• Title/Summary/Keyword: exact methods

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The Improvement Proposal of Control System for Supply and Demand of Korean Optometrist (안경사 인력 수급 및 관리제도 개선방안)

  • Kim, Sang-Hyun;Lim, Yongmoo
    • Journal of Korean Ophthalmic Optics Society
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    • v.12 no.4
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    • pp.9-14
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    • 2007
  • We have studied the problems associated with increasing number of ophthalmic optics students every year. The main problems are surplus supply of the optometrist and poor working condition. Thus all parties concerned who aim to solve the numerical unbalance of optometrist must have the common policy in sight. And we have to make a long-term plan and permanent organization for medical technician to establish supply and demand of medical technician with exact policy. To solve this unbalance of optometrist numbers, we have to establish an exact job category, reform the specialized education course, estimate the practical technique of national licensing examination for Korean optometrist, and innovate the contents and methods of reeducation.

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Modal Parameter Sensitivity Analysis Using Component Mode Synthesis Method (부분 구조물의 모드 합성을 이용한 구조물 모드 매개변수의 민감도 해석)

  • 김형중;박윤식
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1997.04a
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    • pp.184-191
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    • 1997
  • A method, termed as the substructural sensitivity synthesis method, which utilizes the computational merits of the component mode synthesis technique is proposed to calculate design sensitivity of modal parameters of substructurally combined structures. In this method, the sensitivity analysis is combined with component mode synthesis thchnique. thus the degrees of freedom of a combined structure can be dramatically reduced. Free-interface mode method including the residual attachment modes among the component mode synthesis methods is used to calculate the modal sensitivity of the combined structure. For the design sensitivities of modal properties of structure, the Nelson's method, which is exact solving method is used. It is shown that the modal sensitivities of the entire structure can be obtained by synthesizing the substructural modal data, and the sensitivities of the modal data about the design variables of modifiable substructure. Using the proposed method, the final degrees of freedom of entire structure can be remarkably reduced to calculate the modal parameter sensitivities. With a structure composed of beams and plates, as an example, the sensitivities of the eigenvalues and eigenvectors obtained by this proposed method were compared with the exact solutions in terms of accuracy.

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Reduction of Computing Time through FDM using Implicit Method and Latent Heat Treatment in Solidification Analysis (FDM에 의한 응고해석시 계산시간 단축을 위한 음적해법의 적용과 잠열처리방법)

  • Kim, Tae-Gyu;Choi, Jung-Kil;Hong, Jun-Pyo;Lee, Zin-Hyoung
    • Journal of Korea Foundry Society
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    • v.13 no.4
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    • pp.323-332
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    • 1993
  • An implicit finite difference formulation with three methods of latent heat treatment, such as equivalent specific heat method, temperature recovery method and enthalpy method, was applied to solidification analysis. The Neumann problem was solved to compare the numerical results with the exact solution. The implicit solutions with the equivalent specific heat method and the temperature recovery method were comparatively consistent with the Neumann exact solution for smaller time steps, but its error increased with increasing time step, especially in predicting the solidification beginning time. Although the computing time to solve energy equation using temperature recovery method was shorter than using enthalpy method, the method of releasing latent heat is not realistic and causes error. The implicit formulation of phase change problem requires enthalpy method to treat the release of latent heat reasonably. We have modified the enthalpy formulation in such a way that the enthalpy gradient term is not needed, and as a result of this modification, the computation stability and the computing time were improved.

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New Diagnostic Techniques in Cancer of the Pharynx and Esophagus (인두암과 식도암의 새로운 진단내시경)

  • Cho, Joo Young;Cho, Won Young
    • Korean Journal of Bronchoesophagology
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    • v.17 no.1
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    • pp.14-18
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    • 2011
  • The diagnosis and treatment of early gastrointestinal cancers is the gastroenterologists' mission because of national cancer screening program in South Korea. The detection of early cancers is emphasized, because these were previously treated with surgical treatment can be currently cured with endoscopic treatment. Gastroenterologists who achieved at least on some level can make an exact diagnosis regardless of what type of endoscopy, but generally, there are some required conditions for an optimal diagnosis. First, clinically important lesions have to be detected easily. Second, the border and morphology of lesions have to be characterized easily. Third, lesions have to be diagnosed exactly. Precancers and early cancers are often subtle and can pose a challenge to gastroenterologists to visualize using standard white light endoscopy. The use of dye solutions aids the diagnosis of early gastrointestinal cancers, however, it is a quite cumbersome to use dye solutions all the time and the solution often bothers the exact observation by pooling into the depression or ulceration of the lesion. To overcome this weakness, newer endoscopes are now developed so called "image enhanced endoscopy" using optical and/or electronic methods such as narrow band imaging (NBI), autofluorescence imaging (AFI), i-scan, flexible spectral imaging color enhancement (FICE) and confocal endomicroscopy (CLE).

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Genetic association tests when a nuisance parameter is not identifiable under no association

  • Kim, Wonkuk;Kim, Yeong-Hwa
    • Communications for Statistical Applications and Methods
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    • v.24 no.6
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    • pp.663-671
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    • 2017
  • Some genetic association tests include an unidentifiable nuisance parameter under the null hypothesis of no association. When the mode of inheritance (MOI) is not specified in a case-control design, the Cochran-Armitage (CA) trend test contains an unidentifiable nuisance parameter. The transmission disequilibrium test (TDT) in a family-based association study that includes the unaffected also contains an unidentifiable nuisance parameter. The hypothesis tests that include an unidentifiable nuisance parameter are typically performed by taking a supremum of the CA tests or TDT over reasonable values of the parameter. The p-values of the supremum test statistics cannot be obtained by a normal or chi-square distribution. A common method is to use a Davies's upper bound of the p-value instead of an exact asymptotic p-value. In this paper, we provide a unified sine-cosine process expression of the CA trend test that does not specify the MOI and the TDT that includes the unaffected. We also present a closed form expression of the exact asymptotic formulas to calculate the p-values of the supremum tests when the score function can be written as a linear form in an unidentifiable parameter. We illustrate how to use the derived formulas using a pharmacogenetics case-control dataset and an attention deficit hyperactivity disorder family-based example.

An Efficient Intra-Field Deinterlacing Algorithm using Edges Extracted from the Interpolated Binary Image (보간된 이진 영상으로부터 검출된 정확한 에지를 이용한 효율적인 디인터레이싱 알고리즘)

  • Son, Joo-Yung;Lee, Sang-Hoon;Lee, Dong-Ho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.5C
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    • pp.514-520
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    • 2009
  • This paper proposes a new deinterlacing algorithm which improves the performance of the spatial filter. Extracting exact edges is very important element of deinterlacing performance. So the proposed algorithm has interpolated locally adaptive-thresholded binary image, and extracted exact edges from the interpolated binary image. The values of pixels on edges extracted from binary image are interpolated using neighborhood lines on the same edge. With computer simulations for a variety of images, it is shown that the proposed algorithm is much better than traditional methods.

United Kingdom pediatric dentistry specialist views on the administration of articaine in children

  • Ezzeldin, Maryam;Hanks, Gemma;Collard, Mechelle
    • Journal of Dental Anesthesia and Pain Medicine
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    • v.20 no.5
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    • pp.303-312
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    • 2020
  • Background: Lidocaine is the gold standard local anesthetic (LA) for UK pediatric dental treatment. Recent reports suggest frequent Articaine use in Europe and Canada, with evidence indicating more profound anesthesia. The aim of this study was to examine pediatric dentistry specialist experiences and practices relating to Articaine administration in the UK. Methods: A literature review was followed by a survey using an anonymous 15-item electronic questionnaire, which was sent to 200 registered British Society of Pediatric Dentistry (BSPD) specialists. Descriptive analyses, Z score, chi-squared test, Fisher's exact test, and Spearman's correlation test were performed. Results: Sixty-one (30.5%) participants responded, and 12 (19.7%) indicated Articaine as their first line anesthetic. Articaine was used daily or weekly by 38 (62.3%) respondents, depending on the clinical context. Articaine was commonly used to avoid inferior alveolar nerve blocks and gain more profound anesthesia in abscessed or hypomineralized teeth. Participants reported significantly more adverse effects with lidocaine (Fisher's exact test, P < 0.0001) than with Articaine. Articaine was most often administered in children aged > 4 years via infiltration techniques. Only 15 (24.6%) respondents reported awareness of guidelines for Articaine use in pediatric patients. Conclusions: Articaine use in pediatric dentistry is common; however, evidence supporting its practice is limited. Several specialists follow conventions based on anecdotal evidence. Formulating guidance to aid decision-making when treating pediatric patients under LA would be beneficial.

Vertex Normal Computation using Conformal Mapping and Mean Value Coordinates (등각사상과 평균값좌표계를 이용한 정점 법선벡터 계산법)

  • Kim, Hyoung-Seok B.;Kim, Ho-Sook
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.3
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    • pp.451-457
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    • 2009
  • Most of objects in computer graphics may be represented by a form of mesh. The exact computation of vertex normal vectors is essential for user to apply a variety of geometric operations to the mesh and get more realistic rendering results. Most of the previous algorithms used a weight which resembles a local geometric property of a vertex of a mesh such as the interior angle, the area, and so on. In this paper, we propose an efficient algorithm for computing the normal vector of a vertex in meshes. Our method uses the conformal mapping which resembles synthetically the local geometric properties, and the mean value coordinates which may smoothly represent a relationship with the adjacent vertices. It may be confirmed by experiment that the normal vector of our algorithm is more exact than that of the previous methods.

In-Plane Inextensional and Extensional Vibration Analysis of Curved Beams Using DQM (미분구적법(DQM)을 이용한 곡선보의 내평면 비신장 및 신장 진동해석)

  • Kang, Ki-jun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.11
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    • pp.8064-8073
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    • 2015
  • One of the efficient procedures for the solution of partial differential equations is the method of differential quadrature. This method has been applied to a large number of cases to circumvent the difficulties of the complex algorithms of programming for the computer, as well as excessive use of storage due to conditions of complex geometry and loading. In-plane vibrations of curved beams with inextensibility and extensibility of the arch axis are analyzed by the differential quadrature method (DQM). Fundamental frequencies are calculated for the member with various end conditions and opening angles. The results are compared with exact experimental and numerical results by other methods for cases in which they are available. The DQM gives good accuracy even when only a limited number of grid points is used, and new results according to diverse variation are also suggested.

An exact solution for mechanical behavior of BFRP Nano-thin films embedded in NEMS

  • Altabey, Wael A.
    • Advances in nano research
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    • v.5 no.4
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    • pp.337-357
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    • 2017
  • Knowledge of thin films mechanical properties is strongly associated to the reliability and the performances of Nano Electro Mechanical Systems (NEMS). In the literature, there are several methods for micro materials characterization. Bulge test is an established nondestructive technique for studying the mechanical properties of thin films. This study improve the performances of NEMS by investigating the mechanical behavior of Nano rectangular thin film (NRTF) made of new material embedded in Nano Electro Mechanical Systems (NEMS) by developing the bulge test technique. The NRTF built from adhesively-bonded layers of basalt fiber reinforced polymer (BFRP) laminate composite materials in Nano size at room temperature and were used for plane-strain bulging. The NRTF is first pre-stressed to ensure that is no initial deflection before applied the loads on NRTF and then clamped between two plates. A differential pressure is applying to a deformation of the laminated composite NRTF. This makes the plane-strain bulge test idea for studying the mechanical behavior of laminated composite NRTF in both the elastic and plastic regimes. An exact solution of governing equations for symmetric cross-ply BFRP laminated composite NRTF was established with taking in-to account the effect of the residual strength from pre-stressed loading. The stress-strain relationship of the BFRP laminated composite NRTF was determined by hydraulic bulging test. The NRTF thickness gradation in different points of hemisphere formed in bulge test was analysed.