• Title/Summary/Keyword: functional failure

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Embodying RBD and Reliability Analysis Technology base on Web (웹 기반 RBD 구현 및 신뢰도 평가기술)

  • 송준엽;이승우;이후상;조복기
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.1541-1544
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    • 2003
  • In this study, embodying reliability block diagram based on the web and reliability analysis technology are developed. RBD(reliability Block Diagram) represents the functional relation between elements in any product. Among relations between elements. there are serial, parallel, bridge, and stand by, etc. Advantages of developed system are integrated datum about reliability (NPRD, EPRD, MIL-HDBK 217F, NSWC. OREDA. Bellcore, and domestic institutes & companies datum). graphic user interface for convenience, and the various service analyzes the failure history data of parts.

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Characteristics of Some Animal Models of Experimental Renal Failure (실험적 신장해 모델의 특성 비교)

  • Shim, Chang-Koo
    • Journal of Pharmaceutical Investigation
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    • v.17 no.4
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    • pp.205-211
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    • 1987
  • Renal dysfunction can have pronounced effects on the pharmacokinetic and pharmacodynamic characteristics of drugs. Because the exploration of these effects in patients may be limited by ethical and practical considerations, it often become necessary to perform studies on animals with experimental renal failure(ERF). ERF was produced in rats by the administration of uranyl nitrate, glycerol, salicylate, gentamicin and folate in this study. Changes in glomerular filtration rate(GFR) and renal secretion clearance of tetraethylammonium bromide$(CL^{scn}_{TEA})$, together with morphological changes of kidney cortex were evaluated and compared among ERF models. GFR(or glomeruli) and $CL^{scn}_{TEA}$(or renal tubules) were not damaged parallelly in some ERF model rats. Therefore, it seemed to be necessary to adjust dosage regimen of some basic drugs like TEA in renal dysfunction considering the functional changes of renal secretion in addition to glomerular filtration.

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A Reliability Study on the Weak Point Analysis of the Development Parts (개발부품의 설계취약점 분석을 위한 신뢰성 연구)

  • Kim, Sung Ok;Park, Sang Wook;Lee, Sang Hun
    • Journal of Applied Reliability
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    • v.13 no.1
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    • pp.19-30
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    • 2013
  • The requirements of reliability verification for new products and technology are increasing more and more in accordance with the trend change of strength for safety technology, functional skills and emotional quality. In order to conduct the purpose of robust design from the stage of product development recently, the application of reliability technology has gradually increased such as detecting the failure mode throughout the HALT technique, accelerated tests and so on. The main results are as follows; i) through the pre-test and analysis, detected the basic performance and predictable failure mode, ii) HALT technique and process has been developed that can be applied test methods for the next new products.

A Study on Real Time Asynchronous Data Duplication Method for the Combat System (전투체계 시스템을 위한 실시간 환경에서의 비동기 이중화 기법 연구)

  • Lee, Jae-Sung;Ryu, Jon-Ha
    • Journal of the Korea Institute of Military Science and Technology
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    • v.10 no.2
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    • pp.61-68
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    • 2007
  • In a naval combat system, the information processing node is a key functional equipment and performs major combat management functions including control sensor and weapon systems. Therefore, a failure of one of the node causes fatal impacts on overall combat system capability. There were many methodologies to enhance system availability by reducing the impact of system failure like a fault tolerant method. This paper proposes a fault tolerant mechanism for information processing node using a replication algorithm with hardware duplication. The mechanism is designed as a generic algorithm and does not require any special hardware. Therefore all applications in combat system can use this functionality. The asynchronous characteristic of this mechanism provides the capability to adapt this algorithm to the module which has low performance hardware.

A novel story on rock slope reliability, by an initiative model that incorporated the harmony of damage, probability and fuzziness

  • Wang, Yajun
    • Geomechanics and Engineering
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    • v.12 no.2
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    • pp.269-294
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    • 2017
  • This study aimed to realize the creation of fuzzy stochastic damage to describe reliability more essentially with the analysis of harmony of damage conception, probability and fuzzy degree of membership in interval [0,1]. Two kinds of fuzzy behaviors of damage development were deduced. Fuzzy stochastic damage models were established based on the fuzzy memberships functional and equivalent normalization theory. Fuzzy stochastic damage finite element method was developed as the approach to reliability simulation. The three-dimensional fuzzy stochastic damage mechanical behaviors of Jianshan mine slope were analyzed and examined based on this approach. The comprehensive results, including the displacement, stress, damage and their stochastic characteristics, indicate consistently that the failure foci of Jianshan mine slope are the slope-cutting areas where, with the maximal failure probability 40%, the hazardous Domino effects will motivate the neighboring rock bodies' sliding activities.

Reliability Analysis of Machinery system for Failure Mode and Effect Analysis (FMEA를 이용한 기계류 시스템의 신뢰도 분석)

  • 진도훈;우태수;이치우
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2002.10a
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    • pp.30-35
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    • 2002
  • This paper dealt with FMEA, which is a method of the analysis to secure safety and confidence coming up to customers'expectation in consideration of the environment of the corporation, the industrial environment, and the functional improvement. And by using FMEA, We showed the example analyzed the confidence of the Air Supply System. It was proved by the result of the analysis that the rate of the breakdown which is usually regarded as the first important point to reform can't satisfy the selecting basis to improve. Also the result said that it is not right to depend on only the rate of the failure in making the list of the reform. Through the analysis of the breakdown, FMEA can present the important factors of the reform to improve the confidence of the system. In this study would show the important factors of the improvement in order to product the goods guaranteed confidence through the method of FMEA.

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Critical illness neuromyopathy

  • Park, Soo-Hyun;Jeong, Yoon-Jung;Kim, Nam-Hee
    • Annals of Clinical Neurophysiology
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    • v.22 no.2
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    • pp.61-66
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    • 2020
  • Critical illness neuromyopathy (CINM) is a common but frequently underdiagnosed condition in critically ill patients that contributes to ventilator weaning failure and limb weakness in intensive care unit (ICU). CINM is subdivided into critical illness polyneuropathy and critical illness myopathy, and the occurrence of these conditions in the ICU is associated with multiple organ failure due to sepsis or certain medications. CINM survivors might have persistent functional disabilities and a poor quality of life. This situation demonstrates the need for efforts to minimize or prevent CINM in critically ill patients. This article provides a current overview of CINM and the associated clinical strategies.

GENERALIZED LINDLEY DISTRIBUTION USING PROPORTIONAL HAZARD FAMILY AND INFERENCE OF FAILURE TIME DATA

  • Ahmed AL-Adilee;Hawraa A. AL-Challabi;Hassanein Falah;Dalael Saad Abdul-Zahra
    • Nonlinear Functional Analysis and Applications
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    • v.28 no.3
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    • pp.793-800
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    • 2023
  • In this paper, we propose a generalization of Lindley distribution (GLD) via a special structure that is concern with progressively Type-II right censoring and time failure data. We study the modern properties that we have built by such combination, for example, survival function, hazard function, moments, and estimation by non-Bayesian methods. Application on some selected data related to Lindley distribution (LD) and (ED) have been employed to find out the best distribution that can fit data comparing with the GLD.

Influence of Social Support and Negative Emotional Status on Self-care Adherence in Symptomatic Patients with Heart Failure (심부전 환자의 사회적 지지와 부정적 정서상태가 자가간호 이행에 미치는 영향)

  • Yang, In-Suk
    • Korean Journal of Adult Nursing
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    • v.28 no.3
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    • pp.302-313
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    • 2016
  • Purpose: The objective of this study was to identify factors related to self-care adherence in symptomatic patients with heart failure (HF). Methods: Using a cross-sectional design, a convenience sample 209 outpatient clinic patients were recruited at two medical centers. Between October 2011 and August 2012, data were collected using the structured questionnaire. Factors related to self-care adherence were examined using hierarchical multiple regression. Results: Mean age of participants was 67.71 years and a half of them (53.6%) were female. They showed relatively low self-care adherence with mean scores of $61.88{\pm}12.92$. Lower self-care adherence was reported in asking for low sodium items, weighing oneself, checking for ankle edema, and exercising for 30 minutes. The overall model significantly explained 23.9% of variance in self-care adherence. Among the predictors, education, New York Heart Association functional classification, and social support were statistically significant in influencing self-care adherence. The variable of negative emotional status such as anxiety and depression were not found to be significant. Conclusion: These findings demonstrate that social support could help self-care adherence among symptomatic patients with HF. Thus, programs targeting self-care adherence in this population should consider the strategies improving social support.

In-situ monitoring and reliability analysis of an embankment slope with soil variability

  • Bai, Tao;Yang, Han;Chen, Xiaobing;Zhang, Shoucheng;Jin, Yuanshang
    • Geomechanics and Engineering
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    • v.23 no.3
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    • pp.261-273
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    • 2020
  • This paper presents an efficient method utilizing user-defined computer functional codes to determine the reliability of an embankment slope with spatially varying soil properties in real time. The soils' mechanical properties varied with the soil layers that had different degrees of compaction and moisture content levels. The Latin Hypercube Sampling (LHS) for the degree of compaction and Kriging simulation of moisture content variation were adopted and programmed to predict their spatial distributions, respectively, that were subsequently used to characterize the spatial distribution of the soil shear strengths. The shear strength parameters were then integrated into the Geostudio command file to determine the safety factor of the embankment slope. An explicit metamodal for the performance function, using the Kriging method, was established and coded to efficiently compute the failure probability of slope with varying moisture contents. Sensitivity analysis showed that the proposed method significantly reduced the computational time compared to Monte Carlo simulation. About 300 times LHS Geostudio computations were needed to optimize precision and efficiency in determining the failure probability. The results also revealed that an embankment slope is prone to high failure risk if the degree of compaction is low and the moisture content is high.