• Journal of information and communication convergence engineering
• /
• 제15권1호
• /
• pp.53-61
• /
• 2017

The preferred feature selection methods for text classification are filter-based. In a common filter-based feature selection scheme, unique scores are assigned to features; then, these features are sorted according to their scores. The last step is to add the top-N features to the feature set. In this paper, we propose an improved global feature selection scheme wherein its last step is modified to obtain a more representative feature set. The proposed method aims to improve the classification performance of global feature selection methods by creating a feature set representing all classes almost equally. For this purpose, a local feature selection method is used in the proposed method to label features according to their discriminative power on classes; these labels are used while producing the feature sets. Experimental results obtained using the well-known 20 Newsgroups and Reuters-21578 datasets with the k-nearest neighbor algorithm and a support vector machine indicate that the proposed method improves the classification performance in terms of a widely known metric ($F_1$).

• 한국정보과학회논문지:소프트웨어및응용
• /
• 제31권4호
• /
• pp.498-504
• /
• 2004

본 논문은 자질 투영법을 사용한 새로운 문서 분류기를 제안한다. 제안된 문서 분류기는 학습 문서를 각 자질로의 투영으로써 표현한다. 문서를 위한 분류 작업은 투영된 각 자질로부터의 투표(voting)에 기인한다. 실험을 통해서 본 제안된 문서 분류기는 단순한 구조에도 불구하고 높은 성능을 보이고 있으며, 특히 기존의 문서 범주화 기법에서 높은 성능을 보여왔던 최근린법(k-NN)과 지지백터기계(SVM)와 비교했을 때 빠른 수행 속도와 오류 데이타가 많을 환경에서 높은 성능을 보인다는 장점이 있다. 또한 제안된 문서 분류기의 알고리즘이 매우 단순하기 때문에 분류기의 구현과 학습 과정이 쉽게 수행될 수 있다. 이러한 이유로 제안된 문서 분류기는 빠른 수행 속도와 견고성(robustness), 그리고 높은 성능을 요구하는 은서 범주화 응용 영역에 유용하게 사용될 수 있을 것이다.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2002년도 하계종합학술대회 논문집(4)
• /
• pp.359-362
• /
• 2002

In this paper, we propose a new feature-based text watermarking for the binary text image. The structure of specific characters from preprocessed text image are modified to embed watermark. Watermark message are embedded and detected by the following method; Hole line disconnect using the connectivity of the character containing a hole, Center line shift using the hole area and Differential encoding using difference of flippable score points. Experimental results show that the proposed method is robust to rotation and scaling distortion.

• Journal of Information Processing Systems
• /
• 제4권2호
• /
• pp.77-86
• /
• 2008

This research proposes a new neural network for text categorization which uses alternative representations of documents to numerical vectors. Since the proposed neural network is intended originally only for text categorization, it is called NTC (Neural Text Categorizer) in this research. Numerical vectors representing documents for tasks of text mining have inherently two main problems: huge dimensionality and sparse distribution. Although many various feature selection methods are developed to address the first problem, the reduced dimension remains still large. If the dimension is reduced excessively by a feature selection method, robustness of text categorization is degraded. Even if SVM (Support Vector Machine) is tolerable to huge dimensionality, it is not so to the second problem. The goal of this research is to address the two problems at same time by proposing a new representation of documents and a new neural network using the representation for its input vector.

• International Journal of Contents
• /
• 제13권4호
• /
• pp.70-79
• /
• 2017

Images are an important element in patents and many experts use images to analyze a patent or to check differences between patents. However, there is little research on image analysis for patents partly because image processing is an advanced technology and typically patent images consist of visual parts as well as of text and numbers. This study suggests two methods for using image processing; the Scale Invariant Feature Transform(SIFT) algorithm and Optical Character Recognition(OCR). The first method which works with SIFT uses image feature points. Through feature matching, it can be applied to calculate the similarity between documents containing these images. And in the second method, OCR is used to extract text from the images. By using numbers which are extracted from an image, it is possible to extract the corresponding related text within the text passages. Subsequently, document similarity can be calculated based on the extracted text. Through comparing the suggested methods and an existing method based only on text for calculating the similarity, the feasibility is achieved. Additionally, the correlation between both the similarity measures is low which shows that they capture different aspects of the patent content.

• International Journal of Contents
• /
• 제8권1호
• /
• pp.30-38
• /
• 2012

Text extraction and binarization are the important pre-processing steps for text recognition. The performance of text binarization strongly related to the accuracy of recognition stage. In our proposed method, the first stage based on line detection and shape feature analysis applied to locate the position of a business card and detect the shape from the complex environment. In the second stage, several local regions contained the possible text components are separated based on the projection histogram. In each local region, the pixels grouped into several connected components based on the connected component labeling and projection histogram. Then, classify each connect component into text region and reject the non-text region based on the feature information analysis such as size of connected component and stroke width estimation.

• 정보과학회 컴퓨팅의 실제 논문지
• /
• 제23권5호
• /
• pp.322-327
• /
• 2017

문서 분류 문제는 오랜 기간 동안 자연어 처리 분야에서 연구되어 왔다. 우리는 기존 컨볼루션 신경망을 이용했던 연구에서 나아가, 순환 신경망에 기반을 둔 문서 분류를 수행하였고 그 결과를 종합하여 제시하려 한다. 컨볼루션 신경망은 단층 컨볼루션 신경망을 사용했으며, 순환 신경망은 가장 성능이 좋다고 알려져 있는 장기-단기 기억 신경망과 회로형 순환 유닛을 활용하였다. 실험 결과, 분류 정확도는 Multinomial Naïve Bayesian Classifier < SVM < LSTM < CNN < GRU의 순서로 나타났다. 따라서 텍스트 문서 분류 문제는 시퀀스를 고려하는 것 보다는 문서의 feature를 추출하여 분류하는 문제에 가깝다는 것을 확인할 수 있었다. 그리고 GRU가 LSTM보다 문서의 feature 추출에 더 적합하다는 것을 알 수 있었으며 적절한 feature와 시퀀스 정보를 함께 활용할 때 가장 성능이 잘 나온다는 것을 확인할 수 있었다.

• 대한산업공학회지
• /
• 제41권4호
• /
• pp.381-388
• /
• 2015

The rapid growth of the World Wide Web and online information services has generated and made accessible a huge number of text documents. To analyze texts, selecting important keywords is an essential step. In this paper, we propose a feature selection method that combines a term frequency-inverse document frequency technique and symmetrical conditional probability. The proposed method can identify features with N-gram, the sequential multiword. The effectiveness of the proposed method is demonstrated through a real text data from the machine learning repository, University of California, Irvine.

• 전자공학회논문지S
• /
• 제34S권10호
• /
• pp.104-111
• /
• 1997

It is known as a difficult problem to recognize text-background mixed documents. In this paper a new string extraction algorithm, using mathematical morphology for the document consisting of text and overlapped periodic background pattern, is proposed. The algorithm consists of pattern periodicity feature extraction and background removal. The extracted pattern periodicity feature is used to determine the shape of structuring elements for morphological pre- and post-processing to remove background. The effectiveness of the proposed algorithm over the existing one is also verified through the experiments with various test documents.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제3권3호
• /
• pp.285-307
• /
• 2009

This paper introduces DICE, a Domain-Independent text Classification Engine. DICE is robust, efficient, and domain-independent in terms of software and architecture. Each module of the system is clearly modularized and encapsulated for extensibility. The clear modular architecture allows for simple and continuous verification and facilitates changes in multiple cycles, even after its major development period is complete. Those who want to make use of DICE can easily implement their ideas on this test bed and optimize it for a particular domain by simply adjusting the configuration file. Unlike other publically available tool kits or development environments targeted at general purpose classification models, DICE specializes in text classification with a number of useful functions specific to it. This paper focuses on the ways to locate the optimal states of a practical text classification framework by using various adaptation methods provided by the system such as feature selection, lemmatization, and classification models.