• Title/Summary/Keyword: Decreasing Intensity Function

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A Comparative Study on Software Reliability Model for NHPP Intensity Function Following a Decreasing Pattern (강도함수가 감소패턴을 따르는 NHPP 소프트웨어 신뢰모형에 관한 비교 연구)

  • Kim, Hee Cheul;Kim, Jong Buam;Moon, Song Chul
    • Journal of Information Technology Applications and Management
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    • v.23 no.4
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    • pp.117-125
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    • 2016
  • Software reliability in the software development process is an important issue. In infinite failure non-homogeneous Poisson process software reliability models, the failure occurrence rates per fault. can be presented constant, monotonic increasing or monotonic decreasing pattern. In this paper, the reliability software cost model considering decreasing intensity function was studied in the software product testing process. The decreasing intensity function that can be widely used in the field of reliability using power law process, log-linear processes and Musal-Okumoto process were studied and the parameter estimation method was used for maximum likelihood estimation. In this paper, from the software model analysis, we was compared by applying a software failure interval failure data considering the decreasing intensity function The decreasing intensity function model is also efficient in terms of reliability in the arena of the conservative model can be used as an alternating model can be established. From this paper, the software developers have to consider life distribution by preceding information of the software to classify failure modes which can be gifted to support.

A Comparison of Reliability Factors of Software Reliability Model Following Lifetime Distribution Dependent on Pareto and Erlang Shape Parameters (파레토 및 어랑 형상모수에 의존한 수명분포를 따르는 소프트웨어 신뢰성 모형에 대한 신뢰도 특성요인 비교 연구)

  • Kim, Hee Cheul;Moon, Song Chul
    • Journal of Information Technology Applications and Management
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    • v.24 no.2
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    • pp.71-80
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    • 2017
  • Software reliability is one of the most elementary and important problems in software development In order to find the software failure occurrence, the instantaneous failure rate function in the Poisson process can have a constant, incremental or decreasing tendency independently of the failure time. In this study, we compared the reliability performance of the software reliability model using the parameters of Pareto life distribution with the intensity decreasing pattern and the shape parameter of Erlang life distribution with the intensity increasing and decreasing pattern in the software product testing. In order to identify the software failure environment, the parametric estimation was applied to the maximum likelihood estimation method. Therefore, in this paper, we compare and evaluate software reliability by applying software failure time data. The reliability of the Erlang and Pareto life models is shown to be higher than that of the Pareto lifetime distribution model when the shape parameter is higher and the Erlang model is more reliable when the shape parameter is higher. Through this study, the software design department will be able to help the software design by applying various life distribution and shape parameters, and providing basic knowledge using software failure analysis.

The Effects of a Self-Help Empowerment Strategy Program on the Empowerment and Health Status of Rheumatoid Arthritis Patients (능력증강전략을 활용한 자조관리과정이 류마티스관절염 환자의 능력증강과 신체적, 심리적 기능에 미치는 효과)

  • Lee, Eun-Nam;Choi, Eun-Ok;Hwang, Eun-Jeong
    • Korean Journal of Adult Nursing
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    • v.15 no.3
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    • pp.393-401
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    • 2003
  • Purpose: The purpose of this study was to examine the effects of a six week self-help empowerment strategy program on the empowerment status, pain intensity, physical function, joint flexibility and depression status in rheumatoid arthritis patients. Method: The subjects of the study consisted of a convenience sample thirteen rheumatoid arthritis patients. Data was collected from July to November, 2001. All patient received a self-help empowerment strategy program, once a week for six weeks. Result: After receiving the self-help empowerment strategy program, the empowerment status increased significantly, the pain intensity and the depression score decreased significantly and the level of physical function significantly improved but the flexibilities of shoulders, knees and ankles were not significantly changed. Conclusion: Further studies need to be done to determine the feasibility of implementing empowerment strategy and its possibility as an effective intervention program for decreasing pain intensity and depression score and improving the physical function.

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The Comparative Study for NHPP Software Reliability Growth Model Based on Non-linear Intensity Function (비선형 강도함수를 가진 NHPP 소프트웨어 신뢰성장 모형에 관한 비교 연구)

  • Kim, Hee-Cheul
    • Convergence Security Journal
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    • v.7 no.2
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    • pp.1-8
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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 (intensity function). In this paper, intensity function of Goel-Okumoto model was reviewed, proposes Kappa (2) and the Burr distribution, 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 real data set introduced by NTDS (Naval Tactical Data System)

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Vertical Diffusion of Ammonia Into Amorphous Ice Sturcture

  • Kim, Yeong-Sun;Mun, Ui-Seong;Gang, Heon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.280-280
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    • 2012
  • We examined ammonia diffusion on the surface of amorphous ice film through the measurement of decreasing residual quantity of $NH_3$ molecules compared to $H_2O$. The populations of $NH_3$ molecules on the surface of amorphous ice were monitored by using the techniques of temperature programmed reactive ion scattering (TPRIS) method. The ratio of intensity between ammonia and water was examined as a function of time at controlled temperature. When ammonia molecules were externally added onto an ice film at a temperature of 80 K, ammonia coverage with regard to ice was 0.12-0.16 ML. The intensity of ammonia molecules on the surface of ice decreased as time increased and the extent of decreased intensity of ammonia increased as controlled temperature increased. Moreover, energy barrier was estimated to be $51kJmol^{-1}$ on amorphous ice film. The results of the experiment indicate that ammonia molecules have a property of vertical diffusion into amorphous ice and the energy barrier of ammonia diffusion into bulk of ice is higher than that of hydrogen bonding.

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Comparison of Maximum Phonation Time Associated with the Changes in Vocal Intensity in Patients with Unilateral Vocal Fold Palsy and Sulcus Vocalis (성대마비와 성대구증의 강도 변화에 따른 최대발성지속시간 비교)

  • Choi, Se-Jin;Choi, Hong-Shik;Kim, Jae-Ock;Choi, Yae-Lin
    • Phonetics and Speech Sciences
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    • v.4 no.1
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    • pp.125-131
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    • 2012
  • The patients with incomplete glottic closure have an important feature decreasing the maximum phonation time (MPT) because airflow rate or air leakage is greater than people without voice disorders. Also they can appear a problem in the intensity regulation. This study analyzed MPT difference based on the comfortable intensity and louder intensity and the correlation between MPT and respiration volume of unilateral vocal fold palsy (UVFP) and sulcus vocalis (SV) group. The twenty with UVFP, the 21 with SV, the 21 normal subjects measured MPT in /a/ vowel prolongation task with comfortable intensity and louder intensity and compared analysis by measuring FVC, $FEV_1$, $FEV_1/FVC$ to analyze the correlation between MPT and respiration volume. First, a comparison of MPT according to the intensity between groups is that MPT of the normal group was statistically significant long compared to the patient group in comfortable intensity, but MPT between groups was not statistically significant difference in the louder intensity. Second, an analysis of the correlation between MPT and respiration volume is that this was statistically significant correlation between MPT in comfortable intensity and MPT in louder intensity. But this did not show statistically significant correlation between intensity and respiration volume. This study can be supported the preceding study results deduced that shorting MPT of the patient group compared to the normal group was originated in the problem of laryngeal valving mechanism at the level of vocal folds rather than a problem of respiratory function. Also at the phonation by varying the intensity, the result can deduce that in the case of patient group, the length of MPT had been improved by increasing the glottal closure ratio in the louder intensity. These results can support the theoretical basis that should be applied to the clinicians by varying the intensity at the voice evaluation and voice therapy for the patients with the glottis incompetence.

The Comparative Study of NHPP Software Reliability Model Based on Log and Exponential Power Intensity Function (로그 및 지수파우어 강도함수를 이용한 NHPP 소프트웨어 무한고장 신뢰도 모형에 관한 비교연구)

  • Yang, Tae-Jin
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.8 no.6
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    • pp.445-452
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    • 2015
  • Software reliability in the software development process is an important issue. Software process improvement helps in finishing with reliable software product. Infinite 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 reliability model with log and power intensity function (log linear, log power and exponential power), 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 log and power intensity function, was employed. This analysis of failure data compared with log and power intensity function. In order to insurance for the reliability of data, Laplace trend test was employed. In this study, the log type model is also efficient in terms of reliability because it (the coefficient of determination is 70% or more) in the field of the conventional model can be used as an alternative could be confirmed. From this paper, software developers have to consider the growth model by prior knowledge of the software to identify failure modes which can be able to help.

Design of bivariate step-stress partially accelerated degradation test plan using copula and gamma process

  • Srivastava, P.W.;Manisha, Manisha;Agarwal, M.L.
    • International Journal of Reliability and Applications
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    • v.17 no.1
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    • pp.21-49
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    • 2016
  • Many mechanical, electrical and electronic products have more than one performance characteristics (PCs). For example the performance degradation of rubidium discharge lamps can be characterized by the rubidium consumption or the decreasing intensity the lamp. The product may degrade due to all the PCs which may be independent or dependent. This paper deals with the design of optimal bivariate step-stress partially accelerated degradation test (PADT) with degradation paths modelled by gamma process. The dependency between PCs has been modelled through Frank copula function. In partial step-stress loading, the unit is tested at usual stress for some time, and then the stress is accelerated. This helps in preventing over-stressing of the test specimens. Failure occurs when the performance characteristic crosses the critical value the first time. Under the constraint of total experimental cost, the optimal test duration and the optimal number of inspections at each intermediate stress level are obtained using variance optimality criterion.

Phase Doppler Measurements and Probability Density Functions in Liquid Fuel Spray (연료분무의 위상도플러 측정과 확률밀도함수의 도출)

  • 구자예
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.4
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    • pp.1039-1049
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    • 1994
  • The intermitternt and transient fuel spray have been investigated from the simultaneous measurement of droplet sizes and velocities by using Phase/Doppler Particle Analyzer(PDPA). Measurement have been done on the spray axis and at the edge of the spray near nozzle at various gas-to-liquid density ratios(.rho./sub g//.rho./sub l/) that ranges from those found in free atmospheric jets to conditions typical of diesel engines. Probability density distributions of the droplet size and velocity were obtained from raw data and mathematical probability density functions which can fit the experimental distribations were extracted using the principle of maximum likelihood. In the near nozzle region on the spray axis, droplet sizes ranged from the lower limit of the measurement system to the order of nozzle diameter for all (.rho./sub g/ /.rho./sub l/) and droplet sizes tended to be small on the spray edge. At the edge of spray, average droplet velocity peaked during needle opening and needle closing. The rms intensity is greatly incresed as the radial distance from the nozzle is increased. The probability density function which can best fit the physical breakage process such as breakup of fuel drops is exponecially decreasing log-hypebolic function with 4 parameters.

A Comparative Study on Reliability Attributes for Software Reliability Model Dependent on Lindley and Erlang Life Distribution (랜들리 및 어랑 수명분포에 의존한 소프트웨어 신뢰성 모형에 대한 신뢰도 속성 비교 연구)

  • Yang, Tae-Jin
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.10 no.5
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    • pp.469-475
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    • 2017
  • Software reliability is one of the most basic and essential problems in software development. In order to detect the software failure phenomenon, the intensity function, which is the instantaneous failure rate in the non-homogeneous Poisson process, can have the property that it is constant, non-increasing or non-decreasing independently at the failure time. In this study, was compared the reliability performance of the software reliability model using the Landely lifetime distribution with the intensity function decreasing pattern and Erlang lifetime distribution from increasing to decreasing pattern in the software product testing process. In order to identify the software failure phenomenon, the parametric estimation was applied to the maximum likelihood estimation method. Therefore, in this paper, was compared and evaluated software reliability using software failure interval time data. As a result, the reliability of the Landely model is higher than that of the Erlang distribution model. But, in the Erlang distribution model, the higher the shape parameter, the higher the reliability. Through this study, the software design department will be able to help the software design by applying various life distribution and shape parameters, and providing software reliability attributes data and basic knowledge to software reliability model using software failure analysis.