depth of focus, we adopted an angle offset configuration which satisfied the Scheimpflug condition. The distortion compensation procedure was utilized during the in situ calibration. Phase-locked instantaneous data were ensemble averaged and interpolated in order to obtain mean 3-D, volumetric velocity fields on a 60 degree sector of a cylindrical ring volume enclosing the turbine blade. Using the equi-vorticity surface rendering, the spatial structure of the trailing vortices was clearly demonstrated. Detail flow characteristics of the radial jet reported in previous studies of mixer flows were easily identified.