• Title/Summary/Keyword: geometric properties

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Automatic Extraction of 3-Dimensional Road Information Using Road Pavement Markings (도로 노면표지를 이용한 3차원 도로정보 자동추출)

  • Kim, Jin-Gon;Han, Dong-Yeub;Yu, Ki-Yun;Kim, Yong-Il
    • Journal of Korean Society for Geospatial Information Science
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    • v.12 no.4 s.31
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    • pp.61-68
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    • 2004
  • In this paper, we suggest an automatic technique to obtain 3-D road information in complex urban areas using road pavement markings. This method is composed of following three main steps. The first step is extracting the pavement markings from aerial images, the second one is matching the same pavement markings in two aerial images, and the last one is obtaining the 3-D coordinates of those using EOP(exterior orientation parameters) of aerial images. Here, we focus on the first and second step because the last step can be performed by using the well hewn collinearity condition equation. We used geometric properties and spatial relationships of the pavement markings to extract the lane line markings on the images and extracted arrow lane markings additionally using template matching. And then, we obtained 3-D coordinates of the road using relational matching for the pavement markings. In order to evaluate the accuracy of extraction, we did a visual inspection and compared the result of this technique with those measured by digital photogrammetric system.

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Synthetic Seismograms of Non-geometric S* and P* Waves Using the Reflectivity Method (반사도 기법에 의한 비기하적 S* 및 P* 파의 합성 계산)

  • Hong, Dong Hee;Baag, Chang Eob
    • Economic and Environmental Geology
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    • v.23 no.4
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    • pp.393-409
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    • 1990
  • Synthetic seismograms and deduced characteristic properties of the non-geometrical $S^*$ and $P^*$ waves are presented. These waves are excited on the free surface or an interface between two different media by an inhomogeneous P wave from a point source nearby, and propagate as homogeneous waves in the media. Synthetic seismograms are computed using an extended reflectivity method designed for buried source and receiver. An efficient computational procedure for propagator matrices of layers is devised to reduce the computational time and the RAM memory size in the implementation of the reflectivity method. Radiation patterns are obtained from the particle motions of the four types of the "*" waves, i.e., the $S^*$ wave generated near the free surface, and the reflected $S^*$, transmitted $S^*$ and transmitted $P^*$ waves generated near an interface. Some patterns show polarity changes of displacements and others reveal monotonic or non-monotonic variation of amplitude depending on the velocity structure. The decaying trend of amplitude with increasing epicentral distance are also shown for the head wave type of the "*" waves.

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Real-Time Recognition Method of Counting Fingers for Natural User Interface

  • Lee, Doyeob;Shin, Dongkyoo;Shin, Dongil
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.5
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    • pp.2363-2374
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    • 2016
  • Communication occurs through verbal elements, which usually involve language, as well as non-verbal elements such as facial expressions, eye contact, and gestures. In particular, among these non-verbal elements, gestures are symbolic representations of physical, vocal, and emotional behaviors. This means that gestures can be signals toward a target or expressions of internal psychological processes, rather than simply movements of the body or hands. Moreover, gestures with such properties have been the focus of much research for a new interface in the NUI/NUX field. In this paper, we propose a method for recognizing the number of fingers and detecting the hand region based on the depth information and geometric features of the hand for application to an NUI/NUX. The hand region is detected by using depth information provided by the Kinect system, and the number of fingers is identified by comparing the distance between the contour and the center of the hand region. The contour is detected using the Suzuki85 algorithm, and the number of fingers is calculated by detecting the finger tips in a location at the maximum distance to compare the distances between three consecutive dots in the contour and the center point of the hand. The average recognition rate for the number of fingers is 98.6%, and the execution time is 0.065 ms for the algorithm used in the proposed method. Although this method is fast and its complexity is low, it shows a higher recognition rate and faster recognition speed than other methods. As an application example of the proposed method, this paper explains a Secret Door that recognizes a password by recognizing the number of fingers held up by a user.

Multiscale Simulation for Adsorption Process Development: A Case Study of n-Hexane Adsorption on Activated Carbon (흡착공정 개발을 위한 다중규모 모사: 활성탄에서의 n-Hexane 흡착에 관한 사례연구)

  • Son, Hae-Jeong;Lim, Young-Il;Yoo, Kyoung-Seun
    • Korean Chemical Engineering Research
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    • v.46 no.6
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    • pp.1087-1094
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    • 2008
  • This article presents a multi-scale simulation approach starting from the molecular level for the adsorption process development, specifically, in n-hexane adsorption on activated carbon. A grand canonical Monte-Carlo(GCMC) method is used for the prediction of adsorption isotherms of n-hexane on activated carbon at the molecular level. Geometric effects and hydrodynamic properties of the adsorption column are examined by means of the two dimensional CFD(computational fluid dynamics) simulation. The adsorption isotherms from the molecular simulation and the axial diffusivity from the CFD simulation are exploited for the process simulation where the elution curve of n-hexane is obtained. For the first moment(mean residence time) of the pulse-response with respect to temperature and flowrate, the process simulation results obtained from this three-steps multiscale simulation approach show a good agreement with experimental data within 20% of maximum difference. The multi-scale simulation approach addressed in this study will be useful to accelerate the adsorption process development, while reducing the number of experiments required.

Analysis of a damaged industrial hall subjected to the effects of fire

  • Kmet, Stanislav;Tomko, Michal;Demjan, Ivo;Pesek, Ladislav;Priganc, Sergej
    • Structural Engineering and Mechanics
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    • v.58 no.5
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    • pp.757-781
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    • 2016
  • The results of diagnostics and analysis of an industrial hall located on the premises of a thermal power plant severely damaged by fire are presented in the paper. The comprehensive failure-related diagnostics, non-destructive and destructive tests of steel and concrete materials, geodetic surveying of selected structural members, numerical modelling, static analysis and reliability assessment were focused on two basic goals: The determination of the current technical condition of the load bearing structure and the assessment of its post fire resistance as well as assessing the degree of damage and subsequent design of reconstruction measures and arrangements which would enable the safe and reliable use of the building. The current mechanical properties of the steel material obtained from the tests and measured geometric characteristics of the structural members with imperfections were employed in finite element models to study the post-fire behaviour of the structure. In order to compare the behaviour of the numerically modelled steel roof truss, subjected to the effects of fire, with the real post-fire response of the damaged structure theoretically obtained resistance, critical temperature and the time at which the structure no longer meets the required reliability criteria under its given loading are compared with real values. A very good agreement between the simulated results and real characteristics of the structure after the fire was observed.

Two-Dimensional Arrays of Gold Nanoparticles for Plasmonic Nanosensor

  • Sim, Brandon;Monjaraz, Fernando;Lee, Yong-Joong;Park, So-Yeun
    • Korean Journal of Materials Research
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    • v.21 no.10
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    • pp.525-531
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    • 2011
  • Two dimensional (2D) arrays of noble metal nanoparticles are widely used in the sensing of nanoscale biological and chemical events. Research in this area has sparked considerable interest in many fields owing to the novel optical properties, e.g., the localized surface plasmon resonance, of these metallic nanoarrays. In this paper, we report successes in fabricating 2D arrays of gold nano-islands using nanosphere lithography. The reproducibility and the effectiveness of the nano-patterning method are tested by means of spin coating and capillary force deposition. We found that the capillary force deposition method was more effective for nanospheres with diameters greater than 600 nm, whereas the spin coating method works better for nanospheres with diameters less than 600 nm. The optimal deposition parameters for both methods were reported, showing about 80% reproducibility. In addition, we characterize gold nano-island arrays both geometrically with AFM as well as optically with UV-VIS spectrometry. The AFM images revealed that the obtained nano-arrays formed a hexagonal pattern of truncated tetrahedron nano-islands. The experimental and theoretical values of the geometric parameters were compared. The 2D gold nano-arrays showed strong LSPR in the absorption spectra. As the nano-islands increased in size, the LSPR absorption bands became red-shifted. Linear dependence of the plasmon absorption maximum on the size of the gold nano-islands was identified through the increment in the plasmon absorption maximum rate for a one nanometer increase in the characteristic length of the nano-islands. We found that the 2D gold nano-arrays showed nearly seven-fold higher sensitivity of the absorption spectrum to the size of the nano-islands as compared to colloidal gold nano-particles.

IRRADIATION PERFORMANCE OF U-Mo MONOLITHIC FUEL

  • Meyer, M.K.;Gan, J.;Jue, J.F.;Keiser, D.D.;Perez, E.;Robinson, A.;Wachs, D.M.;Woolstenhulme, N.;Hofman, G.L.;Kim, Y.S.
    • Nuclear Engineering and Technology
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    • v.46 no.2
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    • pp.169-182
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    • 2014
  • High-performance research reactors require fuel that operates at high specific power to high fission density, but at relatively low temperatures. Research reactor fuels are designed for efficient heat rejection, and are composed of assemblies of thin-plates clad in aluminum alloy. The development of low-enriched fuels to replace high-enriched fuels for these reactors requires a substantially increased uranium density in the fuel to offset the decrease in enrichment. Very few fuel phases have been identified that have the required combination of very-high uranium density and stable fuel behavior at high burnup. U-Mo alloys represent the best known tradeoff in these properties. Testing of aluminum matrix U-Mo aluminum matrix dispersion fuel revealed a pattern of breakaway swelling behavior at intermediate burnup, related to the formation of a molybdenum stabilized high aluminum intermetallic phase that forms during irradiation. In the case of monolithic fuel, this issue was addressed by eliminating, as much as possible, the interfacial area between U-Mo and aluminum. Based on scoping irradiation test data, a fuel plate system composed of solid U-10Mo fuel meat, a zirconium diffusion barrier, and Al6061 cladding was selected for development. Developmental testing of this fuel system indicates that it meets core criteria for fuel qualification, including stable and predictable swelling behavior, mechanical integrity to high burnup, and geometric stability. In addition, the fuel exhibits robust behavior during power-cooling mismatch events under irradiation at high power.

Fundamental Matrix Estimation and Key Frame Selection for Full 3D Reconstruction Under Circular Motion (회전 영상에서 기본 행렬 추정 및 키 프레임 선택을 이용한 전방향 3차원 영상 재구성)

  • Kim, Sang-Hoon;Seo, Yung-Ho;Kim, Tae-Eun;Choi, Jong-Soo
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.46 no.2
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    • pp.10-23
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    • 2009
  • The fundamental matrix and key frame selection are one of the most important techniques to recover full 3D reconstruction of objects from turntable sequences. This paper proposes a new algorithm that estimates a robust fundamental matrix for camera calibration from uncalibrated images taken under turn-table motion. Single axis turntable motion can be described in terms of its fixed entities. This provides new algorithms for computing the fundamental matrix. From the projective properties of the conics and fundamental matrix the Euclidean 3D coordinates of a point are obtained from geometric locus of the image points trajectories. Experimental results on real and virtual image sequences demonstrate good object reconstructions.

A Study on Receiving Beam Pointing Error and MTI(Moving Target Indication) Performance in a Bistatic Radar Using Pulse Chasing (펄스 체이싱을 이용한 바이스태틱 레이더에서 수신 빔 조향 오차와 MTI(Moving Target Indication) 성능에 대한 연구)

  • Yang, Jin-Mo;Lee, Min-Joon;Kim, Whan-Woo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.21 no.12
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    • pp.1412-1422
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    • 2010
  • A bistatic radar using the pulse chasing can detect a target to track successive transmitted pulses using a receive beam for effectively scanning the cosite search area. When tracking a transmitted pulse with the receive beam, some beam pointing errors within pulse-to-pulse can cause the timing error in received pulse and the variation of the signal strength. In this paper, we have proposed that some errors due to the receive beam pointing error could limit the MTI filter's performance and derived that the relationship between the MTI performance and the geometric factors which are the inherent properties in bistatic configuration. Through the simulation, we have considered the limitations of the improvement performance restricted by the receiving beam pointing error and confirmed the contribution to the performance improvement in maintaining the receiving beam pointing error of under 0.5 degrees.

Brazilian Test of Concrete Specimens Subjected to Different Loading Geometries: Review and New Insights

  • Garcia, Victor J.;Marquez, Carmen O.;Zuniga-Suarez, Alonso R.;Zuniga-Torres, Berenice C.;Villalta-Granda, Luis J.
    • International Journal of Concrete Structures and Materials
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    • v.11 no.2
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    • pp.343-363
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    • 2017
  • The objective of this work was finding out the most advisable testing conditions for an effective and robust characterization of the tensile strength (TS) of concrete disks. The independent variables were the loading geometry, the angle subtended by the contact area, disk diameter and thickness, maximum aggregate size, and the sample compression strength (CS). The effect of the independent variables was studied in a three groups of experiments using a factorial design with two levels and four factors. The likeliest location where failure beginning was calculated using the equations that account for the stress-strain field developed within the disk. The theoretical outcome shows that for failure beginning at the geometric center of the sample, it is necessary for the contact angle in the loading setup to be larger than or equal to a threshold value. Nevertheless, the measured indirect tensile strength must be adjusted to get a close estimate of the uniaxial TS of the material. The correction depends on the loading geometry, and we got their mathematical expression and cross-validated them with the reported in the literature. The experimental results show that a loading geometry with a curved contact area, uniform load distribution over the contact area, loads projected parallel to one another within the disk, and a contact angle bigger of $12^{\circ}$ is the most advisable and robust setup for implementation of BT on concrete disks. This work provides a description of the BT carries on concrete disks and put forward a characterization technique to study costly samples of cement based material that have been enabled to display new and improved properties with nanomaterials.