• Title/Summary/Keyword: Wrapper algorithm

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A Test Wrapper Design to Reduce Test Time for Multi-Core SoC (멀티코어 SoC의 테스트 시간 감축을 위한 테스트 Wrapper 설계)

  • Kang, Woo-Jin;Hwang, Sun-Young
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39B no.1
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    • pp.1-7
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    • 2014
  • This paper proposes an efficient test wrapper design that reduces overall test time in multi-core SoC. After initial local wrapper solution sets for all the cores are determined using well-known Combine algorithm, proposed algorithm selects a dominant core which consumes the longest test time in multi-core SoC. Then, the wrapper characteristics in the number of TAM wires and the test time for other cores are adjusted based on test time of the dominant core. For some specific cores, the number of TAM wires can be reduced by increasing its test time for design space exploration purposes. These modified wrapper characteristics are added to the previous wrapper solution set. By expanding previous local wrapper solution set to global wrapper solution set, overall test time for Multi-core SoC can be reduced by an efficient test scheduler. Effectiveness of the proposed wrapper is verified on ITC'02 benchmark circuits using $B^*$-tree based test scheduler. Our experimental results show that the test time is reduced by an average of 4.7% when compared to that of employing previous wrappers.

MORPHEUS: A More Scalable Comparison-Shopping Agent (MORPHEUS: 확장성이 있는 비교 쇼핑 에이전트)

  • Yang, Jae-Yeong;Kim, Tae-Hyeong;Choe, Jung-Min
    • Journal of KIISE:Software and Applications
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    • v.28 no.2
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    • pp.179-191
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    • 2001
  • Comparison shopping is a merchant brokering process that finds the best price for the desired product from several Web-based online stores. To get a scalable comparison shopper, we need an agent that automatically constructs a simple information extraction procedure, called a wrapper, for each semi-structured store. Automatic construction of wrappers for HTML-based Web stores is difficult because HTML only defines how information is to be displayed, not what it means, and different stores employ different ways of manipulating customer queries and different presentation formats for displaying product descriptions. Wrapper induction has been suggested as a promising strategy for overcoming this heterogeneity. However, previous scalable comparison-shoppers such as ShopBot rely on a strong bias in the product descriptions, and as a result, many stores that do not confirm to this bias were unable to be recognized. This paper proposes a more scalable comparison-shopping agent named MORPHEUS. MORPHEUS presents a simple but robust inductive learning algorithm that antomatically constructs wrappers. The main idea of the proposed algorithm is to recognize the position and the structure of a product description unit by finding the most frequent pattern from the sequence of logical line information in output HTML pages. MORPHEUS successfully constructs correct wtappers for most stores by weakening a bias assumed in previous systems. It also tolerates some noises that might be present in production descriptions such as missing attributes. MORPHEUS generates the wrappers rapidly by excluding the pre-processing phase of removing redundant fragments in a page such as a header, a tailer, and advertisements. Eventually, MORPHEUS provides a framework from which a customized comparison-shopping agent can be organized for a user by facilitating the dynamic addition of new stores.

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On the Performance of Cuckoo Search and Bat Algorithms Based Instance Selection Techniques for SVM Speed Optimization with Application to e-Fraud Detection

  • AKINYELU, Andronicus Ayobami;ADEWUMI, Aderemi Oluyinka
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.3
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    • pp.1348-1375
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    • 2018
  • Support Vector Machine (SVM) is a well-known machine learning classification algorithm, which has been widely applied to many data mining problems, with good accuracy. However, SVM classification speed decreases with increase in dataset size. Some applications, like video surveillance and intrusion detection, requires a classifier to be trained very quickly, and on large datasets. Hence, this paper introduces two filter-based instance selection techniques for optimizing SVM training speed. Fast classification is often achieved at the expense of classification accuracy, and some applications, such as phishing and spam email classifiers, are very sensitive to slight drop in classification accuracy. Hence, this paper also introduces two wrapper-based instance selection techniques for improving SVM predictive accuracy and training speed. The wrapper and filter based techniques are inspired by Cuckoo Search Algorithm and Bat Algorithm. The proposed techniques are validated on three popular e-fraud types: credit card fraud, spam email and phishing email. In addition, the proposed techniques are validated on 20 other datasets provided by UCI data repository. Moreover, statistical analysis is performed and experimental results reveals that the filter-based and wrapper-based techniques significantly improved SVM classification speed. Also, results reveal that the wrapper-based techniques improved SVM predictive accuracy in most cases.

A Knowledge-based Wrapper Learning Agent for Semi-Structured Information Sources (준구조화된 정보소스에 대한 지식기반의 Wrapper 학습 에이전트)

  • Seo, Hee-Kyoung;Yang, Jae-Young;Choi, Joong-Min
    • Journal of KIISE:Software and Applications
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    • v.29 no.1_2
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    • pp.42-52
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    • 2002
  • Information extraction(IE) is a process of recognizing and fetching particular information fragments from a document. In previous work, most IE systems generate the extraction rules called the wrappers manually, and although this manual wrapper generation may achieve more correct extraction, it reveals some problems in flexibility, extensibility, and efficiency. Some other researches that employ automatic ways of generating wrappers are also experiencing difficulties in acquiring and representing useful domain knowledge and in coping with the structural heterogeneity among different information sources, and as a result, the real-world information sources with complex document structures could not be correctly analyzed. In order to resolve these problems, this paper presents an agent-based information extraction system named XTROS that exploits the domain knowledge to learn from documents in a semi-structured information source. This system generates a wrapper for each information source automatically and performs information extraction and information integration by applying this wrapper to the corresponding source. In XTROS, both the domain knowledge and the wrapper are represented as XML-type documents. The wrapper generation algorithm first recognizes the meaning of each logical line of a sample document by using the domain knowledge, and then finds the most frequent pattern from the sequence of semantic representations of the logical lines. Eventually, the location and the structure of this pattern represented by an XML document becomes the wrapper. By testing XTROS on several real-estate information sites, we claim that it creates the correct wrappers for most Web sources and consequently facilitates effective information extraction and integration for heterogeneous and complex information sources.

Feature Subset Selection in the Induction Algorithm using Sensitivity Analysis of Neural Networks (신경망의 민감도 분석을 이용한 귀납적 학습기법의 변수 부분집합 선정)

  • 강부식;박상찬
    • Journal of Intelligence and Information Systems
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    • v.7 no.2
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    • pp.51-63
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    • 2001
  • In supervised machine learning, an induction algorithm, which is able to extract rules from data with learning capability, provides a useful tool for data mining. Practical induction algorithms are known to degrade in prediction accuracy and generate complex rules unnecessarily when trained on data containing superfluous features. Thus it needs feature subset selection for better performance of them. In feature subset selection on the induction algorithm, wrapper method is repeatedly run it on the dataset using various feature subsets. But it is impractical to search the whole space exhaustively unless the features are small. This study proposes a heuristic method that uses sensitivity analysis of neural networks to the wrapper method for generating rules with higher possible accuracy. First it gives priority to all features using sensitivity analysis of neural networks. And it uses the wrapper method that searches the ordered feature space. In experiments to three datasets, we show that the suggested method is capable of selecting a feature subset that improves the performance of the induction algorithm within certain iteration.

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An Efficient Wrapper Design for SOC Testing (SOC 테스트를 위한 Wrapper 설계 기법)

  • Choi, Sun-Hwa;Kim, Moon-Joon;Chang, Hoon
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.41 no.3
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    • pp.65-70
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    • 2004
  • The SOC(System on Chip) testing has required the core re-use methodology and the efficiency of test method because of increase of its cost. The goal of SOC testing is to minimize the testing time, area overhead, and power consumption during testing. Prior research has concentrated on only one aspect of the test core wrapper design problem at a test time. Our research is concentrated on optimization of test time and area overhead for the core test wrapper, which is one of the important elements for SOC test architecture. In this paper, we propose an efficient wrapper design algorithm that improves on earlier approaches by also reducing the TAM(Test Access Mechanism) width required to achieve these lower testing times.

Microblog User Geolocation by Extracting Local Words Based on Word Clustering and Wrapper Feature Selection

  • Tian, Hechan;Liu, Fenlin;Luo, Xiangyang;Zhang, Fan;Qiao, Yaqiong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.10
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    • pp.3972-3988
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    • 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.

Model based Facial Expression Recognition using New Feature Space (새로운 얼굴 특징공간을 이용한 모델 기반 얼굴 표정 인식)

  • Kim, Jin-Ok
    • The KIPS Transactions:PartB
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    • v.17B no.4
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    • pp.309-316
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    • 2010
  • This paper introduces a new model based method for facial expression recognition that uses facial grid angles as feature space. In order to be able to recognize the six main facial expression, proposed method uses a grid approach and therefore it establishes a new feature space based on the angles that each gird's edge and vertex form. The way taken in the paper is robust against several affine transformations such as translation, rotation, and scaling which in other approaches are considered very harmful in the overall accuracy of a facial expression recognition algorithm. Also, this paper demonstrates the process that the feature space is created using angles and how a selection process of feature subset within this space is applied with Wrapper approach. Selected features are classified by SVM, 3-NN classifier and classification results are validated with two-tier cross validation. Proposed method shows 94% classification result and feature selection algorithm improves results by up to 10% over the full set of feature.

Feature Selection for Anomaly Detection Based on Genetic Algorithm (유전 알고리즘 기반의 비정상 행위 탐지를 위한 특징선택)

  • Seo, Jae-Hyun
    • Journal of the Korea Convergence Society
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    • v.9 no.7
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    • pp.1-7
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    • 2018
  • Feature selection, one of data preprocessing techniques, is one of major research areas in many applications dealing with large dataset. It has been used in pattern recognition, machine learning and data mining, and is now widely applied in a variety of fields such as text classification, image retrieval, intrusion detection and genome analysis. The proposed method is based on a genetic algorithm which is one of meta-heuristic algorithms. There are two methods of finding feature subsets: a filter method and a wrapper method. In this study, we use a wrapper method, which evaluates feature subsets using a real classifier, to find an optimal feature subset. The training dataset used in the experiment has a severe class imbalance and it is difficult to improve classification performance for rare classes. After preprocessing the training dataset with SMOTE, we select features and evaluate them with various machine learning algorithms.

A Query Processing Model based on the XML View in Relational Databases (관계형 데이터베이스에서 XML 뷰 기반의 질의 처리 모델)

  • Jung, Chai-Young;Choi, Kyu-Won;Kim, Young-Ok;Kim, Young-Kyun;Kang, Hyun-Syug;Bae, Jong-Min
    • The KIPS Transactions:PartD
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    • v.10D no.2
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    • pp.221-232
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    • 2003
  • This paper addresses the query processing component of a wrapper system for a relational database model based on the XML view in integrating databases. The schema of a relational database is represented as XML Schema that is proposed by W3C. Users submit a query using the XML query language XQuery over the XML Schema. The wrapper system to be developed supports an user-defined XML view. XQuery is also used as the view definition language. In this environment, this paper suggests a new XML query processing model. We propose the composition algorithm of an XML view with an user query, the translation algorithm of XQuery into SQL, and the XML template construction algorithm for generating XML documents.