• KIISE Transactions on Computing Practices
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• v.22 no.4
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• pp.170-177
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• 2016

Character encoding is a method for changing a document to a binary document file using the code table for storage in a computer. When people decode a binary document file in a computer to be read, they must know the code table applied to the file at the encoding stage in order to get the original document. Identifying the code table used for encoding the file is thus an essential part of decoding. In this paper, we propose a method for detecting the character code of the given binary document file automatically. The method uses many techniques to increase the detection rate, such as a character code range detection, escape character detection, character code characteristic detection, and commonly used word detection. The commonly used word detection method uses multiple word database, which means this method can achieve a much higher detection rate for multi-language files as compared with other methods. If the proportion of language is 20% less than in the document, the conventional method has about 50% encoding recognition. In the case of the proposed method, regardless of the proportion of language, there is up to 96% encoding recognition.

• The Journal of Information Systems
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• v.14 no.3
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• pp.37-47
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• 2005

Mining of association rules is to find associations among data items that appear together in some transactions or business activities. As of today, algorithms for association rule mining, as well as for other data mining tasks, are mostly applied to relational databases. As XML being adopted as the universal format for data storage and exchange, mining associations from XML data becomes an area of attention for researchers and developers. The challenge is that the semi-structured data format in XML is not directly suitable for traditional data mining algorithms and tools. In this paper we present an encoding method to encode XML tree-nodes. This method is used to store the XML data in Value Table and Transaction Table that can be easily accessed via indexing. The hierarchical relationship in the original XML tree structure is embedded in the encoding. We applied this method to association rules mining of XML data that may have missing data.

• Journal of Broadcast Engineering
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• v.11 no.3 s.32
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• pp.326-335
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• 2006

Design criteria far a block code which guarantees minimized PAPR of the OFDM signals are proposed in this paper. Encoding procedure of the minimum PAPR codes (MPC) is composed of searching a seed codeword, circular shifting the register elements, and determining codeword inversion. It is shown that the PEP is invariant to the circular shift of register elements and codeword inversion. Based on such properties, systematic encoding rule for MPC is proposed. In addition proposed encoding rule can reduced greatly the size of look up table for MPC.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.1
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• pp.1-15
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• 2020

As differential computation analysis attack(DCA) which is context of side-channel analysis on white-box cryptography is proposed, masking white-box cryptography based on table encoding has been proposed by Lee et al. to counter DCA. Existing higher-order DCA for the masked white box cryptography did not consider the masking implementation structure based on table encoding, so it is impossible to apply this attack on the countermeasure suggested by Lee et al. In this paper, we propose a new higher-order DCA method that can be applied to the implementation of masking based on table encoding, and prove its effectiveness by finding secret key information of masking white-box cryptography suggested by Lee et al. in practice.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.6
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• pp.1443-1454
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• 2016

Balanced encoding method that implement Dual-rail logic style based on hardware technique to software is efficient countermeasure against side-channel analysis without additional memory. Since balanced encoding keep Hamming weight and/or Hamming distance of intermediate values constantly, using this method can be effective as countermeasure against side channel analysis due to elimination of intermediate values having HW and/or HD relating to secret key. However, former studies were presented for Constant XOR operation, which can only be applied to crypto algorithm that can be constructed XOR operation, such as PRINCE. Therefore, our first proposal of new Constant ADD, Shift operations can be applied to various symmetric crypto algorithms based on ARX. Moreover, we did not used look-up table to obtain efficiency in memory usage. Also, we confirmed security of proposed Constant operations with Mutual Information Analysis.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.12
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• pp.75-81
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• 2004

AE-CORDIC improves the CORDIC operation speed with a rotation direction pre-computation algorithm. Its CORDIC iteration stages consist of non-predictable rotation direction states and predictable rotation stages. The non-predictable stages are replaced with lookup-table which has smaller hardware size than CORDIC iteration stages. The predictable stages can determine rotation direction with the input angle and simple encoder. In this paper, a rotation direction pre-computation algorithm with input angle encoder is proposed. and AE-CORDIC which have optimized Lookup-table is compared with the P-CORDIC algorithm. Hardware size, delay, and SQNR of the AE-CORDIC are verified with Samsung 0.18㎛ technology and Synopsys design compiler when input angle bit length is 16.

• Journal of Information Display
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• v.10 no.1
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• pp.6-15
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• 2009

In this paper, a new approach is proposed for the efficient generation of computer-generated holograms (CGHs) using the spatially redundant data on a 3D object and the novel look-up table (N-LUT) method. First, the pre-calculated N-point principle fringe patterns (PFPs) were calculated using the 1-point PFP of the N-LUT. Second, spatially redundant data on a 3D object were extracted and re-grouped into the N-point redundancy map using the run-length encoding (RLE) method. Then CGH patterns were generated using the spatial redundancy map and the N-LUT method. Finally, the generated hologram patterns were reconstructed. In this approach, the object points that were involved in the calculation of the CGH patterns were dramatically reduced, due to which the computational speed was increased. Some experiments with a test 3D object were carried out and the results were compared with those of conventional methods.

• Journal of Korea Multimedia Society
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• v.11 no.6
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• pp.875-882
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• 2008

This research proposes an alternative approach to machine learning based ones for text categorization. For using machine learning based approaches for any task of text mining, documents should be encoded into numerical vectors; it causes two problems: huge dimensionality and sparse distribution. Although there are various tasks of text mining such as text categorization, text clustering, and text summarization, the scope of this research is restricted to text categorization. The idea of this research is to avoid the two problems by encoding a document or documents into a table, instead of numerical vectors. Therefore, the goal of this research is to improve the performance of text categorization by proposing approaches, which are free from the two problems.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.4
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• pp.43-48
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• 2008

This paper presents a design of 8B/10B encoder by the coding table reduction. The proposed encoder has reduced coding table modified disparity control block. Logic simulation and synthesis have been done for the proposed design. After synthesized using Magna CMOS $0.18{\mu}m$ process, the proposed design achieved the operating frequency of 343MHz and chip area of $1886{\mu}m^2$.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.8
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• pp.2913-2929
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• 2014

Traditional vector quantization (VQ) schemes encode image blocks as VQ indices, in which there is significant similarity between the image block and the codeword of the VQ index. Thus, the method can compress an image and maintain good image quality. This paper proposes a novel lossless VQ indices compression algorithm to further compress the VQ index table. Our scheme exploits the high correlation of adjacent image blocks to search for the same VQ index with the current encoding index from the neighboring indices. To increase compression efficiency, codewords in the codebook are sorted according to the degree of similarity of adjacent VQ indices to generate a state codebook to find the same index with the current encoding index. Note that the repetition indices both on the search path and in the state codebooks are excluded to increase the possibility for matching the current encoding index. Experimental results illustrated the superiority of our scheme over other compression schemes in the index domain.