• Title/Summary/Keyword: exact methods

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The effect of the tongue in groove technique on the nasolabial angle and nasal tip projection

  • Khabir, Fatemeh;Sezavar, Mehdi;Bohluli, Behnam;Mesgarzadeh, Vahid;Tavakoli, Hamidreza
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.42
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    • pp.19.1-19.4
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    • 2020
  • Background: The tongue in groove technique (TIG) is a useful technique for the correction of the nasal tip projection and the nasolabial angle. The purpose of this study was to determine the utility of this technique for nasal tip rotation and projection correction in the Iranian society. Methods: This is a retrospective clinical trial study of 20 patients undergoing open septo-rhinoplasty using TIG technique from January 2017 to August 2019 at the oral and maxillofacial unit of Bu Ali Hospital and private sector. Preoperative and postoperative profile view photographs were compared to assess the changes in tip projection and rotation. Results: Fifteen patients (75%) had normal angular size, and 5 of them (25%) were not within the normal range after the surgery. The Fisher exact test showed that this success was statistically significant (P = 0.006). Ten patients (50%) had normal projection size, postoperatively. The Fisher exact test showed that this effect was statistically significant (P < 0.01) Conclusion: The study demonstrated the benefit of TIG on the correction of nasal tip projection and rotation.

Analysis of treatment outcomes based on socioeconomic factors of patients visiting the emergency room (응급실 내원 환자의 사회경제적 요인에 따른 치료 결과 분석)

  • Yo-Han Shin;Sang-Kyu Park;Bo-Kyun Kim
    • The Korean Journal of Emergency Medical Services
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    • v.27 no.1
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    • pp.127-137
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    • 2023
  • Purpose: This study aimed to analyze the treatment outcomes according to the socioeconomic factor of patients who visited the emergency room. Methods: This study conducted frequency analysis, percentage analysis, and Fisher's exact test analysis method, using the R 4.1.2 program based on the 2019 data from the Korea Health Panel. Results: Among the treatment results of 1,648 patients, 392 patients were hospitalized or transferred to other hospitals, 845 were discharged after treatment, 224 were discharged, and 7 died. The Fisher's exact test of treatment outcomes and socioeconomic factors was not statistically significant for status of the worker and employment relationship, but was significant for the housing, household, economic activity, and insurance types, and marital status and education. Conclusion: The results of this study indicate that it is necessary to conduct follow up studies on socioeconomic factors to provide basic data that can contribute to fairness and equity in the health care field.

MESHLESS AND HOMOTOPY PERTURBATION METHODS FOR ONE DIMENSIONAL INVERSE HEAT CONDUCTION PROBLEM WITH NEUMANN AND ROBIN BOUNDARY CONDITIONS

  • GEDEFAW, HUSSEN;GIDAF, FASIL;SIRAW, HABTAMU;MERGIAW, TADESSE;TSEGAW, GETACHEW;WOLDESELASSIE, ASHENAFI;ABERA, MELAKU;KASSIM, MAHMUD;LISANU, WONDOSEN;MEBRATE, BENYAM
    • Journal of applied mathematics & informatics
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    • v.40 no.3_4
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    • pp.675-694
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    • 2022
  • In this article, we investigate the solution of the inverse problem for one dimensional heat equation with Neumann and Robin boundary conditions, that is, we determine the temperature and source term with given initial and boundary conditions. Three radial basis functions(RBFs) have been used for numerical solution, and Homotopy perturbation method for analytic solution. Numerical solutions which are obtained by considering each of the three RBFs are compared to the exact solution. For appropriate value of shape parameter c, numerical solutions best approximates exact solutions. Furthermore, we have shown the impact of noisy data on the numerical solution of u and f.

Analysis and Design of Crossover Junctions including Output Phase (출력 위상을 고려한 크로스오버 접합의 해석 및 설계)

  • Myun-Joo Park
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.23 no.1
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    • pp.146-152
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    • 2024
  • This paper presents the analysis and the design methods of the crossover junctions including the output phase. The general solutions were derived analytically through an even-odd analysis of the reflection coefficients and the impedance parameters for the crossover junction with arbitrary output phase. The general solutions were applied to a real crossover junction structure to derive the exact design formula for the arbitrary output phase. The results agreed well with the existing studies. The designed circuit satisfied the crossover junction operation with the exact output phase.

Piping Analysis for Excavation in a Embankment (굴착에 따른 인접 제방의 파이핑 해석)

  • Lee, Song;Kook, Joong-Jin;Jung, Min-Hyung
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.13 no.1 s.53
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    • pp.59-68
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    • 2009
  • One of the cause of embankment failure for piping is a routine design for piping consideration without exact understanding of that. Therefore, in this study, comparison and analysis of existing piping consideration methods had been conducted through embankment sections when sheet piles constructed on sandy ground. For the Terzaghi method and the critical hydraulic method, safety factors were changed up to double depending on the method. And for the critical velocity method, it was dramatically changed due to design parameters. Consequently, existing piping consideration method currently used is recommended not to be applied to all ground conditions uniformly but to applied with exact understanding of each consideration method characteristics depending on ground conditions.

A Study on the T&E Method for the Aircraft focused on Weapon Accuracy (항공 무장정확도 시험평가 방법에 관한 연구)

  • Hyun, Jun-Ho;Kang, Sung-Jin
    • Journal of the military operations research society of Korea
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    • v.33 no.1
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    • pp.117-133
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    • 2007
  • The weapon accuracy is a basic measure of performance in the area of weapon system acquisition. It requires the establishment of correct concept and the T&E methods. Existing T&E method for aircraft weapon systems have not considered types of exact hitting area for various weapons. This study intends to suggest an optimal T&E methods in Korean T&E environment. In order to sampling and to test aircraft weapon accuracy, we need probability and statistic theories. There are many types of CEP(Circular Error Probable) methods. We recommend 2 types of CEP methods which are Lockheed Martin CEP method and Johnson CEP method. Also, suggest some other T&E methods. These methods can be used to accuracy test in the area of weapon system acquisition in the future.

A Method for Gene Group Analysis and Its Application (유전자군 분석의 방법론과 응용)

  • Lee, Tae-Won;Delongchamp, Robert R.
    • The Korean Journal of Applied Statistics
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    • v.25 no.2
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    • pp.269-277
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    • 2012
  • In microarray data analysis, recent efforts have focused on the discovery of gene sets from a pathway or functional categories such as Gene Ontology terms(GO terms) rather than on individual gene function for its direct interpretation of genome-wide expression data. We introduce a meta-analysis method that combines $p$-values for changes of each gene in the group. The method measures the significance of overall treatment-induced change in a gene group. An application of the method to a real data demonstrates that it has benefits over other statistical methods such as Fisher's exact test and permutation methods. The method is implemented in a SAS program and it is available on the author's homepage(http://cafe.daum.net/go.analysis).

An Eulerian-Lagrangian Hybrid Numerical Method for the Longitudinal Dispersion Equation (Eulerian-Lagrangian 혼합모형에 의한 종확산 방정식의 수치해법)

  • 전경수;이길성
    • Water for future
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    • v.26 no.3
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    • pp.137-148
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    • 1993
  • A hybrid finite difference method for the longitudinal dispersion equation was developed. The method is based on combining the Holly-Preissmann scheme with the fifth-degree Hermite interpolating polynomial and the generalized Crank-Nicholson scheme. Longitudinal dispersion of an instantaneously-loaded pollutant source was simulated by the model and other characteristics-based numerical methods. Computational results were compared with the exact solution. The present method was free from wiggles regardless of the Courant number, and exactly reproduced the location of the peak concentration. Overall accuracy of the computation increased for smaller value of the weighting factor, $\theta$ of the model. Larger values of $\theta$ overestimated the peak concentration. Smaller Courant number gave better accuracy, in general, but the sensitivity was very low, especially when the value of $\theta$ was small. From comparisons with the hybrid method using the third-degree interpolating polynomial and with split-operator methods, the present method showed the best performance in reproducing the exact solution as the advection becomes more dominant.

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Comparative Study on Wave Induced Fatigue Analysis Methods for Steel Catenary Riser (파랑하중에 의한 Steel Catenary Riser 피로손상 평가 방법의 비교검토)

  • Lee, Jeong-Dae;Lee, Sung-Je;Jang, Chang-Hwan;Jun, Seock-Hee;Oh, Yeong-Tae
    • Journal of the Society of Naval Architects of Korea
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    • v.52 no.3
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    • pp.222-235
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    • 2015
  • The purpose of this study is to suggest guidelines for riser fatigue analysis in terms of selection of reasonable analysis method. Three analysis methods (spectral, regular wave, rain-flow counting) are introduced and compared. As the riser systems give non-linear response, the time-domain analysis method is more preferred than frequency-domain analysis method. The spectral fatigue analysis method, however, is still useful for identifying fatigue prone areas. Once stress RAO is established, fatigue damage can be calculated very quickly. The regular wave method and the rain-flow counting method are more time consuming but give more exact results compare to spectral method. In case of regular wave method, a set of regular waves which represent random sea states is considered for dynamic analysis. The rain-flow counting method is the most intuitive and exact method because it refers time history stresses containing most of non-linear effects of the riser system. However, it is not common for early design stage to use rain-flow counting method because of its high cost. In this study, it was confirmed that the regular wave method is the most cost effective way in specific cases. However, if the system is highly non-linear, it seems that the regular wave method gives less accurate results than rain-flow counting method. Therefore, it is imperative that the engineers select appropriate analysis method based on design stage and given engineering period. This paper also discusses the theoretical background of each calculation method and hydrodynamic aspects of marine riser systems. A steel catenary riser (SCR) line on FPSO was considered and marine dynamic program (OrcaFlex) was used for static and dynamic analysis.

Numerical Simulation of Periodic and Oscillatory Problems by Using RK-Butcher Algorithms (RK-Butcher알고리듬의 사용에 의한 주기적 진동 문제의 수치적 시뮬레이션)

  • Park, Dae-Chul;Gopal, Devarajan;Murugesh, V.
    • Journal of the Institute of Convergence Signal Processing
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    • v.9 no.1
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    • pp.82-88
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    • 2008
  • In this paper, Runge-Kutta (RK)-Butcher algorithm is proposed to study the periodic and oscillatory problems. Simulation results obtained using RK-Butcher algorithms and the classical fourth order Runge-Kutta (RK(4)) methods are compared with the exact solutions of a few periodic and oscillatory problems to confirm the performance of the proposed algorithm. The simulation results from RK-Butcher algorithms are always found to be very close to the exact solutions of these problems. Further, it is found that the RK-Butcher algorithm is superior when compared to RK(4) methods in terms of accuracy. The RK-Butcher algorithm can be easily implemented in a programming language and a more accurate solution may be obtained for any length of time. RK-Butcher algorithm is applicable as a good numerical algorithm for studying the problems of orbit and two body as it gives the nearly identical solutions.

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