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Hyperparameter Selection for APC-ECOC

  • Seok, Kyung-Ha
    • Journal of the Korean Data and Information Science Society
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    • v.19 no.4
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    • pp.1219-1231
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    • 2008
  • The main object of this paper is to develop a leave-one-out(LOO) bound of all pairwise comparison error correcting output codes (APC-ECOC). To avoid using classifiers whose corresponding target values are 0 in APC-ECOC and requiring pilot estimates we developed a bound based on mean misclassification probability(MMP). It can be used to tune kernel hyperparameters. Our empirical experiment using kernel mean squared estimate(KMSE) as the binary classifier indicates that the bound leads to good estimates of kernel hyperparameters.

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A Rapid Quantitative Assay of Intact Ambroxol Tablets by FT-NIR Spectroscopy

  • Kim, Do-Hyung;Ah, Woo-Young;Kim, Hyo-Jin
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.213.2-213.2
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    • 2003
  • A simple analytical procedure using FT-NIR for the rapid determination of individual ingredients was evaluated. Direct measurements were made by reflection using a reflectance accessory, by transmittance using tablet accessory and turn table. FT-NIR spectral data were transformed to the first derivative. Partial Least Square Regression(PLSR) was applied to quantify near-infrared (NIR) spectra of 2 ingredients. These calibration models were cross-validated (leave-one-out approach). The prediction ability of the models was evaluated on ambroxol tablets and compared with the real values in manufacturing procedure. (omitted)

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Prediction of Chronic Hepatitis Susceptibility using Single Nucleotide Polymorphism Data and Support Vector Machine (Single Nucleotide Polymorphism(SNP) 데이타와 Support Vector Machine(SVM)을 이용한 만성 간염 감수성 예측)

  • Kim, Dong-Hoi;Uhmn, Saang-Yong;Hahm, Ki-Baik;Kim, Jin
    • Journal of KIISE:Computer Systems and Theory
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    • v.34 no.7
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    • pp.276-281
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    • 2007
  • In this paper, we use Support Vector Machine to predict the susceptibility of chronic hepatitis from single nucleotide polymorphism data. Our data set consists of SNP data for 328 patients based on 28 SNPs and patients classes(chronic hepatitis, healthy). We use leave-one-out cross validation method for estimation of the accuracy. The experimental results show that SVM with SNP is capable of classifying the SNP data successfully for chronic hepatitis susceptibility with accuracy value of 67.1%. The accuracy of all SNPs with health related feature(sex, age) is improved more than 7%(accuracy 74.9%). This result shows that the accuracy of predicting susceptibility can be improved with health related features. With more SNPs and other health related features, SVM prediction of SNP data is a potential tool for chronic hepatitis susceptibility.

Estimation of Flood Quantile in Ungauged Watersheds for Flood Damage Analysis Based on Flood Index of Natural Flow (미계측 유역의 홍수피해분석을 위한 자연유량의 홍수지표 기반 확률홍수량 산정)

  • Chae, Byung Seok;Choi, Si Jung;Ahn, Jae Hyun;Kim, Tae-Woong
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.38 no.1
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    • pp.175-182
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    • 2018
  • In this study, flood quantiles were estimated at ungauged watersheds by adjusting the flood quantiles from the design rainfall - runoff analysis (DRRA) method based on regional frequency analysis. Comparing the flood frequency analysis (FFA) and DRRA, it was found that the flood quantiles estimated by the DRRA method were overestimated by 52%. In addition, a practical method was suggested to make an flood index using natural flows to apply the regional frequency analysis (RFA) to ungauged watersheds. Considering the relationships among DRRA, FFA, and RFA, we derived an adjusting formula that can be applied to estimate flood quantiles at ungauged watersheds. We also employed Leave-One-Out Cross-Validation scheme and skill score to verify the method proposed in this study. As a result, the proposed model increased the accuracy by 23.2% compared to the existing DRRA method.

Searching for Optimal Ensemble of Feature-classifier Pairs in Gene Expression Profile using Genetic Algorithm (유전알고리즘을 이용한 유전자발현 데이타상의 특징-분류기쌍 최적 앙상블 탐색)

  • 박찬호;조성배
    • Journal of KIISE:Software and Applications
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    • v.31 no.4
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    • pp.525-536
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    • 2004
  • Gene expression profile is numerical data of gene expression level from organism, measured on the microarray. Generally, each specific tissue indicates different expression levels in related genes, so that we can classify disease with gene expression profile. Because all genes are not related to disease, it is needed to select related genes that is called feature selection, and it is needed to classify selected genes properly. This paper Proposes GA based method for searching optimal ensemble of feature-classifier pairs that are composed with seven feature selection methods based on correlation, similarity, and information theory, and six representative classifiers. In experimental results with leave-one-out cross validation on two gene expression Profiles related to cancers, we can find ensembles that produce much superior to all individual feature-classifier fairs for Lymphoma dataset and Colon dataset.

Comparison of Univariate Kriging Algorithms for GIS-based Thematic Mapping with Ground Survey Data (현장 조사 자료를 이용한 GIS 기반 주제도 작성을 위한 단변량 크리깅 기법의 비교)

  • Park, No-Wook
    • Korean Journal of Remote Sensing
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    • v.25 no.4
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    • pp.321-338
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    • 2009
  • The objective of this paper is to compare spatial prediction capabilities of univariate kriging algorithms for generating GIS-based thematic maps from ground survey data with asymmetric distributions. Four univariate kriging algorithms including traditional ordinary kriging, three non-linear transform-based kriging algorithms such as log-normal kriging, multi-Gaussian kriging and indicator kriging are applied for spatial interpolation of geochemical As and Pb elements. Cross validation based on a leave-one-out approach is applied and then prediction errors are computed. The impact of the sampling density of the ground survey data on the prediction errors are also investigated. Through the case study, indicator kriging showed the smallest prediction errors and superior prediction capabilities of very low and very high values. Other non-linear transform based kriging algorithms yielded better prediction capabilities than traditional ordinary kriging. Log-normal kriging which has been widely applied, however, produced biased estimation results (overall, overestimation). It is expected that such quantitative comparison results would be effectively used for the selection of an optimal kriging algorithm for spatial interpolation of ground survey data with asymmetric distributions.

Multimodal Parametric Fusion for Emotion Recognition

  • Kim, Jonghwa
    • International journal of advanced smart convergence
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    • v.9 no.1
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    • pp.193-201
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    • 2020
  • The main objective of this study is to investigate the impact of additional modalities on the performance of emotion recognition using speech, facial expression and physiological measurements. In order to compare different approaches, we designed a feature-based recognition system as a benchmark which carries out linear supervised classification followed by the leave-one-out cross-validation. For the classification of four emotions, it turned out that bimodal fusion in our experiment improves recognition accuracy of unimodal approach, while the performance of trimodal fusion varies strongly depending on the individual. Furthermore, we experienced extremely high disparity between single class recognition rates, while we could not observe a best performing single modality in our experiment. Based on these observations, we developed a novel fusion method, called parametric decision fusion (PDF), which lies in building emotion-specific classifiers and exploits advantage of a parametrized decision process. By using the PDF scheme we achieved 16% improvement in accuracy of subject-dependent recognition and 10% for subject-independent recognition compared to the best unimodal results.

Efficient Peer Assignment for Low-Latency Transmission of Scalable Coded Images

  • Su, Xiao;Wang, Tao
    • Journal of Communications and Networks
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    • v.10 no.1
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    • pp.79-88
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    • 2008
  • In this paper, we propose efficient peer assignment algorithms for low-latency transmission of scalable coded images in peer-to-peer networks, in which peers may dynamically join and leave the networks. The objective of our algorithm is to minimize the transmission time of a requested image that is scalable coded. When an image is scalable coded in different bit rates, the bit stream encoded in a lower bit rate is a prefix subset of the one encoded in a higher bit rate. Therefore, a peer with the same requested image coded in any bit rate, even when it is different from the requested rate, may work as a supplying peer. As a result, when a scalable coded image is requested, more supplying peers can be found in peer-to-peer networks to help with the transfer. However, the set of supplying peers is not static during transmission, as the peers in this set may leave the network or finish their transmission at different times. The proposed peer assignment algorithms have taken into account the above constraints. In this paper, we first prove the existence of an optimal peer assignment solution for a simple identity permutation function, and then formulate peer assignment with this identity permutation as a mixed-integer programming problem. Next, we discuss how to address the problem of dynamic peer departures during image transmission. Finally, we carry out experiments to evaluate the performance of proposed peer assignment algorithms.

Hotel housekeepers and occupational health: experiences and perceived risks

  • Xenia Chela-Alvarez;Oana Bulilete;Encarna Garcia-Illan;MClara Vidal-Thomas;Joan Llobera;Arenal Group
    • Annals of Occupational and Environmental Medicine
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    • v.34
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    • pp.29.1-29.14
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    • 2022
  • Background: Hotel housekeepers are one of the most important occupational group within tourism hotel sector; various health problems related to their job have been described, above all musculoskeletal disorders. The objective of this study is to understand the experiences and perceptions of hotel housekeepers and key informants from the Balearic Islands (Spain) regarding occupational health conditions and the strategies employed to mitigate them. Methods: A qualitative study was carried out. Six focus groups with hotel housekeepers and 10 semi-structured interviews with key informants were conducted. Next, we carried out a content analysis. Results: Hotel housekeepers reported musculoskeletal disorders, anxiety and stress as main occupational health problems; health professionals underscored the physical problems. Hotel housekeepers perceived that their work (physically demanding and with repetitive movements) caused their health conditions. To solve health issues, they used medication (anti-inflammatory agents, painkillers, sedatives and anxiolytics), which allowed them to continue working; health public services, generally rated as satisfactory; individual protective equipment; ergonomics (with difficulties due to high work pace and hotel facilities) and physical activity. Two contrasting attitudes were identified regarding sick leave: HHs who refused to accept a doctor-prescribed sick leave (due to fear of being fired, sense of responsibility, ...), and those who accepted it (because they could not continue working, they prioritised health before work). Conclusions: Our results might contribute to plan improvement strategies and programs to address health problems among hotel housekeepers. These programs should include interventions, such as coping strategies for the work-related risk factors (i.e., stress) and strategies to reduce medicine consumption. Additionally, hotel facilities should adopt policies focused on making workplaces more ergonomic (i.e., furniture) and to diminish the work pace.

Spatial merging of satellite based soil moisture and in-situ soil moisture using conditional merging technique (조건부 합성방법을 이용한 위성관측 토양수분과 지상관측 토양수분의 합성)

  • Lee, Jaehyeon;Choi, Minha;Kim, Dongkyun
    • Journal of Korea Water Resources Association
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    • v.49 no.3
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    • pp.263-273
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    • 2016
  • This study applied conditional merging (CM) spatial interpolation technique to obtain the satellite and in-situ composite soil moisture data. For the analysis, 24 gages of hourly in-situ data sets from the Rural Development Administration (RDA) of Korea and the satellite soil moisture data retrieved from Advanced Microwave Scanning Radiometer-Earth observing system (AMSR-E) were used. In order to verify the performance of the CM method, leave-one-out cross validation was used. The cross validation result was spatially interpolated to figure out spatial correlation of the CM method. The results derived from this study are as follow: (1) The CM method produced better soil moisture map over Korean Peninsula than AMSR-E did for the over 100 days out of total 113 days considered for the analysis. (2) The method of CM showed high correlation with gage density and better performance on the western side of Korean peninsula due to high spatial gauge density. (3) The performance of CM is not affected by the non-rainy season unlike to AMSR-E data is. Overall, the result of this study indicates that the CM method can be applied for predicting soil moisture at ungaged locations.