• 제목/요약/키워드: Structure and function

검색결과 6,627건 처리시간 0.038초

Use of the Quantitatively Transformed Field Soil Structure Description of the US National Pedon Characterization Database to Improve Soil Pedotransfer Function

  • Yoon, Sung-Won;Gimenez, Daniel;Nemes, Attila;Chun, Hyen-Chung;Zhang, Yong-Seon;Sonn, Yeon-Kyu;Kang, Seong-Soo;Kim, Myung-Sook;Kim, Yoo-Hak;Ha, Sang-Keun
    • 한국토양비료학회지
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    • 제44권5호
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    • pp.944-958
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    • 2011
  • Soil hydraulic properties such as hydraulic conductivity or water retention which are costly to measure can be indirectly generated by soil pedotransfer function (PTF) using easily obtainable soil data. The field soil structure description which is routinely recorded could also be used in PTF as an input to reduce the uncertainty. The purposes of this study were to use qualitative morphological soil structure descriptions and soil structural index into PTF and to evaluate their contribution in the prediction of soil hydraulic properties. We transformed categorical morphological descriptions of soil structure into quantitative values using categorical principal component analysis (CATPCA). This approach was tested with a large data set from the US National Pedon Characterization database with the aid of a categorical regression tree analysis. Six different PTFs were used to predict the saturated hydraulic conductivity and those results were averaged to quantify the uncertainty. Quantified morphological description was successively used in multiple linear regression approach to predict the averaged ensemble saturated conductivity. The selected stepwise regression model with only the transformed morphological variables and structural index as predictors predicted the $K_{sat}$ with $r^2$ = 0.48 (p = 0.018), indicating the feasibility of CATPCA approach. In a regression tree analysis, soil structure index and soil texture turned out to be important factors in the prediction of the hydraulic properties. Among structural descriptions size class turned out to be an important grouping parameter in the regression tree. Bulk density, clay content, W33 and structural index explained clusters selected by a two step clustering technique, implying the morphologically described soil structural features are closely related to soil physical as well as hydraulic properties. Although this study provided relatively new method which related soil structure description to soil structure index, the same approach should be tested using a datasets containing the actual measurement of hydraulic properties. More insight on the predictive power of soil structure index to estimate hydraulic properties would be achieved by considering measured the saturated hydraulic conductivity and the soil water retention.

Pitch Accent Realization in North Kyungsang Korean: Tonal Alignment as a Function of Nasal Position in Syllables

  • Sohn, Hyang-Sook
    • 말소리와 음성과학
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    • 제3권2호
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    • pp.37-52
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    • 2011
  • This study investigates patterns of the alignment of the accentual peaks in bisyllabic words of the CVNCV, CVNV, and CVNNV structures in North Kyungsang Korean. Based on the tonal alignment, patterns of the F0 pitch excursion are discussed relative to one another. Issues are addressed concerning how the tonal targets are aligned, and how the tonal specifications of nasals in postvocalic, intervocalic, and prevocalic environments are supplied in the LH, HL, and HH classes. Tonal specification of nasals in various environments is accounted for by extension of the L target, displacement of the pitch peak, and interpolation between two tonal targets, depending on the tonal class. The results in this study provide preliminary evidence that the categorical alignment of the tonal targets is implemented by simply checking the presence or absence of a nasal before or after the nucleus vowel on the segmental string, without reference to the constituency of the nasal in the syllable structure. However, the prosodic structure has a key role to play in explaining speaker-dependent variations in the tonal alignment. Sensitivity to tautosyllabicity has an effect on the shape of the F0 contour, and disparity in the patterns of the pitch excursion is represented as a function of syllable structure correlated with segmental composition of the nasal.

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이동 로봇의 경로 추종을 위한 웨이블릿 퍼지 신경 회로망 기반 직접 적응 제어 시스템 (Direct Adaptive Control System for Path Tracking of Mobile Robot Based on Wavelet Fuzzy Neural Network)

  • 오준섭;박진배;최윤호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 하계학술대회 논문집 D
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    • pp.2432-2434
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    • 2004
  • In this paper, we present a novel approach for the structure of Fuzzy Neural Network(FNN) based on wavelet function and apply this network structure to the solution of the tracking problem for mobile robots. Generally, the wavelet fuzzy model(WFM) has the advantage of the wavelet transform by constituting fuzzy basis function(FBF) and the conclusion part to equalize the linear combination of FBF with the linear combination of wavelet functions. However, it is very difficult to identify the fuzzy rules and to tune the membership functions of the fuzzy reasoning mechanism. Neural networks, on the other hand, utilize their learning capability for automatic identification and tuning. Therefore, we design a wavelet based FNN structure(WFNN) that merges these advantages of neural network, fuzzy model and wavelet. To verify the efficiency of our network structure, we evaluate the tracking performance for mobile robot and compare it with those of the FNN and the WFM.

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Coverage Dependent Adsorption Configuration of Phenylalanine on Ge(100)

  • 양세나;윤영상;김예원;황한나;황찬국;김기정;김세훈;이한길
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2010년도 제39회 하계학술대회 초록집
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    • pp.78-78
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    • 2010
  • The Adsorption structures of phenylalanine on Ge(100) surface have been investigated as a function of coverage using high-resolution photoemission spectroscopy (HRPES) and density functional (DFT) calculation. To converge these experimental and theoretical conclusion, we systematically performed HRCLPES measurements and DFT calculation for various coverage in the adsorption structures of phenylalanine molecules on the Ge(100) surface. In this study, we found two different adsorption structure as a function of coverage in phenylalanine on Ge(100), monitoring three core level spectra (Ge 3d, C 1s, N 1s, and O 1s) using HRPES Through analysis of the binding energies, we confirmed that O-H dissociated and N dative-bonded structure emerges at low coverage (0.10 ML), which is the same to the result of glycine and alanine on Ge(100) system, whereas O-H dissociation structure also appears at higher coverage. Moreover, we observed the shape of phenyl group being included in phenylalanine is changed from flat to tilting structure at final state using DFT calculation. Through the spectral analysis for phenylalanine, we will demonstrate variation of coverage dependent structural change for phenylalanine on Ge(100) surface using experimental (HRPES) and theoretical studies (DFT calculation).

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Three-dimensional structural design based on cellular automata simulation

  • Kita, E.;Saito, H.;Tamaki, T.;Shimizu, H.;Xie, Y.M.
    • Structural Engineering and Mechanics
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    • 제23권1호
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    • pp.29-42
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    • 2006
  • This paper describes the design scheme of the three-dimensional structures based on the concept of the cellular automata simulation. The cellular automata simulation is performed according to the local rule. In this paper, the local rule is derived in the mathematical formulation from the optimization problem. The cell density is taken as the design variable. Two objective functions are defined for reducing the total weight of the structure and obtaining the fully stressed structure. The constraint condition is defined for defining the local rule. The penalty function is defined from the objective functions and the constraint condition. Minimization of the penalty function with respect to the design parameter leads to the local rule. The derived rule is applied to the design of the three-dimensional structure first. The final structure can be obtained successfully. However, the computational cost is expensive. So, in order to reduce the computational cost, the material parameters $c_1$ and $c_2$ and the value of the cell rejection criterion (CRC) are changed. The results show that the computational cost depends on the parameters and the CRC value.

회전불변 패턴인식을 위한 WCHF-FSJTC (Wavelet circular harmonic function frequency selective joint transform correlator for rotation invariant pattern recognition)

  • 방준학;이하운;노덕수;김수중
    • 전자공학회논문지S
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    • 제34S권2호
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    • pp.94-103
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    • 1997
  • The WCHF-FSJTC (wavelet circular harmonic function frequency selective joint transform correlator) using th wavelet transformed CHF as the reference image in FSJTC is proposed for rotation invariant pattern recognition. Since the wavelet transform has the property of feature extraction, the proposed system can have the better DC (discrimination cpability) and the higher SNR(signal to noise ratio) compared with the conventional CHF-CJTC(circular harmonic function conventional joint transform correlator). And since the structure of the proposed system is FSJTC which can eliminate auto-correlation and cross-correlation between input images, it can eliminate false alarm caused by the overlapping among correlation peaks. The used wavelet functio is the morlet function, which is proper for the reference image used in this paper. the optimal dialation parameter and oscillation frequency of the wavelet function are also achieved with varying the parameters of the wavelet function. The computer simulation shows that the proposed system has the best performance when the dilation parameter is 0.8 and the oscillation frequency is 0.48.

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이중대격에 대한 자율모듈적 분석 (An Autonomous Modular Account of Double Accusatives)

  • 김경환
    • 한국콘텐츠학회논문지
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    • 제22권10호
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    • pp.74-82
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    • 2022
  • 본 논문은 문장의 통사구조, 의미구조, 형태구조 등을 동시에 그리고 독립적으로 생성되는 모듈로 보는 자율어휘문법을 기반으로 한국어의 이중대격에 대한 다모듈적 분석을 제시하는 것을 목적으로 한다. 통사중심주의적 이론들과 달리 본 논문은 이중대격 구문의 기능-논항구조와 더불어 역할구조와 정보구조를 통해 이중대격에 대한 의미론적 특성을 분석한다. 기능-논항구조에서 이중대격의 첫 번째 대격은 관계명사의 논항인 소유격과는 달리 술어의 논항이 되며, 역할구조에서는 수동자의 역할을 취하게 되어 그 결과 수동문의 주어가 될 수 있다. 반면에 이중대격 구문에서 두 번째 대격인 소유대상은 정보구조에서 초점영역이 된다. 즉, 이중대격의 사용 목적은 두 가지로 정리된다. 소유자를 수동자의 역할을 하는 독립된 논항으로 표현하는 동시에 소유대상을 초점으로 표현하고자 하는 화자의 의도를 나타내는 것이다. 이와 같은 이중대격의 의미론적 특성을 자율어휘문법의 기능-논항구조, 역할구조, 정보구조 등 세 개의 다차원적인 구조로 나타내므로 해서 이중대격에 대한 통합적 설명이 가능해진다.

CRITICAL METRICS ON NEARLY KAEHLERIAN MANIFOLDS

  • Pak, Jin-Suk;Yoo, Hwal-Lan
    • 대한수학회보
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    • 제29권1호
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    • pp.9-13
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    • 1992
  • In this paper, we consider the function related with almost hermitian structure on a copact complex manifold. More precisely, on a 2n-diminsional complex manifold M admitting 2-form .ohm. of rank 2n everywhere, assume that M admits a metric g such that g(JX, JY)=g(X,Y), that is, assume that g defines an hermitian structure on M admitting .ohm. as fundamental 2-form-the 'almost complex structure' J being determined by g and .ohm.:g(X,Y)=.ohm.(X,JY). We consider the function I(g):=.int.$_{M}$ $N^{2}$d $V_{g}$, where N is the norm of Nijenhuis tensor N defined by (J,g). by (J,g).

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16-QAM 신호에 대한 이중 구조 CR-CMA 적응 등화기의 성능 (The Performance of Dual Structure CR-CMA Adaptive Equalizer for 16-QAM Signal)

  • 윤재선;임승각
    • 한국인터넷방송통신학회논문지
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    • 제12권5호
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    • pp.107-114
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    • 2012
  • 본 논문은 기존 블라인드 등화기의 성능인 수렴 특성과 잔류 부호간 간섭의 영향을 경감시키기 위해 축소 신호점을 사용하고 비용 함수를 실수부와 허수부로 분리하여 처리하는 한 이중 구조 CR-CMA(Constellation Reduction CMA)에 관한 것이다. 기존의 CMA는 진폭만을 보상하고 위상은 보상을 하지 못하며, 이를 해결하기 위해 MCMA(Modified CMA)는 비용 함수만을 실수부와 허수부를 따로 처리하여 진폭과 위상을 보상하지만 진폭의 보상 능력과 초기 수렴 속도에서는 CMA보다 성능이 열악해지는 문제점이 있다. 제안하는 이중 구조 CR-CMA는 CMA와 MCMA(Modified CMA) 알고리즘 장점만을 살릴 수 있도록 비용 함수와 오차 함수를 실수부와 허수부로 나누어 처리하고 축소 신호점을 적용할 수 있도록 개량하여 진폭과 위상의 보상, 빠른 수렴 속도 및 잔류 ISI와 MD(Maximum Distortion) 량의 감소 그리고 MSE(Mean Square Error)와 양호한 심볼 오류율 (SER : symbol error ratio) 특성을 얻을 수 있음을 컴퓨터 시뮬레이션으로 확인하였다.