• Title/Summary/Keyword: 3D Topography

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Effects of recycling on the mechanical properties and the surface topography of Nickel-Titanium alloy wires (재생 과정이 니켈-티타늄 호선의 물리적 성질과 표면 거칠기에 미치는 영향)

  • Lee, Sung-Ho;Chang, Young-Il
    • The korean journal of orthodontics
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    • v.30 no.4 s.81
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    • pp.453-465
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    • 2000
  • The purpose of this study was to investigate the change of mechanical properties, surface topography and frictional force of various nickel titanium wires after recycling. Three types of nickel-titanium wires and one type of stainless steel wire were divided to three groups: as-received condition(T0:control group), treated in artificial saliva for four weeks(T1) and autoclaved after being treated in artificial saliva(T2). Some changes were observed for the selected mechanical properties in tensile test, surface topography by means of SEM and 3D profilogram, and frictional coefficient. The findings suggest that: 1. Nickel-titanium wires demonstrated no statistically significant differences in maximum tensile strength, elongation rate and modulus of elasticity, but stainless steel wire demonstrated statistically significant differences in maximum tensile strength, elongation rate and modulus of elasticity between the groups(p<0.05). 2. NiTi, Optimalloy, Stainless Steel wires demonstrated increased pitting and corrosion in SEM finding. 3. Recycled NiTi, Optimalloy and stainless steel wires demonstrated significantly greater surface roughness(Ra and Rq) through 3D profilogram when compared with the control wires(p<0.05), but Sentalloy didn't demonstrate significant difference. 4. Recycled NiTi, Optimalloy and stainless steel wires demonstrated significantly greater maximum frictional coefficient when compared with the control wires(p<0.05), but Sentalloy didn't demonstrate significant difference The changes of surface roughness and frictional coefficient in NiTi and Optimalloy had no clinical implication. Consequently recycled nickel titanium wires demonstrated no clinical problem in tensile properties, surface topography and frictional coefficient.

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3D Terrain Analysis and Suitability Analysis Using KOMPSAT 2 Satellite Images (아리랑2호 영상을 이용한 3차원지형 분석 및 적지분석)

  • Han, seung-hee;Lee, jin-duk
    • Proceedings of the Korea Contents Association Conference
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    • 2008.05a
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    • pp.436-440
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    • 2008
  • Complete consideration on condition and surrounding environment shall be performed to select proper location for complex planning or establishment of facility with special purpose. Especially, in case of living space for human, lighting, ventilation, efficiency in land use, etc. are important elements. Diverse 3D analysis through 3D topography modeling and virtual simulation is necessary for this. Now, it can be processed with relatively inexpensive cost since high resolution satellite image essential in topography modeling is provided with domestic technology through Arirang No. 2 satellite (KOMPSAT2). In this study, several candidate sites is selected for complex planning with special purpose and analysis on proper location was performed using the 3D topography modeling and land information. For this, land analysis, land price calculation, slope analysis and aspect analysis have been carried out. As a result of arranging the evaluation index for each candidate site and attempting the quantitative evaluation, proper location could be selected efficiently and reasonably.

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3-D Gravity Terrain Inversion for High Resolution Gravity Survey (고정밀 중력 탐사를 위한 3차원 중력 지형 역산 기법)

  • Park, Gye-Soon;Lee, Heui-Soon;Kwon, Byung-Doo
    • Journal of the Korean earth science society
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    • v.26 no.7
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    • pp.691-697
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    • 2005
  • Recently, the development of accurate gravity-meter and GPS make it possible to obtain high resolution gravity data. Though gravity data interpretation like modeling and inversion has significantly improved, gravity data processing itself has improved very little. Conventional gravity data processing removes gravity effects due to mass and height difference between base and measurement level. But, it would be a biased density model when some or whole part of anomalous bodies exist above the base level. We attempted to make a multiquadric surface of the survey area from topography with DEM (Digital Elevation Map) data. Then we constituted rectangular blocks which reflect real topography of the survey area by the multiquadric surface. Thus, we were able to carry out 3-D inversions which include information of topography. We named this technique, 3-D Gravity Terrain Inversion (3DGTI). The model test showed that the inversion model from 3DGTI made better results than conventional methods. Furthermore, the 3-dimensional model from the 3DGTI method could maintain topography and as a result, it showed more realistic geologic model. This method was also applied on real field data in Masan-Changwon area. Granitic intrusion is an important geologic characteristic in this area. This method showed more critical geological boundaries than other conventional methods. Therefore, we concluded that in the case of various rocks and rugged terrain, this new method will make better model than convention ones.

Basic Research about Building Data of Virtual Reality Space Using forborne LiDAR Data (LiDAR 자료를 이용한 가상현실공간 자료 구축에 관한 기초적 연구)

  • Choi, Hyun;Kim, Na-Young
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.2
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    • pp.419-424
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    • 2009
  • This paper show about the possibility of practical application after building VR(virtual reality) data based on Airborne LiDAR data which determines complicated topography quickly for the 3D-GIS construction. In this paper, we collected Airborne LiDAR data, digital map, serial photo and a basic design. The results are expected some effective determination by 3D-GIS construction based on LiDAR data. Hereafter, because the research will be able to be given quickly topography information on ubiquitous environment the field of construction and GIS will be able to be helped.

Variation of Paleotopography around the Ssangsujeong Pavilion Area in Gongsanseong Fortress using GIS and 3D Geospatial Information

  • Lee, Chan Hee;Park, Jun Hyoung
    • Journal of Conservation Science
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    • v.38 no.4
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    • pp.347-359
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    • 2022
  • Gongsanseong Fortress was registered of a World Heritage Site in 2015 as a representative cultural heritage from the Woongjin Baekje period, and it has been used throughout the entire period from Baekje Kingdom to the Joseon Dynasty. Within Gongsanseong Fortress, the area around Ssangsujeong is presumed the site of royal palace of the Woongjin Baekje. Also, the excavated culture layers of the Baekje Kingdom, the Unified Silla period, and the Joseon Dynasty were confirmed. In this study, paleotopography was modeled by digitally converting the elevation data obtained through surveying the excavation process, and the use of the topography in the Ssangsujeong area was considered by examining the variations in the topography according to the periods. As a result, the topography of the slope around the peak changed by periods, and the topography did not change on the flat land. The topography between the Baekje Kingdom and the Unified Silla period appeared to be almost identical, and it seems that the space of the Baekje period was maintained as it is. Also, during the Joseon Dynasty, it is confirmed that flat surfaces in the previous period were used. However, sediments on the slopes flowed down, reducing the area of the flatland, and architectural techniques that could utilize the natural topography of the changed slope were applied to interpret it as having a different topography from the previous period. In order to model and interpret the paleotopography, excavation data, geological and topographic analysis, and digital data must be secured. It is expected that location conditions and ancient human life can be identified if the analysis technique in the study is applied to other archaeological sites in the future.

Reconstruction of 3D Topography from Contour Line Data using Artificial Neural Networks (신경회로망을 이용한 등고선 데이터로부터 3차원 지형 복원)

  • Su-Sun Kim
    • Journal of the Korea Computer Industry Society
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    • v.2 no.3
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    • pp.297-308
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    • 2001
  • We propose an algorithm which can reconstruct the 3D information from geographical information. The conventional techniques, the triangular patches and the Random Fractal Midpoint Displacement (RFMD) method, etc., have often been used to reconstruct natural images. While the RFMD method using Gaussian distribution obtains good results for the symmetric images, it is not reliable on asymmetric images immanent in the nature. Our proposed algorithm employs neural networks for the RFMD method to present the asymmetrical images. By using a neural network for reconstructing the 3D images, we can utilize statistical characteristics of irregular data. We show that our algorithm has a better performance than others by the point of view on the similarity evaluation. And, it seems that our method is more efficient for the mountainous topography which is more rough and irregular.

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Site-Suitability Analysis Using Spatial Information Analysis (공간정보 분석기법을 이용한 적지분석)

  • Han, Seung-Hee;Kim, Sung-Gil
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.12
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    • pp.5207-5215
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    • 2010
  • Selecting proper location for complex facility with special purpose need comprehensive consideration on the condition and surrounding environment. Especially, in case of living space for human, lighting, ventilation, efficiency in land use, etc. are important elements. Diverse 3D analysis through 3D topography modeling and virtual simulation is necessary for this. Now, it can be processed with relatively inexpensive cost since high resolution satellite image essential in topography modeling is provided with domestic technology through Arirang No. 2 satellite (KOMPSAT2). In this study, several candidate sites is selected for complex planning with special purpose and analysis on proper location was performed using the 3D topography modeling and land information. For this, land analysis, land price calculation, slope analysis and aspect analysis have been carried out. As a result of arranging the evaluation index for each candidate site and attempting the quantitative evaluation, proper location could be selected efficiently and reasonably.

The Accuracy Estimation of Profile Generation for Planning using 3D Topographical Model (3차원 지형모델을 이용한 설계용 프로파일 생성 정확도 평가)

  • Um, dae-yong;Lee, eun-soo;Kim, ji-hye
    • Proceedings of the Korea Contents Association Conference
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    • 2008.05a
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    • pp.892-896
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    • 2008
  • In construction work's process of a basic planning, we must carry out a topographical for construction reserved land and to the basis of this, production of profile is Indispensable factor for the purpose of every construction work such as road, rail way, canal and etc. From this research, the production of profile about construction reserved land, using topography information of numerical value topographical map produced by NGIS construction project, construct precision 3D topography model and from this, propose plans for utilizing by producing automatic profile. With the aim of this, abstract every layers of main facilities and altitude from numerical value topographical map and while producing 3D topography model by using this, we produce and product automatic profile from construct precision 3D topography. And about the produced profile's process, a topographical by mutual analysis was carried out to check whether the automatic produced profile's accuracy could be accepted at actual estimation and permissible accuracy. It is considered that the result of the research could be suggested as a new formation techniques concept which can reduce the designing time and expenses and increase the efficiency of planning in the basic design process for the construction.

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Real-Time Shooting Area Analysis Algorithm of UAV Considering Three-Dimensional Topography (입체적 지형을 고려한 무인항공기의 실시간 촬영 영역 분석 알고리즘)

  • Park, Woo-Min;Choi, Jeong-Hun;Choi, Seong-Geun;Hwang, Nam-Du;Kim, Hwan-Chul
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38C no.12
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    • pp.1196-1206
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    • 2013
  • In this paper, based on the information about navigation system of UAV with PTZ camera and 3D topography, algorithm able to show us in real-time UAV's geographical shooting location and automatically calculate superficial measure of the shooting area is proposed. And the method that can automatically estimate whether UAV is allowed to shoot a specific area is shown. In case of an UAV's shooting attempt at the specific area, obtainability of valid image depends on not only UAV's location but also information of 3D topography. As a result of the study, Ground Control Center will have real-time information about whether UAV can shoot the needed topography. Therefore, accurate remote flight control will be possible in real-time. Furthermore, the algorithm and the method of estimating shooting probability can be applied to pre-flight simulation and set of flight route.

Comparison of the Corneal Topography Changes as a Result of Near Task between Myopes and Emmetropes (근시와 정시 사이에서 근거리 작업의 결과로서 각막 지도 변화와 비교)

  • Chen, A.H.;Othman, R.;Kim, D.H.
    • Journal of Korean Ophthalmic Optics Society
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    • v.8 no.1
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    • pp.11-15
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    • 2003
  • Purpose : The purpose of this study is to investigate the corneal topography changes as a result of near task in myopes and emmetropes. Methods : Thirty university students, aged from 18 to 24 years old, were randomly selected. They were divided into two refractive groups of fifteen each : myopia and emmetropia. The corneal topography of each subject was measured with the Eye-Sys Videokeratography system. Measurements were taken : before and after 30 minutes of near task (copy N10 text at 20 cm working distance). Both simulated keratometry and semi-meridian keratometric map program were used in the data analysis. Results : Our results reveal no significant changes in both simulated keratometry and semi-meridian presentation as a result of near task for both myopes and emmetropes, except a significant change (p<0.05) found at the flattest meridian of the central (3 mm) portion of the corneal topography after near task for emmetropes only. Conclusions : We conclude that the corneal topography, does not change significantly as a result of near task in both myopes and emmetropes.

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