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CLASSIFICATION AND EXISTENCE OF NONOSCILLATORY SOLUTIONS OF HIGHER ORDER NONLINEAR NEUTRAL DIFFERENCE EQUATIONS

  • ZHOU YONG;LI C. F.
    • Journal of applied mathematics & informatics
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    • v.18 no.1_2
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    • pp.127-144
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    • 2005
  • In this paper, we consider the higher order nonlinear neutral delay difference equation of the form $\Delta^{\gamma}(x_{n}+px_{n-\gamma})+f(n, x_{n-\sigma_1(n)}, x_{n-\sigma_2(n)}, \ldots, x_{n-\sigma{_m}(n)})=0$. We give an integrated classification of nonoscillatory solutions of the above equation according to their asymptotic behaviours. Necessary and sufficient conditions for the existence of nonoscillatory solutions with designated asymptotic properties are also established.

ASYMPTOTIC BEHAVIOUR AND EXISTENCE OF NONOSCILLATORY SOLUTIONS OF SECOND-ORDER NEUTRAL DELAY DIFFERENCE EQUATIONS

  • Li, Xianyi;Zhou, Yong
    • Journal of applied mathematics & informatics
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    • v.11 no.1_2
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    • pp.173-183
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    • 2003
  • In this paper, we give a classification of nonoscillatory solution of a second-order neutral delay difference equation of the form △²(x/sub n/-c/sub n/x/sub n-r/)=f(n, x/sub g1(n)/, …, x/sub gm(n)/). Some existence results for each kind of nonoscillatory solutions we also established.

Time-Dependent Optimal Heater Control Using Finite Difference Method

  • Li, Zhen-Zhe;Heo, Kwang-Su;Choi, Jun-Hoo;Seol, Seoung-Yun
    • Proceedings of the KSME Conference
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    • 2008.11b
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    • pp.2254-2255
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    • 2008
  • Thermoforming is one of the most versatile and economical process to produce polymer products. The drawback of thermoforming is difficult to control thickness of final products. Temperature distribution affects the thickness distribution of final products, but temperature difference between surface and center of sheet is difficult to decrease because of low thermal conductivity of ABS material. In order to decrease temperature difference between surface and center, heating profile must be expressed as exponential function form. In this study, Finite Difference Method was used to find out the coefficients of optimal heating profiles. Through investigation, the optimal results using Finite Difference Method show that temperature difference between surface and center of sheet can be remarkably minimized with satisfying Temperature of Forming Window.

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A Study on the Construction of Modern Architectural Form and the Characteristics of Deconstructional Fashion (현대 건축의 형태구성과 해체주의 패션의 특성에 관한 연구)

  • 김혜정;임영자
    • Journal of the Korean Society of Costume
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    • v.40
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    • pp.137-147
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    • 1998
  • Fahion as the form construction of decon-structivistic architecture was analyzed by dividing it into the intrinsic aspect and the formal aspect through an introduction of three characteristic architectural principles into fashion. Intrinsic deconstructivistic fashion as the construction of architectural form has the mixurte of genders both in a form of transvestic and in a form of genderless look as dualism, and can be characterized by pluralistic nationlism with the emergence of the Third World alienated from the international society, and so forth. Difference and the prefixes of dis-and de- are schizophrenic mystic illusionism, chance effect and the differance of space and time and is supporting Jacques Derrida's chiasmus that is the perspective of collage in painting and the multiple observation of collage in painting and the multiple observation point as the play of borrowing the surrealistic technique. The formal construction of deconstructivistic fashion the construction of architectural form has intertextuality material, hybridization of items and the blending of modes and another sphere. Trace as icon deconstrucion attains historical analysis. Dis and de in fashion are showing the retrogre-ssion of gravity through decomposition, decon-tinuity and disjunction emerge nonstructural silho-uette, juxtaposition, inversion and replace- ment of underwear and outer garments. Their decentring expression emerged as construction through mixture and repetition as well as overlapping of planes or spaces. And their disjuctive representation appeared in the form of mutual juxtaposition and substitution with the double-side of formal construction in functional terms.

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Study on Forms of Engel Curves in the Analysis of Household Budgets (가계분석에 있어서 Engel curvedml 함수형태에 관한 연구)

  • 배연수
    • Journal of the Korean Home Economics Association
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    • v.28 no.4
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    • pp.87-101
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    • 1990
  • This study was undertaken to test to fit forms of the Engel curves to data. The comparisons were confined to the linear, semi-logarithmic and double-logarithmic forms. Data from the 1970-1987 Urban Household Economy Survey were used to estimate the Engel curves. The twelve categories of consumption expenditure were considered for investigation. Parameters of the Engel curves were derived from OLS and TSLS. In this paper the size of the family was used as the deflater. The results could be summarized as follows: 1. Comparing with the R2 of three foms, it could be concluded that, the linear form generally gave a better fit to data than the other forms did. Only for housing and clothing and foot wear, did the semi-logarithmic form give a better fit. Only for meals outside the home, fuel, light and water charges, and miscellaneous, did the double-logarithmic form give a better fit. 2. Comping with the income elasticities based on the alternative forms, it could be concluded that the differences between the estimates were since each form made different assumption as to the way in which elasticity varied. In general, the semi-logarithmic form gave the highest estimate and double-logarithmic form did the lowest estimate. The difference between semi-logarithmic and the other forms were greater than the those of linear and double-logarithmic form. 3. It was found that the income elasticity varied with the difinition of income used as an explanatory variable in Engel curves.

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Experimental Study on Magnetic Compaction for Reducing Bughole of Free-Form Concrete Panels (비정형 콘크리트 패널 표면 공극저감을 위한 자력 다짐 실험연구)

  • Youn, Jong-Young;Kim, Ji-Hye;Kim, Hye-Kwon;Lee, Donghoon
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2023.05a
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    • pp.25-26
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    • 2023
  • Free-form buildings serve as landmarks, and interest and demand are increasing. However, in the case of free-form concrete members, different curved surfaces are required depending on the location where they are used, and the formwork is custom-made and used. Concrete is poured into the manufactured formwork to produce FCP (Free-form Concrete Panel). However, since it is an atypical building that requires precise curvature, compaction cannot be performed after concrete is poured. This leads to the occurrence of bughole, which reduce the strength and aesthetics of concrete. Therefore, in this study, we intend to conduct basic experiments to develop a magnetic compaction device that can be used for FCP. As a result of the experiment, it was confirmed that the bug hole was improved when the magnetic compaction device was applied, and there was no significant difference in compressive strength and flexural strength. This technology can be used in the field of Free-form concrete where it is difficult to perform compaction work, and it is expected to be used as a basic research related to technology for new automatic compaction.

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A Study on the Real Somatotype and the Recognized Somatotype of Middle Ages Women (중년 여성의 실제 체형과 이상적 체형에 관한 연구)

  • Lee, Young-A;Lee, Sang-Eun
    • Journal of the Korea Fashion and Costume Design Association
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    • v.10 no.1
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    • pp.1-9
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    • 2008
  • The purpose of this research is to lay the foundation that middle aged woman takes care of more healthy, beautiful, attractive external features and prepares successful ageing on studying a difference of recognition between an actual somatotype and an ideal somatotype after we examine an actual somatotype and an ideal somatotype in the object of about $40{\sim}50$ middle-aged woman, dwells in Seoul, is the main group of a home consumption socially. The result of comparing a difference between an actual somatotype and an ideal somatotype was showing that in case of a facial form, the group which their faces are an egg-shaped prefers an egg-shaped and the group which their faces are a round-shaped prefers a round-shaped. In case of a silhouette, all groups prefers a normal type most. In case of a shoulder's type, all groups prefer a normal type most. In case of a shoulder-waist line, all groups prefers a Y line most. In case of a breast's form, all groups prefer a normal type most. In case of a back's form, all groups prefer a normal type most. In case of a buttocks' form, all groups prefers a normal type most. In case of a leg's form, all groups prefers a normal type most. On putting together research result as yet, middle aged women wish a similar somatotype irrespective of an age, an obesity measurement and this means a recognition of making an effort to be beautiful is alike. Therefore, it is necessary to recognize a somatotype of middle aged women uprightly and it must be accomplished a continuous, systematic consultation and education about a weight-control on exercising and not to mention of making a desirable eating habit.

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Bow-Hull Form Development of a Container Ship by Using Finite Difference Method (유한차분법을 이용한 컨테이너선의 선수선형 개량)

  • S.C. Shin;U.C. Jeong;Y.G. Lee;K.J. Kang
    • Journal of the Society of Naval Architects of Korea
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    • v.29 no.4
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    • pp.1-6
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    • 1992
  • The finite difference simulation method for ship waves is introduced for hull form improvement. Numerical simulations were performed for a series of modified hull forms and the simulated results were used for the determination of the better hull forms. A 4,400 TEU container carrier which was designed and experimented in towing tank was chosen for the purpose. The calculation results are compared with those of model test, of simplified Neumann-kelvin problems and of Rankine source method. In this study, it is shown that the combination of the computer simulation by our method with the experiment provides one of the most economical and reliable procedures of hull form improvement and that the degree of accuracy of this method is so high that it can cope with very practical design purposes.

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Acoustic Features of Oral Vowels in the Esophagus Speakers (식도음성의 모음종류에 따른 음향학적 특성)

  • Yun, Eunmi;Mok, Eunhee;Minh, Phan huu Ngoc;Hong, Kihwan
    • Phonetics and Speech Sciences
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    • v.7 no.4
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    • pp.85-92
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    • 2015
  • This study aimed to establish characteristics related to voice and speech through the natural base frequency analysis of esophagus vocalization. In the study, 8 subjects were selected for esophagus vocals, and 10 other subjects were selected for a control group. MDVP(Multi-dimensional Voice Program, Model 4800, USA, 2001), Multi Speech(Model 3700, Kaypantax, USA, 2008) were used as experiment equipment. The speech samples selected for evaluation were vowels and sentences (both declarative and interrogative). For acoustic analysis, the intonation form of fo, jitter, energy, shimmer, HNR, and intonation patterns of the speech sample were measured. The results were as follows: First, the natural intrinsic frequency of extended vowels in the esophagus vocal group was lower than the frequency in the normal vocal group. In particular, the intrinsic frequency difference for high vowel /i/ was much greater than the frequency difference for low vowel /a/. Second, the jitter values of the esophagus vocal group were higher than the control group. In particular, there was a large difference between the jitter values for /a/ and /i/, with the jitter values being highest for /i/. Third, there was no significant difference in vocal strength between the esophagus vocal patient group and the control group. Fourth, the shimmer values of the voices in the esophagus vocal group were higher than shimmer values in the control group. In particular, there was a large difference in shimmer values for low vowel /a/. Fifth, the HNR values of the esophagus vocal group were showed significantly lower than the control group. In particular, the largest difference in HNR values between the two groups was for high vowel /i/. Sixth, the pitch contours of interrogative and declarative sentences of the esophagus vocal patient group showed a different form or only had with small differences compared to the pitch contours of the normal vocal group, thus presenting an inconsistent pattern.

Vortex pairing in an axisymmetric jet using fundamental and subharmonic forcing (기본교란 및 분수조화교란을 이용한 원형제트에서의 보텍스병합)

  • Jo, Seong-Gwon;Yu, Jeong-Yeol;Choe, Hae-Cheon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.21 no.10
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    • pp.1350-1362
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    • 1997
  • An experimental study has been performed on vortex pairing under fundamental and subharmonic forcing with controlled initial phase differences through hot-wire measurements and a multi-smoke wire flow visualization. For the range of St$_{D}$ < 0.6, vortex pairing was controlled by means of fundamental and subharmonic forcing with varying initial phase differences. Much larger mixing rate was achieved by two-frequency forcing with a proper phase difference than one frequency forcing. As St$_{D}$ decreased, vortex pairing was limited to a narrow region of the initial phase difference between two disturbances and higher amplitudes of the fundamental and its subharmonic at the nozzle exit were required for more stable pairing. As the amplitude of the subharmonic at the nozzle exit increased for fixed St$_{D}$ and fundamental amplitude, the distribution of the subharmonic mode against the variation of the initial phase difference changed from a sine function form into a cusp-like form. Thus, vortex pairing can be controlled more precisely for the former case. For St$_{D}$ > 0.6, non-pairing advection of vortices due to the improper phase difference was sometimes observed in several fundamental forcing amplitudes when only the fundamental was applied. However, when its subharmonic was added, vortex pairing readily occurred. As the initial amplitude of this subharmonic increased, the position of vortex pairing moved upstream. This was thought to be due to the fact that the variation of the initial phase difference between the fundamental and its subharmonic has less effects on vortex pairing in the region of fundamental-only vortex pairing.pairing.