• International Journal of Reliability and Applications
• /
• v.16 no.1
• /
• pp.1-13
• /
• 2015

In this paper, we investigate reliability and availability of repairable systems with two types of failure. The first one is to one unit and the second one is to M units in parallel structure. Let failure rate and repair rate of [type1, type2] components are assumed to be exponentially distributed. The expressions of availability and reliability characteristics such as the system reliability and the mean time to failure are derived for two systems. We used several cases to analyze graphically the effect of various system parameters on the reliability system and availability system.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.9
• /
• pp.1717-1722
• /
• 2016

Availability, one of the important metrics used to assess the performance of network system, is defined as the probability that a system is operational at a given point in time under a given set of environmental conditions. To improve the availability of the network service, the redundancy models and the rejuvenation schemes are the effective schemes to be typically used. In this paper, we analyse the effect of 2N redundancy model and/or rejuvenation scheme on the availability of network service. The 2N redundancy model consists of one active and one standby component and the performance of time-based rejuvenation scheme mainly depends on its rejuvenation period. We design stochastic reward net model for the 2N redundancy model with time-based rejuvenation scheme and analyse the service availability of the model using stochastic Petri net package. We provide some numerical examples of the service availability, which shows that the system with rejuvenation has higher availability than the system without rejuvenation.

• The Journal of Asian Finance, Economics and Business
• /
• v.7 no.12
• /
• pp.959-968
• /
• 2020

Tourist loyalty is created through good tourism service quality and the availability of tourism products. This study discussed the various attributes of tourism service quality, namely, tour agents, efficient personnel, accessible transportation, and information service quality. Whereas for tourism product availability attributes were varieties of product availability, wide selection of tour agents and tourist products, and wide variety of amenity services. As a general rule, the minimum is to have at least five times as many observations as the number of variables to be analyzed, and the more acceptable sample size would have a 10:1 ratio. A total of 424 questionnaires were returned, with 35 removed due to errors. Finally, 389 questionnaires respondents were used via accidental sampling method through the distribution of questionnaires to foreign tourists at Soekarno Hatta International Airport. In addition, AMOS 7.0 software is used to test models in confirmatory factor analysis (CFA) as well as hypothetical testing using structural equation modeling (SEM). The results showed that all hypotheses were accepted, except for the effect of tourism service quality on tourist loyalty in Indonesia. This research aims to contribute significantly to the existing knowledge of tourism, specifically from a foreign tourist perspective in Indonesia.

• Korean Journal of Poultry Science
• /
• v.23 no.4
• /
• pp.169-175
• /
• 1996

An experiment was conducted with male broiler chicks to determine the effect of different dietary phosphorus sources and evaluate the biological availability of phosphorus sources. The biological availability of phosphorus from dicalcium phosphate (DCP) was used as a reference standard (100%) compared to defluorinate phosphate (DFP). DCP and DFP was supplemented to a corn-soy basal diet at levels of 0.05, 0.15, 0.25, 0.35%. Each of 24 pens of 10 male broiler chicks with three replications was used for three weeks. The results indicated that weight gain, feed in-take, feed efficiency, nonphytic phosphorus (NPP) and tibia ash were significantly different among treatments. Dietary supplemental phosphorus of DFP improved weight gain, NPP intake and feed efficiency consistently, whereas supplements of DCP did not show consistent increase. Regression equations was used for the availability of DPP compared with DCP when percent bone ash was a function of total phosphorus in the diet. The percent (%) bone ash of DFP groups compared to that of DCP groups showed a value of 59.98% as a slope ratio. DFP indicated lower biological availability compared to DCP, but it's dietary supplementation tended to increase bone ash and maximize the growth of young broiler chicks.

• Journal of the Korean Home Economics Association
• /
• v.42 no.3
• /
• pp.91-104
• /
• 2004

This study analyzes the critical factors that decide the job continuity of married women after one of their life events, childbirth. It is based on the employment data from KLIPS(Korea Labor and Income Panel Study). Vols. 1-4, having observed 128 young mothers who gave birth to children after 1997. The analysis showed that women's employment after their maternity leave depend on whether new mother return to their previous job or not. The Following results are obtained: First, women's age, education, availability of caretakers for their children, and family income have a positive effect on the women's return to their pre-leave employers after childbirth. Second, professional or office work and the frequency of job transition before childbirth have a positive effect on women's employment in new jobs after childbirth. Third, women's age, availability of caretakers of their children, and professional or office work are critical factors that have a positive effect on women's job continuity after childbirth, whereas the frequency of job transitions has a negative effect on employment for women.

• Journal of Science Education
• /
• v.41 no.1
• /
• pp.135-151
• /
• 2017

This study set out to investigate the challenges to science teacher's teaching practices in the Anglophone sub-system of education in Cameroon secondary schools. A sample of 331 of these teachers was selected using the purposive sampling method. Data was collected by use of a questionnaire and was subjected to inferential analysis. The major findings from the multiple regression were challenges associated with the size and management of a science class have an effect on the teaching practices of a science teacher. However, challenges with availability of instructional resources did not have an effect on science teaching practices. Recommendations to solve the identified drawbacks include the provision of more classrooms to accommodate the ever growing population of students and the organization of many seminars through which teachers could be educated on how to handle classroom problems and improvise when necessary.

• The Journal of Asian Finance, Economics and Business
• /
• v.7 no.12
• /
• pp.535-543
• /
• 2020

Investors from the whole world are looking for those stock markets that are less affected by interest rates. Pakistan is a good place to invest and the investors from the whole world are considering Pakistan for future ventures. The current study, therefore, aims to analyze the factors affecting investors' decision making in Pakistan with the interaction effect of locus of control. The primary data are gathered from 300 respondents. Structural equation modelling (SEM-PLS) is used to analyze the interactions among variables. The study finds positive impact of availability and representative biases on investment decision making. The study could not find any moderating role of locus of control. The results imply that decisions made by Pakistani investors are driven by the most easily or currently available information and they trust on the information obtained from family and friends without any authentication and verification. One possible description of insignificant moderation effect of locus of control can be the sample traits used in the study, e.g., personal characteristics, that change from culture to culture. Another description of these findings may be the association between heuristic biases, including availability, representative and psychological biases and decision-making regarding investment is not personality specific.

• Korean Journal of Child Studies
• /
• v.33 no.2
• /
• pp.223-242
• /
• 2012

The main purpose of this study is to examine the relationship between the variables of infant temperament, maternal emotional availability, infant emotional responsiveness and involvement. A total of 60 infants and their mothers participated in this study. Mother-infant dyads were observed and mothers then completed questionnaires. Data was analyzed by means of descriptive statistics, t-tests, Pearson's correlations and hierarchical regressions. In terms of infant emotional responsiveness, maternal sensitivity and non-hostility, these were revealed to have had an effect on infant emotional responsiveness. Moreover, infants who have mothers who had the ability to read their infants' emotional signals accurately, responded in appropriate ways and interacted with affection, showed a higher level of responsiveness. In terms of infant emotional involvement, maternal structuring had an effect on infant emotional involvement. That is, infants who have mothers willing to support their infants through appropriate guidance and facilitate their interaction were more emotionally involved during the play sessions. In conclusion, maternal sensitivity, non-hostility and structuring were all related to infant emotional responsiveness and involvement, however, the degree of the effects of these variables differed.

• Proceedings of the IEEK Conference
• /
• 2003.07c
• /
• pp.2545-2548
• /
• 2003

Reliability is the very important issue for nuclear fields. In this paper, an analysis method is suggested to evaluate the level of availability improvement by adding the fault diagnosis function in the control system of Reactor Protection System. The Failure Mode Effect Analysis(FMEA), MIL-HDBK-217F, and Makov modelling techniques are used for availability assessment.

• Journal of Applied Reliability
• /
• v.16 no.4
• /
• pp.313-322
• /
• 2016

Purpose: We introduce ways to employ Markov chain model to evaluate the effect of preventive maintenance process. While the preventive maintenance process decreases the failure rate of each subsystems, it increases the downtime of the system because the system can not work during the maintenance process. The goal of this paper is to introduce ways to analyze this trade-off. Methods: Markov chain models are employed. We derive the availability of the system consisting of N repairable subsystems by the methods under various maintenance policies. Results: To validate our methods, we apply our models to the real maintenance data reports of military truck. The error between the model and the data was about 1%. Conclusion: The models developed in this paper fit real data well. These techniques can be applied to calculate the availability under various preventive maintenance policies.