• 제목/요약/키워드: sampling designs

검색결과 92건 처리시간 0.03초

HPV Vaccine Knowledge and Perceived Risk of Cervical Cancer among Female College Students in Taiwan

  • Wang, Hsiu-Ho;Wu, Shiao-Ying
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권12호
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    • pp.7371-7374
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    • 2013
  • Aims: The study targeted the HPV vaccine knowledge and perceived risk of cervical cancer among female college students in Taiwan as well as the relationship between knowledge of the HPV vaccine and perceived risk of cervical cancer. Materials and Method: The results of this study on female college students are described using descriptive and correlation designs. A convenience sampling approach was employed with a self-filling structured questionnaire. Results: A total of 150 students completed the questionnaire. Values were 7.49 for the mean HPV vaccine knowledge scale and 18.0 for their mean perceived risk of cervical cancer scale. HPV vaccine knowledge was positively correlated with perceived risk of cervical cancer. Conclusions: The findings of this study can serve as a reference for future HPV prevention in Taiwan.

철근콘크리트 쌍곡냉각탑의 설계 및 해석 (Design and Analysis of Reinforced Concrete Hyperbolic Cooling)

  • 장현옥;민창식
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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    • pp.501-506
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    • 2000
  • An iterative numerical computational algorithm is presented to design a plate or shell element subjected to membrane and flexural forces. Based on equilibrium consideration, equations for capacities of top and bottom reinforcements in two orthogonal directions have been derived. The amount of reinforcement is determined locally, i.e., for each sampling point, from the equilibrium between applied and internal forces. Based on nonlinear analyses performed in a hyperbolic cooling tower, the analytically calculated ultimate load exceeded the design ultimate load from 50% to 55% for an analysis with relatively low to high tension stiffening, cases $\gamma$=10 and 15. For these cases, the design method gives a lower bound on the ultimate load with respect to Lower bound theorem, This shows the adequacy of th current practice at least for this cooling tower shell case studied. To generalize the conclusion more designs - analyses should be reformed with different shell configurations.

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가중평균대리모델을 사용한 천음속 압축기 블레이드 최적화 (Blade Optimization of a Transonic Compressor Using a Multiple Surrogate Model)

  • 압두스 사마드;최재호;김광용
    • 대한기계학회논문집B
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    • 제32권4호
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    • pp.317-326
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    • 2008
  • The main purpose of the present study is to perform shape optimizations of transonic compressor blade in order to enhance its performance. In this study, the Latin hypercube sampling of design of experiments and the weighted average surrogate model with the help of a gradient based optimization algorithm are used within design space by the lower and upper limits of each design variable and for finding optimum designs, respectively. 3-D Reynolds-averaged Navier-Stokes solver is used to evaluate the objective functions of adiabatic efficiency and pressure ratio. Six variables from lean and airfoil thickness profile are selected as design variables. The results show that the adiabatic efficiency is enhanced by 1.43% by efficiency optimization while the pressure ratio is increased very small, and pressure ratio is increased by 0.24% by pressure ratio optimization.

한의학 연구에서 표본조사를 위한 가이드라인 (Some Guidelines for Academic Sample Survey Studies in Korea Traditional Medicine)

  • 김선웅;이승덕
    • 대한한의학회지
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    • 제32권1호
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    • pp.84-96
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    • 2011
  • Objectives: Sample surveys have been increasingly used by Korean medical doctors for many studies. We present how to conduct higher quality sample surveys in Korea. Methods: According to the 11 principal steps for sample surveys, the concrete issues that academic researchers tend to overlook are illustrated and a variety of methods for improving survey quality are discussed. Results: The survey statistics produced by some researchers could be subject to large errors. This would be mainly due to misunderstandings about the system of principles called survey methodology. The best strategy for avoiding these errors will be to follow the suggested guidelines. Conclusions: For the development of traditional Korean medicine, the role of survey studies is important. Conducting surveys of a better quality based on survey methodology will be beneficial to researchers.

Multi-Objective Optimal Design of a NEMA Design D Three-phase Induction Machine Utilizing Gaussian-MOPSO Algorithm

  • Zhang, Dianhai;Ren, Ziyan;Koh, Chang-Seop
    • Journal of Electrical Engineering and Technology
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    • 제9권1호
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    • pp.184-189
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    • 2014
  • This paper presents a multi-objective optimization approach to design rotor slot geometry of three-phase squirrel cage induction machine to achieve NEMA design D torque-speed (T-S) characteristics with high efficiency. The multi-objective Particle Swarm Optimization (MOPSO) algorithm combined with the adaptive response surface method and Latin hypercube sampling strategy is applied to obtain the Pareto optimal designs. In order to demonstrate the validity of the suggested optimal algorithm, an application to rotor slot design of three-phase induction motor is presented.

익형의 형상최적화를 통한 고효율 축류송풍기 설계 (High-Efficiency Design of Axial Flow Fan through Shape Optimization of Airfoil)

  • 이기상;김광용;최재호
    • 한국유체기계학회 논문집
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    • 제11권2호
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    • pp.46-54
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    • 2008
  • This study presents a numerical optimization to optimize an axial flow fan blade to increase the efficiency. The radial basis neural network is used as an optimization method with the numerical analysis by Reynolds-averaged Navier-Stokes equations using SST model as turbulence closure. Four design variables related to airfoil maximum camber, maximum camber location, leading edge radius and trailing edge radius, respectively, are selected, and efficiency is considered as objective function which is to be maximized. Thirty designs are evaluated to get the objective function values of each design used to train the neural network. Optimum shape shows the efficiency increased by 1.0%.

조사 데이터 분석용 소프트웨어 패키지 (software packages for survey data analysis)

  • 성내경
    • 한국조사연구학회지:조사연구
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    • 제1권1호
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    • pp.109-123
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    • 2000
  • 복잡한 확률표본설계를 기초로 수집된 데이터를 적법하게 분석하려면 반드시 조사설계를 고려하여 통계적 추론을 전개해야한다. 만일 설계를 무시하고 분석을 하면 각종 추정량의 분산이 과소추정되면 이 결과 제 1종 오류의 확률이 매우높아진다. 본고에서는 조사데이터를 전문적으로 분석하는 소프트웨어 패키지들을 소개하고 특히 SUDAAN 7.5판 과 SAS 8판의 분석 능력들에 대한 정보를 요약한다.

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TDOA기법 기반의 다중 재머 위치 추정 알고리즘 설계 (A Design of Multiple Jammers Localization Algorithm Based on TDOA Method)

  • 강희원;임덕원;허문범
    • 한국군사과학기술학회지
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    • 제15권6호
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    • pp.729-737
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    • 2012
  • In case that multiple jammers are transmitting the signals which are the same type a general algorithm based on TDOA method cannot estimate the positions of multiple jammers because there are many TDOA measurements including true and false values. This paper, therefore, designs a new algorithm based on TDOA method to localize multiple jammers. In this algorithm, TDOA measurements are obtained by rotating the reference sensor, and then the positions of multiple jammers can be estimated by detecting congregated point among the multiple estimated positions from TDOA measurements. Through computer simulations, it is verified that this algorithm localizes the multiple jammers well. The performance of the algorithm are also analysed by changing the distance between sensors and jammer, and sampling frequency.

THREE-WAY BALANCED MULTI-LEVEL ROTATION SAMPLING DESIGNS

  • Park, Y. S.;Kim, K. W.;Kim, N. Y.
    • Journal of the Korean Statistical Society
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    • 제32권3호
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    • pp.245-259
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    • 2003
  • The 2-way balanced one-level rotation design has been discussed (Park et al., 2001), where the 2-way balancing is done on interview time in monthly sample and rotation group. We extend it to 3-way balanced multi-level design to obtain more information of the same sample unit for one or more previous months. The 3-way balancing is accomplished not only on interview time in monthly sample and rotation group but also on recall time as well. The 3-way balancing eliminates or reduces any bias arising from unbalanced interview time, rotation group and recall time, and all rotation groups are equally represented in the monthly sample. We present the rule and rotation algorithm which guarantee the 3-way balancing. In particular, we specify the necessary and sufficient condition for the 3-way balanced multi-level rotation design.