• Journal of Chest Surgery
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• v.34 no.7
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• pp.534-538
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• 2001

Background: Knowledge of size and morphology of the normal trachea is important for airway management and tracheal reconstruction. Conventional radiography is a simple method used to measure the tracheal diameter, but it is not accurate because of the artifacts related to image magnification and overlapping by the shoulder. The purpose of this study was to provide the normal values of the tracheal size and anatomy in Korean adults using Computerized Topography. Material and Method: There were 43 men and 34 women included in this study. They were divided into three age groups(group 1, 20-39 years ; group 2, 40-59 yeas , groups 3, $\geq$60 years). The anteroposterior and transverse diameters and cross - sectional areas of the trachea were measured at the level of the thoracic inlet(Level 1) and the aortic arch(Level 2). These values obtained at each level were compared between age groups and sexes. Result: In 43 men, the anteroposterior / transverse diameters(mean SD in millimeters) of the trachea at levels 1 and 2 were 19.95$\pm$2.99 / 17.72$\pm$2.13 and 19.77$\pm$2.57 / 18.02$\pm$2.19, respectively. In 34 women, those values at levels 1 and 2 were 15.56$\pm$2.12 / 14.18$\pm$2.07 and 15.35$\pm$1.82 / 15.00$\pm$1.60, respectively. At both levels, the anteroposterior and transverse diameters were significantly greater in men than in women (p<0.05). The cross-sectional area of the trachea at levels 1 and 2 were 279.14$\pm$61.37 / 281.93$\pm$63.97 $\textrm{mm}^2$ in men and 173.29$\pm$35.81 / 181.88$\pm$34.74 in women, respectively. They also showed significantly greater values in men than in women(P<0.05). There was no significant difference in diameters and cross-sectional areas of the trachea between age groups. Conclusion: There are significant differences in the internal diameter and cross- sectional area of the trachea between men and women in normal Korean adults, while the age difference was insignificant. We believed CT is a relatively accurate and safe way to measure the internal diameter and cross-sectional areas of the trachea.

• Structural Engineering and Mechanics
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• v.41 no.2
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• pp.285-297
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• 2012

An inverse approach is presented for calculating the flexibility coefficient of open-side cracks in the cross sectional of beams. The cracked cross section is treated as a massless rotational spring which connects two segments of the beam. Based on the Euler-Bernoulli beam theory, the differential equation governing the forced vibration of each segment of the beam is written. By using a mathematical manipulation the time dependent differential equations are transformed into the static substitutes. The crack characteristics are then introduced to the solution of the differential equations via the boundary conditions. By having the time history of transverse response of an arbitrary location along the beam, the flexibility coefficient of crack is calculated. The method is applied for some cracked beams with solid rectangular cross sections and the results obtained are compared with the available data in literature. The comparison indicates that the predictions of the proposed method are in good agreement with the reported data. The procedure is quite general so as to it can be applicable for both single-side crack and double-side crack analogously. Hence, it is also applied for some test beams with double-side cracks.

• Transactions of Materials Processing
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• v.24 no.3
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• pp.187-193
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• 2015

The objective of the current study is to determine cross-sectional profile of intermediate dies in order to improve the plastic strain homogeneity which directly affects not only the dimensional accuracy but also the mechanical properties of final product by redesigning the intermediate dies using the conventional electric field analysis (EFA) method. Initially, the multi-pass shape wire drawing was designed by using the equivalent potential lines from EFA. The area reduction ratio was calculated from the number of passes in multi-pass shape wire drawing but constrained by the capacity of the drawing machine and the drawing force. In order to compensate for a concentration of strain in a region of the cross section of the wire, the process for multi pass wire drawing from initial round material to an intermediate die was redesigned again using the electric field analysis. Both drawing process designs were simulated by the finite element method in which the strain distribution and standard deviation plastic strain of the cross section of drawn wires were examined.

• Korean Journal of Agricultural Science
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• v.50 no.4
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• pp.645-652
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• 2023

The aleurone layer in maize is crucial as it contains essential nutrients such as minerals, vitamins, and high-quality proteins. While most of the maize varieties are known to possess a single aleurone layer, several multi-aleurone layer mutants and landraces have been suggested for hierarchical genetic control of aleurone development. Conventional microscopy analysis often involves using immature seeds or sampling only a portion of the kernel sample, and whole kernel section analysis using a microtome is technically difficult and time-consuming. Additionally, the larger size of maize kernels posed challenges for comprehensive cross-sectional analysis compared to other cereal crops. Consequently, this study aimed to develop an efficient method to comprehensively understand the aleurone layer characteristics of the entire cross-section in maize. Through observations of diverse maize genetic resources, we confirmed irregular aleurone layer patterns in those with multiple aleurone layers, and we discovered a landrace having multiple aleurone layers. By selectively identifying genetic resources with multiple aleurone layers, this method may contribute to efficient breeding processes in maize.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.705-711
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• 2000

This paper presents a fast 3D mesh generation method using a surface based method with a stitching algorithm. This method uses the surface based method since the volume based method that uses 3D Delaunay triangulation can hardly deal with a large scale of scanned points. To reduce the processing time, this method also uses a stitching algorithm: after dividing the whole point data into several sections and performing mesh generation on individual sections, the meshes from several sections are stitched into one mesh. Stitching method prevents the surface based method from increasing the processing time exponentially as the number of the points increases. This method works well with different types of scanned points: a scattered type points from a conventional 3D scanner and a cross-sectional type from CT or MRI.

• Journal of Fashion Business
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• v.21 no.1
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• pp.74-87
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• 2017

The aim of this study was to analyze the features of bodice patterns modeled using a dress form that represents Korean female fashion models' body features. A controlled experiment was carried out using an existing dress form that has been frequently used in South Korea. The purpose of the study was to suggest notable findings derived from understanding the development of bodice patterns for Korean female fashion models. The comparison of features of bodice patterns from the developed and existing dress forms was carried out with consideration of the upper body features of the developed dress form, such as body angles and body cross-sectional shapes. The following results were derived from the investigations. (1) The angles of the upper and lower breast cups of the developed dress form differed to those of the existing dress form, showing a 5.0cm smaller front shoulder dart and a 3.5 larger ㎝ ㎝ front waist dart within the bodice patterns. (2) The body angle features of the developed dress form included a straighter neck and shoulder blade and more concave center back than the existing dress form, with a 2.0 reduced back neck height and a 4.8 larger back waist dart for ㎝ ㎝ the bodice back panel. The more realistic body angles of the developed dress form anticipate the improvement of garment pattern-making. (3) The altered shoulder angles resulted in an increased size of the back shoulder dart and a decreased size of the front shoulder height within the bodice patterns. (4) The increased rate of curvature of cross-sectional shapes on the bust and waist circumferences of the developed dress form resulted in an increase in the sizes of the front and back waist darts.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.5
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• pp.698-707
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• 1998

For inverse scattering problems reconstructing cross-sectional permittivity distributions of dielectric cylinders, the angular spectral inverse technique using the moment method with pulse basis function suffers from large reconstruction error even if very small noise due to requiring the higher spectral informations on the larger cross-section of the cylinder. To reduce the number of higher-order spectra, this paper presents an improved inverse technique in angular spectral domain applying the moment procedure with a series-expansion basis function for the induced field in each enlarged cross-sectional cell. By choosing adequate spectra and averaging over the enlarged cells with a suitable weighting function, the reconstruction profiles reveal fine enough to suppress the noise effect significantly.

• Journal of Urban Science
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• v.11 no.2
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• pp.19-24
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• 2022

Conventional RC beams for crossing small and medium-sized rivers do not have a cross-sectional area, so the floating debris is accumulated and disasters such as damage to bridges occur. To improve this, the PSC method was invented. However, this also had problems such as transverse curvature, increase in dead weight due to cross-sectional shape, and negative moment generated during serialization, so it was necessary to develop a new type of girder. Therefore, it was intended to propose a LIT(Leton Interaction Thrust) girder bridge that is safer and has better performance than the conventional PSC girder with improved section efficiency. Unlike existing girder bridges, the LIT girder has the feature that the change in the strands of the entire girder occurs only in the vertical direction when the first tension is applied because the tendon arrangement is symmetrical by applying the raised portion. In addition, slab continuation generates a secondary moment that is advantageous to the continuous point, effectively controlling the negative moment and preventing the corrosion of the tendon. The dimensions of the cross section were determined, and the arrangement of the strands was designed to conduct structural analysis and detailed analysis. As a result of the structural analysis, the stress of the girder showed results within the allowable compressive stress, and the deflection showed the result within the allowable deflection. showed results. In addition, a detailed analysis was performed to examine the stress distribution around the girder body and the anchorage area and the stress distribution of the embossed portion, and as a result, the stress of the girder body due to the tension force showed a stable level.

• Restorative Dentistry and Endodontics
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• v.30 no.4
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• pp.327-334
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• 2005

This study investigated the effect of anticurvature filing method on preparation of the curved root canal using ProFile. Thirty six resin blocks were divided equally into three groups by instrumentation motions: anticurvature filing motion. circumferential filing motion and straight up-and-down motion. Each resin block was sectioned at 8mm level from the apex and at the greatest curvature of the canal and reassembled in metal mold by a modified Bramante technique. All groups were instrumented with the ProFile system. At each levels. image of sectioned surface were taken using CCD camera under a stereomicroscope at $\times40$ magnification and stored. Distances of transportation at the inner and outer area of curvature and the centering ratio were determined and compared by statistical analysis. along with the assessment of the increase of root canal cross-sectional area. The results were as follows; 1. In all groups. there was no statistical difference in the mean increase of root canal cross-sectional area. the centering ratio. and the mean distances of transportation at the inner area of curvature at each level. 2. At 8mm level from the apex. the mean distances of transportation at the outer area of curvature decreases in following order anticurvature filing motion. circumferential filing motion. straight up-and­down motion but. no significant difference at the greatest curvature of the canal among three groups. Effect of anticurvature filing motion using ProFile does not seem to be different from other instrumentation motions at the inner area of curvature in curved root canal.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.24 no.3
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• pp.149-158
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• 2012

This study analyzed cross-sectional variations in residual current and strengths of stratification by observing cross-sectional velocity and salinity during spring tide and neap tide, respectively, for continuous 13-hour periods at 2 observation lines at northern and southern end of Seokmo Channel, which is located west of Ganghwado. Salinity distribution of channel depends on not only neap and spring tide but also impact of salinity. The residual current component was obtained by removing $M_2$ and $M_4$ tidal components that were extracted using the least squares method on 13-hour velocity component. Cross-section of residual velocity at northern and southern end of Seokmo Channel exhibited southward residual components at channel's surface layer, but northward residual current was observed at channel's bottom layer, clearly showing a 2-layer tidal circulation between surface and bottom layers. The variation in location of appearing northward residual current according to changes in spring and neap tidal cycle and its correlation with stratification were analyzed using the Richardson number and Simpsonhunter index. At northern and southern end of Seokmo Channel, northward residual current appears in the location where Richardson number is large, Simpson-hunter index appears as a value greater than 4.