• Title/Summary/Keyword: multiple roots

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A Unit Root Test for Multivariate Autoregressive Model with Multiple Unit Roots

  • Shin, Key-Il
    • Journal of the Korean Statistical Society
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    • v.26 no.3
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    • pp.397-405
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    • 1997
  • Recently maximum likelihood estimators using unconditional likelihood function are used for testing unit roots. When one wants to use this method the determinant term of initial values in the multivariate unconditional likelihood function produces a complicated function of the elements in the coefficient matrix and variance matrix. In this paper an approximation of the determinant term is calculated and based on this aproximation an approximated unconditional likelihood function is calculated. The approximated unconditional maximum likelihood estimators can be used to test for unit roots. When multivariate process has one unit root the limiting distribution obtained by this method and the limiting distribution using exact unconditional likelihood function are the same.

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An Observation on Dries Van Noten's Collections (2) - Focus on Men's Collections from 1992 S/S to 2014 F/W - (드리스 반 노튼 컬렉션 고찰 (2) - 1992년 S/S ~ 2014년 F/W 남성복을 중심으로 -)

  • Park, Shinmi
    • Journal of the Korean Society of Costume
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    • v.66 no.3
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    • pp.51-74
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    • 2016
  • The purpose of this research is to analyze the relationship between the inspirations and designs of Dries Van Noten's Men's collections from 1992 S/S to 2014 F/W. The specific questions of this research are as follows: what are the important design features of the Dries Van Noten's Mixed collections from 1985 S/S to 1991 F/W? What are 'the roots of inspiration' of Dries Van Noten's Men's collections from 1992 S/S to 2014 F/W, and what are the aesthetic criterions of Noten's works? How can the roots of inspiration be categorized and what are its features? How did these roots of inspiration influence the Noten's designs? The paper is a reference of how ideas turn to practical works, and what the relationship between inspiration and design. Researchers utilized a qualitative research method providing a systematic review of the previous studies by analyzing the content. To conclude, roots of inspiration of Dries Van Noten's Men's collections can be classified into nine categories: 'Interpretation', 'Ethnic', 'Multiple Contents', 'Subculture', 'Region', 'Artist', 'Fashion Item', 'Sports', and 'New Trend'. Through the roots of inspiration, sensibility of Belgium, England, Italy, French chic, inquiry of ethnic, artist, sports, the neuter gender image, 1950's, 1960's & 1970's trend & style of street fashion, elegance for men, romanticism, zoot, rock 'n' roll, teddy boy, mods, punk, new romantic and 19th century's Anglo-Saxon style are extracted and applied to the designs through cross impact. The identity of Dries Van Noten's Men's collections are cross culture contents and harmony of the old generation and new generation.

An Observation on Dries Van Noten's Collections (1) - Focus on Women's Collections from 1994 S/S to 2014 F/W - (드리스 반 노튼 컬렉션 고찰 (1) - 1994년 S/S ~ 2014년 F/W 여성복을 중심으로 -)

  • Park, Shinmi
    • Journal of the Korean Society of Costume
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    • v.65 no.5
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    • pp.14-34
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    • 2015
  • The aim of this paper is to analyze the relationship between the inspirations and designs of Dries Van Noten's women's collections from 1994 S/S to 2014 F/W. From the research purpose the following questions arise: how are the brands of Dries Van Noten developed and what are the important features? What are 'the roots of inspiration' for Dries Van Noten's women's collections from 1994 S/S to 2014 F/W, and what are the aesthetic criterions of Noten's works? How are the roots of inspiration categorized, what are the features of each category, and how do these roots of inspiration influence the Noten's designs? The paper is a practical reference of how ideas turn to practical works and what is the relationship between inspiration and design. Researchers utilized a qualitative research method to provide a systematic review of the previous studies. To sum it up, roots of inspiration of Dries Van Noten's women's collections can be classified into seven categories: 'ethnic', 'trend & style', 'flowers', 'artists', 'interpretation', 'fabric & pattern' and 'multiple contents'. Through the roots of inspiration, sensibility of Belgium, inquiry of ethnic & oriental, Artists, England, longing of street fashion, 1920's & 1950's trend & style of French high fashion, romanticism, atmosphere of medieval, gypsy, punk and hippie are extracted and applied to the designs through cross impact. The identities of Dries Van Noten's women's collections are fusion and harmony of cross culture and diversity.

A Study on the Control of Asymmetric Sidelobe Levels and Multiple Nulling in Linear Phased Array Antennas (선형 위상 배열 안테나의 비대칭 Sidelobe 레벨 제어 및 다중 Nulling에 관한 연구)

  • Park, Eui-Joon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.20 no.11
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    • pp.1217-1224
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    • 2009
  • This paper newly proposes a methodology towards computing antenna element weights which are satisfying asymmetric sidelobe levels(SLLs) specified arbitrarily on both sides of the main beam pattern, in the linear phased array antenna pattern synthesis problem. Opposite to the conventional methods in which the element weights are directly optimized from the array factor, this method is based on the optimum perturbations of complex roots inherent to the Schelkunoff's polynomial form which is described for the array factor. From the proposed methodology, the capability of nulling the directions of multiple jammers is also possible by independently perturbing only the complex roots corresponding to each jamming direction, hence allowing an enhancement of the simplicity of the numerical procedure by means of a proper reduction of the dimension of the solution space. The complex weights over the array are then easily computed by substituting the optimally perturbed complex roots to the Schelkunoff's polynomial. Some examples are examined and numerically verified by substituting the extracted weights into the array factor equation.

A Parameter Estimation Method of Multiple Time Interval for Low Frequency Oscillation Analysis (저주파진동 해석을 위한 다구간 파라미터 추정 방법)

  • Shim, Kwan-Shik;Kim, Sang-Tae;Choi, Joon-Ho;Nam, Hae-Kon;Ahn, Seon-Ju
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.7
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    • pp.875-882
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    • 2014
  • In this paper, we propose a new parameter estimation method that can deal with the data of multiple time intervals simultaneously. If there are common modes in the multiple time intervals, it is possible to create a new polynomial by summing the coefficients of the prediction error polynomials of each time interval. By calculating the roots of the new polynomial, it is possible to estimate the common modes that exist in each time interval. The accuracy of the proposed parameter estimation method has been proven by using appropriate test signals.

Plant Regeneration from Turnip (Brassica rapa ssp. rapifera) Organs

  • Gendaram Sarantuya;Bae Chang-Hyu
    • Plant Resources
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    • v.8 no.3
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    • pp.286-292
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    • 2005
  • Shoot induction system was developed in the recalcitrant plant species, Brassica rapa ssp. rapifera by using optimum selection of profit organ, phytohormone combination, seedling age and kind of culture container. Out of in vitro cultured leaf segment, petiole, hypocotyl, and cotyledon with petiole, only cotyledon with petiole derived from 4 day-old seedlings induced multiple shoot. The optimum combination of auxin and cytokinin for the multiple shoot induction was MS medium containing 5mg/L BA and 0.5mg/L NAA. The major factors for multiple shoot propagation were part of plant organ, age of seedling, and ratio of auxin and cytokinin. In addition, shoot regeneration was promoted in the 100ml Erlenmeyer flask compared with the $90mm{\times}20mm$ Petri-dish. The induced shoots formed roots easy on MS medium containing 0.1mg/L IBA and the whole plants were successfully cultivated in soil.

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In vitro multiple shoot proliferation and plant regeneration in rose(Rosa hybrida L.)

  • Lee, Su-Young;Jung, Ji-Hye;Kim, Jeong-Hee;Han, Bong-Hee
    • Journal of Plant Biotechnology
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    • v.35 no.3
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    • pp.223-228
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    • 2008
  • This study was conducted to investigate an optimal condition for shoot proliferation and regenerate shoots from in vitro leaflet and embryogenic calli from in vitro roots in rose. The effect of BAP on shoot proliferation was somewhat different depending upon genotypes or gelling agents. Leaflets with petiole cut from donor shoots which had been cultured in MS medium supplemented with 0.1 $mg{\cdot}L^{-1}$ NAA for six weeks was effective for regeneration of adventitious buds(ABs) as well as shoot elongation of Rosa hybrida cv. Sweet Pink. Culturing seven leaflet explants per petri plate($100mm{\times}15mm$) was effective for regeneration of ABs. Embryogenesis was shown in the calli induced from roots of Rosa hybrida cv. Sweet Pink cultured in the SH medium supplemented with 11 $mg{\cdot}L^{-1}$ 2, 4-D for four weeks. Color of calli induced from roots was yellow although their color was a little different as type of basal medium.

Antioxidative Activity and Tyrosinase Inhibitory Activity of the Extract and Fractions from Arctium lappa Roots and Analysis of Phenolic Compounds (우엉 뿌리 추출물의 항산화 및 Tyrosinase 저해 활성과 Phenolic Compound 분석)

  • Im, Do Youn;Lee, Kyoung In
    • Korean Journal of Pharmacognosy
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    • v.45 no.2
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    • pp.141-146
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    • 2014
  • In this study, we investigated on antioxidative activities and tyrosinase inhibitory activities of methanol extract and its fractions from roots of Arctium lappa. The total phenolic compound and flavonoid content of the ethylacetate fraction was found to be 818.29 mg/g and 360.59 mg/g as the highest content. In the measurement of DPPH radical scavenging ability and tyrosinase inhibitory activity, the ethylacetate fraction was higher than the other fractions and the extract. In addition, comparative analysis of phenolic compounds by liquid chromatography-mass spectrometry (MS)/MS system under the multiple-reaction monitoring (MRM) with negative-ion electrospray ionization mode. The main phenolic compounds in the extract and fractions of roots from Arctium lappa were cynarin and chlorogenic acid. The main phenolic compound of the ethylacetate fraction was cynarin. n-Butanol fraction had a significantly higher chlorogenic acid content than other samples. In conclusion, DPPH radical scavenging ability and tyrosinase inhibitory activity of the cynarin-riched ethylacetate fraction showed the highest activity.

Determination of Bulk Density and Internal Structure of Red Ginseng Root Using NMR (NMR을 이용한 홍삼의 용적밀도 측정 및 내부 조직 판별)

  • ;R. Ruan
    • Journal of Ginseng Research
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    • v.22 no.2
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    • pp.96-101
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    • 1998
  • This paper describes the determination of bulk density and the discrimination of internal structure of red ginseng by nuclear magnetic resonance (NMR). The 102 red ginseng roots were tested for bulk density. The NMR properties measured by NMR parameters such as spin-lattice relaxation time ($T_1$) and spin-spin relaxation time ($T_2$) were determined using the low field proton NMR analyzer. Bulk density of red ginseng root showed a highly negative significant correlation (r=-0.8934) with the value of $T_1$, but a highly positive significant correlation (r=0.7672 and 0.5909) with the value of T21 (short T2) and T22 (long T2), respectively. Multiple regression equation, Y=-0.0069.$T_1$+0.3044.$T_{21}$-0.0156.$T_{22}$-0.6368, using the MNR parameter values of 80 red ginseng roots can effectively predict the bulk density of 22 red ginseng roots with the correlation coefficient of 0.9396 and the standard error of 0.086. The differences in the internal structure of normal and inside white part of red ginseng were easily found by the signal intensity of NMR image based on magnetic properties of proton nucleus.

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Local Modification of a Surface and Multiple Knot Insertion by Using the Chebyshev Polynormial (Chebyshev 다항식에 기초한 다수개의 절점 삽입과 곡면의 국부 수정)

  • 최성일;김태규;변문현
    • Korean Journal of Computational Design and Engineering
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    • v.3 no.2
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    • pp.103-112
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    • 1998
  • In this paper insertion of numerous control points to be performed by using the Chebyshev polynomial root at the selection of knot vector. This method introduces a simple method of knot refinement and it is applied in a developed program. The Chebyshev roots exist densely in broth ends of the range and are proposed more effective knot refinement to modify a surface. Therefore, generated control points are relatively uniform in specified knot interval. In the surface generation, a local insertion of numerous control points are easily inserted by using the characteristic of Chebyshev polynomial roots at knot refinement. It is possible to create a complex surface with a single surface. The number of control point can be reduced by using the local insertion of control points in a required shape

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