• Title/Summary/Keyword: Correlation identification

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Identification of Backlash Nonlinear System by use of M-sequence and correlation

  • Kashiwagi, H.;Rong, Li.;Harada, H.
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.470-470
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    • 2000
  • This paper describes a new method of identifcation of backlash nonlinear systems by use of M-sequence correlation method. In this method, we can obtain not only Volterra kernels of up to 3rd order of the nonlinear system, but also the width of the backlash element from observing the crosscorrelation between the input and the output. Here strictly speaking, a multi-valued nonlinear system such as backlash element can not be expressed by Volterra kernel representation mathematically. But in practice, we encounter many cases where it is difficult to treat them mathematically but they can be controlled from experience. So we here dare to suppose that backlash nonlinear system can be approximated by Volterra kernel representation. Simulations are carried out on a nonlinear system consisting of linear part plus backlash element. And Volterra kernels are measured. The output calculated from the observed Volterra kernels is in good agreement wi th the actual output. And we show that we can obtain the width of backlash element, which is one of the most important parameters, by observing the maximum value of crosscorrelation function between the input M-sequence and the output.

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A Practical Implementation of Fuzzy Fingerprint Vault

  • Lee, Sun-Gju;Chung, Yong-Wha;Moon, Dae-Sung;Pan, Sung-Bum;Seo, Chang-Ho
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.5 no.10
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    • pp.1783-1798
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    • 2011
  • Recently, a cryptographic construct, called fuzzy vault, has been proposed for crypto-biometric systems, and some implementations for fingerprint have been reported to protect the stored fingerprint template by hiding the fingerprint features. In this paper, we implement the fuzzy fingerprint vault, combining fingerprint verification and fuzzy vault scheme to protect fingerprint templates. To implement the fuzzy fingerprint vault as a complete system, we have to consider several practical issues such as automatic fingerprint alignment, verification accuracy, execution time, error correcting code, etc. In addition, to protect the fuzzy fingerprint vault from the correlation attack, we propose an approach to insert chaffs in a structured way such that distinguishing the fingerprint minutiae and the chaff points obtained from two applications is computationally hard. Based on the experimental results, we confirm that the proposed approach provides higher security than inserting chaffs randomly without a significant degradation of the verification accuracy, and our implementation can be used for real applications.

Application of UPOV Data for the Analysis of Genetic Variation in Rose Cultivars

  • Kim, Gi-Jun;Song, Young-Ha;Gi, Gwang-Yeon;Kim, Seong-Tae;Lee, Ja-Hyun;Han, Tae-Ho
    • Horticultural Science & Technology
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    • v.29 no.3
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    • pp.240-246
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    • 2011
  • The principal objective of this study was to estimate the availability of morphological data on the basis of the guidelines of the International Union for the Protection of New Varieties of Plants (UPOV) with regard to the identification of the rose germplasm. The correlation of morphological traits and random amplified polymorphic DNA (RAPD) marker data among 44 rose cultivars was assessed via a mantel test. Thirty eight phenotypes were employed for morphological analysis. Sixteen primers were utilized for RAPD analysis, and these generated 225 polymorphic bands. The dendrogram based on the RAPD markersgrouped 44 rose cultivars according to their horticultural types. No significant correlation was observed between the morphological and RAPD marker data. We concluded that current UPOV traits could not be applied to study genetic variation. Further studies on morphological traits are required for the analysis of genetic variation among cultivars.

A SENSITIVITY ANALYSIS OF THE KEY PARAMETERS FOR THE PREDICTION OF THE PRESTRESS FORCE ON BONDED TENDONS

  • Jang, Jung-Bum;Lee, Hong-Pyo;Hwang, Kyeong-Min;Song, Young-Chul
    • Nuclear Engineering and Technology
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    • v.42 no.3
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    • pp.319-328
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    • 2010
  • Bonded tendons have been used in reactor buildings at some operating nuclear power plants in Korea. Assessing prestress force on these bonded tendons has become an important pending problem in efforts to assure continued operation beyond their design life. The System Identification (SI) technique was thus developed to improve upon the existing indirect assessment technique for bonded tendons. As a first step, this study analyzed the sensitivity of the key parameters to prestress force, and then determined the optimal parameters for the SI technique. A total of six scaled post-tensioned concrete beams with bonded tendons were manufactured. In order to investigate the correlation of the natural frequency and the displacement to prestress force, an impact test, a Single Input Multiple Output (SIMO) sine sweep test, and a bending test using an optical fiber sensor and compact displacement transducer were carried out. These tests found that both the natural frequency and the displacement show a good correlation with prestress force and that both parameters are available for the SI technique to predict prestress force. However, displacements by the optical fiber sensor and compact displacement transducer were shown to be more sensitive than the natural frequency to prestress force. Such displacements are more useful than the natural frequency as an input parameter for the SI technique.

Identification of Genetic Relationships Among Morus alba Genotypes Based on RAPD and ISSR Fingerprinting

  • Kalpana, Duraisamy;Cha, Hyo-Jung;Choi, Tae-Ki;Lee, Yang-Soo
    • Korean Journal of Plant Resources
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    • v.24 no.6
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    • pp.675-687
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    • 2011
  • Mulberries have importance in the sericulture industry as food for Bombyx mori, silkworm reared for its silk. Korean Morus alba have many cultivars and, for the protection of these cultivars and for utilization in plant-breeding programs, genetic information and the diversity among cultivars are essential. This study with 14 mulberry genotypes was undertaken using RAPD and ISSR fingerprinting to discover the genetic divergences between cultivars. Polymorphism rate among the cultivars produced by RAPD primer was found to be 64.48% and 66.29% relative to ISSR primer. The genetic relationships among the cultivars were identified using a dendrogram constructed with the UPGMA clustering method. Nei's method was used to calculate the genetic dissimilarity coefficients between each pair of genotypes, and the highest dissimilarity coefficient of 0.246 was exhibited between Suwon and Hwanggum cultivars. To determine the efficiency of each primer, a polymorphic index was calculated, and the robustness of the dendrogram was checked using cophenetic correlation coefficient. The results of this study can be utilized for the improvement of mulberry varieties in plant-breeding programs.

Understanding of unsteady pressure fields on prisms based on covariance and spectral proper orthogonal decompositions

  • Hoa, Le Thai;Tamura, Yukio;Matsumoto, Masaru;Shirato, Hiromichi
    • Wind and Structures
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    • v.16 no.5
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    • pp.517-540
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    • 2013
  • This paper presents applications of proper orthogonal decomposition in both the time and frequency domains based on both cross spectral matrix and covariance matrix branches to analyze multi-variate unsteady pressure fields on prisms and to study spanwise and chordwise pressure distribution. Furthermore, modification of proper orthogonal decomposition is applied to a rectangular spanwise coherence matrix in order to investigate the spanwise correlation and coherence of the unsteady pressure fields. The unsteady pressure fields have been directly measured in wind tunnel tests on some typical prisms with slenderness ratios B/D=1, B/D=1 with a splitter plate in the wake, and B/D=5. Significance and contribution of the first covariance mode associated with the first principal coordinates as well as those of the first spectral eigenvalue and associated spectral mode are clarified by synthesis of the unsteady pressure fields and identification of intrinsic events inside the unsteady pressure fields. Spanwise coherence of the unsteady pressure fields has been mapped the first time ever for better understanding of their intrinsic characteristics.

Identification of Anti-Oxidant and Anti-Tyrosinase Activity of Phenolic Components Isolated from Betula schmidtii (박달나무로부터 분리된 페놀성 화합물의 항산화 및 Tyrosinase 저해 활성 연구)

  • Wang, Da-Hye;Chung, Ha Sook
    • The Korean Journal of Food And Nutrition
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    • v.34 no.5
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    • pp.553-559
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    • 2021
  • The aim of study to investigate the phytochemicals and biological activities the bark of Betula schmidtii. The studies consisted of the solvent extraction, followed by the isolation of phenolic components 1~3 from ethyl acetate-soluble fraction of Betula schmidtii Bark. Their chemical structures were identified as arbutin (1), ρ-coumaric acid (2) and ferulic acid (3) using Ultraviolet-Visible (UV-Vis) Spectrophotometer, Electrospray Ionization Mass Spectrometry (ESI-MS) (negative ion mode), 1H-Nuclear Magnetic Resonance (NMR), 13C-NMR, 1H-1H Correlation Spectroscopy (COSY) and 1H-13C Hetero Nuclear Multiple Quantum Correlation (HMQC) spectral data. Compounds 1~3 shows the anti-oxidant effect with IC50 values of 29.74±1.52, 21.32±1.07 and 34.41±1.24 in 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, respectively. Also, compounds 1~3 exhibited mushroom tyrosinase inhibitory activity with IC50 values of 31.14±1.07, 42.54±1.46 and 69.22±1.43 µM, respectively.

Time delay estimation by iterative Wiener filter based recursive total least squares algorithm (반복형 위너 필터 방법에 기반한 재귀적 완전 최소 제곱 방법을 사용한 시간 지연 추정 알고리즘)

  • Lim, Jun-Seok
    • The Journal of the Acoustical Society of Korea
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    • v.40 no.5
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    • pp.452-459
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    • 2021
  • Estimating the mutual time delay between two acoustic sensors is used in various fields such as tracking and estimating the location of a target in room acoustics and sonar. In the time delay estimation methods, there are a non-parametric method, such as Generalized Cross Correlation (GCC), and a parametric method based on system identification. In this paper, we propose a time delay estimation method based on the parametric method. In particular, we propose a method that considers the noise in each receiving acoustic sensor. Simulation confirms that the proposed algorithm is superior to the existing generalized cross-correlation and adaptive eigenvalue analysis methods in white noise and reverberation environments.

Critical heat flux in a CANDU end shield - Influence of shielding ball diameter

  • Spencer, Justin
    • Nuclear Engineering and Technology
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    • v.54 no.4
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    • pp.1343-1354
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    • 2022
  • Experiments were performed to measure the critical heat flux (CHF) on a vertical surface abutting a coarse packed bed of spherical particles. This geometry is representative of a CANDU reactor calandria tubesheet facing the end shield cavity during the in-vessel retention (IVR) phase of a severe accident. Deionized light water was used as the working fluid. Low carbon steel shielding balls with diameters ranging from 6.4 to 12.7 mm were used, allowing for the development of an empirical correlation of CHF as a function of shielding ball diameter. Previously published data is used to develop a more comprehensive empirical correlation accounting for the impacts of both shielding ball diameter and heating surface height. Tests using borosilicate shielding balls demonstrated that the dependence of CHF on shielding ball thermal conductivity is insignificant. The deposition of iron oxide particles transported from shielding balls to the heating surface is verified to increase CHF non-trivially. The results presented in this paper improve the state of the knowledge base permitting quantitative prediction of CHF in the CANDU end shield, refining our ability to assess the feasibility of IVR. The findings clarify the mechanisms governing CHF in this scenario, permitting identification of potential future research directions.

Study on the Anthropometric and Body Composition Indices for Prediction of Cold and Heat Pattern

  • Mun, Sujeong;Park, Kihyun;Lee, Siwoo
    • The Journal of Korean Medicine
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    • v.42 no.4
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    • pp.185-196
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    • 2021
  • Objectives: Many symptoms of cold and heat patterns are related to the thermoregulation of the body. Thus, we aimed to study the association of cold and heat patterns with anthropometry/body composition. Methods: The cold and heat patterns of 2000 individuals aged 30-55 years were evaluated using a self-administered questionnaire. Results: Among the anthropometric and body composition variables, body mass index (-0.37, 0.39) and fat mass index (-0.35, 0.38) had the highest correlation coefficients with the cold and heat pattern scores after adjustment for age and sex in the cold-heat group, while the correlation coefficients were relatively lower in the non-cold-heat group. In the cold-heat group, the most parsimonious model for the cold pattern with the variables selected by the best subset method and Lasso included sex, body mass index, waist-hip ratio, and extracellular water/total body water (adjusted R2 = 0.324), and the model for heat pattern additionally included age (adjusted R2 = 0.292). Conclusions: The variables related to obesity and water balance were the most useful for predicting cold and heat patterns. Further studies are required to improve the performance of prediction models.