• Proceedings of the KSME Conference
• /
• 2003.04a
• /
• pp.822-827
• /
• 2003

Topological maps have drawn more attention recently because they are compact, provide natural interfaces, and are applicable to path planning easily. To build a topological map incrementally, Voronoi diagram was used by many researchers. The Voronoi diagram, however, has difficulty in applying to arbitrarily shaped objects and needs long computation time. In this paper, we present a new method for global topological map from the local topological maps incrementally. The local topological maps are created through a thinning algorithm from a local grid map, which is built based on the sensor information at the current robot position. A thinning method requires simpler computation than the Voronoi diagram. Localization based on the topological map is usually difficult, but additional nodes created by the thinning method can improve localization performance. A series of experiments have been conducted using a two-wheeled mobile robot equipped with a laser scanner. It is shown that the proposed scheme can create satisfactory topological maps.

• Nuclear Engineering and Technology
• /
• v.40 no.7
• /
• pp.607-614
• /
• 2008

Since pipes with wall-thinning defects can collapse at fluid pressure that are lower than expected, the collapse moment of wall-thinned pipes should be determined accurately for the safety of nuclear power plants. Wall-thinning defects, which are mostly found in pipe bends and elbows, are mainly caused by flow-accelerated corrosion. This lowers the failure pressure, load-carrying capacity, deformation ability, and fatigue resistance of pipe bends and elbows. This paper offers a support vector regression (SVR) model further enhanced with a fuzzy algorithm for calculation of the collapse moment and for evaluating the integrity of wall-thinned piping systems. The fuzzy support vector regression (FSVR) model is applied to numerical data obtained from finite element analyses of piping systems with wall-thinning defects. In this paper, three FSVR models are developed, respectively, for three data sets divided into extrados, intrados, and crown defects corresponding to three different defect locations. It is known that FSVR models are sufficiently accurate for an integrity evaluation of piping systems from laser or ultrasonic measurements of wall-thinning defects.

• The KIPS Transactions:PartB
• /
• v.8B no.6
• /
• pp.651-656
• /
• 2001

In this paper, we propose Improved Self-Organized Graph(Improved SOG：$SOG^*$)thinning method, which maintains the excellent thinning results of Self-organized graph(SOG) built from Self-Organizing features map and improves the performance of modified SOG using a new incremental learning method of Kohonen features map. In the experiments, this method shows the thinning results equal to those of SOG and the time complexity O((logM)3) superior to it. Therefore, the proposed method is useful for the feature extraction from digits and characters in the preprocessing step.

• Proceedings of the IEEK Conference
• /
• 1998.06a
• /
• pp.745-748
• /
• 1998

Recently, image and voice processing part is using wavelet transform. We propose thining algorithm using wavelet tranform. Wavelet transform consists of low frequency and high frequency in the spatial and frequency domain. After the wavelet decomposition, more than 90 percents of energy are contained in lowest frequency band. Therefor, for images with large difference of gray value between foreground and background like character images, we can more accurately in the lowest frequency band. Lowest frequency band has wavelet transform significant coefficient(WTS) that is required for the thinning algorithm we proposed Paper [3][5][7][8] can not separate consonants and vowels of korean characters. Becuase korean characters have structural feature. This paper can separate consonants and vowels. Simulation executed low frequency image and data compression can reduce 1/4$^{n}$ with level n. we can redcue time complexity 3/8.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.05a
• /
• pp.493-496
• /
• 2010

This paper proposes an effective hardware scheme for thinning stage processing of a fingerprint identification algorithm based on minutiae with 40% cycle occupation of 32-bit RISC microprocessor. The thinning step is needed to be processed by hardware block, because it is performed repeatedly by processing the same operation using an image window masking method. It can reduce the burden of the system and improve speed. The hardware is implemented by HDL and simulated. The result is compared with a conventional one.

• Proceedings of the IEEK Conference
• /
• 1999.11a
• /
• pp.1101-1104
• /
• 1999

This paper performed a comparative study on contour tracing based thinning algorithms. These algorithms are widely used for extracting skeleton due to its superiority to other techniques in processing speed to perform comparison. We selected general eight images consisted of fingerprints, characters, and figures. According to experimental results, we compared each algorithm in performance and ability made skeleton.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2009.10a
• /
• pp.941-944
• /
• 2009

In this paper, we present a improved algorithm for thinning vein pattern. The vein image scanned using near infra-red is sliced in the horizontality or verticality direction, and then average value is gained from each slice image. Using curvature value changed from average value, search candidate part and extract vein pattern through re-searched candidate part in overlapping area. For the extracted vein pattern connecting, we proposed a DAL method that verify distance, angle and luminosity on pattern before tracking pattern extracted. The proposed improved thinning method is helpful for accurate connecting of vein pattern more than method used distance material in candidate part.

• The KIPS Transactions:PartB
• /
• v.11B no.1
• /
• pp.7-12
• /
• 2004

This thesis studies about thinning compensation and the removal of pseudo minutiae using ridge trace. As for the process of thinning compensation, first, it removes unnecessary pixel when 8-neighbor connection sum among the pixels with the crossing count number 6 is not 3. Second, it deals with repeatedly until there is no pixel to remove while tracing the ridge, beginning with the pixel equivalent to the ridge and the pixel with the crossing count number 2 among the 8 pixels around the pixels with the crossing count number 6. When the thinning compensation is finished, it extracts substitute minutiae to use the crossing count number and the 8-neighbor connection sum. Among the extracted substitute minutiaes, it extracts the real minutiae to utilize the pseudo minutiae removal algorithm again. It compares with the existing method for the performance evaluation of proposal method. By the experimental results, The proposal method indicated that a degree of thinning is excellent and a lot of minutiaes were removed.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.14 no.5
• /
• pp.15-21
• /
• 1977

The syntactic pattern recognition system of Korean characters is composed of three main functional parts; Preprocessing, Graph-representation, and Segmentation. In preprocessing routine, the input pattern has been thinned using the Hilditch's thinning algorithm. The graph-representation is the detection of a number of nodes over the input pattern and codification of branches between nodes by 8 directional components. Next, segmentation routine which has been implemented by top down nondeterministic parsing under the control of tree grammar identifies parts of the graph-represented Pattern as basic components of Korean characters. The authors have made sure that this system is effective for recognizing Korean characters through the recognition simulations by digital computer.

• The Transactions of the Korea Information Processing Society
• /
• v.4 no.6
• /
• pp.1652-1663
• /
• 1997

This paper proposes a distinction algorithm of Korean and English characters which can be applied to multi-font from the results of thinning. The proposed algorithm distinguishes Korean and English characters as the number of connected components. If it can not distinguish those characters with the number of connected component, it distinguishes them as the vowel included in Korean characters. In experimental results, the distinction rate is about 99.82% for the 21,150 characters of three widely used fonts.