• 한국지형공간정보학회:학술대회논문집
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• 2004.10a
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• pp.25-31
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• 2004

To obtain the 3-D coordinates of the urban roads from aerial images, the accurate matching technique in road areas is required. In this paper, we suggest the relational matching method that is performed by comparison of relationships of road pavement markings after they are extracted from aerial images using geometric properties and spatial relationships of the pavement markings. Relational matching requires not only high level description of features but also the solution for inexact matching problems. In addition, it needs a lot of tests for the reliable final result. In this research, we described features as calculating geometric properties of the pavement markings, suggested the solution for inextact matching problems, and performed tests to decide whether the result is acceptable or not, which use the property that road areas are flat. In order to evaluate the accuracy of matching, we made a visual evaluation and compared the result of this technique with those measured by analytical photogrammetry.

• Korean Journal of Applied Biomechanics
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• v.16 no.1
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• pp.139-149
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• 2006

This study is to analyze the kinematic variables of inward $1{\frac{1}{2}}$ somersault in platform diver. For the manner, 3 people form the national diving team in the year 2000were chosen as the subjects and two S-VHS video cameras set in 60frames/sec were used for recording their motions. Coordinated raw positions data through digitizing are smoothing by butter-worth's low-pass filterin method at a cut off frequency 6.0Hz. and the direct linear transformation(DLT) method was employed to obtain 3-D position coordinates. The conclusions were as follows. However, horizontal distance which is the change of the COG, form the point of the jump to the point of Event 3 where the player is out of the board range completely, Subject B showed 105.1cm and 71.1cm of the vertical distance which are shorter horizontal distance and higher vertical distance, thus, took a great advantage of the position to prepare for the entry. Therefore, if a player takes higher position by speeding up the vertical velocity at the moment of the jumping off the board, and stays in the air longer, the player can have more time to show his skill. Because of the use of the characteristics of the inward somersault, keeping the safe distance form the board is important but in order to higher the completeness, it is ideal to keep the horizontal distance little over 100cm. Also, the angles of shoulder and elbow from Event 1 to 4, depending on swing of the arms, motions in the air, getting ready for the entry, showed some difference individual by individual, according to the velocity of the thigh and shank showed much difference while getting ready and take-off, and it's because of the individual's different bending and straightening for horizontal and vertical distance.

• The Transactions of the Korean Institute of Power Electronics
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• v.3 no.1
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• pp.15-22
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• 1998

The goal of this paper is to propose analyzing and evaluating method of power parameters for motor drive system with various experimental graphic screens and numerical results and to develop the proposed system. A developed system is made up 586-PC and DSP board, motor drive system, power parameters analyzing and evaluating software for windows. Power parameters are analyzed using correlation signal processing techniques based on the correlation between voltage and current waveforms. Analysis results are visualized by 3-D current coordinates, and it is compared and evaluated with conventional time/ frequency domain. To verify the validity of the proposed system, capacitor run type single phase induction motor and thyristor speed controller is used for analyzing. Power and harmonic parameters of motor drive system is analyzed and verified, with varying fire angle of thyristor speed controller, and the proposed approach is to confirm validity.

• Journal of Information Display
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• v.4 no.2
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• pp.13-18
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• 2003

We synthesized bis (2-methyl-8-quinolinolato)(triphenylsiloxy) aluminum (III) (SAlq), a blue-emitting material having a high luminous efficiency, through a homogeneous-phase reaction. The photoluminescence (PL) and electroluminescence (EL) spectra of SAlq show two peaks at 454 nm and 477 nm. Efficient white light-emitting devices are fabricated by doping SAlq with a red fluorescent dye of 4-dicyanomethylene-2-methyl-6-{2-(2,3,6,7-tetrahydro-1H,5H-benzo[i,j]quinolizin-8yl) vinyl}-4H-pyran (DCM2). The incomplete energy transfer from blue-emitting SAlq to red-emitting DCM2 results in light-emission of both blue and orange colors. Devices with the structure of ITO/TPD (50 nm)/SAlq:DCM2 (30 nm, 0.5 %)/$Alq_3$ (20 nm)/LiF (0.5 nmj/Al show EL peaks at 456 nm and 482 nm originating from SAlq and at 570 nm from DCM2, resulting in the Commission Internationale d'Eclairage (CIE) chromaticity coordinates of (0.32, 0.37). The device exhibits an external quantum efficiency of about 2.3 % and a luminous efficiency of about 2.41m/W at 100 $cd/m^2$. A maximum luminance of about 23,800 $cd/m^2$ is obtained at the bias voltage of 15 V.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.42
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• pp.27.1-27.9
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• 2020

Background: Mandibular setback surgery can change the position of the mandible which improves occlusion and facial profile. Surgical movement of the mandible affects the base of the tongue, hyoid bone, and associated tissues, resulting in changes in the pharyngeal airway space. The aim of this study was to analyze the 3-dimensional (3D) changes in the hyoid bone and tongue positions and oropharyngeal airway space after mandibular setback surgery. Methods: A total of 30 pairs of cone-beam computed tomography (CBCT) images taken before and 1 month after surgery were analyzed by measuring changes in the hyoid bone and tongue positions and oropharyngeal airway space. The CBCT images were reoriented using InVivo 5.3 software (Anatomage, San Jose, USA) and landmarks were assigned to establish coordinates in a three-dimensional plane. The mean age of the patients was 21.7 years and the mean amount of mandibular setback was 5.94 mm measured from the B-point. Results: The hyoid bone showed significant posterior and inferior displacement (P < 0.001, P < 0.001, respectively). Significant superior and posterior movements of the tongue were observed (P < 0.05, P < 0.05, respectively). Regarding the velopharyngeal and glossopharyngeal spaces, there were significant reductions in the volume and minimal cross-sectional area (P < 0.001). The anteroposterior and transverse widths of the minimal cross-sectional area were decreased (P < 0.001, P < 0.001, respectively). In addition, the amount of mandibular setback positively correlated with the amount of posterior and inferior movement of the hyoid bone (P < 0.05, P < 0.05, respectively). Conclusion: There were significant changes in the hyoid bone, tongue, and airway space after mandibular setback surgery.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.8
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• pp.1-8
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• 2020

Air ducts installed for ventilation inside buildings accumulate contaminants during their service life. Robots are installed to clean the air duct at low cost, but they are still not fully automated and depend on manpower. In this study, an intersection detection algorithm for autonomous driving was applied to an air duct cleaning robot. Autonomous driving of the robot was achieved by calculating the distance and angle between the extracted point and the center point through the intersection detection algorithm from the camera image mounted on the robot. The training data consisted of CAD images of the duct interior as well as the cross-point coordinates and angles between the two boundary lines. The deep learning-based CNN model was applied as a detection algorithm. For training, the cross-point coordinates were obtained from CAD images. The accuracy was determined based on the differences in the actual and predicted areas and distances. A cleaning robot prototype was designed, consisting of a frame, a Raspberry Pi computer, a control unit and a drive unit. The algorithm was validated by video imagery of the robot in operation. The algorithm can be applied to vehicles operating in similar environments.

• Journal of Korean Society for Geospatial Information Science
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• v.1 no.1 s.1
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• pp.141-152
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• 1993

This study aims to generate digital elevation model from digital satellite imagery. Digital elevation model is being increasingly used for geo-spatial information system database development and for digital map production. Image matching technique was applied to acquire conjugate image coordinates and the algorithm for digital elevation model generation is presented in this study The exterior orientation parameters of the satellite imagery is determined by bundle adjustment and standard correlation was applied for image matching conjugate of image points. The window as well as the searching area have to be defined in image matching. Different sizes of searching area were tested to study the appropriate size of the searching area. Various coordinate transformation methods were applied to improve the computation speed as well as the geometric accuracy. The results were then statistically analysed after which the searching area is determined with the safety factor. To evaluate the accuracy of digital elevation model, 3-D coordinates were extracted from 1/5000 scale topographic map and this was compared to the digital elevation model generated from satellite imagery. The algorithm for generation of digital elevation model generated from satellite imagery is presented in this study which will prove effective in the database development of geo-spatial information system and in digital elevation modelling of large areas.

• Journal of Astronomy and Space Sciences
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• v.30 no.4
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• pp.269-277
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• 2013

In this study, we present results of precise orbital geodetic parameter estimation using satellite laser ranging (SLR) observations for the International Laser Ranging Service (ILRS) associate analysis center (AAC). Using normal point observations of LAGEOS-1, LAGEOS-2, ETALON-1, and ETALON-2 in SLR consolidated laser ranging data format, the NASA/GSFC GEODYN II and SOLVE software programs were utilized for precise orbit determination (POD) and finding solutions of a terrestrial reference frame (TRF) and Earth orientation parameters (EOPs). For POD, a weekly-based orbit determination strategy was employed to process SLR observations taken from 20 weeks in 2013. For solutions of TRF and EOPs, loosely constrained scheme was used to integrate POD results of four geodetic SLR satellites. The coordinates of 11 ILRS core sites were determined and daily polar motion and polar motion rates were estimated. The root mean square (RMS) value of post-fit residuals was used for orbit quality assessment, and both the stability of TRF and the precision of EOPs by external comparison were analyzed for verification of our solutions. Results of post-fit residuals show that the RMS of the orbits of LAGEOS-1 and LAGEOS-2 are 1.20 and 1.12 cm, and those of ETALON-1 and ETALON-2 are 1.02 and 1.11 cm, respectively. The stability analysis of TRF shows that the mean value of 3D stability of the coordinates of 11 ILRS core sites is 7.0 mm. An external comparison, with respect to International Earth rotation and Reference systems Service (IERS) 08 C04 results, shows that standard deviations of polar motion $X_P$ and $Y_P$ are 0.754 milliarcseconds (mas) and 0.576 mas, respectively. Our results of precise orbital and geodetic parameter estimation are reasonable and help advance research at ILRS AAC.

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.6
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• pp.623-634
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• 2003

In this paper, we propose a collaborative multimedia authoring system. Our authoring system represents a multimedia presentation in a 3D coordinate system. One axis represents the traditional timeline information (T-zone), and the other two axes represent spatial coordinates (XY-zone). Our system represents a visual media objects as a 3D parallelepipeds and audio media objects as cylinders. This interface allows for simultaneous authoring and manipulation of both the temporal and the spatial aspects of a presentation. Using our system, users can design multimedia presentations collaboratively in the unified spatio-temporal space while freely traversing the spatial domain and the temporal domain without changing the context of authoring. In addition, we suggest an efficient mechanism of concurrency control for shared objects generated by our collaborative writing system. The mechanism is mainly based on the user awareness, the multiple versions, and the access permission of shared objects. Our concurrency control mechanism is designed to keep data consistency by minimizing the collision due to the delay or the failure of network communication and to allow maximum responsiveness for users using optimistic concurrency control. Also, the mechanism maximize the responsiveness by refining the locking granularity and applying different concurrency control mechanisms to each.

• Korean Journal of Materials Research
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• v.10 no.4
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• pp.290-294
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• 2000

ZnS:Mn TFEL devices were fabricated by electron-beam evaporation method and then the electro-optical properties were investigated. To investigate the capacitance which was due to oxygen vacancy at the $Ta_2O_5$ thin film, AES(Auger Electron Spectroscopy) and C-F(capacitance-frequency) measurements were used. It was found that the capacitance was decreased by annealing the $Ta_2O_5$ film in oxygen ambience. From EL emission measurement, we observed the EL emission spectrum which had the peak range from 550nm and 650nm. This emission is associated with the transition from $^4T_1(^4G)$ first excited state to $^6A_1(^6S)$ ground state in the $3d^5$ energy level configuration of $Mn^{2+}$ occurs. The threshold voltage of EL device with $Ta_2O_5$ insulator layer was found to be 24V~28V. The CIE color coordinates of these emission are X=0.5151, Y=0.4202 which is yellowish orange emitting. The EL device using $Ta_2O_5$ insulator layer can be driven with a low voltage which is beneficial to the practical application.