• Journal of Korean Society for Geospatial Information Science
• /
• v.6 no.2 s.12
• /
• pp.133-141
• /
• 1998

Terrain modelling is composed of a method using the rectangular grid and another using the triangulated irregular network. The method using the triangulated irregular network is most widely used because it can express the characteristics of the terrain well with only a small amount of information on the terrain and also reduces the rendering time. The process of extracting the surface-specific point and a triangular process is needed to construct such triangulated irregular network. This paper concentrates on the process of extracting the surface-specific point. The 8-direction neighborhood method and other transformed methods of the former method are frequently used to extract the surface-specific point. Another method which eliminates the unnecessary points using the Polygon reduction method is also suggested However, the 8-direction neighborhood method has a big fault of also drawing out some unnecessary points. To resolve such problem, we suggest a method of extracting the surface-specific point using the cross section of the terrain. This method reduces the time to extract the surface-specific point and enables a more precise extraction with less terrain information.

• Proceedings of the Korea Society of Design Studies Conference
• /
• 2005.10a
• /
• pp.52-53
• /
• 2005

• The Korean Journal of Food And Nutrition
• /
• v.20 no.1
• /
• pp.14-19
• /
• 2007

Caffeine is one of the most well known stimulants which can potentially increase mental performance, release fatigue and decrease depression. Green beans from different soils and climates contain different levels of caffeine, and as well as extracted coffee with different roasting and extracting methods. An investigation looking at pH, acidity, extractable solid and caffeine contents was assessed according to roasting and extracting conditions of various coffee beans. Brazilian coffee beans did not show much variation in pH with respect to roasting and extracting temperature, however, acidity increased in low roasting and extracting temperatures. This was however most prominently observed in Ethiopian and Indonesian coffee beans. The large expansion of coffee bean cells renders them highly porous to the passage of water, consequently extracted solids were found to increase with increasing temperature. This was especially apparent in Columbian coffee which had the highest extracted solids. The amount of caffeine extracted from coffee beans also increased with the higher temperature extraction. The Indonesian and Vietnam robusta coffee varieties showed the highest caffeine content.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.35 no.12C
• /
• pp.995-1003
• /
• 2010

The content-based hashing for authentication and copy protection of image, video and 3D model has to satisfy the robustness and the security. For the security analysis of the hash value, the modelling method based on differential entropy had been presented. But this modelling can be only applied to the image hashing. This paper presents the modelling for the security analysis of the hash feature value in 3D model hashing based on differential entropy. The proposed security analysis modeling design the feature extracting methods of two types and then analyze the security of two feature values by using differential entropy modelling. In our experiment, we evaluated the security of feature extracting methods of two types and discussed about the trade-off relation of the security and the robustness of hash value.

• The Journal of Korean Association of Computer Education
• /
• v.21 no.1
• /
• pp.51-58
• /
• 2018

Recently artificial neural networks have shown excellent performance in various fields. However, there is a problem that it is difficult for a person to understand what is the knowledge that artificial neural network trained. One of the methods to solve these problems is an algorithm for extracting rules from trained neural network. In this paper, we extracted rules from artificial neural networks using ordered-attribute search(OAS) algorithm, which is one of the methods of extracting rules, and analyzed result to improve extracted rules. As a result, we have found that the distribution of output values of the hidden layer unit affects the accuracy of rules extracted by using OAS algorithm, and it is suggested that efficient rules can be extracted by binarizing hidden layer output values using hidden unit clarification.

• Proceedings of the Korean Society for Bioinformatics Conference
• /
• 2003.10a
• /
• pp.268-274
• /
• 2003

Most currently known molecular structures were determined by X-ray crystallography or Nuclear Magnetic Resonance (NMR). These methods generate a large amount of structure data, even far small molecules, and consist mainly of three-dimensional atomic coordinates. These are useful for analyzing molecular structure, but structure elements at higher level are also needed for a complete understanding of structure, and especially for structure prediction. Computational approaches exist for identifying secondary structural elements in proteins from atomic coordinates. However, similar methods have not been developed for RNA due in part to the very small amount of structure data so far available, and extracting the structural elements of RNA requires substantial manual work. Since the number of three-dimensional RNA structures is increasing, a more systematic and automated method is needed. We have developed a set of algorithms for recognizing secondary and tertiary structural elements in RNA molecules and in the protein-RNA structures in protein data banks (PDB). The present work represents the first attempt at extracting RNA structure elements from atomic coordinates in structure databases. The regularities in the structure elements revealed by the algorithms should provide useful information for predicting the structure of RNA molecules bound to proteins.

• Korean Journal of Medicinal Crop Science
• /
• v.21 no.4
• /
• pp.276-281
• /
• 2013

This study was conducted to compare the contents of ginsenoside according the water extract conditions of red ginseng. In method A, red ginseng extract was prepared at $75^{\circ}C$ for 18 hours by 1 time extraction, and method B, the preparation was done at $85^{\circ}C$ for 18 hours by 1 time extraction. In method C, the primary extract prepared at $75^{\circ}C$ for 9 hours was blended with the secondary extract prepared by re-extracting the red ginseng residue obtained after the primary extraction, at $85^{\circ}C$ for 9 hours. Method D was the same procedure as method C but the extraction temperature for the primary extraction was $85^{\circ}C$ and that for the secondary extraction was $95^{\circ}C$. The contents of total and $Rb_1$, $Rg_1$ and $Rg_3$ ginsenoside were highest in Method C. The content of prosapogenin (ginsenoside $Rg_2$, $Rg_3$, $Rb_1$ and $Rb_2$) was highest in Method B. There was no consistent tendency in Brix, pH, Hue value and absorbance among extraction methods.

• Environmental Engineering Research
• /
• v.18 no.2
• /
• pp.57-63
• /
• 2013

Arid areas have a significant problem with water supply due to climate change and high water demand. More than 3,000 years ago, Persians started constructing elaborate tunnel systems called Qanat for extracting groundwater for agriculture and domestic usages in arid and semi-arid areas and dry deserts. In this paper, it has been demonstrated that ancient methods of water management, such as the Qanat system, could provide a good example of human wisdom to battle with water scarcity in a sustainable manner. The purpose of this paper is twofold: Review of old wisdom of Qanat-to review the history of this ancient wisdom from the beginning until now and study the Qanat condition at the present time and to explore why (notwithstanding that there are significant advantages to the Qanat system), it will no longer be used; and suggestions for future water management-to suggest a number of new methods based on new materials and technology to refine and protect Qanats. With these new suggestions it could be possible to refine and reclaim this method of extracting water in arid areas. Also, a new multi-purpose water management model has been introduced based on rainwater infiltration management over the Qanat system as the model can be applied either in dry or wet cities to solve current urban water problems.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.14 no.10
• /
• pp.3972-3988
• /
• 2020

Existing methods always rely on statistical features to extract local words for microblog user geolocation. There are many non-local words in extracted words, which makes geolocation accuracy lower. Considering the statistical and semantic features of local words, this paper proposes a microblog user geolocation method by extracting local words based on word clustering and wrapper feature selection. First, ordinary words without positional indications are initially filtered based on statistical features. Second, a word clustering algorithm based on word vectors is proposed. The remaining semantically similar words are clustered together based on the distance of word vectors with semantic meanings. Next, a wrapper feature selection algorithm based on sequential backward subset search is proposed. The cluster subset with the best geolocation effect is selected. Words in selected cluster subset are extracted as local words. Finally, the Naive Bayes classifier is trained based on local words to geolocate the microblog user. The proposed method is validated based on two different types of microblog data - Twitter and Weibo. The results show that the proposed method outperforms existing two typical methods based on statistical features in terms of accuracy, precision, recall, and F1-score.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2004.11a
• /
• pp.1-6
• /
• 2004

This paper shows the study on the design and another applications of the spray-freeze dryer for the production of valuable material powders. Powder production and handling has been an integral part of material extracting processing and pharmaceutical processing because of the wide use of oral dosage forms. There are a few commonly used powder preparation methods including mechanical milling, precipitaion, spray drying, freeze drying, and so on. In general, methods available for preparing inhalation powders are limited due to certain inhalation powder's sensitive nature to the processing environments. This is particularly true for preparing dry powder aerosols where the aerodynamic particle size($<5{\mu}m$) and the size distribution are pivotal. Supercritical fluid antisolvent and spray freeze drying have recently emerged as promising techniques for producing powders for use in microcapsulation. However, the aerosol applications of these powders are yet to be explored. The purpose of this study is to test the feasibility of using spray freeze-dried valuable material powders for aerosolization.