• Title/Summary/Keyword: cross over

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Some Statistical Considerations on 2×k Crossover Designs for Bioequivalence Trial (생물학적 동등성 시험을 위한 2×k 교차설계법의 통계적 고려)

  • Noh, So-Young;Park, Sang-Gue
    • The Korean Journal of Applied Statistics
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    • v.26 no.4
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    • pp.675-686
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    • 2013
  • The Korea Food and Drug Administration(KFDA) recommends the use of a $2{\times}2$ crossover design to assess the bioequivalence of generic drugs. However, a standard $2{\times}2$ crossover design for bioequivalence trials is often considered problematic due to ethical and economic issues as highly variable drugs are usually required by large numbers of subjects when designing the trial. To overcome this problem a $2{\times}4$ crossover design has been a recommended option as per US regulations; in addition, a $2{\times}3$ crossover design has also recently drawn special attention as an efficient alternative. The current KFDA regulation requires an ANOVA table for every bioequivalence study; however, ANOVA tables of $2{\times}4$ and $2{\times}3$ crossover designs have never been published in the literature. This study shows the derivation of tables of analysis of variance for a $2{\times}4$ cross-over design and a $2{\times}3$ cross-over design. We also suggest a sample size formulas for $2{\times}2$, $2{\times}4$ and $2{\times}3$ crossover designs to provide information on the selection of efficient designs for highly variable drugs.

A Study on the Compound Colors by Cross-Dyeing of Cotton/PET Union Fabrics (면(綿)/PET 교직물(交織物)의 Cross Dyeing에 의한 복합색상(複合色相) 연구(硏究))

  • Lee, Mi-Kyung
    • Journal of Fashion Business
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    • v.11 no.1
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    • pp.15-25
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    • 2007
  • As a part of the study for the materials development of compound feelings, therefore, this study investigated into the effects of the colors of warp and weft on the overall colors of fabrics, along with the visual changes of colors by the measuring angle of both warp and weft, by means of cross-dyeing of cotton/PET union fabrics. First, the dyeing of cotton and PET fabrics individually with the same color, the dyeing of PET fabrics followed by that of cotton fabrics resulted in a small difference in color than the dyeing in the reversed order. Second, in the case of the dyeing of cotton/PET union fabrics with the color of one fiber fixed and that of the other in ten colors, the color of cotton fiber, which is warp, gave much influence. In addition, the color change was remarkable among complementary colors, while it was negligible among adjacent colors. Third, in the case of dyeing of cotton/PET union fabrics with the color of one fiber fixed and that of the other in ten colors, the results were different by the measuring angle. When PET was fixed in green and cotton was dyed in ten colors, color-deepening was observed by the inclination in the direction of warp and weft without the dominance over all colors like cotton. When cotton was dyed in red and PET in ten colors, the color of PET appeared dimly in the horizontal case by the direction of the light, and red appeared as inclined in the direction of warp and weft. This is because of the dominance of cotton color over the overall color, since the density of cotton fiber, the warp of union fabrics, is higher than that of PET, the weft. Thus, this is to be considered in the selection of the warp's color. In view of the above results, the color changes are outstanding when the color of warp dominates the overall color and when the colors of warp and weft are complementary, in comparison with the case when the colors are adjacent. The colors also change by the measuring angle.

CLO (Cross Layer Optimization) Technique for Multi-view Video Streaming Service over WiBro Network (WiBro망에서의 다시점 비디오 스트리밍 서비스를 위한 계층 간 최적화 방식)

  • Son, Jung-Hyun;Cho, Ye-Jin;Suh, Doug-Young;Park, Gwang-Hoon;Kim, Kyu-Heon
    • Journal of Broadcast Engineering
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    • v.13 no.5
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    • pp.719-731
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    • 2008
  • This paper defines QoE (Quality of Experience) for multi-view video streaming service over WiBro and proposes the CLO (Cross-Layer Optimization) algorithm can maximize this. Proposal CLO algorithm contains from physical layer to video layer. Under the time-varying wireless channel condition, the CLO technique takes view-wise and the temporal priority of the multi-view video into consideration in order to decide the transmission of frames and its FEC level. At the handover situation, it is shown through computer simulation that the optimal quality of the multi-view video can be achieved using the minimum amount of resources if the proposed CLO technique is applied.

A Symbolic Sense of Transvestism in the Renaissance Novels (르네상스 소설에서의 복장전도가 갖는 상징적 의미)

  • Lim, Juin
    • Cross-Cultural Studies
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    • v.19
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    • pp.149-179
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    • 2010
  • This article is concerned about the symbolic meaning of the transvestism Renaissance perspective through analysis of Triumph Over Persecution work and The Merchant of Venice, and Jealous Ioan Tornese. The transvestism is frequently present in the comedies of the golden age. A woman author Maria de Zayas has a special interest in female identity with critical and defying view. Also the subject of the transvestism in Spanish literature originated in Italian tradition. In Italian literature, there were two types of disguised women, who urge for love and warrior-heroine(amazon). Both types are also listed in Spanish literature. The dress-crossing heroine of Triumph Over Persecution displays a type of heroine, who corrects a male prejudice and reset a harmonious order. Shakespeare is also one of the Renaissance writers under the influence of the Italian Renaissance novel. Heroine of Merchant of Venice symbolizes a triumphant challenge against the blocks of the patriarchal system. In spite of the social system blocks, cross-dressing women may receive in the patriarchal scenes without problems. Based on the notion of paradox and irony, the Italian novel reflects popular psychology of the time when the link between the internal identity and social outside puts into question. The cross-dressing Torneses' wife, symbolizes the mockery or renaissance deception. Their deception emphasis on an ironic way in the point view of inhuman man who consider women material belongs to the man without any free-will. The costume of the characters make it possible to change their original identity into the other. From this point of view, we can say that the transvestism in these works could be interpreted in two ways: first, the destruction of the traditional categories of women's identity and second, the burlesque contempt on the patriarchal renaissance society.

Effect of internal angles between limbs of cross plan shaped tall building under wind load

  • Kumar, Debasish;Dalui, Sujit Kumar
    • Wind and Structures
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    • v.24 no.2
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    • pp.95-118
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    • 2017
  • The present study revealed comparison the pressure distribution on the surfaces of regular cross plan shaped building with angular cross plan shaped building which is being transformed from basic cross plan shaped building through the variation of internal angles between limbs by $15^{\circ}$ for various wind incidence angle from $0^{\circ}$ to $180^{\circ}$ at an interval of $30^{\circ}$. In order to maintain the area same the limbs sizes are slightly increased accordingly. Numerical analysis has been carried out to generate similar nature of flow condition as per IS: 875 (Part -III):1987 (a mean wind velocity of 10 m/s) by using computational fluid dynamics (CFD) with help of ANSYS CFX ($k-{\varepsilon}$ model). The variation of mean pressure coefficients, pressure distribution over the surface, flow pattern and force coefficient are evaluated for each cases and represented graphically to understand extent of nonconformities due to such angular modifications in plan. Finally regular cross shaped building results are compared with wind tunnel results obtained from similar '+' shaped building study with similar flow condition. Reduction in along wind force coefficients for angular crossed shaped building, observed for various skew angles leads to develop lesser along wind force on building compared to regular crossed shaped building and square plan shaped building. Interference effect within the internal faces are observed in particular faces of building for both cases, considerably. Significant deviation is noticed in wind induced responses for angular cross building compared to regular cross shaped building for different direction wind flow.

Fabrication and Performance Demonstration of the 20kW Class Inverted-type Cross-flow Turbine Based on Computational Fluid Dynamics Analysis (전산유체역학 해석에 기반한 20kW급 도립형 횡류수차의 제작 및 성능 실증)

  • Ham, Sangwoo;Choi, Ji-Woong;Jeong, Changho;Kim, Taeyun;Choi, Sangin;Jin, Glenn Young;Lee, Jeong Wan;Ha, Hojin
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.20 no.2
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    • pp.107-119
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    • 2021
  • The cross-flow turbine is one of the most famous and widely used hydraulic power systems for a long time. The cross-flow turbine is especially popular in many countries and remote regions where off-grided because of its many benefits such as low cost, high efficiency at low head, simple structure, and easy maintenance. However, most modern turbines, including the cross-flow turbine, are unsuitable for the ultra-low head situation, known as less than 3m water head or zero head with over 0.5m/s flow velocity. In this study, we demonstrated a 20kW class inverted-type cross-flow turbine's performance. First, we reevaluated our previous studies and introduced how to design the inverted-type cross-flow turbine. Secondly, we fabricated the 20kW class inverted-type cross-flow turbine for the performance test. And then, we designed a testbed and installed the turbine system in the demonstration facility. In the end, we compare the demonstration with its previous CFD results. The comparing result shows that both CFD and real model fitted on guide vane angle at 10 degrees. At the demonstration, we achieved 42% turbine efficiency at runner speed 125 RPM.

Dehydration as an Etiologic Factor of Halitosis: A Case-Control Study

  • Ok, Soo-Min;Jeong, Sung-Hee;Lee, Chang-Hyung
    • Journal of Oral Medicine and Pain
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    • v.46 no.4
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    • pp.117-124
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    • 2021
  • Purpose: Salivation is considered to be an important factor in the control of halitosis, and the amount of salivation has been shown to be closely related to the level of hydration. The purpose of our study was to evaluate the relationship between dehydration and halitosis. Methods: Twenty healthy young females with no dental problems were recruited. All participants were induced to become dehydrated and then over-hydrated. After inducing each hydration state, the severity of hydration and halitosis factor (organoleptic scores, amounts of resting and functional saliva, gas examinations, and tongue coatings) were measured. Hydration statuses were graded as dehydration, normal, or over-hydration according to urine osmolality. This was a cross sectional study with a cross over design. Results: The dehydrated status was associated with higher organoleptic scores than the normal or over-hydrated status (1.75±0.75 vs. 0.87±0.63, and 0.65±0.53, respectively. p<0.05). Mean values of CH3SH, (CH3)2S in portable gas chromatography for the dehydrated, normal, and over-hydrated status were 11.70±37.00, 6.75±13.50, and 2.80±5.87 nmol/mol, 10.50±15.59, 7.25±10.87, and 1.50±2.55 nmol/mol, respectively. p>0.05). (CH3)2S (r=0.410, p=0.009) showed a moderate positive correlation with dehydration status. The resting salivation rates were relatively lower for the dehydrated status than for the normal or overhydrated status (p>0.05), and tongue coating results were also higher for the dehydrated status (p>0.05). Conclusions: Dehydration status appears to be positively correlated with a low resting salivation rate and high portable gas chromatography results. This shows that dehydration might be an etiologic factor of halitosis.

Osmotic Cross Second Virial Coefficient ($B_{23}$) of Unfavorable Proteins: Modified Lennard-Jones Potential

  • Choi, Sang-Ha;Bae, Young-Chan
    • Macromolecular Research
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    • v.17 no.10
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    • pp.763-769
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    • 2009
  • A chromatographic method is used to measure interactions between dissimilar proteins in aqueous electrolyte solutions as a function of ionic strength, salt type, and pH. One protein is immobilized on the surface of the stationary phase, and the other is dissolved in electrolyte solution conditions flowing over that surface. The relative retention of proteins reflects the mean interactions between immobile and mobile proteins. The osmotic cross second virial coefficient calculated by assuming a proposed potential function shows that the interactions of unfavorable proteins depend on solution conditions, and the proposed model shows good agreement with the experimental data of the given systems.

Diffusion Coefficients for Electrons in SF6-Ar Gas Mixtures by MCS-BEq (MCSBEq에 의한 SF6-Ar혼합기체의 확산계수)

  • Kim, Sang-Nam
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.64 no.3
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    • pp.125-129
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    • 2015
  • Energy distribution function for electrons in SF6-Ar mixtures gas used by MCS-BEq algorithm has been analysed over the E/N range 30~300[Td] by a two term Boltzmann equation and a Monte Carlo Simulation using a set of electron cross sections determined by other authors experimentally the electron swarm parameters for 0.2[%] and 0.5[%] $SF_6-Ar$ mixtures were measured by time-of-flight(TOF) method, The results show that the deduced longitudinal diffusion coefficients and transverse diffusion coefficients agree reasonably well with theoretical for a rang of E/N values. The results obtained from Boltzmann equation method and Monte Carlo simulation have been compared with present and previously obtained data and respective set of electron collision cross sections of the molecules.

Natural frequencies and mode shapes of thin-walled members with shell type cross section

  • Ohga, M.;Shigematsu, T.;Hara, T.
    • Steel and Composite Structures
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    • v.2 no.3
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    • pp.223-236
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    • 2002
  • An analytical procedure based on the transfer matrix method to estimate not only the natural frequencies but also vibration mode shapes of the thin-walled members composed of interconnected cylindrical shell panels is presented. The transfer matrix is derived from the differential equations for the cylindrical shell panels. The point matrix relating the state vectors between consecutive shell panels are used to allow the transfer procedures over the cross section of the members. As a result, the interactions between the shell panels of the cross sections of the members can be considered. Although the transfer matrix method is naturally a solution procedure for the one-dimensional problems, this method is well applied to thin-walled members by introducing the trigonometric series into the governing equations of the problem. The natural frequencies and vibration mode shapes of the thin-walled members composed of number of interconnected cylindrical shell panels are observed in this analysis. In addition, the effects of the number of shell panels on the natural frequencies and vibration mode shapes are also examined.