• International Journal of Heart Failure
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• 제6권3호
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• pp.107-116
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• 2024

Frailty is highly prevalent among patients with heart failure (HF) and independently predicts adverse outcomes. However, optimal frailty definitions, assessments, and management in HF remain unclear. Frailty is common in HF, affecting up to 80% of patients depending on population characteristics. Even pre-frailty doubles mortality risk versus robust patients. Frailty worsens HF prognosis through systemic inflammation, neurohormonal changes, sarcopenia, and micronutrient deficiency. Simple screening tools like gait speed and grip strength predict outcomes but lack HF-specificity. Comprehensive geriatric assessment is ideal but not always feasible. Exercise, nutrition, poly-pharmacy management, and multidisciplinary care models can help stablize frailty components and improve patient-centred outcomes. Frailty frequently coexists with and exacerbates HF. Routine frailty screening should guide supportive interventions to optimize physical, cognitive, and psychosocial health. Further research on HF-specific frailty assessment tools and interventions is warranted to reduce this dual burden.

• International Journal of Computer Science & Network Security
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• 제21권4호
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• pp.306-312
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• 2021

The main goal of higher education institutions is to present a high level of quality education to its students. This study uses data mining techniques to extract educational data from cumulative databases and used them to make the right decisions. This paper also aims to find the factors affecting students' academic performance in Majmaah University, KSA, during 2010 - 2017 period. The study utilized a sample of 6,158 students enrolled from two colleges, males and females. The results showed a high percentage of stumbling and dismissed between graduate and regular students where more than 62.5% failed to follow the plan. Only 2% of students scored distinction during their study of all graduated since their grade point average, secondary level, was statistically significant, where p<0.05. Dismissed percentage was higher among males. These results promoted some recommendations in which decision-makers could take them in considerations for better improvement of academic achievements: including of specialized programs to follow-up in regards to stumbling and failure. Utilization of different communication tools are needed to activate academic advisory for dismiss and dropout evaluation.

• 대한기계학회논문집A
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• 제32권6호
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• pp.496-503
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• 2008

With the improvement of computer power and technology, fracture modelling by finite element methods has become a topic of extensive studies. However, fracture simulation much limited to an academic study of crack propagation with a fine mesh. Element deletion method is a useful tool for estimating damage due to accidental or extreme loads on structures, provided that an effective and realistic criterion is established for simulating the material failure and subsequent element deletion. In this study, ABAQUS/Explicit is used to simulate the material failure on the basis of experimental results by X. Huang et al. Through numerical experiments, we suggest a formulation to determine the failure strain associated with the size and thickness of removed elements.

• 한국기계가공학회지
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• 제7권1호
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• pp.22-31
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• 2008

The operating window method is a novel approach in quality improvement. But it has not received deserved attention in academic research. If a critical factor for competing failure modes can be identified, the probability of failure can be reduced by widening the operating window of this factor. Traditional SN ratio for the operating window advocated by Taguchi has a critical shortcoming, which has been derived under the assumption that failure rates are determined by the operating window factor only. A new metric for robustness is given for the operating window method, which has relaxed the restrictive assumption of Taguchi's SN ratio. And procedures for determining optimal conditions based on the new metric is presented. The effectiveness of the proposed approach over the traditional practice is tested with the aid of a wave soldering process.

• 한국신뢰성학회지:신뢰성응용연구
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• 제18권3호
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• pp.220-228
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• 2018

Purpose: The purpose of this study is to investigate the tail behavior of the life distribution which exhibits an increasing failure rate or other positive aging effects after a certain time point. Methods: We characterize the tail behavior of the life distribution with regard to certain reliability measures such as failure rate, mean residual life and reliability function and derive several stochastic properties regarding such life distributions. Also, utilizing an L-statistic and its asymptotic normality, we propose new nonparametric testing procedures which verify if the life distribution has an increasing tail failure rate. Results: We propose the IFR-Tail (Increasing Failure Rate in Tail), DMRL-Tail (Decreasing Mean Residual Life in Tail) and NBU-Tail (New Better than Used in Tail) classes, all of which represent the tail behavior of the life distribution. And we discuss some stochastic properties of these proposed classes. Also, we develop a new nonparametric test procedure for detecting the IFR-Tail class and discuss its relative efficiency to explore the power of the test. Conclusion: The results of our research could be utilized in the study of wide range of applications including the maintenance and warranty policy of the second-hand system.

• 의학교육논단
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• 제15권1호
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• pp.46-53
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• 2013

The purpose of this study was to analyze the relationship among medical students' learning motivation, characteristics of multiple intelligence, and academic achievement. The participants were 144 medical students. The data were collected by administering learning motivation tests (self-confidence, self-efficacy, level of task, emotion of learning, learning behavior, failure tolerance, task difficulty, and academic self-efficacy), a multiple intelligence test (linguistic intelligence, logical-mathematical intelligence, musical intelligence, bodily-kinesthetic intelligence, spatial intelligence, interpersonal intelligence, intrapersonal intelligence, and naturalistic intelligence), and two semesters of grades. There is a correlation between multiple intelligences and learning motivation. Among academic self-efficacy of academic motivation, the self-control efficacy (0.28) and behavior (0.18) subscales are significantly positively correlated with academic achievement. However, the emotion subscale (-0.18) was significantly negatively correlated. Learning motivation was correlated with two of the eight multiple intelligence profiles: the intrapersonal intelligence (0.18) and bodily-kinesthetic intelligence (-0.19). The structural equation modeling analysis showed that the behavior and self-control efficacy subscales of intrapersonal intelligence had an impact on academic achievement. An analysis according to the academic achievement group showed significant differences in self-control efficacy and emotion subscales with intrapersonal intelligence. A positive relationship can be observed between learning motivation and some characteristics of multiple intelligence of medical school students. In light of the findings, it is worth examining whether we can control medical students' learning motivation through educational programs targeting self-control efficacy and intrapersonal intelligence.

• 한국정보전자통신기술학회논문지
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• 제9권4호
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• pp.351-358
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• 2016

과학기술이 급속하게 발전함에 따라 더 강력한 소프트웨어 기능의 급속한 발전과 함께 소프트웨어의 복잡성이 크게 증가함으로써 소프트웨어 테스트 및 신뢰성 평가의 어려움이 증가하고 있다. 소프트웨어 고장분석을 위한 비동질적인 포아송 과정에서 결함당 고장발생률이 상수이거나, 단조 증가 또는, 단조 감소하는 패턴을 가질 수 있다. 본 논문에서는 결함의 기대값을 가정하는 유한고장 소프트웨어 NHPP 모형과 수리시점에서도 고장이 발생할 상황을 반영하는 무한고장 NHPP 모형들을 상호 비교 제시하였다. 소프트웨어 신뢰성 분야에서 많이 사용되는 어랑분포에 근거한 유한고장과 무한고장 소프트웨어 신뢰성 모형에 대한 신뢰도 성능을 비교 분석하였다. 그 결과 유한고장 모형이 무한고장 모형보다 효율적으로 좋게 나타났으며, 이 과정에서 모수추정법은 최우추정법을 이용하였다. 본 연구결과를 통하여 소프트웨어 개발자들에게 소프트웨어 고장현상을 파악하는데 도움을 줄 수 있을 것으로 판단된다.

• Journal of Information Technology Applications and Management
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• 제23권4호
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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.

• 한국비블리아학회지
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• 제23권2호
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• pp.209-233
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• 2012

이 연구에서는 웹기반 온라인목록 이용자들의 전반적인 검색행태를 알아보기 위해, 7년 동안의 트랜잭션 로그를 분석하였다. 웹기반 온라인목록의 검색형태는 검색전략과 검색실패의 관점에서 조사하였다. 검색전략에서는 검색유형, 접근점, 연산자, 검색문의 길이, 단어 사용횟수, 웹기반 온라인목록 이용횟수, 시간대별 및 요일별 이용횟수를 분석하였다. 또한 검색실패는 검색실패율과 접근점별 검색실패율, 연산자별 검색실패율을 분석하였다. 이 연구결과는 향후 웹기반 온라인목록 시스템과 서비스 개선에 활용될 수 있을 것으로 기대된다.

• Structural Engineering and Mechanics
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• 제78권2호
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• pp.209-218
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• 2021

For engineering, there are two major challenges in reliability analysis. First, to ensure the accuracy of simulation results, mechanical products are usually defined implicitly by complex numerical models that require time-consuming. Second, the mechanical products are fortunately designed with a large safety margin, which leads to a low failure probability. This paper proposes an efficient and high-precision adaptive active learning algorithm based on the Kriging surrogate model to deal with the problems with low failure probability and time-consuming numerical models. In order to solve the problem with multiple failure regions, the adaptive kernel-density estimation is introduced and improved. Meanwhile, a new criterion for selecting points based on the current Kriging model is proposed to improve the computational efficiency. The criterion for choosing the best sampling points considers not only the probability of misjudging the sign of the response value at a point by the Kriging model but also the distribution information at that point. In order to prevent the distance between the selected training points from too close, the correlation between training points is limited to avoid information redundancy and improve the computation efficiency of the algorithm. Finally, the efficiency and accuracy of the proposed method are verified compared with other algorithms through two academic examples and one engineering application.