• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
• /
• 2004.03a
• /
• pp.241-246
• /
• 2004

The ocean signal that reaches the detector of an imaging system after multiple interactions with the atmospheric molecules and aerosols was retrieved from the total signal recorded at the top of the atmosphere (TOA). A simple method referred to as 'Path Extraction' applied to the Landsat-TM ocean imagery of turbid coastal water was compared with the conventional dark-pixel subtraction technique. The shape of the path-extracted water-leaving radiance spectrum resembled the radiance spectrum measured in-situ. The path-extraction was also extended to the SeaWiFS ocean color imagery and compared with the standard SeaWiFS atmospheric correction algorithm, which relays on the assumption of zero water leaving radiance at the two NIR wavebands (765 and 865nm). The path-extracted water-leaving radiance was good agreement with the measured radiance spectrum. In contrast, the standard SeaWiFS atmospheric correction algorithm led to essential underestimation of the water-leaving radiance in the blue-green part of the spectrum. The reason is that the assumption of zero water-leaving radiance at 755 and 865nm fails due to backscattering by suspended mineral particles. Therefore, the near infrared channels 765 and 865nm used fur deriving the aerosol information are no longer valid for turbid coastal waters. The path-extraction is identified as a simple and efficient method of extracting the path radiance largely introduced due to light interaction through the complex atmosphere carried several aerosol and gaseous components and at the air-sea interface.interface.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.13 no.3
• /
• pp.329-336
• /
• 2000

A method for automatic extraction of 2-dimensional finite element connectivities by searching the shortest closed path from a certain node to the starting node was developed. Only the best path among the possible paths was probed. The uniqueness and validity of the extracted path were examined. The proposed method was proved to be complete. Examples show that the proposed method can extract elements exactly from the irregular mesh which can not be handled easily by the conventional automatic mesh generation.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.29A no.1
• /
• pp.48-59
• /
• 1992

This paper presents the design of a layout processing system that performs circuit and symbolic extraction from hierarchical designs containing arbitrarily shaped layout. The system is flexible enough to deal with various technologies, MOS or bipolar, by providing extraction rules in the form of technology files. In this paper, new efficient algorithms for trapezoidal decomposition of polygon and symbolic path extraction using trapezoidal template are proposed for symbolic extraction. Circuit and symbolic extractor is developed as an integrated design environment of SOLID system.

• Proceedings of the KSRS Conference
• /
• 1999.11a
• /
• pp.290-295
• /
• 1999

Lineament extraction from mountain area often provides valuable geological information. In many cases, the lineaments correspond to a series of continuous large valleys. This paper introduces a new lineament extraction method from Digital Elevation Model (DEM) using Raindrop Tracing Algorithm (RTA). The main advantage of this algorithm over conventional Segment Tracing Algorithm (STA) is that it utilizes DEM directly unlike the STA Which utilizes the shaded relief of DEM. The RTA simulates the real life of raindrops that converge into a large valley. The simulation has been done by sprinkling the randomized raindrops over DEM and counting the number of raindrop path that follows the negative gradient of the DEM. The large counting number indicates the location of a big valley where the raindrops converge. With the help of the counting number array (accumulator array) recording the flowing path information, RTA can produce perfectly unbiased binary image of the lineament.

• Journal of Internet Computing and Services
• /
• v.2 no.4
• /
• pp.11-24
• /
• 2001

XML documents found over internet are generally fairly irregular and hove no fixed schema, The SQL and OQL are not suitable for query processing in XML documents, So, there are many researches about schema extraction and query language for XML documents, We propose a schema extraction method using the frequency of label path in XML documents, Our proposed method produces multi-level schemas and those are useful for query processing.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.23 no.6
• /
• pp.711-718
• /
• 2019

BDD is a well-known alternative to the conventional Boolean logic method in fault tree analysis. As the size of fault tree increases, the calculation time and computer resources for BDD dramatically increase. A new failure path search and path restructure method is proposed for efficient calculation of CS and MCS from BDD. Failure path grouping and bottom-up path search is proved to be efficient in failure path search in BDD and path restructure is also proved to be used in order to reduce the number of CS comparisons for MCS extraction. With these newly proposed methods, the top event probability can be calculated using the probability by ASDMP(Approximate Sum of Disjoint MCS Products), which is shown to be equivalent to the result by the conventional MCUB(Minimal Cut Upper Bound) probability.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.16 no.1
• /
• pp.39-53
• /
• 1998

The extraction rate of ginger from Korean-grown ginger root with supercritical carbon dioxide was measured as a function of flow rate of supercritical carbon dioxide, particle size, temperature and pressure. the extraction rate increased as the particle size decreased due to a decrease in the diffusion path. The extraction rate were independent of flow rate of supercritical carbon dioxide in a plot of ginger oil yield versus extraction time. This indicated that the extraction process is controlled by intraparticle diffusion within a particle of ginger root. In the case of temperature and pressure effect, the experimental results showed that the extraction rate decreased with an increase in temperature and increased with an increase in pressure.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.16 no.2
• /
• pp.365-372
• /
• 2002

The mineral medicines mean a sort of mineral or rock for medical treatment and natural material using their chemical components and physical properties. In this study, it was apprehended the mineralogical characteristics of As-bearing group mineral medicines. The extraction test is an vitro test system for predicting the bioavailability of the major and minor elements from mineral medicines and incorporates gastrointestinal tract parameters representative of a human(including stomach and small intestinal pH, stomach mixing time and velocity). The results of the extraction test are used for reaction path modeling in human body. Reaction path modeling in human body can predict digestion with gastric juice as well as bioavailability, speciation. Also, it can predict accumulation of arsenic as pH condition. As the results of the extraction test for digestion, the amounts of Fe extraction was the highest, followed by As, Ca, Ni. In addition, as the results of the reaction path modeling between arsenic compounds and gastric juice using thermodynamic data, when absorbed, major species are followed by H₃As₃S/sub 6/(aq), As₃S/sub 6/ (aq), AsO/sup +/, H₂As₃S/sup 6-/, H₂AsO/sup 3-/, HAs₃S6/sup 2-/, HAsO/sub 3//sup 2-/ and AsO/sub 3//sup 3-/. Specifically the concentration of H₃As₃S/sub 6/(aq) is the highest. As pH increases, the concentration of H₂AsO/sup 3-/, HAsO/sub 3//sup 2-/, HAsO/sub 3//sup 3-/, HAs₃S/sub 6//sup 2-/, H₂As₃S/sup 6-/, and H₃As₃S/sub 6/ increases, whereas the concentration of H₃As₃S/sub 6/ and AsO/sup +/ decreases. On the results of this study, it is able to find out effective and toxic components of poisonous arsenic group of mineral medicines and expected to be widely used for the development of new medicines.

• Korean Journal of Remote Sensing
• /
• v.22 no.2
• /
• pp.123-129
• /
• 2006

High-resolution aerial color image offers great possibilities for geometric and semantic information for spatial data generation. However, shadow casts by buildings and trees in high-density urban areas obscure much of the information in the image giving rise to potentially inaccurate classification and inexact feature extraction. Though many researches have been implemented for solving shadow casts, few studies have been carried out about the extraction of features hindered by shadows from aerial color images in urban areas. This paper presents a asphalt road boundary extraction technique that combines information from aerial color image and LIDAR (LIght Detection And Ranging) data. The following steps have been performed to remove shadow effects and to extract road boundary from the image. First, the shadow regions of the aerial color image are precisely located using LEAR DSM (Digital Surface Model) and solar positions. Second, shadow regions assumed as road are corrected by shadow path reconstruction algorithms. After that, asphalt road boundary extraction is implemented by segmentation and edge detection. Finally, asphalt road boundary lines are extracted as vector data by vectorization technique. The experimental results showed that this approach was effective and great potential advantages.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.11 no.1
• /
• pp.202-210
• /
• 2019

The obstacles modeling is a fundamental and significant issue for path planning and automatic navigation of Unmanned Surface Vehicle (USV). In this study, we propose a novel obstacles modeling method based on high resolution satellite images. It involves two main steps: extraction of obstacle features and construction of convex hulls. To extract the obstacle features, a series of operations such as sea-land segmentation, obstacles details enhancement, and morphological transformations are applied. Furthermore, an efficient algorithm is proposed to mask the obstacles into convex hulls, which mainly includes the cluster analysis of obstacles area and the determination rules of edge points. Experimental results demonstrate that the models achieved by the proposed method and the manual have high similarity. As an application, the model is used to find the optimal path for USV. The study shows that the obstacles modeling method is feasible, and it can be applied to USV path planning.