Traditional Reliability Testing Research Articles

Impact of Workload, Training, and Inspirations for Worker Performance at R-Hotel Rancamaya Bogor

The purpose of this study is to ascertain how employee performance at R-Hotel Rancamaya Bogor is impacted by workload, training, and motivation. Primary and secondary data make up the study's data 104 employees completed questionnaires that yielded primary data. On the other hand, secondary data came from pertinent company and other sources. This study used a survey approach along with a type of verification and descriptive research methodology. The questionnaire makes use of traditional assumption testing, reliability tests, and validity tests. Prior to doing multiple regression testing, the Likert scale is employed. This is done in order to ascertain how one dependent variable is affected by the four independent variables that were employed. Based on the findings of validity and reliability tests, which demonstrate that all indicators are deemed valid and reliable, the study's conclusions are drawn. Workload (X1), training (X2), and motivation (X3) all have an impact on employee performance (Y) at R-Hotel Rancamaya Bogor at the same time. Employee performance is impacted by all independent variables, however somewhat.

Traditional Chinese-version reliability test of the Pieper-Zulkowski pressure ulcer knowledge: Psychometric and assessment.

This study was to translate the Pieper-Zulkowski pressure ulcer knowledge test (PZ-PUKT) into Traditional Chinese and evaluate its psychometric properties as well as identify the predictors of knowledge on pressure injury. The PZ-PUKT was translated into Traditional Chinese (TC-PZ-PUKT), and its content validity was evaluated. A total of 296 nurses participated in this study and completed the 72-item TC-PZ-PUKT online. The reliability of the TC-PZ-PUKT was analysed by evaluating its internal consistency and test-retest reliability. Hierarchical regression was used to determine factors associated with TC-PZ-PUKT scores. Content validity was achieved with a score of 0.986. Internal consistency was observed to be reliable, with a Cronbach's alpha of 0.858. The mean knowledge score on the TC-PZ-PUKT was 72.5%, with a 1-week test-retest reliability of r = 0.849. Education level, certification as a wound specialist and self-learning through reading articles, books or guidelines on pressure injury were significantly associated with TC-PZ-PUKT scores. The TC-PZ-PUKT is a valid and reliable tool. Education level, certification as a wound specialist and self-learning regarding pressure injury are related to knowledge of pressure injury.

MCMC Method for Exponentiated Lomax Distribution based on Accelerated Life Testing with Type I Censoring

Accelerated Life Testing (ALT) is an effective technique which has been used in different fields to obtain more failures in a shorter period of time. It is more economical than traditional reliability testing. In this article, we propose Bayesian inference approach for planning optimal constant stress ALT with Type I censoring. The lifetime of a test unit follows an exponentiated Lomax distribution. Bayes point estimates of the model parameters and credible intervals under uniform and log-normal priors are obtained. Besides, optimum test plan based on constant stress ALT under Type I censoring is developed by minimizing the pre-posterior variance of a specified low percentile of the lifetime distribution at use condition. Gibbs sampling method is used to find the optimal stress with changing time. The performance of the estimation methods is demonstrated for both simulated and real data sets. Results indicate that both the priors and the sample size affect the optimal Bayesian plans. Further, informative priors provide better results than non-informative priors.

Reliability analysis for DC motors under voltage step-stress scenario

In reliability analysis, different stress techniques are used to know the lifetime and performance of electrical devices via accelerated life testing. One of these stress technique is the step stress, which combines the traditional reliability testing and over-stress testing; with this method, it is easy to obtain the failure time in a short time. Nonetheless, the analysis of step-stress data can be difficult, and the specialist has usually have to trust on shortcuts or estimations to obtain reliability information from step-stress data. In this paper, a model based on Weibull distribution, inverse power law, cumulative damage model and step-tress technique is proposed to analyze the behavior of electronic devices under a voltage step-stress scenario. The parameters of the model were analyzed via a maximum likelihood. A case of study is based on DC motors is presented in this paper. The results obtained in this paper helped to design department in order to improve the lifetime and performance of the device under analysis.

FPGA‐based fault injection design for 16K‐point FFT processor

There are a number of satellites working in the harsh space environment. The charged particles in space may strike the electron devices causing the undesired influences, such as soft errors in memory devices or permanent damage in hardware circuits. Aiming at reliability evaluation of very-large-scale integration circuits implemented in SRAM-based field programmable gate arrays, a fault injection platform is constructed based on the soft error mitigation controller in this study. The authors adopt a 16K-point fast Fourier transformation processor as the design under test (DUT) and inject errors into different positions. The effectiveness of this platform is varied by comparing the results of DUT with Golden data. Compared with the traditional reliability testing techniques, the fault injection method proposed in this study has the advantages of low cost, short test period and low resource consumption. Hence, the proposed fault injection design is suitable for circuits consuming huge resources and large number of repeating tests.

Investigation of Step-Stress Accelerated Degradation Test Strategy for Ultraviolet Light Emitting Diodes

III-nitride-based ultraviolet light emitting diode (UV LED) has numerous attractive applications in air and water purification, UV photolithography, and in situ activation of drugs through optical stimulus, solid state lighting, polymer curing, and laser surgery. However, the unclear failure mechanisms and uncertainty reliability have limited its application. Therefore, a design of an appropriate reliability test plan for UV LEDs has become extremely urgent. Compared to traditional reliability tests recommended in LED lighting industry, the step-stress accelerated degradation test (SSADT) is more cost-effective and time-effective. This paper compares three SSADT testing plans with temperature and driving currents as stepwise increasing loads to determine an appropriate test strategy for UV LEDs. The study shows that: (1) the failure mechanisms among different SSADT tests seem to be very different, since the driving current determines the failure mechanisms of UV LEDs more sensitively, and (2) the stepped temperature accelerated degradation test with an appropriate current is recommended for UV LEDs.

Metodologia prognozowania trwałości zmęczeniowej oraz jej walidacja w oparciu o przyspieszone badania niezawodności dźwigni skoku wirnika nośnego

Because the industrial products have lifetimes, without failing, of up to millions of cycles, it is mandatory that the aerospace field puts into practice the accelerated testing techniques. The lifetime prediction methodology for industrial products presented in this paper was put into practice by performing accelerated reliability testing on an aerospace product (the pitch link of a helicopter). The results showed a significant reduction of the testing time and costs. One important aspect highlighted in this paper is the equivalence between accelerated reliability testing and the traditional reliability testing, by using the two fundamental principles of the accelerated experiments: first, the stresses applied must not alter the physical mechanism through which the defects are produced and second, the conservation of the distribution laws of the failure times. In this way, by equivalence of the accelerated experiments, the methodology contained in this paper was validated.

Integrated circuit failure analysis and reliability prediction based on physics of failure

It is difficult to obtain the failure data of actual prototype to support reliability analysis because the development stage has been shortened drastically and the traditional reliability tests are gradually unaffordable under the market pressure. In this paper, a reliability simulation based on physics of failure is proposed to test the reliability of a CPU circuit board, in which the digital model of the circuit board, Computational Fluid Dynamics (CFD) method and Finite Element Analysis (FEA) are used synthetically to perform the analysis. The failure points of the circuit board are analyzed and the failure distribution is obtained by fitting the simulation data, so the life can be predicted by Monte Carlo simulation. Moreover, some improvement measures and suggestions can be supplied based on the failure mechanism of the circuit board to improve its inherent reliability. Comparing with the traditional methods, the method of reliability simulation prediction based on physics of failure has the advantages of fast, accurate, economical, efficient and can identify more detailed failure information.

Multiaxis Loading Device for Reliability Tests of Machine Tools

Reliability of machine tools is critical to high- efficiency manufacturing, and the failure data of feeding systems are requisite to analyze the reliability. This paper presents a multiaxis loading device (MLD) to simulate loading condition of an operating feeding system of a machine tool in a real machining process; this could cause breakdowns of the system and collect failure data. The MLD was developed based on a six-degree-of-freedom (6-DOF) parallel mechanism, and its prototype was presented. Its kinematics was analyzed, and dynamic equations were established based on the principle of virtual work. A fuzzy proportional-integral-derivative controller was designed to build an explicit force control system, whose proportional and integral gain can be adjusted according to the errors between reference and actual forces; and a force and a velocity feedforward were integrated to improve the performance of the control system. Loading experiments were conducted on an experimental platform to validate the loading capacity of the MLD; the spindle of the platform was set to be stationary and driven to perform feeding motions with different dimensions. Results of the experiment with the stationary spindle indicate that the MLD can simultaneously provide a 3-DOF force and a 3-DOF moment with acceptable errors. Experiments with moving spindle illustrate that the MLD accomplished tracking a spindle that is executing a 3-DOF trajectory-unknown feeding motion and adding 3-DOF forces on the feeding system through the spindle. The actual output multiaxis forces have little hysteresis and errors less than 10%. Compared with the long-term machining to load the feeding system in traditional reliability tests of machine tools, the proposed MLD provides an efficient method to simulate the loading condition of the system with reduced testing costs.

Reliability assessment of the spindle systems with a competing risk model

Traditional reliability assessment of spindle systems of machine tools suffers from long testing time and high cost. Accelerated life testing is an alternative that overcomes the shortcomings of traditional reliability testing. In a life testing, identification of critical factors of service life and an accurate model are important. Based on the characteristic analysis and engineering experience, four reliability factors, which are the average power of spindle systems, the number of tool changing, the number of spindles restarting and environment temperature, are selected as accelerating environment variables. An accelerated failure time model is used to describe the inverse relationship between the variables and reliability for the catastrophic failure mode and the degradation failure mode separately. Then a competing risk model is built by considering competing risks of two modes. Parametric reliability models are proposed to capture the statistical independency and dependency separately, in which the Gumbel–Hougaard copula function is used to establish the joint cumulative distribution for dependency. Thereby the hypothesis testing is developed to determine the failure modes dependency. The reliability sensitivity of each environment variable is analyzed. Finally, the proposed model is illustrated with a real field case study.

Development and testing of the Quint Leveled Clinical Competency Tool

BackgroundSimulation practice evaluation has evolved from self-reports of indirect measures such as learner satisfaction and confidence to more direct measures of learning and performance improvement. There is a need for psychometrically tested instruments to document direct learner outcomes. MethodsThis article describes the history, development, and initial psychometric testing of the Quint Leveled Clinical Competency Tool using both generalizability theory and traditional reliability testing. The instrument can be used in both simulation and clinical environments and is designed to rate observed learner performance for ten competencies derived from Tanner’s model. Results and ConclusionsThe QLCCT instrument has a high inter-rater reliability (0.87) and coefficient alpha (0.83), but generalizability theory analysis indicates that additional psychometric testing and factor analysis is necessary to complete full psychometric testing.

Semiconductor package qualification based on the swelling temperature

Currently, as semiconductor packages are becoming increasing smaller with improved performances, many are being constructed using stacked structures. However, these types of packages are not easy to qualify owing to the potential swelling of the stacked layers. In this paper, we propose a new method for reliability testing that directly measures the adhesion strength using the swelling temperature to assess the reliability of the package. The swelling temperature is the temperature at which a peel-off occurs between the layers. The advantage of the proposed method in comparison with the traditional reliability testing methods is that the proposed method enables a quick assessment of the product reliability. Through testing and actual case studies, we found that the product reliability qualification can be determined solely by measuring the swelling temperature.

Accelerated Life Testing to Predict Service Life and Reliability for an Appliance Door Hinge

Appliance manufacturers have traditionally performed physical testing using prototypes to assess reliability and service integrity of new product designs. However, for white goods where service lives are measured in years or decades, the use of endurance testing to analyze long time reliability is uneconomical. As accelerated life testing (ALT) is more efficient and less costly than traditional reliability testing, the methodology is finding increased usage by appliance manufacturers. In the present study, a simulation-based ALT approach was used to predict the service life of a polyacetal hinge cam from a consumer refrigerator. A predictive life stress model based on cumulative surface wear under accelerated stress conditions was developed and used to predict time to failure under consumer use. Results show that the life stress model demonstrated good agreement with performance testing data and reasonably predicts hinge life.

Optimization of Reliability Test on the Shell of Portable Electronic Products Based on Taguchi Method

Traditional reliability test of electronic products has the feature of many contents, long cycle and rising test fees. This paper analyzes the feasibility of combination of Taguchi method and reliability test. Then, the process of optimizing reliability test is proposed with emphasis on use of Taguchi method such as orthogonal table and signal-to-noise ratio (SNR). Finally, the process is applied to the reliability test on the shell of a new type of portable electronic product developed by C Company, verifying that the new process is operable and can reduce test numbers, time and cost while guaranteeing effectiveness of reliability test compared with the traditional approach.

Combined Reliability Testing Profile Model and Application for Embedded System

Embedded system is applied more and more extensively in the fields of national defense weapon equipment. With the increasing complexity of embedded systems, the combination of the hardware with software is more and closer. Because of the overall characteristic of hardware and software combination in embedded system, traditional reliability test can hardly accurately identify the reliability of embedded systems. The proposed combined reliability testing method, which combines software reliability test with system integrated environmental stress test to simulate the state of system running, provides the basis for the accurate validation and evaluation of reliability of embedded system.

Study on Reliability Tests to a Few Samples of Mechanical System

The reliability tests play more and more important role in mechanical systems. A new method named a few samples and combined the probability and the fuzzy mathematics has been set up to explore the unknown system of a few samples with the help of the life samples of the known probabilistic distribution. The method reduced the traditional reliability test samples by some auxiliary information. It converted lots of reliability test into a few samples. This paper introduced two engineering examples to verify the method as an effective way to carry out the reliability tests. It provides the theory basis for the reliability of complicated mechanical systems. The loss caused by fatigue failure is as high as 3%~4% of Gross National Product. Fatigue fracture owned to the cycle load accounts for 95% of the total number of mechanical structure failure. Unfortunately no evidence of failure is observed when fatigue failure reaches its life. This causes human casualties and great economic loss. So the reliability research on complicated mechanical systems has to realize from reliability assessment to the active reliability design. One of the key problems of the active reliability design for complicated mechanical system is to reduce the great waste of the resources used in the probability reliability test. For example, dozens of the high precision gears made of certain material may be run out in the fatigue test which would be running day and night for several months. It has been described many methods about system reliability design in the former research [1-3]. But for many high technological products and important mechanical devices, it is impossible to get the test sample to carry out probability analysis. To exert the advantages of the active reliability design and to realize the green reliability design [4], the only way is to study small samples in the reliability tests and to develop new technique. It is named as a few samples reliability tests method of the complicated mechanical systems.

Testing the significance of interobserver agreement measures in the presence of autocorrelation: The jackknife procedure

Users of interobserver agreement statistics have heretofore ignored the problem of autocorrelation in behavior sequences when testing the statistical significance of agreement measures. Due to autocorrelation traditional reliability tests based on the 2 × 2 contingency-table model (e.g., kappa, phi) are incorrect. Correct tests can be developed by using the bivariate time series as a statistical model. Seen from this perspective, testing the significance of interobserver agreement becomes formally equivalent to testing the significance of the lag-zero cross-correlation between two time series. The robust procedure known as the jackknife is suggested for this purpose.