• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.19 no.4
• /
• pp.355-362
• /
• 2009

Sound source localization method based on the time delay of arrival(TDOA) is applied to many research fields such as a robot auditory system, teleconferencing and so on. When multi-microphones are utilized to localize the source in 3 dimensional space, the conventional localization methods based on TDOA decide the actual source position using the TDOAs from all microphone arrays and the detection measure, which represents the errors between the actual source position and the estimated ones. Performance of these methods usually depends on the number of microphones because it determines the resolution of an estimated position. In this paper, we proposed the localization method using spatially mapped GCC functions. The proposed method does not use just TDOA for localization such as previous ones but it uses spatially mapped GCC functions which is the cross correlation function mapped by an appropriate mapping function over the spatial coordinate. A number of the spatially mapped GCC functions are summed to a single function over the global coordinate and then the actual source position is determined based on the summed GCC function. Performance of the proposed method for the noise effect and estimation resolution is verified with the real environmental experiment. The mean value of estimation error of the proposed method is much smaller than the one based on the conventional ones and the percentage of correct estimation is improved by 30% when the error bound is ${\pm}20^{\circ}$.

• The Journal of the Acoustical Society of Korea
• /
• v.23 no.8
• /
• pp.562-569
• /
• 2004

An experiment for observation of the distribution of the seagrass (zostera marina) beds and characteristics of high-frequency backscattering by the photosynthesis was conducted off the coast. Acoustic data were taken as a function of the grazing angles and the relative azimuth angles on the seagrass beds of which bottom type was sandy-mud. The transmitted source signal was a 120 kHz CW waveform. Mapping of the seagrass beds distribution was drawn up using the seagrass backscattering strength with azimuth and grazing angles. The result of the comparison backscattering strength distribution of the seagrass beds was shown to be the similar to the photograph of real seagrass beds. The seagrass backscattering strength was also compared between day and night to verify the effects of the acoustical scattering by the bubbles of Photosynthetic oxygen formed on the seagrass. In these results. it is clear that observation of the seagrass beds between day and night showed the different characteristics because the bubbles of Photosynthetic oxygen affect the acoustical scattering.

• Journal of the Korean Institute of Telematics and Electronics C
• /
• v.35C no.11
• /
• pp.76-88
• /
• 1998

While most of the research on reinforcement learning assumed a discrete control space, many of the real world control problems need to have continuous output. This can be achieved by using continuous mapping functions for the value and action functions of the reinforcement learning architecture. Two questions arise here however. One is what sort of function representation to use and the other is how to determine the amount of noise for search in action space. The ubiquitous neural network is used here to learn the value and policy functions. Next, the reinforcement predictor that is intended to predict the next reinforcement is introduced that also determines the amount of noise to add to the controller output. The proposed reinforcement learning architecture is found to have a sound on-line learning control performance especially at high-speed road following of high curvature road. Both computer simulation and actual experiments on a test vehicle have been performed and their efficiency and effectiveness has been verified.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.11 no.4
• /
• pp.319-324
• /
• 2018

In this paper, we designed and implemented a code conversion method between ISO/IEC 10646 and the multi-byte code set. The Universal Multiple-Octet Coded Character Set(UCS) provides codes for more than 65,000 characters, huge increase over ASCII's code capacity of 128 characters. It is applicable to the representation, transmission, interchange, processing, storage, input and presentation of the written form of the language throughout the world. Therefore, it is so important to guide on code conversion methods to their customers during customer systems are migrated to the environment which the UCS code system is used and/or the current code systems, i.e., ASCII PC code and EBCDIC host code, are used with the UCS together. Code conversion utility including the mapping table between the UCS and IBM new host code is shown for the purpose of the explanation of code conversion algorithm and its implementation in the system. The programs are successfully executed in the real system environments and so can be delivered to the customer during its migration stage from the UCS to the current IBM code system and vice versa.

• Journal of Korea Multimedia Society
• /
• v.15 no.8
• /
• pp.977-985
• /
• 2012

The purpose of this study was to present a non-photorealistic rendering technique that is efficient in single images and moving images. In case of single images, they could be processed in a real-time base by realizing flow-based DoG filter and bilateral filter, which have been frequently used in the single image NPR technique recently, in the CUDA environment. In case of moving images, the investigator presented not the existing method of NPR moving images which generating images by applying the single image NPR technique to every frame, but the method of using the single image NPR technique in the first frame and stylizing it, and then of using the motion vector-based pixel mapping in the second frame on and copying the bright values of pixels that move on the frame into the location of next frame's motion vector, thus reducing unnecessary volume of calculation and maintaining the consistency between frames. In this study, the performance of this method was proved via an experiment.

• Journal of Korean Society for Geospatial Information Science
• /
• v.13 no.1 s.31
• /
• pp.55-61
• /
• 2005

Digital Elevation Model (DEM) generation from remotely sensed imagery is crucial for a variety of mapping applications such as ortho-photo generation, city modeling. High resolution imaging satellites such as SPOT-5, IKONOS, QUICK-BIRD, ORBVIEW constitute an excellent source for efficient and economic generation of DEM data. However, prerequisite knowledge in the areas of sensor modeling, epipolar resampling, and image matching is required to generate DEM from these high resolution satellite imagery. From the above requirements, epipolar resampling emerges as the most important factors. Research attempts in this area are still in high demand and short supply. Another cause that adds to the complication of the problem is that most studies of DEM generation from IKONOS scenes have been based on rational function model. In this paper, we proposed a new methodology for DEM generation from satellite scenes using parallel projection model which is sensor independent, makes it possible for sensor modeling and epipolar resampling by only few control points. The performance and feasibility of the developed methodology is evaluated through real dataset captured by IKONOS.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.05a
• /
• pp.53-54
• /
• 2006

The main purpose of tunnel ventilation system is to maintain CO pollutant and VI (visibility index) under an adequate level to provide drivers with safe driving condition. Moreover, it is necessary to minimize power consumption used to operate ventilation system. To achieve the objectives, the control algorithm used in this research is reinforcement teaming (RL) method. RL is a goal-directed teaming of a mapping from situations to actions. The goal of RL is to maximize a reward which is an evaluative feedback from the environment. Constructing the reward of the tunnel ventilation system, two objectives listed above are included. RL algorithm based on actor-critic architecture and natural gradient method is adopted to the system. Also, the recursive least-squares (RLS) is employed to the learning process to improve the efficiency of the use of data. The simulation results performed with real data collected from existing tunnel are provided in this paper. It is confirmed that with the suggested controller, the pollutant level inside the tunnel was well maintained under allowable limit and the performance of energy consumption was improved compared to conventional control scheme.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.25 no.6_1
• /
• pp.545-555
• /
• 2007

3D buildings are the most prominent feature comprising urban scene. A few of mega-cities in the globe are virtually reconstructed in photo-realistic 3D models, which becomes accessible by the public through the state-of-the-art online mapping services. A lot of research efforts have been made to develop automatic reconstruction technique of large-scale 3D building models from remotely sensed data. However, existing methods still produce irregular building polygons due to errors induced partly by uncalibrated sensor system, scene complexity and partly inappropriate sensor resolution to observed object scales. Thus, a geometric regularization technique is urgently required to rectify such irregular building polygons that are quickly captured from low sensory data. This paper aims to develop a new method for regularizing noise building outlines extracted from airborne LiDAR data, and to evaluate its performance in comparison with existing methods. These include Douglas-Peucker's polyline simplication, total least-squared adjustment, model hypothesis-verification, and rule-based rectification. Based on Minimum Description Length (MDL) principal, a new objective function, Geometric Minimum Description Length (GMDL), to regularize geometric noises is introduced to enhance the repetition of identical line directionality, regular angle transition and to minimize the number of vertices used. After generating hypothetical regularized models, a global optimum of the geometric regularity is achieved by verifying the entire solution space. A comparative evaluation of the proposed geometric regulator is conducted using both simulated and real building vectors with various levels of noise. The results show that the GMDL outperforms the selected existing algorithms at the most of noise levels.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.32 no.6
• /
• pp.625-635
• /
• 2014

Multiple strips are required for large area mapping using ALS (Airborne Laser Scanner) system. LiDAR (Light Detection And Ranging) data collected from the ALS system has discrepancies between strips due to systematic errors of on-board laser scanner and GPS/INS, inaccurate processing of the system calibration as well as boresight misalignments. Such discrepancies deteriorate the overall geometric quality of the end products such as DEM (Digital Elevation Model), building models, and digital maps. Therefore, strip adjustment for minimizing discrepancies between overlapping strips is one of the most essential tasks to create seamless point cloud data. This study implemented area-based matching (ABM) to determine conjugate features for computing 3D transformation parameters. ABM is a well-known method and easily implemented for this purpose. It is obvious that the exact same LiDAR points do not exist in the overlapping strips. Therefore, the term "conjugate point" means that the location of occurring maximum similarity within the overlapping strips. Coordinates of the conjugate locations were determined with sub-pixel accuracy. The major drawbacks of the ABM are sensitive to scale change and rotation. However, there is almost no scale change and the rotation angles are quite small between adjacent strips to apply AMB. Experimental results from this study using both simulated and real datasets demonstrate validity of the proposed scheme.

• Journal of Korea Spatial Information System Society
• /
• v.3 no.1 s.5
• /
• pp.89-94
• /
• 2001

The purpose of this study is development of the management system for convenient use of new address guide system for systematic management and use of spatial information gained by mapping of numerical map of building and road to large basic new address, survey and input of main gate, decision of the road session, naming and input of road name, grant of numbering of all houses and buildings, new address guide, real life geographical information and added information service on Web-site in Jecheon-city area. In this study, the development and establishment of new address management in local cities are designed by making full use of GIS function of client server based system. In the result, the effectiveness of new address management system of Jecheon- city could be highly increased owing to not only citizens' easy access but also easy availability of various informations necessary in life by developed its system.