• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.3
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• pp.274-278
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• 2005

Purpose : Prediction for soft tissue change after orthognathic surgery is very important for the final esthetics. In this study, we have tried to get the amount of upper lip movement relative to bony segment movement after anterior segmental osteotomy by cephalmetric analysis to predict final upper lip position after surgery. Material and Methods : 20 patients was studied on whom anterior segmental osteotmy as performed by Cupar method during the years 2002 to 2003. Cephalometric radiograph were taken at 1month before surgery and 6 month after surgery. Change of upper lip was measured on landmark Ls and Sto relative to hard tissue (landmark Ia) setback on these X-rays and analyzed. Results : 1. Upper lip setback movement. Setback of upper lip showed proportional relation to the hard tissue setback and the ratio was about 84%(p=0.001). 2. Upper lip downward movement. Downward movement of upper lip showed no proportional relation to hard tissue setback And the amount was mean 1.38 mm and SD 1.21mm (p=0.922). Conclusion : The posterior movement of upper lip is affected by hard tissue movement and shows good proportional change whereas downward movement is not so much influenced by hard tissue movement. And we think slight downward movement shown in this study could be explained by the V-Y closure performed during surgery.

• Journal of the Korean Geographical Society
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• v.46 no.2
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• pp.115-133
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• 2011

Yamada's mountain ordering is to be said as an upward system, because the area and volume of the mountains become the larger as more than two lower order mountains constitute the higher order mountain. However, his mountain ordering shows some limitations to totally understand the mountain systems and to systematically manage the various kinds of mountainous informations. Because the independent third, fourth and so on, as well as the second lower order mountains are included in the higher order mountain. In order to solve the problem above, the downward system is suggested as the alternative of his upward system. The downward system means that the higher order mountain is classified into the second lower order mountains, and the second lower order mountain is classified into the third lower order mountains and finally the 2nd order mountain classified into the 1st order mountains. The method to classify a certain mountain systematically into all mountainous elements and the new nomenclature to be used for the classified elements are developed, using the downward system above. And the structure of database could be also suggested for the integrated and systematic management of mountain informations.

• The korean journal of orthodontics
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• v.24 no.3 s.46
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• pp.735-758
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• 1994

This study was designed to investigate the displacements and reaction forces of teeth caused by the application of the rectangular shape-memory arch wires with curve of Spee. Computer-aided three dimensional finite element method was adopted. This finite element model consists of brick element for teeth, beam element for the wire, and contact element for the periodontal ligament. And the application of the MEAW(Multiloop Edgewise Arch Wire) was also studied so that the results of the two methods can be compared each other. Total number of the nodes and elements were found to be 5925 and 4031, repectively. In addition, several types of elastics and corresponding displacements and reaction forces were examined. The findings of this study were as follows: 1. When the rectangular shape-memory arch wire with curve of Sun was used alone, the intrusion and labioversion was noticeable on the upper incisors, while the upper molars showed less intrusion. With MEAW, the intrusion and labioversion of the upper incisors were slightly larger than those when the shape-memory arch wire was used, but on the upper molars the opposite result was obtained with respect to the intrusion. 2. The shape-memory arch wire with the vertical elastics caused the larger downward displacement on the upper canine than that when the MEAW was used with the vertical elastics. However, the downward displacement of the upper incisors was larger in MEAW. The uprighting and buccoversion of the molars were observed in both cases. 3. The use of the Class II or III elastics showed the extrusion and changes in torque of the corresponding teeth. The downward displacement of the upper canine was increased when the Class II and vertical elastics were applied simultaneously, but it was decreased when both of the Class III and vertical elastics were used.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.1
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• pp.197-208
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• 1998

This study was carried out to compare the amount of the maxillary bone remodeling and tooth displacement in each three maxillary superimposition methods, Ricketts, Best-fit, Structural method. Forty cases of the lateral cephalometric radiographs from 27 boys and 13 girls who had been treated to correct anterior cross-bite were selected for the study. The initial radiographs were taken at about 8-year-old and the second radiographs were taken in about 3.3 years later. Followings were the results: 1. With the Structural method, backward movement was shown in PNS, while forward movement was observed in ANS and point A. With the Ricketts method, however, all structures were shown significant backward movement comparing with Structural method(P<0.05). With the Best-fit method, the amount of horizontal movement was similar to that of the Structural method(P>0.05). 2. The palate seemed to be moved downward with Structural method, but there was no measured downward remodeling on nasal floor with Ricketts and Best-fit method(P<0.05). 3. Comparing with Structural method, Ricketts and Best-fit method significantly underestimated the eruption of the teeth by 20% to 30% (P<0.05). 4. The Structural method showed the anteroinferior rotation (43%) and posteroinferior rotation(57%) of the palatal plane, while the Best-fit method showed mostly anterosuperior rotation(87%), but no change was found in the Ricketts method. 5. With the Structural method, there was a statistically significant correlation between the amount of the rotation of the palatal plane and that of N-S line(r=0.86). 6. The measured angles of the long axis of the incisors and molars showed no significant difference in each 3 methods(P>0.05).

• Economic and Environmental Geology
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• v.23 no.3
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• pp.353-358
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• 1990

This paper presents numerical experiments on migration of synthetic seismograms using by $45^{\circ}$ wave equation. The seismograms used are zero-offset seismogram (corresponding to stacked section) on point reflectors, dipping plane reflector, faulted and folded layers. The seismograms are constructed by upward continuation of seismic source wavelets, exploading on subsurface reflection interfaces, to the earth surface. The synthetic seismograms are migrated by downward continuation and imaging. The upward and downward continuations are implemented by solving the $45^{\circ}$ wave equation with the finite-difference method. Migration of the synthetic data used in this study results in relatively accurate reposition of subsurface structures while the synthetic sections are quite different from the structures.

• Journal of KSNVE
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• v.11 no.2
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• pp.329-335
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• 2001

The analytical model of the ground wave can be used for the prediction of the noise level from a source above a plain and homogeneous ground surface with no obstacles nearby. Sound propagation along the surface of the ground can be affected by the roughness of the ground surface and the direction of the wind. The effects of the ground surface and the wind can be formulated in terms of the ground coefficient and the noise source parameter. Upward and downward conditions can also be addressed by considering the direction of the wind. The ground coefficient and the noise source parameter are estimated using the measured noise levels of two points under particular environmental condition, and the noise levels of arbitrary points under the same environmental condition can be estimated. The proposed method can be utilized to estimate the noise level of specific noise environment and its validity was confirmed with the results of actual field measurement.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.315-318
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• 2005

Vlasov's hypothesis provides a way to solve the torsional problem with warping torsion of double T-beam section. Not only the warping torsion of the gross section of double T-beam but the torsional resistances of PS tendons and reinforcements have to be considered together in the analysis in which the latter is the restoring roles provided by the upward and downward force components in a geometrical symmetric configuration. It means that the torsional resistances of PS tendons and reinforcements, usually ignored, store the strain energies due to up-downward geometrical changes. Space frame element with 7-degrees of freedom are used for the finite element approximation of the real behaviors. Bimoments and angles of twist obtained from the proposed method show good agreements with those of 3-D. finite element analysis and analytical analysis

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1997.10a
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• pp.110-114
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• 1997

The major object in this report is the curvature prediction of front end downward bending in plate rolling. Because of relations front end shape and curvature in plate, many simulations were carried out to obtain empirical model. Simulation conditions, for example the position and the size of bottom stripper or roller table etc., were limited to the POSCO conditions. Though the result in this report can be applied to the special case, the tendency of this result is similar to the many cases. So the empirical model equation can be improved or expanded to many simulation conditions.

• Journal of the Korean Society of Clothing and Textiles
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• v.5 no.2
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• pp.63-68
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• 1981

Succeding to Report I, to determine the effect of opening conditions and areas of clothes ($10\%,\;20\%,\;30\%,\;40\%$ of total area) on the warmth keeping properties, cooling method was employed by using Latin Square Design, The following results were obtained: 1) The warmth keeping ratio was varied with the opening conditions and the: order was downward, upward, horizontal and up & downward opening 2) The size of opening areas was in inverse proportion to the warmth keeping ratio, 3) In the horizontal opening, the thickness of air layers in clothes did not effect on the warmth keeping ratio.

• Geomechanics and Engineering
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• v.25 no.2
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• pp.135-142
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• 2021

This study provided a new research perspective for processing and analyzing AE data to evaluate rock failure. Cluster method and information entropy theory were introduced to investigate temporal and spatial correlation of acoustic emission (AE) events during the rock failure process. Laboratory experiments of granite subjected to compression were carried out, accompanied by real-time acoustic emission monitoring. The cumulative length and dip angle curves of single links were fitted by different distribution models and distribution functions of link length and directionality were determined. Spatial scale and directionality of AE event distribution, which are characterized by two parameters, i.e., spatial correlation length and spatial correlation directionality, were studied with the normalized applied stress. The entropies of link length and link directionality were also discussed. The results show that the distribution of accumulative link length and directionality obeys Weibull distribution. Spatial correlation length shows an upward trend preceding rock failure, while there are no remarkable upward or downward trends in spatial correlation directionality. There are obvious downward trends in entropies of link length and directionality. This research could enrich mathematical methods for processing AE data and facilitate the early-warning of rock failure-related geological disasters.