Quantified reliability of aerospace optoelectronics

The attributes of and challenges in the recently suggested probabilistic design for reliability (PDfR) concept, and the role of its major constituents - failure oriented accelerated testing (FOAT) and physically meaningful predictive modeling (PM) - are addressed, advanced and discussed. The emphasis is on the application of the powerful and flexible Boltzmann-Arrhenius-Zhurkov (BAZ) model, and particularly on its multi-parametric aspect. The model can be effectively used to analyze and design optoelectronic (OE) devices and systems with the predicted, quantified, assured, and, if appropriate and cost-effective, even maintained probability of failure in the field. The numerical example is carried out for an OE system subjected to the combined action of the ionizing radiation and elevated voltage as the major stimuli (stressors). The measured leakage current is used as a suitable characteristic of the degree of degradation. It is concluded that the suggested methodology can be accepted as an effective means for the evaluation of the operational reliability of the aerospace electronics and OE systems and that the next generation of qualification testing (QT) specifications and best practices for such systems could be viewed and conducted as a “quasi-FOAT,” a sort of an “initial stage of FOAT” that adequately replicates the initial non-destructive segment of the previously conducted comprehensive “full-scale” FOAT

Pengaruh Persepsi Risiko, Kemudahan Dan Manfaat Terhadap Keputusan Pembelian Secara Online (Survei Terhadap Pengguna Situs Website Www.kaskus.co.id)

The purpose of this study was to determine how the effect of Perceived risk, Perceived usefulness, and Perceived benefits on Online Purchase Buying. This type of research is explanatory research. The samples in this study were 82 respondents who are consumer of Website kaskus.co.id. Methods of data collection by questionnaire. Data analysis using descriptive analysis and multiple regression analysis. The results showed that of the three variables that Perceived risk, Perceived usefulness, and Perceived benefits jointly influence on online purchase buying. SPSS 13.0 for calculation of the F test is known that the F value = 31,096 > F 2,717 with a significance of 0.000 <0.5. Partially known Perceived risk, Perceived usefulness, and Perceived benefits that significantly influence online purchase buying. In addition to the F test and t-test, known R2 (R Square) value of 0,545, which means the magnitude of the independent variable on the dependent variable of 54,5 %

A unified multiple stress reliability model for microelectronic devices — Application to 1.55 μm DFB laser diode module for space validation

The establishment of European suppliers for DFB Laser Modules at 1.55 µm is considered to be essential in the context of future European space programs, where availability, cost and schedule are of primary concerns. Also, in order to minimize the risk, associated with such a development, the supplier will be requested to use components which have already been evaluated and/or validated and/or qualified for space applications. The Arrhenius model is an empirical equation able to model temperature acceleration failure modes and failure mechanisms. The Eyring model is a general representation of Arrhenius equation which takes into account additional stresses than temperature. The present paper suggests to take advantage of these existing theories and derives a unified multiple stress reliability model for electronic devices in order to quantify and predict their reliability figures when operating under multiple stress in harsh environment as for Aerospace, Space, Nuclear, Submarine, Transport or Ground. Application to DFB laser diode module technologies is analyzed and discussed based on evaluation test program under implementation

Semi-quantitative temperature accelerated life test (ALT) for the reliability qualification of concentrator solar cells and cell on carriers

An adequate qualification of concentrator photovoltaic solar cells and cell-on-carriers is essential to increase their industrial development. The lack of qualification tests for measuring their reliability together with the fact that conventional accelerated life tests are laborious and time consuming are open issues. Accordingly, in this paper, we propose a semi-quantitative temperature-accelerated life test to qualify solar cells and cell-on-carriers that can assure a minimum life when failure mechanisms are accelerated by temperature under emulated nominal working conditions with an activation energy >0.9 eV. A properly designed semi-quantitative accelerated life test should be able to determine if the device under test will satisfy its reliability requirements with an acceptable uncertainty level. The applicability, procedure, and design of the proposed test are detailed in the paper

Crime in Teluk Intan - A socio - Legal study / Shaharul Anuar Suhir

It is possible to point to certain characteristics which are generally found in acts which are crimes before we can define what crime is. The first characteristic of crimes is that they are acts which have a particularly harmful effect on the public and do more than interfere with merely private rights. Sir Carleton Allen writes: “crimes is crime because it consists in wrong-doing which directly and in serious degree threatens the security or well-being of society and because it is not safe to leave it redress- -able only by compensation of the party injured". This explains why acts have been made crimes either by judicial decision or by legislation and it does not necessarily accurately represent the present state of affairs. A crime may remain a long after it has ceased to be a threat to the security or well-being of society

Collaborative Robotics: Application of Delphi Method

In the domain of collaborative robotics, it is often needed to make complex multiparametric choices or assessments that combine heterogeneous criteria, such as task performance, reliability, safety, and ergonomics. The Delphi method, a process of arriving at group consensus by providing experts with rounds of questionnaires, as well as the group response before each subsequent round, can be applied to solve this type of problems. The following Delphi method efforts are addressed in our analysis with application to finding appropriate criteria and their relative weights for the evaluation of the teleoperation task of a robotic platform: (1) Contribution of experts; (2) estimates using student\u27s distribution; and (3) decision making support using Fischer criterion. A consensus emerged among eight experts, who selected the criteria of duration, number of trajectory corrections, and feeling of the operator. Weights have been proposed for each criterion and statistical tools have been used to evaluate the consensus

Degraded situation awareness risk assessment in the aerospace domain

International audienceNumerous accidents are due to situation awareness degradation. However, as there exist many different causes and human factors are not well understood, it is very difficult for experts to provide probability risks assessments. It is proposed here to simplify the problem by classifying accidents according to the main demons that degrade situation awareness and to use a Bayesian approach with the Noisy-Or nodes. Interestingly, it is possible to use the same approach in the robotics domain

Attitudes Towards Mental Illness Among Undergraduate Nursing Students: Grant Proposal

This grant proposal seeks funding for a project to determine if undergraduate nursing student’s attitudes and stigma associated with mental illness are positively impacted by a formal presentation done by a person living with schizophrenia. Research has shown that personal contact with stigmatized groups of people can have a positive impact on participants negative attitudes, however the more similar these groups are the more positive the impact is. According to previous research, negative attitudes and the stigma associated with mental illness continue to create disparities in access to care for those with a mental illness. The disparities are not only related to mental health care, but to care for physical needs as well. Research has shown that those with a mental illness have significantly shorter life spans, in part due to the disparities in health care for those with a mental illness. Undergraduate nursing students are required to complete a psychiatric mental health clinical and theory course, and many studies have been conducted on the impact of this required coursework on the stigmas students may hold about mental illness. However, few studies have been conducted examining the impact of personal contact with a professional person with schizophrenia on undergraduate nursing students, especially prior to the start of any of their psychiatric nursing coursework. Data for this project will be collected from undergraduate nursing students enrolled in the traditional BSN program at a Southern California University. Statement of Problem Negative attitudes and its associated stigma towards mental illness continue to create disparities in care for those with a mental illness. Despite nationwide campaigns to attack this issue, there is still much progress to be made. Undergraduate nursing students are currently only required to interact with those with a mental illness when they are patients, and therefore are not granted the opportunity to have personal contact with a professional person with a mental illness that is not currently hospitalized or in crisis. This quasi-experimental pre and posttest research design will fill a research gap, as only a few small scale similar studies have been conducted. Sources of Data: Data will be collected using The Attitudes towards Mental Illness Questionnaire (AMIQ) (Cunningham et al., 1993) for both the pre-and-post-test survey to measure attitudes towards people with schizophrenia before and after the intervention. In addition, demographic information will be collected

Visualizing Real Time Vasomotion in vivo Using Optical Coherence Tomography.

As blood vessel imaging techniques facilitate the fundamental understanding in vascular performance diagnosis and biomedical research improvement, we aimed to visualize and understand the blood vessels dynamics under human skin and their underlying mechanisms in real time. In this study, a noninvasive imaging system was selected to provide an investigation of the real time oscillation of blood vessels in vivo, using Spectral Radar Optical Coherence Tomography (SROCT). This main goal was achieved by evaluating the precision and confidence in recorded data by using a phantom made of Intralipid (IL) to mimic the physical properties of the skin. Then, we successfully managed to visualize for the first time the vasomotion under human skin using MatLab Image Processing Toolbox. After that, we explored mathematically the cyclic variations of the vascular area obtained from the images for a cohort of six participants. The Fourier and wavelet transforms were applied to identify the characteristic frequencies related to the oscillations in vascular cross sectional area. Finally, we investigated dynamical aspects of vasomotion, in response to temperature change, by using a Melcor Thermoelectric Temperature Controller (MTTC) to produce local heating in conjunction with Spectral Radar Optical Coherence Tomography (SROCT)