Performance degradation simulation of electronic product for reliability analysis
To study analysis method of performance degradation during long term operation based on function simulation, accelerated degradation test was carried out on the power supply module directly, and the test data was used for reliability analysis. As the same time, accelerated degradation test was carried out on the key components in power supply circuit. The test data was injected into the functional simulation model of power supply to simulate performance degradation and analyze reliability. Finally the results of the two kinds of analysis were compared to demonstrate the effectiveness of the proposed simulation method. Comparison shows that average life span of power supply is 281560 hours based on accelerated degradation test while 357290 hours based on degradation simulation. Since only considering degradation of the key components, the result of simulation method is of partial optimism. But the deviation is in a reasonable range, which proved that the method is effective.
Reliability Analysis of Circuit Boards Based on Accelerated Degradation Test Data
Constant stress accelerated degradation tests under 80℃,100 ℃ and 120 ℃ respectively were conducted on a certain 24 V-2 A power supply board.Degradation rules of output voltages changing with temperatures were shown.The reliability statistical inferences were carried on by regression method based on B-S model and compared with other approaches.Conclusions show that,the method of using accelerated degradation data to evaluate the reliability of circuit boards is feasible,the result is reliable,the method can save time and cost,and can be applied to reliability analysis with zero-failure data.
Nursing theory and administrative practice: Agenda for the 1990s
&NA; Despite past progress in the development of nursing theory, a theoretical nursing perspective is not yet common to the practice of nursing administration. Such a perspective could serve as a catalyst both to advance knowledge development for administrative nursing practice and to align clinical and administrative practice within a common framework. In this article assumptions, concepts, and questions common to both clinical and administrative nursing practice are identified. Select domain concepts are used to exemplify the themes shared by nurse clinicians and nurse administrators. The article concludes with a five‐item agenda as a guide for future theory development.