• Title, Summary, Keyword: Modification

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Semiparametric and Nonparametric Modeling for Matched Studies

  • Kim, In-Young;Cohen, Noah
    • Proceedings of the Korean Statistical Society Conference
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    • pp.179-182
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    • 2003
  • This study describes a new graphical method for assessing and characterizing effect modification by a matching covariate in matched case-control studies. This method to understand effect modification is based on a semiparametric model using a varying coefficient model. The method allows for nonparametric relationships between effect modification and other covariates, or can be useful in suggesting parametric models. This method can be applied to examining effect modification by any ordered categorical or continuous covariates for which cases have been matched with controls. The method applies to effect modification when causality might be reasonably assumed. An example from veterinary medicine is used to demonstrate our approach. The simulation results show that this method, when based on linear, quadratic and nonparametric effect modification, can be more powerful than both a parametric multiplicative model fit and a fully nonparametric generalized additive model fit.

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A Rapid Local Modification Algorithm for NURBS surface (NURBS 곡면의 고속 부분 수정 알고리듬 개발)

  • 김호찬;최홍태;김준안;이석희
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.1402-1405
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    • 2004
  • Algorithms on modification of NURBS surface requires modeling history to change its boundary conditions. The history is stored when the surface is modeled and saved in the corresponding model file. But when the model is transferred to other systems the history generally cannot be recognized. So modification algorithms without history is highly required. Previous works on the field is concentrated in the point based modification without any restriction condition. Therefore this study is intended to develope a curved based modification algorithm with restriction conditions. A rapid modification algorithm is suggested, implemented and tested.

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Aerodynamic Performance Improvement by Divergent Trailing Edge Modification to a Supercritical Airfoil

  • Yoo, Neung-Soo
    • Journal of Mechanical Science and Technology
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    • v.15 no.10
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    • pp.1434-1441
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    • 2001
  • A computational study has been performed to determine the effects of divergent trailing edge (DTE) modification to a supercritical airfoil in transonic flow field. For this, the computational result with the original DLBA 186 supercritical airfoil was compared to that of the modified DLBA 283. A wavier-Stokes code, Fluent 5. 1, was used with Spalart-Allmaras's one-equation turbulence model. Results in this study showed that the reduction in drag due to the DTE modification is associated with weakened shock and delayed shock appearance. The decrease in drag due to the DTE modification is greater than the increase in base drag. The effect of the recirculating flow region on lift increase was also observed. An airfoil with DTE modification achieved the same lift coefficient at a lower angle of attack while giving a lower drag coefficient. Thus, the lift-to-drag ratio increases in transonic flow conditions compared to the original airfoil. The lift coefficient increases considerably whereas the lift slope increases just a little due to DTE modification.

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A Note on the Propeller Rotational Speed Increase due to the Propeller Blade Edge Modification (프로펠러 Edge 수정에 의한 프로펠러 회전수 증가에 관한 소고)

  • 최군일;김동진;박명규
    • Journal of Advanced Marine Engineering and Technology
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    • v.17 no.2
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    • pp.1-8
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    • 1993
  • The cases and the treatments of the rotational speed losses of marine propellers are examined and practical modification methods are discussed. The cutting of the propeller diameter, the modification of propeller pitch and the propeller blade edge modification are briefly reviewed. An example for the propeller blade edge modification, which is regarded to have advantages in cost and workmanship, is presented for a propeller of a large ship.

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Interior Noise Reduction Using Sensitivity Analysis and Structural Dynamic Modification (민감도 해석 및 구조 변경법을 이용한 차실 소음 저감)

  • 황우석
    • Journal of KSNVE
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    • v.9 no.6
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    • pp.1145-1151
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    • 1999
  • Sensitivity analysis and structural modification technique are used to reduce the interior noise of a passenger car. The sensitivity analysis for the noise level at the rear seat shows that the stiffness change at the front lower member and the rear roof rail are sensitive. Using the structural modification method, we verified that the reinforcements at those members decrease the noise transfer function from the body to the rear seat. The combined application of the sensitivity analysis and structural modification method can decrease the noise level effectively.

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Body Modification in Fashion Illustrations Based on the Theory of 'Corps sans Organes' of Deleuze (들뢰즈의 기관 없는 신체론에 기반한 현대 패션일러스트레이션의 신체특성)

  • Lee, Jee-Hyun
    • Journal of the Korean Society of Costume
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    • v.61 no.9
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    • pp.27-38
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    • 2011
  • This study focused on the body modification in fashion illustration based on 'Corps sans Organes' of Deleuze. An argument about the changes of ideal body to define the aesthetic consciousness of times has lasted for a long time. Therefore, analyzing body modification in fashion illustration to express the ideal beauty could be effective motives to understand the changes of ideal bodies related with socio-cultural meanings, and be helpful to understand the overall trends of modern fashion illustration. To classify the types of body modification, the concept of 'Corps sans Organes' of Deleuze was used as an analyzing tool. As the final result, the characteristics of body modification could be divided into three groups; the fragmentation of bodies, the pastiche of bodies, and the abstraction of bodies. First, in the fragmentation of bodies, which is related with flexibility, pluralism, and subjective views on body, the bodies were separated as molecules. Second, the elements of pastiche of bodies could be subdivided into five sub-groups; sex, plants, animals, texts and figure, and machines. The pastiche of bodies was used to extend the limitation of human capabilities and to reinterpret the human identities. Last, the abstraction of bodies based on contingency, indeterminacy, and subjective associations could be related with the nomadic and indefinite body images. The body modification could be considered as the context of nomadism, indeterminacy, and virtuality of modern-times, and it would be the basic data to understand the body modification in fashion illustrations.

Changes in Pasting and Fluid Properties of Corn and Rice Starches after Physical Modification by Planetary Mill

  • Kim, Bum-Keun;Lee, Jun-Soo;Cho, Yong-Jin;Park, Dong-June
    • Food Science and Biotechnology
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    • v.17 no.4
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    • pp.814-818
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    • 2008
  • Com and rice starches were physically modified by planetary mill. While native starches showed high peak viscosities (1,001 and 563 cp), it decreased largely (42 and 20 cp for rice and com starch, respectively) after 2 hr of physical modification. When two starches were co-ground, peak viscosities decreased more largely than single ground one only in 30 min, indicating the pasting properties could be easily changed by co-grinding. Especially, the higher the amount of com starch, the viscosity decreased more largely, which means that paste stability could be controlled also by changing the ratio of com and rice starch. Mean particle size increased with physical modification time since particles became spread because of shear force. There were also changes in surface morphology after physical modification. Fluid property, such as mean time to avalanche (MTA), was improved (from $6.16{\pm}0.47$ and $8.37{\pm}1.23\;sec$ to $5.47{\pm}0.78$ and $5.26{\pm}1.37\;sec$ for rice and com starch, respectively) by physical modification. Pasting property, such as swelling power, was also improved by physical modification. These mean that native starches can be applied to both conventional powder and new paste-food industry more efficiently by physical modification.

Design parameter dependent force reduction, strength and response modification factors for the special steel moment-resisting frames

  • Kang, Cheol Kyu;Choi, Byong Jeong
    • Steel and Composite Structures
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    • v.11 no.4
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    • pp.273-290
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    • 2011
  • In current ductility-based earthquake-resistant design, the estimation of design forces continues to be carried out with the application of response modification factors on elastic design spectra. It is well-known that the response modification factor (R) takes into account the force reduction, strength, redundancy, and damping of structural systems. The key components of the response modification factor (R) are force reduction ($R_{\mu}$) and strength ($R_S$) factors. However, the response modification and strength factors for structural systems presented in design codes were based on professional judgment and experiences. A numerical study has been accomplished to evaluate force reduction, strength, and response modification factors for special steel moment resisting frames. A total of 72 prototype steel frames were designed based on the recommendations given in the AISC Seismic Provisions and UBC Codes. Number of stories, soil profiles, seismic zone factors, framing systems, and failure mechanisms were considered as the design parameters that influence the response. The effects of the design parameters on force reduction ($R_{\mu}$), strength ($R_S$), and response modification (R) factors were studied. Based on the analysis results, these factors for special steel moment resisting frames are evaluated.

An Effective Hangul Modification System Using Jamo Modification Window (자모 수정 창을 활용한 효과적인 한글 수정 시스템)

  • Ceong, Hyi-Thaek
    • The Journal of the Korea institute of electronic communication sciences
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    • v.8 no.10
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    • pp.1535-1544
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    • 2013
  • There are many Hangul input systems to input Korean letter on computer or smart phone. However, the existing systems need to be required more efforts to modify the already inputted letters. This research suggests the Hangul letter modification method which can modify letter effectively based on reusing the alphabets previously inputted. The Hangul modification system using "Jamo Modification Window" follows the composition principle of Hangul, and utilize the already inputted alphabets. It can be applicable to the existing input system without any modification using only "Jamo Modification Window". Especially, this system is very useful on smart phone with small screen.

Influence of Reaction Conditions on the Grafting Pattern of 3-Glycidoxypropyl trimethoxysilane on Montmorillonite

  • He, Wentao;Yao, Yong;He, Min;Kai, Zhang;Long, Lijuan;Zhang, Minmin;Qin, Shuhao;Yu, Jie
    • Bulletin of the Korean Chemical Society
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    • v.34 no.1
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    • pp.112-116
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    • 2013
  • Surface modification of montmorillonite (MMT) with 3-glycidoxypropyl trimethoxysilane (3GTO) in mild methanol/water mixture has been investigated in detail. The influence of reaction conditions (including silane concentration in feed, reaction time and reaction temperature) on the grafting amount and yield of silane, and further on the grafting pattern of silanes was studied by thermogravimetric analysis, elemental analysis, X-ray diffraction (XRD) and BET. Higher silane concentration, longer reaction time and higher reaction temperature are all benefit to higher grafting amount. When the grafting reaction was performed with 3 mmol/g silane concentration, at $90^{\circ}C$ for 24 h, the grafted amount and yield of silane reached 1.4443 mmol/g and 30%, respectively. Based on the XRD and BET data analysis, a speculation that the grafting pattern of silanes was concentration dependence was proposed.