• Title/Summary/Keyword: width function

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The new approach to maxillary and mandibular anterior dental arch forms - In Korean normal occlusion models (상하악 전치부 치열궁 형태에 대한 새로운 접근 - 한국성인 정상교합자 모델에서)

  • Ha, Man-Hee;Son, Woo-Sung;Yang, Hoon-Chul
    • The korean journal of orthodontics
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    • v.31 no.3 s.86
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    • pp.347-355
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    • 2001
  • Maxillary and mandibular anterior dental arches often have the problems of occlusal relation and esthetics by malformations of teeth, congenital missing, et at. Though the clinician usually use the anterior ratio to overcome this problems, he has the limitation of a direct application this ratio to the prediction of anterior occlusal relationship by the change of anterior ratio as dental arch form, intercanine width, segment depth and arch perimeter. So this study examine maxillary and mandibular anterior dental arch forms by least square method using Korean normal occlusion models(man : 20 casts, woman : 20 casts). Maxillary and mandibular anterior dental arches of Korean normal occlusion models are curve fitted to polynomial function, beta function, hyperbolic cosine function in order. And this accuracy of curve fitting is constant regardless of man/woman and maxilla/mandible. The relationships between intercanine width, segment depth, and arch perimeter based on this owe fitted dental arch form are acquired. This relationships will give the prediction of anterior dental arch form and the information of more accurate anterior ratio according to intercanine width.

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Parameters Estimation of Clark Model based on Width Function (폭 함수를 기반으로 한 Clark 모형의 매개변수 추정)

  • Park, Sang Hyun;Kim, Joo-Cheol;Jung, Kwansue
    • Journal of Korea Water Resources Association
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    • v.46 no.6
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    • pp.597-611
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    • 2013
  • This paper presents the methodology for construction of time-area curve via the width function and thereby rational estimation of time of concentration and storage coefficient of Clark model within the framework of method of moments. To this end time-area curve is built by rescaling the grid-based width function under the assumption of pure translation and then the analytical expressions for two parameters of Clark model are proposed in terms of method of moments. The methodology in this study based on the analytical expressions mentioned before is compared with both (1) the traditional optimization method of Clark model provided by HEC-1 in which the symmetric time-area curve is used and the difference between observed and simulated hydrographs is minimized (2) and the same optimization method but replacing time-area curve with rescaled width function in respect of peak discharge and time to peak of simulated direct runoff hydrographs and their efficiency coefficient relative to the observed ones. The following points are worth of emphasizing: (1) The optimization method by HEC-1 with rescaled width function among others results in the parameters well reflecting the observed runoff hydrograph with respect to peak discharge coordinates and coefficient of efficiency; (2) For the better application of Clark model it is recommended to use the time-area curve capable of accounting for irregular drainage structure of a river basin such as rescaled width function instead of symmetric time-area curve by HEC-1; (3) Moment-based methodology with rescaled width function developed in this study also gives rise to satisfactory simulation results in terms of peak discharge coordinates and coefficient of efficiency. Especially the mean velocities estimated from this method, characterizing the translation effect of time-area curve, are well consistent with the field surveying results for the points of interest in this study; (4) It is confirmed that the moment-based methodology could be an effective tool for quantitative assessment of translation and storage effects of natural river basin; (5) The runoff hydrographs simulated by the moment-based methodology tend to be more right skewed relative to the observed ones and have lower peaks. It is inferred that this is due to consideration of only one mean velocity in the parameter estimation. Further research is required to combine the hydrodynamic heterogeneity between hillslope and channel network into the construction of time-area curve.

Fourier Transformations (TEM 관련 이론해설 (2): Fourier 변환)

  • Lee, Hwack-Joo
    • Applied Microscopy
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    • v.32 no.3
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    • pp.195-204
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    • 2002
  • In this review, the fundamental concepts of delta function, convolution integral and Fourier transformation are discussed. The applications of Fourier transformation to slit function, two very narrow slits, two slits of appreciable width, periodic array of narrow slits, arbitary periodic function, diffraction gratings and gaussian functions are also introduced.

Evaluation of the maxillary intermolar width (U6-U6) on frontal cephalogram (정모두부방사선선사진을 이용한 상악 제 1대구치간 폭경의 평가)

  • Park, Young Guk;Chung, Kyu Rhim;Lee, Young-Jun;Lee, Soung Hee
    • Journal of Dental Rehabilitation and Applied Science
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    • v.16 no.1
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    • pp.61-67
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    • 2000
  • It was the aim of present study to grope the relationship of the maxillary first molar width to the various transverse skeletal measurements in frontal headfilm, and to formulate the predictive equations of the maxillary intermolar width (U6-U6) from each of the variables. Frontal cephalograms of 17 males from 18 to 26 YO and 13 females from 17 to 25 YO who manifested balanced skeletal profiles, normal occlusion, and no history of orthodontic and prosthodontic treatment were employed as subjects. Nine transverse measurements were scrutinized with Pearson's correlation analysis, simple and stepwise multiple regression analysis in specific regards to the intermolar width of maxillary first molar. Statistical output demonstrated that there were intimate relationships within the various transverse skeletal measurements each other, and among the others, high correlation was found between facial width and maxillary first intermolar width. Regression analyses provided the reliable and clinically applicable predictive equations to set the ideal maxillary first intermolar width(U6-U6) from the given skeletal framework.

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Suggestion of Synthetic Unit Hydrograph Method Considering Hydrodynamic Characteristic on the Basin (유역의 동수역학적 특성을 고려한 합성단위도 기법의 제시)

  • Kim, Joo Cheol;Choi, Yong Joon;Jeong, Dong Kug
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.1B
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    • pp.47-55
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    • 2011
  • This study suggests new synthetic unit hydrograph method considering hydrodynamic characteristic on the basin. The suggested method based on width function GIUH, and the procedure is summarized as follows; 1) Draw up a travel distance distribution map (width function) which is raster of length between from center of individual cells to the outlet by GIS. 2) Calculation of travel time distribution map (rescaled width function) by hydrodynamic parameters and travel distance distribution map. 3) Derivation of IUH and Duration UH from rescaled width function. 4) Comparison of shape of UH between suggested method and existing synthetic unit hydrograph methods. The target basins are selected Ipyeong and Tanbu subwatershed in the Bocheong Basin. The target basins are similar scale (watershed area), but different drainage structure (drainage density et al.). Therefore we anticipate that there are different hydrologic response functions because different hydrodynamic characteristics. As a result of derivation of UH, existing synthetic unit hydrograph methods are similar shape of UHs about Ipyeong and Tanbu watersheds, but the suggested method is different shape of ones. As a result of application to observed data, the peak discharge by suggested method is similar to existing synthetic unit hydrograph methods, but the peak time is well correspondence between those. Henceforth, if the suggested method combines with the rational velocity estimation method, it is useful method for synthetic of UH in ungauged watershed.

Optimum Design of Dye-Sensitized Solar Module for Building-Integrated Photovoltaic Systems

  • Lee, Kyu-Seok;Kang, Man Gu
    • ETRI Journal
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    • v.39 no.6
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    • pp.859-865
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    • 2017
  • This paper presents a method for determining the optimum active-area width (OAW) of solar cells in a module architecture. The current density-voltage curve of a reference cell with a narrow active-area width is used to reproduce the current density profile in the test cell whose active area width is to be optimized. We obtained self-consistent current density and electric potential profiles from iterative calculations of both properties, considering the distributed resistance of the contact layers. Further, we determined the OAW that yields the maximum efficiency by calculating efficiency as a function of the active-area width. The proposed method can be applied to the design of the active area of a dye-sensitized solar cell in Z-type series connection modules for indoor and building-integrated photovoltaic systems. Our calculations predicted that OAW increases as the sheet resistances of the contact layers and the intensity of light decrease.

Analysis of surface settlement troughs induced by twin shield tunnels in soil: A case study

  • Ahn, Chang-Yoon;Park, Duhee;Moon, Sung-Woo
    • Geomechanics and Engineering
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    • v.30 no.4
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    • pp.325-336
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    • 2022
  • This paper analyzes the ground surface settlements induced by side-by-side twin shield tunnels bored in sedimentary soils, which primarily consist of sand with clay strata above the tunnel crown. The measurements were obtained during the construction of twin tunnels underneath the Incheon International Airport (IIA) located in Korea. The measured surface settlement troughs are approximated with Gaussian functions. The trough width parameters i and K of the settlement troughs produced by the first and second tunnel passings are determined, along with those for the total settlement trough. The surface settlement troughs produced by the first shield passing are reasonably represented by a symmetric Gaussian curve. The surface settlement troughs induced by the second shield tunnel display marginal asymmetric shapes at selected sections. The total settlement troughs are fitted both with a shifted symmetric Gaussian function and the superposition method utilizing an asymmetric function for the incremental trough produced by the second tunnel. It is revealed that the superposition method does not always produce better fits with the total settlement. Instead, the shifted symmetric Gaussian function is overall demonstrated to provide more favorable agreements with the recordings. Therefore, the shifted symmetric Gaussian function is recommended to be used in the design for the prediction of the settlement in clays caused by twin tunneling considering the simplicity of the procedure compared with the superposition method. The amount of increase in the width parameter K for the twin tunnel relative to that for the single tunnel is quantified, which can be used for a preliminary estimate of the surface settlement in clay induced by twin shield tunnels.

Evaluation of shear lag parameters for beam-to-column connections in steel piers

  • Hwang, Won-Sup;Kim, Young-Pil;Park, Yong-Myung
    • Structural Engineering and Mechanics
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    • v.17 no.5
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    • pp.691-706
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    • 2004
  • The paper presents shear lag parameters for beam-to-column connections in steel box piers. Previous researches have analyzed beam-to-column connections in steel piers using a shear lag parameter ${\eta}_o$ obtained from a simple beam model, which is not based on a reasonable design assumption. Instead, the current paper proposes a cantilever beam model and has proved the effectiveness through theoretical and experimental studies. The paper examines the inaccuracy of the previous researches by estimating the effective width, the width-span length ratio L/b, and the sectional area ratio S of a cantilever beam. Two different shear lag parameters are defined using the cantilever model and the results are compared each other. The first type of shear lag parameter ${\eta}_c$ of a cantilever beam is derived using additional moments from various stress distribution functions while the other shear lag parameter ${\eta}_{eff}$ of a cantilever beam is defined based on the concept of the effective width. An evaluation method for shear lag stresses has been investigated by comparing analytical stresses with test results. Through the study, it could be observed that the shear lag parameter ${\eta}_{eff}$ agrees with ${\eta}_c$ obtained from the $2^{nd}$ order stress distribution function. Also, it could be observed that the shear lag parameter ${\eta}_c$ using the $4^{th}$ order stress distribution function almost converges to the upper bound of test results.

Investigation on the integrated transfer function characteristics for the buffeting response prediction of elongated structures

  • Yi Su;Mingshui Li;Jin Di;Yang Yang;Shaopeng Li
    • Wind and Structures
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    • v.37 no.6
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    • pp.399-412
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    • 2023
  • Previous studies have shown that the integrated transfer function (ITF) is independent of turbulence characteristics and can be effectively applied to predict the buffeting response of elongated structures, assuming that the strip hypothesis is valid. However, existing research has not effectively identified the ITF through segment model vibration tests, and the influence of the 3D effect on the accuracy of the strip hypothesis and the characteristics of the ITF in wind tunnel tests has not been quantitatively studied. A segment model vibration measurement device that can change a test model's span-width ratio was designed in this study. An airfoil section and a streamlined box girder section structure were taken as the background, and their ITFs were effectively identified under different L/B (L denotes the turbulent integral scale and B denotes the structural width) and model span-width ratios. The influence laws of the 3D effect on the accuracy of the strip hypothesis and ITF identification in wind tunnel tests were systematically investigated. The results showed that L/B and the structural span-width ratio are two significant controlling factors that affect the accuracy of the strip hypothesis and ITF identification. The research provides an effective experimental method for accurately predicting the buffeting response of elongated structures based on ITFs identified through segment model vibration tests.

Visual Acuity of Fish - 1 . Relationship Between line Width and Distance at Visual Limit of Filefish Stephanolepis Cirrhifer - (어류의 시각에 관한 연구 - 1 . 쥐치의 시인한계에서의 선의 굵기와 거리와의 관계 -)

  • An, Young-Il;Yang, Yong-Rhim
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.32 no.3
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    • pp.241-248
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    • 1996
  • The relationship between width of line target and distance at the limit of discrimination was examined by means of the behavioral method, for filefish Stephanolepis cirrhifer from 11 to 15cm body length. Target distance was distance from beginning of partition board to target plate, and was varied from 50cm to 200cm. The target plate was made of white acrylic resin with a vertical black line in the center. The width of line target was varied from 0.2mm to 8.0mm. Fish were trained to respond to a line target and the width of line target reduced until the minimum width required to elicit a response was established. Rate of success was expressed as the percentage of target choices in 90 trials. The line acuity of filefish was found to be 0.58 at a target distance of 50cm. The rate of success decreased slowly as line target width decreased from 8.0mm to 1.5mm, and decreased suddenly for target widths less than about 1.5mm. The width of the line target D(mm) at the limit of discrimination was shown to be an exponential function of the target distance L(cm) as follows : D=exp(9.947$\times$$10^-3$.L+0.146)

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