• Title/Summary/Keyword: bisection

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The Comparative Study based on Gompertz Software Reliability Model of Shape Parameter (곰페르츠형 형상모수에 근거한 소프트웨어 신뢰성모형에 대한 비교연구)

  • Shin, Hyun Cheul;Kim, Hee Cheul
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.10 no.2
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    • pp.29-36
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    • 2014
  • Finite failure NHPP software reliability models presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault. In this paper, proposes the Gompertz distribution reliability model, which made out efficiency application for software reliability. Algorithm to estimate the parameters used to maximum likelihood estimator and bisection method, model selection based on mean square error (MSE) and coefficient of determination$(R^2)$, for the sake of efficient model, was employed. Analysis of failure using real data set for the sake of proposing fixed shape parameter of the Gompertz distribution was employed. This analysis of failure data compared with the Gompertz distribution model of shape parameter. In order to insurance for the reliability of data, Laplace trend test was employed. In this study, the proposed Gompertz model is more efficient in terms of reliability in this area. Thus, Gompertz model can also be used as an alternative model. From this paper, software developers have to consider the growth model by prior knowledge of the software to identify failure modes which can was helped.

Finite element simulation for steel tubular members strengthened with FRP under compression

  • El-Kholy, Ahmed M.;Mourad, Sherif A.;Shaheen, Ayman A.;Mohamed, Yomna A.
    • Structural Engineering and Mechanics
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    • v.72 no.5
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    • pp.569-583
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    • 2019
  • Tubular steel sections are widespread all over the world because of their strength and aesthetic appearance. Tubular steel members may exhibit local buckling such as elephant foot or overall buckling under extreme compression load. Recently, external bonding of fiber reinforced polymers (FRP) sheets for strengthening these members has been explored through experimental research. This paper presents three-dimensional nonlinear finite element analysis (FEA) to investigate the structural behavior of strengthening tubular steel members with FRP against local and overall buckling phenomena. Out-of-roundness and out-of-straightness imperfections were introduced to the numerical models to simulate the elephant foot and overall buckling, respectively. The nonlinear analysis preferences such as the integration scheme of the shell elements, the algorithm for solution of nonlinear equations, the loading procedure, the bisection limits for the load increments, and the convergence criteria were set, appropriately enough, to successfully track the sophisticated buckling deformations. The agreement between the results of both the presented FEA and the experimental research was evident. The FEA results demonstrated the power of the presented rigorous FEA in monitoring the plastic strain distribution and the buckling phenomena (initiation and propagation). Consequently, the buckling process was interpreted for each mode (elephant foot and overall) into three sequential stages. Furthermore, the influence of FRP layers on the nonlinear analysis preferences and the results was presented.

The Comparative Study for ENHPP Software Reliability Growth Model based on Modified Coverage Function (변형 커버리지 함수를 고려한 ENHPP 소프트웨어 신뢰성장 모형에 관한 비교 연구)

  • Kim, Hee-Cheul;Kim, Pyong-Koo
    • Journal of the Korea Society of Computer and Information
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    • v.12 no.6
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    • pp.89-96
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    • 2007
  • Finite failure NHPP models presented in the literature exhibit either constant. monotonic increasing or monotonic decreasing failure occurrence rates per fault. Accurate predictions of software release times. and estimation of the reliability and availability of a software product require quality of a critical element of the software testing process : test coverage. This model called Enhanced non-homogeneous Poission process(ENHPP). In this paper, exponential coverage and S-type model was reviewed, proposes modified(the superosition and mixture) model, which make out efficiency application for software reliability. Algorithm to estimate the parameters used to maximum likelihood estimator and bisection method. model selection based on SSE statistics for the sake of efficient model, was employed.

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The Study for NHPP Software Reliability Growth Model Based on Hyper-exponential Distribution (초지수분포(Hyper-exponential)를 이용한 소프트웨어 신뢰성장 모형에 관한 연구)

  • Kim, Hee-Cheul;Shin, Hyun-Cheul
    • Convergence Security Journal
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    • v.7 no.1
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    • pp.45-53
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    • 2007
  • Finite failure NHPP models presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault. In this paper, Goel-Okumoto and Yamada-Ohba-Osaki model was reviewed, proposes the hyper-exponential distribution reliability model, which maked out efficiency application for software reliability. Algorithm to estimate the parameters used to maximum likelihood estimator and bisection method. For model determination and selection, explored goodness of fit (the error sum of squares). The methodology developed in this paper is exemplified with a software reliability random data set introduced by of Weibull distribution (shape 0.1 & scale 1) of Minitab (version 14) statistical package.

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A Robust and Efficient Method to Compute the Closest Approach Distance between Two Ellipsoids (두 타원체 사이의 최단 접근 거리를 구하는 안정적이며 효율적인 방법)

  • Choi, Min Gyu
    • Journal of Korea Game Society
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    • v.19 no.6
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    • pp.99-106
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    • 2019
  • This paper addresses a method to compute the closest approach distance between two ellipsoids in their inter-center direction. This is the key technique for collision detection and response between ellipsoids. We formulate a set of conditions with the inter-center distance, the contact point and the contact normal vector of the two externally-contacting ellipsoids. The equations are solved robustly and efficiently using a hybrid of Newton's method and the bisection method with root bracketing. We demonstrate the robustness and efficiency of the proposed method in various experiments.

A New Fast Algorithm for Short Range Force Calculation (근거리 힘 계산의 새로운 고속화 방법)

  • Lee, Sang-Hwan;Ahn, Cheol-O
    • 유체기계공업학회:학술대회논문집
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    • 2006.08a
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    • pp.383-386
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    • 2006
  • In this study, we propose a new fast algorithm for calculating short range forces in molecular dynamics, This algorithm uses a new hierarchical tree data structure which has a high adaptiveness to the particle distribution. It can divide a parent cell into k daughter cells and the tree structure is independent of the coordinate system and particle distribution. We investigated the characteristics and the performance of the tree structure according to k. For parallel computation, we used orthogonal recursive bisection method for domain decomposition to distribute particles to each processor, and the numerical experiments were performed on a 32-node Linux cluster. We compared the performance of the oct-tree and developed new algorithm according to the particle distributions, problem sizes and the number of processors. The comparison was performed sing tree-independent method and the results are independent of computing platform, parallelization, or programming language. It was found that the new algorithm can reduce computing cost for a large problem which has a short search range compared to the computational domain. But there are only small differences in wall-clock time because the proposed algorithm requires much time to construct tree structure than the oct-tree and he performance gain is small compared to the time for single time step calculation.

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The effects of vibration stimulation applied to the left forearm on unilateral neglect in patients with stroke: A pilot randomized controlled trial

  • Park, Jin-hyuck;Park, Ji-hyuk
    • Therapeutic Science for Rehabilitation
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    • v.4 no.2
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    • pp.63-71
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    • 2015
  • Objective : The purpose of this study was to investigate the effects of vibratory stimulation applied to the left forearm on unilateral neglect in patients with stroke. Methods : The subjects were 11 unilateral neglect patients with stroke. They were divided into 2 groups; 6 experimental subjects and 5 control subjects. Both groups received standardized rehabilitation program and occupational therapy for the intervention of unilateral neglect in a day. In random order, line bisection test (LBT), Albert test, and star cancellation test (SCT) were conducted at baseline, the next day. During the process of all assessments of the next day, vibration stimulation was provided for the 6 subjects in the experimental group (EG), while the 5 subjects in CG carried out all assessments without vibration stimulation. Result : No significant differences were found between groups on any demographic variable or baseline assessments scores. In the next day, there was significant improvement in the EG for the LBT(p<0.05), Albert's test(p<0.05), and SCT(p<0.05). However, there was no significant improvement in the CG for the LBT(p<0.05), Albert's test(p<0.05), and SCT(p<0.05). Conclusion : These result indicate that vibratory stimulation has a positive effect on the unilateral neglect, and may be considered as alternative choice in clinical occupational therapy for reducing unilateral neglect.

A Comparative Study of Software finite Fault NHPP Model Considering Inverse Rayleigh and Rayleigh Distribution Property (역-레일리와 레일리 분포 특성을 이용한 유한고장 NHPP모형에 근거한 소프트웨어 신뢰성장 모형에 관한 비교연구)

  • Shin, Hyun Cheul;Kim, Hee Cheul
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.10 no.3
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    • pp.1-9
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    • 2014
  • The inverse Rayleigh model distribution and Rayleigh distribution model were widely used in the field of reliability station. In this paper applied using the finite failure NHPP models in order to growth model. In other words, a large change in the course of the software is modified, and the occurrence of defects is almost inevitable reality. Finite failure NHPP software reliability models can have, in the literature, exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault. In this paper, proposes the inverse Rayleigh and Rayleigh software reliability growth model, which made out efficiency application for software reliability. Algorithm to estimate the parameters used to maximum likelihood estimator and bisection method, model selection based on mean square error (MSE) and coefficient of determination($R^2$), for the sake of efficient model, were employed. In order to insurance for the reliability of data, Laplace trend test was employed. In many aspects, Rayleigh distribution model is more efficient than the reverse-Rayleigh distribution model was proved. From this paper, software developers have to consider the growth model by prior knowledge of the software to identify failure modes which can helped.

Characteristics of Functional Recovery in Hemiplegia with and without Pusher Syndrome (편마비 환자의 밀기증후군 유무에 따른 기능 회복의 특성)

  • Kim Seung-Won;Chang Woo-Nam;Hwang Byong-Yong
    • The Journal of Korean Physical Therapy
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    • v.15 no.4
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    • pp.34-45
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    • 2003
  • A 'pusher syndrome' encompassing postural imbalance and hemi-neglect is believed to aggravate the prognosis of stroke patients. The patients with pusher syndrome show a particular posture that pushing away from the unaffected side of the body. The objective of this study was to investigate associated proprioception, associated neuro-psychological symptoms and characteristics of functional outcome with and without pusher syndrome. The subjects of this study were 58 acute stroke patients who been rehabilitated at two university hospitals in Seoul and Buchun. Data were collected using proprioception test and line bisection test. The ability of ADL was assessed by the Modified Barthel Index, transfer by the Functional Independence Measure, and balance by the Modified Motor Assessment Scale. The results were that significant difference was found in the presence of proprioception, in the incidence of hemineglect and anosognosia, and in the score of ADL, transfer and balance between patients with and without pusher syndrome. Patients without pusher syndrome gained more motor score than patients with pusher syndrome. From improvement of view, patients with pusher syndrome gained the lowest score in ability of transfer. The finding suggest that the patients with pusher syndrome is a poorer functional outcome, be related to proprioception, hemineglect and anosognosia.

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The Study for ENHPP Software Reliability Growth Model based on Superposition Coverage Function (중첩커버리지 함수를 고려한 ENHPP 소프트웨어 신뢰성장 모형에 관한 연구)

  • Kim, Hee-Cheul;Shin, Hyun-Cheul
    • Convergence Security Journal
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    • v.7 no.3
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    • pp.7-13
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    • 2007
  • Finite failure NHPP models presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault. Accurate predictions of software release times, and estimation of the reliability and availability of a software product require quantification of a critical element of the software testing process : test coverage. This model called Enhanced non-homogeneous poission process (ENHPP). In this paper, exponential coverage and S-shaped model was reviewed, proposes the superposition model, which maked out efficiency application for software reliability. Algorithm to estimate the parameters used to maximum likelihood estimator and bisection method, model selection based on SSE statistics for the sake of efficient model, was employed.

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