• Journal of the Korea Safety Management & Science
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• v.17 no.2
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• pp.241-247
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• 2015

The purpose of the warranty data analysis can be classified into two categories. Two goals is a failure cause analysis and life prediction analysis. In this paper first, we applied multivariate analysis method that can be estimated in consideration of various factors on the failure cause warranty data. In particular, we apply the Tree model and Cox model. The advantage of the Tree is easy to interpret this result as compared to other models. In addition Cox model can quantitatively express the risk. Second, this paper proposed a multivariate life prediction model (AFT) considering a variety of factors. By applying the actual warranty data confirmed the usability.

• International Journal of Reliability and Applications
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• v.5 no.2
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• pp.81-103
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• 2004

Improvements of a bridge network system are studied in this paper. Then equivalence between different improved designs of the bridge network system is discussed. Three different methods are used to get different better designs of the network in the sense of having higher reliability and mean time to failure. Then two different types of reliability equivalence factors of the system are derived. It is assumed here that the failure rates of the system's components are identical and constant. The reliability functions and mean time to failure of the original and improved designs of the network are derived. Comparison between the mean time to failures of the original system and improved designs of the system are presented. Numerical studies and conclusion are presented in order to explain how one can apply the the theoretical results obtained.

• International Area Studies Review
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• v.21 no.4
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• pp.271-294
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• 2017

Despite a huge amount of foreign assistance and close economic guidance by international donors throughout the past decades, Zambia today still suffer from a high level of aid dependency and the absence of sustainable economic development. In this study, I investigate the factors that resulted in aid (and development) failure in Zambia, focusing on institutional/historical contexts. I propose that in Zambia, government has largely failed to implement (or even produce) effective economic policies that could lead to successful use of foreign assistance for long-term, sustainable development. In particular, I focus on the nature of state and politics in Zambia, and argue that failed politics is one of the main causes of development and aid failure in Zambia and highlight colonial legacies and other contextual/institutional factors to understand the nature of politics and state in Zambia. In particular, this paper proposes that the Zambian case demonstrates that foreign aid and donor influence could worsen the situation directly by simply providing wrong guidance and also by further weakening the state (and institutional) capacity of the recipient country.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.595-601
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• 2020

During the safety inspection of nitrocellulose-made explosive containers stored for more than 10 years, cracks were found in the containers. Therefore, a failure cause analysis test was performed. First, the cause of failure through the failure tree analysis was conducted to select the factors that influenced failure. The changes in the properties of the container caused by the acceleration of the reaction were found to be the cause of the failure by confirming the influence on the environment and internal/external factors that may occur during storage. To confirm this, environmental tests, such as thermal shock test and vacuum thermal stability test, were performed using a naturally aged container to analyze the cause of failure, and an accelerated aging test was performed to reproduce the failure. Through this, the chemical reaction was accelerated by heat and charge, as in the result of the fault tree analysis, and it was confirmed that the physical properties of the container were changed. In addition, the service life of the container was estimated using the Arrhenius model for the storage life due to thermal aging.

• Journal of Industrial Technology
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• v.3
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• pp.53-63
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• 1983

The probability of failure is used to analyze the reliability of three dimensional slope failure, instead of conventional factor of safety. The strength parameters are assumed to be normal variated and beta variated. These are interval estimated under the specified confidence level and maximum likelihood estimation. The pseudonormal and beta random variables are generated using the uniform probability transformation method according to central limit theorem and rejection method. By means of a Monte-Carlo Simulation, the probability of failure is defined as; Pf=M/N N : Total number of trials M : Total number of failures Some of the conclusions derived from the case study include; 1. Three dimensional factors of safety are generally much higher than 2-D factors of safety. However situations appear to exist where the 3-D factor of safety can be lower than the 2-D factor of safety. 2. The F3/F2 ratio appears to be quite sensitive to c and ${\phi}$ and to the shape of the 3-D shear surface and the slope but not to be to the unit weight of soil. 3. In cases that strength parameters are assumed to be normal variated and beta variated, the relationships between safety factor and the probability of failure are fairly consistent, regardless of the shape of the 3-D shear surface and the slope. 4. As the c-value is increased, the probability of failure for the same safety factor is increased and as the ${\phi}-value$ is increased, the probability of failure for the same safety factor is decreased.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.5
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• pp.141-157
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• 2023

Start-ups are the driving force of economic development and play an important role in improving national competitiveness. The country's start-up support policies are increasing every year, but indicators that do not challenge them and do not consider future start-ups can predict employment reduction and unemployment can increase further. You can. The increase in the number of young people doing nothing is causing economic hardship and neglect of future precious human resources, which calls for a more realistic national entrepreneurship policy. Accordingly, this study sought to identify bias and environmental factors in order to reveal factors that influence the will to start a business among potential entrepreneurs in Korea. For this purpose, descriptive statistical analysis was performed using SPSS on a sample of 227 responses from the general public who are potential entrepreneurs interested in starting a business. As a result, prejudice decreased the will to start a business and increased fear of failure. On the other hand, the entrepreneur's environmental factors reduced the fear of failure and increased the will to start a business. Lastly, fear of failure was found to play a mediating role between the two independent variables and the will to start a business. The results of this study showed that prejudice was a negative factor in the will to start a business, and the environment was a positive factor. These research results suggest that in order to revitalize entrepreneurship, positive environmental factors that can provide entrepreneurs' correct recognition and support for entrepreneurship are necessary.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.249.2-250
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• 2003

${\beta}$-blockers are considered as standard therapy for patients with stable chronic heart failure (CHF) and to prolong survival and reduce hospitalizations. We examined the effects of the ${\beta}$-blocker on mortality, hospitalization and symptoms in patients with CHF and the related factors to the use of ${\beta}$-blockers. Patients in New York Heart Association class II-IV were included if they were treated for heart failure from January 2002 to June 2002. At baseline, 6 months, and 12 months, they were assessed for the change of NYHA class and all deaths and hospital admissions. (omitted)

• Geomechanics and Engineering
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• v.13 no.2
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• pp.301-318
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• 2017

Based on the existing research results, a three-dimensional failure mechanism of tunnel face was constructed. The dynamic seismic effect was taken into account on the basis of quasi-static method, and the nonlinear Mohr-Coulomb failure criterion was introduced into the limit analysis by using the tangent technique. The collapse pressure along with the failure scope of tunnel face was obtained through nonlinear limit analysis. Results show that nonlinear coefficient and initial cohesion have a significant impact on the collapse pressure and failure zone. However, horizontal seismic coefficient and vertical seismic proportional coefficient merely affect the collapse pressure and the location of failure surface. And their influences on the volume and height of failure mechanism are not obvious. By virtue of reliability theory, the influences of horizontal and vertical seismic forces on supporting pressure were discussed. Meanwhile, safety factors and supporting pressures with respect to 3 different safety levels are also obtained, which may provide references to seismic design of tunnels.

• Journal of the Korean Society of Safety
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• v.31 no.2
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• pp.10-17
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• 2016

The purpose of this paper is to deduct components that are in the group of highest risk(top 10%). the group is conducted for classification into groups by values according to risk priority through risk priority number(RPN) of FMEA(Failure modes and effects analysis) sheet. Top 10% of failure mode among total potential failure modes(72 failure modes) of ESS included 5 BMS(battery included) failure modes, 1 invert failure mode, and 1 cable connectors failure mode in which BMS was highest. This is because ESS is connected to module, try, and lack in the battery part as an assembly of electronic information communication and is managed. BMS is mainly composed of the battery module and communication module. There is a junction box and numerous connectors that connect these two in which failure occurs most in the connector part and module itself. Finally, this paper proposes RPN by each step from the starting step of ESS design to installation and operation. Blackouts and electrical disasters can be prevented beforehand by managing and removing the deducted risk factors in prior.

• Journal of Ocean Engineering and Technology
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• v.27 no.2
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• pp.19-26
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• 2013

Stress triaxiality is recognized as one of the most important factors for predicting the failure strain of ductile metals. This study dealt with the effect of the average stress triaxiality on the failure strain of a typical low-temperature high-strength marine structural steel, EH36. Tensile tests were carried out on flat specimens with different notches, from relatively smooth to very sharp levels. Numerical simulations of each specimen were performed by using ABAQUS. The failure initiation points in numerical simulations were identified from a comparison of the engineering stress vs. strain curves obtained from experiments with simulated ones. The failure strain curves for various dimensionless critical energy levels were established in the average stress triaxiality domain and compared with the identified failure strain points. It was observed that most of the failure initiation points were approximated with a 100% dimensionless critical energy curve. It was concluded that the failure strains were well expressed as a function of the average stress triaxiality.