• The Journal of Korean Institute of Next Generation Computing
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• v.13 no.2
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• pp.18-25
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• 2017

In computer science, an encoding is a standardization of converting information to one format for audio, video or text. Therefore, the encoding information of the data should be known to open and read it and there are algorithms detecting encoder of the data. However, some informations of data could be disappeared by packet loss when transmitted on network, especially, if the data is snatched by packet sniffing or eavesdropping from wireless communications. In this paper, we improve the performance of encoding detection algorithm of 'uchardet' program for multi-byte encoded data with errors based on bit-shift algorithm. To simulate the performance, we generated Korean and Japanese text data with errors that is removed some random bits at random positions. Then the detection algorithm are tested using the data and 'uchardet-bitshift' showed better performance than 'uchardet'. When Korean texts are used, 'uchardet' could detect perfectly with ≤0.005% errors but it showed 0% detection rate with ≥1% errors while 'uchardet-bitshift' detected perfectly with ≤0.05% errors and it showed correct detection cases with ≥1% errors. Japanese texts with errors tend to report falsely as Chinese encoding because Japanese texts include lots of Chinese characters. As a results, we improved encoding detection algorithms by applying bit shift operation.

• Proceedings of the Acoustical Society of Korea Conference
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• 1993.06a
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• pp.125-127
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• 1993

오디오 혹은 비디오화의, 방송 고품질전화 등의 음성신호의 전송을 위해 마련된 CCITT Recommendation G.722에 의거 Codec을 구성하고 이를 통과한 연속음성을 CMU의 불특정 화자 연속음성인식 시스템인 SPHINX에 입력하여 인식률을 조사 한 후 CODING전의 인식결과와 비교하였다. 이때 CODEC은 크게 네 부분(Trans Quarature Mirror Filter, Encoder, Decoder, Receive QMF)으로 구성하고 입력음성 데이터는 150화자에 의한 1018문장을 훈련용으로, 140문장을 테스트용으로 하였을 때의 단어 인식률을 인식률로 하였다. 또 이때 특징벡터로는 12차 Melcepstrum 계수를 사용하였다. 인식결과 코딩전(close talk Mic를 이용하여 직접입력)의 단어 인식률이 86.7%인데 비해 코딩후의 인식률은 85.6%로 나타나 약 1%의 인식률 저하를 가져와 코딩으로 인한 Error에 비해 비교적 양호한 결과를 얻을 수 있었다. 인식률 저하의 원인으로서는 코딩시의 BER(Bit Error Rate)에 의한 것으로 생각된다.

• Journal of Convergence for Information Technology
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• v.11 no.9
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• pp.1-7
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• 2021

Since recently only an auto-correlated superposition coding (SC) scheme for non-orthogonal multiple access(NOMA) has been investigated, this paper proposes a cross-correlated SC scheme for NOMA. First, we derive the closed-form expression of the sum rate of the proposed cross-correlated SC scheme. Then, numerical analyses demonstrate that the sum rate of the proposed cross-correlated SC scheme is larger than that of the conventional auto-correlated SC scheme. We also show that for the stronger channel gain user, the signal-to-noise ratio (SNR) gain of the proposed cross-correlated SC scheme is about 15, compared with the conventional auto-correlated SC scheme. As a result, the proposed cross-correlated SC scheme could be a promising technology for 6G ultra-reliable low-latency communications (URLLC).

• 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.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.95-98
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• 2015

문자 인코딩은 컴퓨터에 저장하거나 네트워크상에서 전송하기 위해 문서를 이진화 하는 방법이다. 문자 인코딩은 고유의 문자 코드 테이블을 이용하여 문서를 이진화 하기 때문에, 문서에 적용된 문자 인코딩과 다른 문자 인코딩을 이용하여 디코딩 하면 원본과 다른 문서가 출력되어 문서를 읽을 수 없게 된다. 따라서 문서를 읽기 위해서는 문서에 적용된 문자 인코딩을 알아내야 한다. 본 논문에서는 문서의 문자 인코딩을 자동으로 판별하는 방법을 제시한다. 제안하는 방법은 이스케이프 문자를 이용한 판별법, 문서에 나타난 코드 값 범위 판별법, 문서에 나타난 코드 값의 특징 판별법, 단어 데이터베이스를 이용한 판별법과 같은 여러 단계를 걸쳐 문서에 적용된 문자 인코딩을 판별한다. 제안하는 방법은 문서를 언어별로 분류하여 문자 인코딩을 판별하기 때문에, 높은 문자 인코딩 인식률을 보인다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.10
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• pp.2281-2287
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• 2013

Network Coding(NC) is a new paradigm for network communication. In network coding, intermediate nodes create new packets by algebraically combining ingress packets and send it to its neighbor node by broadcast manner. Network Coding has rapidly emerged as a major research area in information theory due to its wide applicability to communication through real networks. Network coding is expected to improve throughput and channel efficiency in the wireless multi-hop network. Prior researches have been carried out to employ network coding to wireless ad-hoc network. In our study, intermediate nodes identify one-hop bidirectional flows for network coding decision. We expect that the proposed scheme shall improve decoding success rate of network coded packet. From the simulation, the proposed network coding scheme achieved better performance in terms of coding gain and packet delivery rate than traditional network coding scheme.

• Journal of the Korean Society for information Management
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• v.17 no.4
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• pp.27-45
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• 2000

National statistical data such as Korean Census is fundamental data for national administration. In this paper, we present an automatic coding system utilizing morphological analyser and knowledge dictionaries. Knowledge bases are constructed based on an authority dictionaries which were developed by authors utilizing a newly learning theory. Test data indicates 99.5% of productivity and 83.3% of accuracy. The presented methods can be effectively applied to analyze statistical information.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.1
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• pp.33-42
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• 2016

In Korea, the address-point matching technique has been used to provide geocoding services. In fact, this technique brings the high positional accuracy. However, the quality of geocoding result can be limited, since it is significantly affected by data quality. Also, it cannot be used for the 3D address geocoding and the reverse geocoding. In order to alleviate issues, the paper has implemeted proposed geocoding methods, based on street-based addresses matching technique developed by US census bureau, for street-based addresses in Korea. Those proposed geocoding methods are illustrated in two ways; (1) street address-matching method, which of being used for not only 2D addresses representing a single building but also 3D addresses representing indoor space or underground building, and (2) reverse geocoding method, whichas converting a location point to a readable address. The result of street-based address geocoding shows 82.63% match rates, while the result of reverse geocoding shows 98.5% match rates within approximately 1.7(m) the average position error. According to the results, we could conclude that the proposed geocoding techniques enable to provide the LBS(Location Based Service). To develop the geocoding methods, the study has perfoermed by ignoring the parsing algorithms for address standardization as well as the several areas with unusual addresses, such as sub-urban areas or subordinate areas to the roads, etc. In the future, we are planning the improved geocoding methods for considering these cases.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.07a
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• pp.321-322
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• 2020

본 논문에서는 Intra 코딩 기반의 위상 홀로그램 압축 방법을 제안한다. 제안하는 방법은 다음과 같다. 홀로그램을 Intra 코딩의 블록 단위로 세그먼트를 나누는 과정, Intra 코딩의 예측을 고려한 위상 펼침 과정, H.265/HEVC 입력을 고려한 양자화 과정, 마지막으로 H.265/HEVC를 이용한 압축과정으로 구성된다. 제안한 알고리즘은 위상정보에 아무런 전후처리를 하지않고 H.265/HEVC를 압축한 결과보다 100:1 이상의 고압축률 구간에서 압축효율이 향상되었다.

• Journal of the Korea Society of Computer and Information
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• v.4 no.1
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• pp.1-6
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• 1999

In this paper We propose the new lossless compression method which use Huffman Coding using the preprocessing to compress the still image. The proposed methode divide into two parts according to activity of the image. If activities are high, the original Huffman Coding method was used directly. IF activities are low, the nibble run-length coding and the bit dividing method was used. The experimental results show that compression rate of the proposed method was better than the general Huffman Coding method.