• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.578-585
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• 2018

This paper proposes a design method for a 3-phase interior permanent magnet synchronous motor (IPMSM) and clamping force control method for an electro-mechanical brake (EMB) using co-simulation for a high-speed train (HST). A traditional pneumatic brake system needs much space for the compressor, brake reservoir, and air pipe. However, an EMB system uses up to 50% less space due to the use of a motor and electric wires for controlling the brake caliper. In addition, it can reduce the latency time for brake control because of the fast response and precise control. A train that has many brakes is advantageous for safety because of the control by sharing the braking force. In this paper, a driving method for a cam-shaft-type EMB is modeled. It is different from the ball-screw-type brakes that are widely used in automobiles. In addition, a co-simulation method is proposed using JMAG and Matlab/Simulink. The IPMSM was designed and analyzed with the JMAG tool, and the control system was simulated using Matlab/Simulink. The effectiveness of the co-simulation results of the mechanical clamping force and braking force was verified by comparison with the clamping force specifications of a HEMU-430X HST.

• Journal of Korean Academy of Nursing
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• v.24 no.4
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• pp.517-528
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• 1994

The purpose of this study was to compare the circumference, skinfold thickness and strength of the normal and casted lower limb prior to casting and following removal of the cast. The subjects for the study were nine orthopedic patients who had had long and short leg casts due to a tibial, fibula, or calcaneus fracture, or to a lateral collateral ligament rupture. Circumference, skinfold thickness, and strength of the normal and casted lower limb following removal of the cast were compared with those prior to the application of the cast. Measurements were made before cast application and after removal of the cast. Skinfold thickness was measured by fat caliper, circumference was measured by tape and strength was determined by measuring the length of time the leg was held elevated at 45$^{\circ}$. The results can be summarized as follows 1. There was no change in the normal limb in the circumference of the midthigh and midcalf after casting as compared to before cast application. 2. In the casted limb the circumference of the midthigh decreased by 3.23% and that of the midcalf decreased significantly by 7.49% during the period of casting. 3. In the normal limb skinfold thickness of the quadriceps decreased and that of gastrocnemius increased by 20.63% during the period of cast application. 4. In the casted limb skinfold thickness of the quadriceps decreased significantly by 12.37% and that of gastrocnemius decreased by 10% during the period of cast application. 5. Strength of the normal lower extremity decreased significantly by 48.37% and that of casted lower extremity decreased remarkably by 73.07% during the period of cast application. 6. Circumference of the midthigh and the midcalf decreased significantly by 7.6% and 9.4% respectively on the casted side as compared to the normal side. Skinfold thickness of the quadriceps and the gastrocnemius on the casted side decreased by 6.12% and 18.55% respectively as compared to the normal side and strength in the lower extremity on the casted side decreased significantly by 44.32% as compared to the nor-mal side. From these results, it may be concluded that muscle atrophy occurs in the casted lower limb and muscle strength of the normal lower limb are also reduced during the period of application of a leg cast.

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.1
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• pp.17-24
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• 2020

The purpose of this study was to evaluate the accuracy and precision of the three-dimensional (3D) imaging system of children's facial soft tissue by comparing linear measurements. The subjects of the study were 15 children between the ages of 7 and 12. Twenty-three landmarks were pointed on the face of each subject and 16 linear measurements were directly obtained 2 times using an electronic caliper. Two sets of 3D facial images were made by the 3D scanner. The same 16 measurements were obtained on each 3D image. In the accuracy test, the total average difference was 0.9 mm. The precision of 3D photogrammetry was almost equivalent to that of direct measurement. Thus, 3D photogrammetry by the 3D scanner in children had sufficient accuracy and precision to be used in clinical setting. However, the 3D imaging system requires the subject's compliance for exact images. If the clinicians provide specific instructions to children while obtaining 3D images, the 3D device is useful for investigating children's facial growth and development. Also the device can be a valuable tool for evaluating the results of orthodontic and orthopedic treatments.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.457-460
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• 2002

The image quality of three-dimensional (3D) images has been widely investigated by the qualitative analysis method. A need remains for an objective and quantitative method to assess the image quality of 3D volume-rendered images. The purpose of this study was to evaluate the quantitative accuracy of distance measurements on 3D volume-rendered images of a dry human skull by using multi-detector computed tomography (MDCT). A radiologist measured five times the twenty-one direct measurement line items composed among twelve reference points on the skull surface with a digital vernier caliper. The water filled skull specimen was scanned with a MDCT according to the section thicknesses of 1.25, 2.50, 3.75, and 5.00 mm for helical (high quality; pitch 3:1) scan mode. MDCT data were reconstructed with its acquisition section thickness and with 1.25 mm section thickness for all scans. An observer also measured seven times the corresponding items on 3D volume-rendered images with measuring tools provided by volumetric analysis software. The quantitative accuracy of distance measurements on the 3D volume-rendered images was statistically evaluated (p-value < 0.05) by comparatively analyzing these measurements with the direct distance measurements. The accuracy of distance measurements on the 3D volume-rendered MDCT images acquired with 1.25, 2.50, 3,75 and 5.00 mm section thickness and reconstructed with its section thickness were 48%, 33%, 23%, and 14%, respectively. Meanwhile, there were insignificant statistical differences in accuracy of distance measurements among 3D volume-rendered images reconstructed with 1.25 mm section thickness for the each acquisition section thickness. MDCT images acquired with thick section thickness and reconstructed with thin section thickness in helical scan mode should be effectively used in medical planning of 3D volume-rendered images. The quantitative analysis of distance measurement may be a useful tool for evaluating the quantitative accuracy and the defining optimal parameters of 3D volume-rendered CT images.

• Journal of dental hygiene science
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• v.15 no.4
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• pp.393-398
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• 2015

One of the most critical causes in determining the clinical outcomes of dental prostheses is the validity of models. However, studies that evaluated validity of digital models are few. The objectives of this study were to evaluate validity of edentulous digital models for full denture fabrication. Twenty stone models (edentulous model) were manufactured and scanned by dental blue light emitting diode scanner. Twenty digital models were manufactured. Six linear distances (inter-canine distance, inter-molar distance, two dental arch lengths (right, left), two diagonal of dental arch lengths (right, left) were measured for validity evaluation. The measurements of distances of stone models were used by digital vernier caliper and digital models were used by computer program. The mean${\pm}$deviations values of six distances were calculated. The means were compared by the Mann Whitney U test (${\alpha}=0.05$). All statistical analysis were performed using IBM SPSS Statistics ver. 20.0. Although digital models were smaller than stone models in six distances, there were no significant differences (p>0.05) and non exceeded the clinical acceptable range. The edentulous digital models for full denture fabrication can be considered clinically acceptable.

• Journal of Korean society of Dental Hygiene
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• v.12 no.3
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• pp.513-520
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• 2012

Objectives : In this study, contact angle and shore D hardness were measured, and a shark fin test was conducted after selecting five addition silicon(Blu-Mousse, BM; EXABITE II, EX; PERFECT, PF; Regisil$^{(R)}$ Rigid, RE; Silagum$^{(R)}$, SI) in order to figure out the properties of elastomeric interocclusal recording materials and reduce errors at interocclusal recording. 8) Methods : A contact angle was measured using a contact angle analyzer. After placing a drop of liquid on the surface of the specimens of interocclusal recording materials, a contact angle was photographed with a CCD camera on the equipment. In terms of a shark fin test, interocclusal recording materials were mixed for the time proposed by the manufacturer and inserted into the split ring of the Shark fin device. Twenty (20) seconds exactly, a metal rod was removed to make the materials slowly absorbed. Once they hardened, fin height was measured with a caliper after separating molds and trimming the specimens. The shore D hardness was measured with a shore D hardness tester(Model HPDSD, Hans Schmidt & Co. Gmbh, Germany) in sixty (60) minutes after fabricating specimens. In each experiment, five specimens, mean and standard deviation were calculated. A one-way ANOVA test was performed at the p>0.05 level of significance. In terms of correlation among the tests, Pearson correlation coefficient was estimated. For multiple comparison, Scheffe's test was carried out. Results : A contact angle was the highest in EX with $99.23^{\circ}$ (p<0.05) while the result of the shark fin test was the longest in RE with 5.45mm. SI was the lowest (0.27mm) with statistical significance. Among the interocclusal recording materials, significant difference was observed in terms of means (p<0.05). The shore D hardness was the highest in SI with 31.0 while RE was significantly low with 16.4 (p<0.05). Among the materials, statistically significant difference was observed in terms of means when compared to the rest materials (RE), BM, RE and SI (PF and EX) and the remaining materials (BM and SI) (p<0.05). In terms of correlations among the tests, a negative correlation occurred between shore D hardness and shark fin test(r=-0.823, p=0.000). Conclusions : According to the study above, it is necessary to understand the properties of interocclusal recording materials and consider contact angle, shark fin test and properties of shore D hardness to select appropriate materials.

• Journal of Veterinary Clinics
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• v.29 no.4
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• pp.301-305
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• 2012

The purpose of the present study was to prove our empirical tendency of relatively high small intestinal diameter (SI) to fifth lumbar vertebral height (L5) ratio, which has been used in dogs. In this study, the ratio of SI/L5 was determined in small breed dogs weighing less than 5 kg. In addition, the effect of large volume of contrast media on the intestinal dilation was determined by performing upper gastrointestinal contrast study. Abdominal radiography and upper gastrointestinal series were performed in twelve healthy dogs weighing less than 5 kg. Small intestinal diameter (SI), fifth lumbar vertebral height (L5), and twelfth rib diameter were measured on abdominal radiographs. The range of values of SI/L5 is from 1.03 to 2.26 in plain radiography, and from 1.55 to 2.5 in contrast studies. Contrast agent significantly increased small intestinal diameter, and could be considered as mildly dilated intestinal model. Therefore, a value of 2.1 for SI/L5 is recommended as the upper limit of the normal range suggesting nonobstructive intestinal dilation.

• Journal of the Korean Wood Science and Technology
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• v.43 no.6
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• pp.746-756
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• 2015

The goal of this study was to review the wood shrinkage published in Journal of The Korean Wood Science and Technology from 1976 to 2015. Previous studies reported that shrinkage from Larix kaempferi in the tangential, radial, longitudinal directions ranged from 4.21%-9.79%, 2.09%-4.67%, 0.17%-0.33%, respectively. When different drying methods including closed cylinder drying, oven drying, and room temperature drying were used, volumetric shrinkage of Dipterocarpus grandiflorus was different, ranging from 31.6% to 21.0%. With an increment of the drying temperature of $115^{\circ}C$, $120^{\circ}C$, $125^{\circ}C$, the shrinkage of Larix kaempferi did not show a consistent trend. When sample size of Pinus densiflora was increased from $20{\times}20{\times}20mm$ to $100{\times}100{\times}100mm$, the tangential, radial and volumetric shrinkage decreased 2.61%, 1.32%, 0.80%, respectively. When a caliper having a sensitivity of 0.01 mm was used to measure $20mm^3$ specimen from Cryptomeria japonica, the measurement error occurred 1.97% in the radial direction and 35.7% in the longitudinal direction. From the previous studies, wood shrinkage could be influenced by sample size, drying method and measurement technique.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.3
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• pp.355-362
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• 2001

Data derived from odontometric studies are useful in many areas. Especially crown diameter of primary teeth is important in not only anthropology but also clinical dentistry. The purposes of this study were to compare diameters of primary molars of Korean children with those of preformed stainless steel crown, and examine racial characteristics of primary molars of Korean children. The mesiodistal and buccolingual diameters of primary molars were measured on dental casts taken from 235 children(male 105, female 131), with digital calipers. And the data were compared with those of preformed stainless steel crowns. The results were as follows; 1. No significant difference was observed between the right and left members of antimeric teeth and all primary molars of male were larger than those of female. 2. The diameters of primary molars of Korean are smaller than those of Austrailian aborigines and there was significant difference between diameters of primary molars of Korean and those of other populations. 3. There were size differences between diameters of maxillary, mandibular first molar and preformed stainless steel crown than other primary molars, relatively.

• The korean journal of orthodontics
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• v.33 no.3 s.98
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• pp.157-167
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• 2003

The purpose of this study was to find whether there is a correlation between tooth size and jaw size. Dental stone models and cephalometric radiographic films of 87 untreated individuals were evaluated. Repeated measurements of the maximum mesiodistal width of the teeth were taken by means of a digital vernier caliper. Linear measurements of jaw size were assessed by means of a digitizer and Visual C++ program. All measurements were taken separately according to the subject's gender. To determine the relationship between jaw and tooth size, the Pearson correlation was used. The results were as follows: 1. Male and female subjects showed a statistical difference in regard to tooth size and jaw size 2. In contrast to the results of the male subjects, there were no statistically significant correlations between maxillary size and maxillary teeth size in female subjects 3. In male subjects, the two maxillary sizes of PTM vert-ANS vert (FH plane) and PTM vert-A yen (palatal plane) were significantly correlated with themaxillary teeth size. Especially, the size of the upper central incisor showed significant correlation with all maxillary sizes. 4. In both male and female subjects, mandibular size B vert- Point J vert (mandibular plane) showed significant correlation with mandibular teeth size. As gleaned kom the results of this study, the relationship between jaw size and tooth size was fair or little in natural occurring good occlusion.