• Title/Summary/Keyword: Weighting Schemes

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Text Classification for Patents: Experiments with Unigrams, Bigrams and Different Weighting Methods

  • Im, ChanJong;Kim, DoWan;Mandl, Thomas
    • International Journal of Contents
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    • v.13 no.2
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    • pp.66-74
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    • 2017
  • Patent classification is becoming more critical as patent filings have been increasing over the years. Despite comprehensive studies in the area, there remain several issues in classifying patents on IPC hierarchical levels. Not only structural complexity but also shortage of patents in the lower level of the hierarchy causes the decline in classification performance. Therefore, we propose a new method of classification based on different criteria that are categories defined by the domain's experts mentioned in trend analysis reports, i.e. Patent Landscape Report (PLR). Several experiments were conducted with the purpose of identifying type of features and weighting methods that lead to the best classification performance using Support Vector Machine (SVM). Two types of features (noun and noun phrases) and five different weighting schemes (TF-idf, TF-rf, TF-icf, TF-icf-based, and TF-idcef-based) were experimented on.

Visual-Weighted DCT Coding for Monochrome Still Images (흑백 정지 영상의 시기 하중 DCT 부호화)

  • 황재정;양근호;이문호
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.29B no.11
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    • pp.93-101
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    • 1992
  • HVS based transform coding techniques for still images take the lowest spatial frequency and luminance contrast sensitivity as the most crucial factors in determining the image quality perceived by human eye. Only the frequency weighting has been main issue. The proposed Weighted Discrete Cosine Transform (WDCT) has the lowest frequency of about 4 [cyc/deg] in 8$\times$8 subblock with the contrast-weighted DC coefficient. The error criteria have been rederived to adapt the contrast weighting for performance evaluation. The proposed scheme has produced higher quality images compared to the unweighted and other schemes.

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Development of a High-Order Accurate Hybrid Scheme Using the Central Flux and WENO Schemes (Central Flux Scheme과 WENO Scheme을 이용한 고차 정확도 Hybrid Scheme의 개발)

  • Kim D.;Kwon J. H.
    • 한국전산유체공학회:학술대회논문집
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    • 2005.04a
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    • pp.135-141
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    • 2005
  • A hybrid central-WENO scheme is proposed. The fifth order WENO-LF scheme is coupled with a central flux scheme at cell face. Two sub-schemes, the WENO-LF scheme and the central flux scheme, are switched by a weighting function. The efficiency and accuracy of the proposed hybrid central-WENO scheme is validated through several numerical experiments.

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Adaptive Exponentially Weighted Moving Average Control Chart Using a Kalman Filter (칼만필터를 적용한 Adaptive EWMA관리도)

  • 김양호;정윤성;김광섭
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.16 no.28
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    • pp.93-101
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    • 1993
  • In this paper, two adaptive exponentially weighted moving avenge control chart schemes which available for real-time are proposed. The weighting coefficient is estimated using a recursive kalman filter algorithm. Simulated average run lengths indicate the proposed schemes are sensitive to process shifts And their performance is comparable to CUSUM control chart and customary EWMA control chart.

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Design and Performance Analysis of the SPW Method for PAPR Reduction in OFDM System (OFDM 시스템에서 PAPR 처감을 위한 SPW 방식의 설계와 성능 분석)

  • 이재은;유흥균;정영호;함영권
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.14 no.7
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    • pp.677-684
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    • 2003
  • This paper addresses the subblock phase weighting(SPW) method to reduce the PAPR in OFDM system. This method divides the input block of OFDM signal into many subblocks and lower the peak power by weighting the phase of each subblocks properly. SPW method can be realized by only one IFFT. PAPR reduction performance is novelly examined when the adjacent, interleaved and random subblock partitioning schemes are used in the SPW system. The random subblock partition scheme has the most effective. More subblocks can effectively reduce the PAPR, but there is a problem that the processing time of iteration is increased. We propose a new weighting factor combination of the complementary sequence characteristic with threshold technique. OFDM data can be recovered by the inserted side information of weighting factor in the feed forward type. Also, BER performance of this SPW system is analyzed when error happens in the side information.

Use of Word Clustering to Improve Emotion Recognition from Short Text

  • Yuan, Shuai;Huang, Huan;Wu, Linjing
    • Journal of Computing Science and Engineering
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    • v.10 no.4
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    • pp.103-110
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    • 2016
  • Emotion recognition is an important component of affective computing, and is significant in the implementation of natural and friendly human-computer interaction. An effective approach to recognizing emotion from text is based on a machine learning technique, which deals with emotion recognition as a classification problem. However, in emotion recognition, the texts involved are usually very short, leaving a very large, sparse feature space, which decreases the performance of emotion classification. This paper proposes to resolve the problem of feature sparseness, and largely improve the emotion recognition performance from short texts by doing the following: representing short texts with word cluster features, offering a novel word clustering algorithm, and using a new feature weighting scheme. Emotion classification experiments were performed with different features and weighting schemes on a publicly available dataset. The experimental results suggest that the word cluster features and the proposed weighting scheme can partly resolve problems with feature sparseness and emotion recognition performance.

Gateway Discovery Algorithm Based on Multiple QoS Path Parameters Between Mobile Node and Gateway Node

  • Bouk, Safdar Hussain;Sasase, Iwao;Ahmed, Syed Hassan;Javaid, Nadeem
    • Journal of Communications and Networks
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    • v.14 no.4
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    • pp.434-442
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    • 2012
  • Several gateway selection schemes have been proposed that select gateway nodes based on a single Quality of Service (QoS) path parameter, for instance path availability period, link capacity or end-to-end delay, etc. or on multiple non-QoS parameters, for instance the combination of gateway node speed, residual energy, and number of hops, for Mobile Ad hoc NETworks (MANETs). Each scheme just focuses on the ment of improve only a single network performance, i.e., network throughput, packet delivery ratio, end-to-end delay, or packet drop ratio. However, none of these schemes improves the overall network performance because they focus on a single QoS path parameter or on set of non-QoS parameters. To improve the overall network performance, it is necessary to select a gateway with stable path, a path with themaximum residual load capacity and the minimum latency. In this paper, we propose a gateway selection scheme that considers multiple QoS path parameters such as path availability period, available capacity and latency, to select a potential gateway node. We improve the path availability computation accuracy, we introduce a feedback system to updated path dynamics to the traffic source node and we propose an efficient method to propagate QoS parameters in our scheme. Computer simulations show that our gateway selection scheme improves throughput and packet delivery ratio with less per node energy consumption. It also improves the end-to-end delay compared to single QoS path parameter gateway selection schemes. In addition, we simulate the proposed scheme by considering weighting factors to gateway selection parameters and results show that the weighting factors improve the throughput and end-to-end delay compared to the conventional schemes.

Development of Short-Run Standardized Control Charts and Acceptance Control Charts Classified by the Demand Volume and Variety (수요량과 다양성 패턴에 의해 유형화된 단기간 표준화 관리도와 단기간 합격판정 관리도의 개발)

  • Choi, Sung-Woon
    • Journal of the Korea Safety Management & Science
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    • v.12 no.4
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    • pp.255-263
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    • 2010
  • The research developes short-run standardized control charts(SSCC) and short-run acceptance control charts(SACC) under the various demand patterns. The demand patterns considered in this paper are three types such as high-variety and repetitive low-volume pattern, extremely-high-variety and nonrepetitive low-volume pattern, and high-variety and extremely-low-volume pattern. The short-run standardized control charts developed by extending the long-run ${\bar{x}}$-R, ${\bar{x}}$-s and I-MR charts have strengths for practioners to understand and use easily. Moreover, the short-range acceptance control charts developed in the study can be efficiently used through combining the functions of the inspection and control chart. The weighting schemes such as Shewhart, moving average (MA) and exponentially weighted moving average (EWMA) can be considered by the reliability of data sets. The two types according to the use of control chart are presented in the short-range standardized charts and acceptance control charts. Finally, process capability index(PCI) and process performance index(PPI) classified by the demand patterns are presented.

Development of Robot Vision Control Schemes based on Batch Method for Tracking of Moving Rigid Body Target (강체 이동타겟 추적을 위한 일괄처리방법을 이용한 로봇비젼 제어기법 개발)

  • Kim, Jae-Myung;Choi, Cheol-Woong;Jang, Wan-Shik
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.17 no.5
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    • pp.161-172
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    • 2018
  • This paper proposed the robot vision control method to track a moving rigid body target using the vision system model that can actively control camera parameters even if the relative position between the camera and the robot and the focal length and posture of the camera change. The proposed robotic vision control scheme uses a batch method that uses all the vision data acquired from each moving point of the robot. To process all acquired data, this robot vision control scheme is divided into two cases. One is to give an equal weight for all acquired data, the other is to give weighting for the recent data acquired near the target. Finally, using the two proposed robot vision control schemes, experiments were performed to estimate the positions of a moving rigid body target whose spatial positions are unknown but only the vision data values are known. The efficiency of each control scheme is evaluated by comparing the accuracy through the experimental results of each control scheme.

Latent Semantic Indexing Analysis of K-Means Document Clustering for Changing Index Terms Weighting (색인어 가중치 부여 방법에 따른 K-Means 문서 클러스터링의 LSI 분석)

  • Oh, Hyung-Jin;Go, Ji-Hyun;An, Dong-Un;Park, Soon-Chul
    • The KIPS Transactions:PartB
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    • v.10B no.7
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    • pp.735-742
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    • 2003
  • In the information retrieval system, document clustering technique is to provide user convenience and visual effects by rearranging documents according to the specific topics from the retrieved ones. In this paper, we clustered documents using K-Means algorithm and present the effect of index terms weighting scheme on the document clustering. To verify the experiment, we applied Latent Semantic Indexing approach to illustrate the clustering results and analyzed the clustering results in 2-dimensional space. Experimental results showed that in case of applying local weighting, global weighting and normalization factor, the density of clustering is higher than those of similar or same weighting schemes in 2-dimensional space. Especially, the logarithm of local and global weighting is noticeable.