• 한국컴퓨터정보학회논문지
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• 제24권6호
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• pp.57-65
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• 2019

In this paper, we study on finding the rail space in elevators by analyzing each image captured with CCD camera. We propose a method that applies one-dimensional matched filter to the pixels of a selected search space in the vertical line at a horizontal position and decides the position with the thickness of the space being represented by a black thick line in captured images. The pattern similarity representing how strongly the associated image pixels resemble with the thick line is defined and calculated with respect to each position along the vertical line of pixels. The position and thickness of the line are decided from the point having the maximum in pattern similarity graph. In the experiments of the proposed method under different illuminational conditions, it is observed that all the pattern similarity graphs show similar shape around door area independent of the conditions and the method can effectively detect the rail space if the rails are illuminated with even weak light. The method can be used for real-time embedded systems because of its simple algorithm, in which it is implemented in simple structure of program with small amount of operations in comparison with the conventional approaches using Canny edge detection and Hough transform.

• 대한치과교정학회지
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• 제12권2호
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• pp.79-93
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• 1982

The purpose of orthodontic treatment is to achieve normal occlusion and good facial esthetics for individual patients. To produce harmonized facial balance, treatment planning for patient who require orthodontic treatment should include both a hard tissue and soft tissue cephalometric analysis. Author studied to derive the normal standards of soft tissue profile in Koreans by roentgenocephalometric analysis. For this study 12 soft tissue profile landmarks were plotted and 23 linear length, 9 soft tissue thickness, 8 vertical height length, 12 angles of soft tissue profile, and 3 vertical proportion were measured. The subjects consisted of 166 males and 209 females from 7 to 19 years with normal occlusion and acceptable profiles, and were divided into five groups according to age. The obtained results were as follows; 1. From the basis of N-Pog (Nasion-Pogonion) plane, the growth of facial soft tissue in the middle region especially nose area was greater than others facial region. 2. From the basis of G-Pog' (Glabella-soft tissue Pogonion) plane, the values of linear measurement of soft tissue Nasion and Inferior labial sulcus decreased and nose tip grew forward as growing older. 3. The growth of the facial soft tissue thickness was greatest in superior labial sulcus and the thickness of soft tissue nasion gradually became thinner as growing old. 4. The thickness of upper and lower lip was 14.47mm, 14.57mm in adulr male, 12.76mm, 13.78mm in adult female. 5. The soft tissue thickness of the lower lip was thicker than that of upper lip in all age groups and both sexes, 6. The vertical length of the upper and lower lips were 25.04mm, 49.97mm in adult male and 23.50mm, 48.39mm in adult female. 7. By the significant test, there were significant difference between male and female in fifth adult group on all vertical length measurements of lower face. 8. In fifth adult group, the perpendicular distance from LS, LI to Steiner's line and Ricketts' esthetic line were as follow; Steiner line to LS, LI were 7.98mm, 5.84mm in male. Steiner line to LS, LI were 6.71mm, 5.08mm in female. Ricketts' esthetic line to LS, LI were -0.40mm, 1.72mm in male. Ricketts' esthetic line to Ls, LI were -1.38mm 0.65mm in female. 9. In fifth adult group, the facial convexity angle and lower facial component angle were $171.17^{\circ}142.94^{\circ}$ in male and $172.5^{\circ}$, $144.41^{\circ}$ in female.

• 한국분무공학회지
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• 제2권4호
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• pp.29-35
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• 1997

Liquid film thickness is measured by $moir\acute{e}$ topography which monitored liquid surface. $Moir\acute{e}$ fringe measurement techniques share the inherent simplicity found in optical interferometric techniques have the advantage of use over a greater range of displacement. $Moir\acute{e}$ fringe are the geometric interference patterns observed when two dense line grating are superposed. Light transmitted through a fixed line grating is deviated by the liquid film surface, producing a distored image of the grating. The $moir\acute{e}$ fringe produced by projection of this optically distored grating onto a second stationary grating permit visualization of the liquid surface and measurement of the liquid film thickness. This study measured the small amplitude of liquid film thickness to the $moir\acute{e}$ fringe pattern produced when spherical metal was dropped glycerin put)1 And the measurement of liquid film thickness flowing down an inclined plate are required to calculate the liquid slope in a position.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제20권3호
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• pp.269-273
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• 1998

To clarify the clinical utility of the calvarial bone graft in the maxillofacial reconstruction, we performed on anatomical study by measuring the regional thickness of the parietal bone on 17 Korean adult dry skulls. Before the sectioning the calvarium, the anatomical landmarks were marked on each specimens. And then we measured the total thickness of the parietal bone, the thickness of the outer and inner cortical plates on various points in each sections of parietal bones using a digital caliper under the stereomicroscope. The total thickness of the parietal bone was ranged from 5.17mm to 7.50mm, and there were no statistical difference in the total thickness of the parietal bone on the same points bilaterally. But there was a tendency that the thickness of the parietal bone was thicker toward to the lambda point than the coronal suture area. At the other hand, the thickness of the outer and inner plate of the parietal bone was the thickest at the first point of the right aspect on the line 1, the first point of the left aspect on the line 5, respectively. In conclusion, this study showed that the donor site of the parietal bone for the maxillofacial reconstruction should be located at more posterior and medial area of the parietal bone than the prevalent known donor site.

• Journal of Oral Medicine and Pain
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• 제44권3호
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• pp.112-117
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• 2019

Purpose: The aim of this study was to assess the thickness of the roof of the glenoid fossa (RGF) in Korean adult population without symptoms of temporomandibular disorder (TMD) using cone-beam computed tomography (CBCT). Methods: CBCT Data from 111 Korean adult patients aged ${\geq}25years$ (55 males and 56 females) without signs and symptoms of TMD were analyzed retrospectively in this study. The thickness of the RGF was determined as the perpendicular distance between the 'glenoid fossa line' and 'middle cranial fossa line' on parasagittal and paracoronal reconstructions, respectively. The thickness of the RGF according to sex and age was analyzed using t-tests (p<0.05). Differences were also examined between the right and left sides, and between the paracoronal and parasagittal sides. Results: The mean thickness of the RGF in all subjects was $0.75{\pm}0.39mm$; there was no significant difference in thickness between male ($0.78{\pm}0.36mm$) and female ($0.72{\pm}0.30mm$). We found no correlation between age and the mean thickness of the RGF, when age was grouped by decade. However, when subjects were divided into >40 years and ${\leq}40years$ age groups, the thickness of the RGF was significantly different between the groups. Conclusions: We found that the thickness of the RGF did not differ by sex, but might be affected by aging. Further studies with larger numbers of subjects are needed to confirm the results of this study.

• 한국도로학회논문집
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• 제18권6호
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• pp.145-152
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• 2016

OBJECTIVES : Visibility at night can be improved by using retroreflection for short distances and phosphorescent line markings for long distances. In this study, we analyzed the characteristics of the phosphorescent line marking through a laboratory luminance test. Field performance analysis was performed through tests conducted on the road. We also examined the luminance measurement methods using the digital image obtained during the phosphorescent visibility evaluation. METHODS : In this study, the laboratory luminance test of the phosphorescent line marking was conducted using seven specimens to characterize the luminance changes according to the type of the glass beads, the thickness of the phosphorescent line marking, and the brightness and irradiation time of the light source. Phosphorescent and general line markings were made at 150 m to investigate the field luminance performance. A preliminary review of the luminance measurement methods was made using a digital image from a digital single-lens reflex (DSLR) camera. The measured luminance ratio of the general and the phosphorescent line markings was compared with the calculated luminance ratio using luminance analysis. RESULTS : Through the laboratory luminance test, it was seen that the change in luminance, which corresponds to the brightness of the light source, appears large but the influence of the thickness and irradiation time is low. The field performance test of the phosphorescent line marking conducted on the road involved measuring the luminance on the day the marking was made and 7 days after the marking was made. The luminance was found to be $190mcd/m^2$ at 30 min after sunset and approximately $10-12mcd/m^2$ 4h after sunset. The results of the luminance test were captured using a digital image for each time group. The luminance ratio of the phosphorescent line marking, when compared to that of the general line marking, showed a similar trend within a 13% maximum error. Additionally, when this luminance ratio is compared to the direct field measurement, it could be confirmed that the luminance ratio, as captured in the digital image, showed a similar tendency. CONCLUSIONS : 1) The change in luminance corresponding to the brightness of the light source is significant in comparison with that corresponding to the thickness and the irradiation time. In addition, the results of the field test for the phosphorescent line marking satisfied the phosphorescent fire protection standard. 2) We examined the validity of the luminance measurement method using a digital image and we concluded that the change in the luminance ratio shows a similar tendency in both the cases. The results can form the basis for luminance measurement methodology for the construction and maintenance of phosphorescent line markings.

• International Journal of Fluid Machinery and Systems
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• 제2권1호
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• pp.1-12
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• 2009

Surrogate modeling is applied to a compressor blade shape optimization to modify its stacking line and thickness to enhance adiabatic efficiency and total pressure ratio. Six design variables are defined by parametric curves and three objectives; efficiency, total pressure and a combined objective of efficiency and total pressure are considered to enhance the performance of compressor blade. Latin hypercube sampling of design of experiments is used to generate 55 designs within design space constituted by the lower and upper limits of variables. Optimum designs are found by formulating a PRESS (predicted error sum of squares) based averaging (PBA) surrogate model with the help of a gradient based optimization algorithm. The optimum designs using the current variables show that, to optimize the performance of turbomachinery blade, the adiabatic efficiency objective is improved substantially while total pressure ratio objective is increased a very small amount. The multi-objective optimization shows that the efficiency can be increased with the less compensation of total pressure reduction or both objectives can be increased simultaneously.

• Tribology and Lubricants
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• 제14권1호
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• pp.85-93
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• 1998

The Bair & Winer's limiting shear stress rheological model is incorporated into the Reynolds equation to successfully predict the traction and film thickness for an isothermal line contact using the primary rheological properties. The modified WLF viscosity model and Barus viscosity model are also adapted for the realistic prediction of EHD tractional behavior. The influences of the limiting shear stress and slide-roll ratio on the pressure spike, film thickness, distribution of shear stress and nonlinear variation of traction are examined. A good agreement between the disc machine experiments and numerical traction prediction has been established. The film thickness due to non-Newtonian effects does not deviate significantly from the fdm thicknesss with Newtonian lubricant.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2001년도 제34회 추계학술대회 개최
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• pp.364-373
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• 2001

This paper describes the variation of lubricant's temperature effects on elastohydrodynamic lubrication. The Newton-Raphson technique was used to solve the simultaneous system of Reynolds and elasticity equations. To show effects of lubricant's temperature, average temperature across the oil film was calculated using the energy equation. Pressure distribution, film shape, and temperature distribution were obtained for fully flooded conjunctions, and various dimensionless speed parameters while load and material parameters were held constant. Minimum film thickness were obtained for various material properties while load and velocity were held constant. It is drawn that the thermal effects have a strong influence on a minimum film thickness under high rolling velocity and slip ratio.

• 인터넷정보학회논문지
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• 제11권1호
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• pp.21-26
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• 2010

본 논문에서는 LCD TV용 필름의 균일성을 개선하고자, 소프트 엑스레이(soft X-ray)를 이용하여 볼트 연결기법과 컨벌루션(convolution) 함수기반의 영상처리를 결합한다. 필름의 프로파일에서 두께를 측정하는 라인 스캔과정에서 선원 변경 시 오프셋 오류가 발생한다. 이러한 선원의 오프셋 오류를 제거하고자, 인접한 3개 볼트의 영상에 대해 컨벌루션 함수를 적용함으로써 자동으로 두께 측정이 가능하고, 영상분석 성능을 향상한다.