• Proceedings of the KIEE Conference
• /
• 2000.07a
• /
• pp.397-399
• /
• 2000

This paper presents a method for assessing reliability indices of transmission system. Because successful operation of electric power under the deregulated electricity market depends on transmission system reliability management, quantity evaluation of transmission system reliability is very important. The key point idea is based on that the reliability level of transmission system is equal to reliability level difference of between composite power system(HLII) and generation system(HLI). It is sure that risk indices of reliability of composite power system are larger than those of generation system. It is the reason that composite power system includes uncertainties and capacity limit of transmission lines. The characteristics and effectiveness of this methodology are illustrated by the case study using MRBTS.

• International Journal of Reliability and Applications
• /
• v.16 no.2
• /
• pp.99-111
• /
• 2015

In this paper, we study the reliability analysis of a repairable system with two types of failure in which switching failures and reboot delay are considered. Let units in this system be cold standby, and failure rate and repair rate of [type1, type2] components be exponentially distributed. The expressions of reliability characteristics - such as the system reliability and the mean time to system failure MTTF - are derived. We use several cases to graphically analyze the effect of various system parameters on the system reliability and MTTF. We also perform a sensitivity analysis of the reliability characteristics with changes in specific values of the system's parameters.

• Journal of the Korean Society of Industry Convergence
• /
• v.12 no.4
• /
• pp.209-214
• /
• 2009

Usually, it says that reliability is failure rate achieved by required functions for some period under limited use environment conditions. The reliability can be researched by automotive part or system module and it can be affected by using environment condition, such as using atmosphere temperature and using user's behavior. Also, the time can be influence on the reliability. Recently, the oil leakage from eng oil pan was raised by customer in the field. So, there is the purpose of this paper that research predicting the reliability of eng oil pan efficiently by using reliability method described below.

• The Journal of Asian Finance, Economics and Business
• /
• v.1 no.4
• /
• pp.29-37
• /
• 2014

This study investigated effects of five consumption values of family restaurants, that is to say, functional value, economic value, social value, creative value and emotional value, upon consumers'satisfaction and brand reliability, and effects of satisfactions upon brand reliability, and effects of satisfaction and brand reliability upon consumers' behavioral intention to help develop family restaurant industry. Frequency analysis was done. The interviewees had demographic characteristics of gender: 156 men (54.4%) and 131 women (45.6%). The interviewees live in the places: 136 persons (47.4%) in Gyeonggi and Metropolitan area, 57 persons (27.0%) in Gangbuk, Seoul, 38 persons (13.2%) in other areas in Seoul, 34 persons (11.8%) in Gangnam, Seoul, 18 persons (6.3%) in Incheon and 4 persons (1.4%) in other regions. Values of the use of family restaurants, for instance, functional value, economic value, social value, emotional value and rarity value had influence upon satisfaction and brand reliability, had influence upon satisfaction as well as brand reliability. This study investigated consumption values of which consumers thought much, effects of consumption values upon satisfaction and brand reliability, effects of consumer's satisfaction upon brand reliability, and consumer's satisfaction and brand reliability upon behavioral intention, and to verify effects having influence upon local and foreign family restaurant.

• Journal of the Korea Safety Management & Science
• /
• v.7 no.2
• /
• pp.73-83
• /
• 2005

This paper is to propose tolerance intervals for expected time at the given reliability and confidence level for continuous and discrete reliability model. We consider guaranteed - coverage tolerance intervals, that is, reliability - confidence level tolerance intervals. These proposed methodologies can be applied to any industrial application where the customer's operating specification require a high level of reliability.

• Journal of Industrial Technology
• /
• v.28 no.B
• /
• pp.149-156
• /
• 2008

A reliability model of Level II AFDA is developed to analyze the stability of armor units on the sloped coastal structures. Additionally, the partial safety factors of random variables related to armor units can be straightforwardly evaluated by applying the inverse-reliability method in which influence coefficients and uncertainties of random variables, and target probability of failure are combined directly. In particular, a design equation for armor units is derived in terms of the same criteria as deterministic design method in order to apply the reliability-based design method of Level I without some understanding to the reliability analysis. Finally, it is confirmed that several results redesigned by the reliability-based design method of Level I have satisfactorily agreement with results of CEM as well as those of Level II AFDA.

• Journal of Applied Reliability
• /
• v.3 no.1
• /
• pp.41-58
• /
• 2003

Recently, the reliability evaluation and analysis are applied for many industrial products, and many products are required to guarantee in quality and in efficiency. The purpose of this paper is to present some of reliability prediction methodologies that are applicable to machine tools. Especially ATC (Automatic Tool Changer) and Interface Card of PC-NC, which are core components of the machine tools, were chosen as the target of the reliability evaluation and analysis. The results of this research has shown the failure rate, MTBF(Mean Time Between Failure), and reliability for those components. It is expected that proposed methodologies will be applicable to evaluation of reliability for other industrial products.

• ETRI Journal
• /
• v.44 no.6
• /
• pp.936-944
• /
• 2022

The mobile network allows redundant transmission via disjoint paths to support high-reliability communication (e.g., ultrareliable and low-latency communications [URLLC]). Although redundant transmission can improve communication reliability, it also increases network costs (e.g., traffic and control overhead). In this study, we propose a reliability-guaranteed multipath allocation algorithm (RG-MAA) that allocates appropriate paths by considering the path setup time and dynamicity of the reliability paths. We develop an optimization problem using a constrained Markov decision process (CMDP) to minimize network costs while ensuring the required communication reliability. The evaluation results show that RG-MAA can reduce network costs by up to 30% compared with the scheme that uses all possible paths while ensuring the required communication reliability.

• Journal of Environmental Science International
• /
• v.15 no.3
• /
• pp.261-269
• /
• 2006

In this study, an optimization technique was developed from the application of allocation rule. The results obtained from the water supply analysis and reliability indices analysis of Andong dam and Imha dam which are consist of parallel reservoir system are summarized as the followings; Allocation rule(C) is effective technique at the parallel reservoir system because results of the water supply analysis, storage analysis and reliability indices analysis is calculated reasonable results. Also, reliability indices analysis results are not sufficient occurrence based reliability or quantity based reliability. Thus reliability indices analysis are need as occurrence based reliability, quantity based reliability vulnerability, resilience, average water supply deficits and average storage. And water supply condition is better varying water supply condition than constant water supply condition.

• Journal of Applied Reliability
• /
• v.12 no.3
• /
• pp.165-176
• /
• 2012

Hydrostatic bearing improves performance and life time of a product by avoiding solid friction and reducing viscosity friction with the help of creating pressure equilibrium between two faces doing relative motion. This study suggests failure analysis and test evaluation for a ball joint that adopts the hydrostatic bearing and introduces the entire process to improve reliability of the product by design improvement. A typical failure is growth of friction torque by solid friction, and its failure cause is determined and the improvement is proposed. Finally, reliability improvement is established by analysis of the results of before and after acceleration test.