• Title/Summary/Keyword: Approach Analysis

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Skeletal stability after 2-jaw surgery via surgery-first approach in facial asymmetry patients using CBCT

  • Hwang, Dae Seok;Seo, Jeong Seok;Choi, Hong Seok
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.42
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    • pp.11.1-11.8
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    • 2020
  • Background: The purpose of this study is to compare the skeletal stability of two-jaw surgery via surgery-first approach with conventional two-jaw surgery in facial asymmetry patients by measuring the skeletal changes after surgery from a three-dimensional analysis. From January 2010 to January 2014, 40 patients with facial asymmetry who underwent two-jaw surgery in Pusan National University Hospital were included in this study. They were classified into experimental group (n = 20) who underwent two-jaw surgery via surgery-first approach and control group (n = 20) who underwent conventional two-jaw surgery. After selection of 24 landmarks and the construction of horizontal and sagittal, coronal reference planes, changes in 10 linear measurements and 2 angular measurements were compared between the surgery-first approach and conventional groups in the preoperative, immediate postoperative, and postoperative periods. The paired t test and Student t test were used for statistical analysis. The mean and standard deviation of the measurement were calculated for the experimental and control groups. Results: The statistical analysis showed that changes in skeletal measurements were similar between the surgery-first approach and conventional groups, according to each period. However, U1-SRP measurement showed statistically significant changes in surgery-first approach groups at postsurgical change (T1 to T2). Also, the mean treatment duration in the treatment group was 15.9 ± 5.48 months whereas that in the control group was 32.9 ± 14.05 months. Conclusion: In facial asymmetry patients, similar results were observed in the postoperative skeletal stability when 2-jaw surgery via surgery-first approach was compared with conventional 2-jaw surgery. However, significant lateral deviation of upper incisor midline was observed. In addition, a shorter average treatment duration was observed. To stabilize the unstable occlusion after surgery, increased wearing of the stent and proactive rubber guidance will be needed.

A Finite Element Method for Localized Failure Analysis of Concrete (콘크리트에서 국소화된 파괴해석을 위한 유한요소법)

  • 송하원;김형운;우승민
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.04a
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    • pp.233-238
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    • 1999
  • Localized failure analysis of concrete structures can be carried out effectively by modeling fracture process zone of concrete during crack initiation and propagation. But, the analysis techniques are still insufficient for crack modeling because of difficulties in numerical analysis procedure which describe progressive crack. In this paper, a finite element with embedded displacement discontinuity is introduced to remove the difficulties of remeshing for crack propagation in discrete crack model during progressive failure analysis of concrete structures. The performance of this so-called embedded crack approach for concrete failure analysis is verified by several analysis examples. The analysis results show that the embedded crack approach retains mesh size objectivity and can simulate localized failure under mixed mode loading. It can be concluded that the embedded crack approach cab be an effective alternate to the smeared and discrete crack approaches.

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Using Bayesian Estimation Technique to Analyze a Dichotomous Choice Contingent Valuation Data (베이지안 추정법을 이용한 양분선택형 조건부 가치측정모형의 분석)

  • Yoo, Seung-Hoon
    • Environmental and Resource Economics Review
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    • v.11 no.1
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    • pp.99-119
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    • 2002
  • As an alternative to classical maximum likelihood approach for analyzing dichotomous choice contingent valuation (DCCV) data, this paper develops a Bayesian approach. By using the idea of Gibbs sampling and data augmentation, the approach enables one to perform exact inference for DCCV models. A by-product from the approach is welfare measure, such as the mean willingness to pay, and its confidence interval, which can be used for policy analysis. The efficacy of the approach relative to the classical approach is discussed in the context of empirical DCCV studies. It is concluded that there appears to be considerable scope for the use of the Bayesian analysis in dealing with DCCV data.

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Radioactive waste sampling for characterisation - A Bayesian upgrade

  • Pyke, Caroline K.;Hiller, Peter J.;Koma, Yoshikazu;Ohki, Keiichi
    • Nuclear Engineering and Technology
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    • v.54 no.1
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    • pp.414-422
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    • 2022
  • Presented in this paper is a methodology for combining a Bayesian statistical approach with Data Quality Objectives (a structured decision-making method) to provide increased levels of confidence in analytical data when approaching a waste boundary. Development of sampling and analysis plans for the characterisation of radioactive waste often use a simple, one pass statistical approach as underpinning for the sampling schedule. Using a Bayesian statistical approach introduces the concept of Prior information giving an adaptive sample strategy based on previous knowledge. This aligns more closely with the iterative approach demanded of the most commonly used structured decision-making tool in this area (Data Quality Objectives) and the potential to provide a more fully underpinned justification than the more traditional statistical approach. The approach described has been developed in a UK regulatory context but is translated to a waste stream from the Fukushima Daiichi Nuclear Power Station to demonstrate how the methodology can be applied in this context to support decision making regarding the ultimate disposal option for radioactive waste in a more global context.

A Study on the Approach Method for the Excavation of the Outstanding Projects in the Agricultural Sector (농업분야 국제개발협력 우량사업 발굴을 위한 접근법 연구)

  • Ji, Seong Tae
    • Journal of Agricultural Extension & Community Development
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    • v.21 no.3
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    • pp.181-213
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    • 2014
  • This study analyzes the approach method for the excavation of the outstanding projects in order to improve the ODA quality in the agricultural sector in a situation of the recent quantitative expansion of the Korea's ODA. This analysis is based on the ODA development paradigm of the international society, Korea's ODA development trends, the problems of system, procedure and contents. The analysis drew five approaches, such as an approach based on the strategies, an approach based on the comparative advantage, an approach based on the partnership, an approach based on the networking, an approach of modeling. If each approach method is applied to the excavation of project closely linked to other approach methods, it would be easier to excavate outstanding project. And it could lead to enhancement of project effectiveness. This study introduced the KAPEX program which excavate the customized ODA projects through the application of these approach methods.

A Composite Cluster Analysis Approach for Component Classification (컴포넌트 분류를 위한 복합 클러스터 분석 방법)

  • Lee, Sung-Koo
    • The KIPS Transactions:PartD
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    • v.14D no.1 s.111
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    • pp.89-96
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    • 2007
  • Various classification methods have been developed to reuse components. These classification methods enable the user to access the needed components quickly and easily. Conventional classification approaches include the following problems: a labor-intensive domain analysis effort to build a classification structure, the representation of the inter-component relationships, difficult to maintain as the domain evolves, and applied to a limited domain. In order to solve these problems, this paper describes a composite cluster analysis approach for component classification. The cluster analysis approach is a combination of a hierarchical cluster analysis method, which generates a stable clustering structure automatically, and a non-hierarchical cluster analysis concept, which classifies new components automatically. The clustering information generated from the proposed approach can support the domain analysis process.

Seismic response analysis of layered soils considering effect of surcharge mass using HFTD approach. Part II: Nonlinear HFTD and numerical examples

  • Saffarian, Mohammad A.;Bagheripour, Mohammad H.
    • Geomechanics and Engineering
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    • v.6 no.6
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    • pp.531-544
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    • 2014
  • Studies of earthquakes over the last 50 years and the examination of dynamic soil behavior reveal that soil behavior is highly nonlinear and hysteretic even at small strains. Nonlinear behavior of soils during a seismic event has a predominant role in current site response analysis approaches. Common approaches to ground response analysis include linear, equivalent linear and nonlinear methods. These methods of ground response analysis may also be categorized into time domain and frequency domain concepts. Simplicity in developing analytical relations and accuracy in considering soils' dynamic properties dependency to loading frequency are benefits of frequency domain analysis. On the other hand, nonlinear methods are complicated and time consuming mainly because of their step by step integrations in time intervals. In part Ι of this paper, governing equations for seismic response analysis of surcharged and layered soils were developed using fundamental of wave propagation theory based on transfer function and boundary conditions. In this part, nonlinear seismic ground response is analyzed using extended HFTD method. The extended HFTD method benefits Newton-Raphson procedure which applies regular iterations and follows soils' fundamental stress-strain curve until convergence is achieved. The nonlinear HFTD approach developed here are applied to some examples presented in this part of the paper. Case studies are carried in which effects of some influencing parameters on the response are investigated. Results show that the current approach is sufficiently accurate, efficient, and fast converging. Discussions on the results obtained are presented throughout this part of the paper.

An improved approach for multiple support response spectral analysis of a long-span high-pier railway bridge

  • Li, Lanping;bu, Yizhi;Jia, Hongyu;Zheng, Shixiong;Zhang, Deyi;Bi, Kaiming
    • Earthquakes and Structures
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    • v.13 no.2
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    • pp.193-200
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    • 2017
  • To overcome the difficulty of performing multi-point response spectrum analysis for engineering structures under spatially varying ground motions (SVGM) using the general finite element code such as ANSYS, an approach has been developed by improving the modelling of the input ground motions in the spectral analysis. Based on the stochastic vibration analyses, the cross-power spectral density (c-PSD) matrix is adopted to model the stationary SVGM. The design response spectra are converted into the corresponding PSD model with appropriate coherency functions and apparent wave velocities. Then elements of c-PSD matrix are summarized in the row and the PSD matrix is transformed into the response spectra for a general spectral analysis. A long-span high-pier bridge under multiple support excitations is analyzed using the proposed approach considering the incoherence, wave-passage and site-response effects. The proposed approach is deemed to be an efficient numerical method that can be used for seismic analysis of large engineering structures under SVGM.

The Effect of Presentation of Apparel Products on Consumers' Approach Behavior using 3D Avatar Model (3차원 아바타 모델을 활용한 의류상품 제시가 소비자 접근행동에 미치는 영향)

  • Yang, Hee-Soon;Choi, Young-Lim
    • Fashion & Textile Research Journal
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    • v.15 no.1
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    • pp.65-72
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    • 2013
  • This study utilizes a S-O-R model to investigate the effects of apparel product presentations using a 3D avatar model in Internet fashion malls for pleasure(emotional state) and approach behavior. We chose a 3D avatar model to present a fashion product in this study. The model walked for about one minute on stage; subsequently, respondents completed a questionnaire after they viewed it. The questionnaire consists of telepresence, pleasure and approach behavior. Respondents are limited to females 20s and 30s years old who have purchased fashion products in an Internet mall and are highly interested in fashion products. A total of 226 samples were used for the final analysis. Cronbach's alpha, correlation analysis, confirmatory factor analysis, and structural equation modeling were utilized in this study. The results are as follows. First, telepresence has a significant influence on pleasure; subsequently, pleasure influenced consumer approach behavior. Second, telepresence positively influenced the approach behavior (directly and indirectly). This verified the effectiveness of a 3D avatar model using S-O-R. A 3D avatar model can be a strategic alternative in the fiercely competitive Internet shopping sector.

Large displacement analysis of inelastic frame structures by convected material frame approach

  • Chiou, Yaw-Jeng;Wang, Yeon-Kang;Hsiao, Pang-An;Chen, Yi-Lung
    • Structural Engineering and Mechanics
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    • v.13 no.2
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    • pp.135-154
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    • 2002
  • This paper presents the convected material frame approach to study the nonlinear behavior of inelastic frame structures. The convected material frame approach is a modification of the co-rotational approximation by incorporating an adaptive convected material frame in the basic definition of the displacement vector and strain tensor. In the formulation, each discrete element is associated with a local coordinate system that rotates and translates with the element. For each load increment, the corresponding strain-displacement and nodal force-stress relationships are defined in the updated local coordinates, and based on the updated element geometry. The rigid body motion and deformation displacements are decoupled for each increment. This modified approach incorporates the geometrical nonlinearities through the continuous updating of the material frame geometry. A generalized nonlinear function is used to derive the inelastic constitutive relation and the kinematic hardening is considered. The equation of motion is integrated by an explicit procedure and it involves only vector assemblage and vector storage in the analysis by assuming a lumped mass matrix of diagonal form. Several numerical examples are demonstrated in close agreement with the solutions obtained by the ANSYS code. Numerical studies show that the proposed approach is capable of investigating large deflection of inelastic planar structures and providing an excellent numerical performance.