Wafer level reliability for high-performance VLSI design

As very large scale integration architecture requires higher package density, reliability of these devices has approached a critical level. Previous processing techniques allowed a large window for varying reliability. However, as scaling and higher current densities push reliability to its limit, tighter control and instant feedback becomes critical. Several test structures developed to monitor reliability at the wafer level are described. For example, a test structure was developed to monitor metal integrity in seconds as opposed to weeks or months for conventional testing. Another structure monitors mobile ion contamination at critical steps in the process. Thus the reliability jeopardy can be assessed during fabrication preventing defective devices from ever being placed in the field. Most importantly, the reliability can be assessed on each wafer as opposed to an occasional sample

Automatic control of clock duty cycle

In general, this disclosure is directed to a duty cycle correction (DCC) circuit that adjusts a falling edge of a clock signal to achieve a desired duty cycle. In some examples, the DCC circuit may generate a pulse in response to a falling edge of an input clock signal, delay the pulse based on a control voltage, adjust the falling edge of the input clock signal based on the delayed pulse to produce an output clock signal, and adjust the control voltage based on the difference between a duty cycle of the output clock signal and a desired duty cycle. Since the DCC circuit adjusts the falling edge of the clock cycle to achieve a desired duty cycle, the DCC may be incorporated into existing PLL control loops that adjust the rising edge of a clock signal without interfering with the operation of such PLL control loops

Barriers to the Employment of Welfare Recipients

Dramatic reductions in welfare caseloads since passage of the Personal Responsibility and WorkOpportunity Reconciliation Act of 1996 have not allayed policy concerns about the employability of recipients remaining on the rolls. Analysis of potential barriers to employment can address whether current recipients have problems that either singly or in combination make it difficult for them to comply with the new requirements for getting and keeping jobs. In this paper, we explore the prevalence and work effects of 14 potential barriers in a new survey of a representative sample of 753 urban single-mother recipients. We report the prevalence of the barriers and how their number predicts employment rates, controlling for demographic characteristics. We also analyze which individual barriers are associated with employment and how a model inclusive of a comprehensive array of barriers improves upon a traditional human capital model of the work effects of education and work and welfare history. Single mothers who received welfare in 1997 had higher rates of personal health and mental health problems, domestic violence, and children’s health problems than do women in national samples, but they were no more likely than the general population to be drug or alcohol dependent. Only 15 percent of respondents had none of the barriers and almost two-thirds had two or more barriers. The numbers of multiple barriers were strongly and negatively associated with working, and among the individual barriers, low education, lack of access to transportation, poor health, having drug dependence or a major depressive disorder, and several experiences of workplace discrimination reduced employment. Welfare-to-work programs need to be more finely targeted with respect to exemptions and service provision, and states should consider providing longer-term and enhanced supports for those who face low prospects of leaving welfare for employment.

Getting Jobs, Keeping Jobs, and Earning a Living Wage: Can Welfare Reform Work?

Most discussions of welfare and work have focused on how demographic characteristics, schooling, training, and work experience limit welfare mothers’ employment and wages, but they have largely ignored factors such as inappropriate workplace behaviors, expectations of discrimination and harassment, depression, alcoholism, and domestic violence, all of which may affect welfare mothers and make employment difficult. In this paper we review the prevalence of these individual-level barriers and argue that they, in combination with an economy which does not pay low-skill workers well, are likely to impede employment and self-sufficiency for a large proportion of welfare mothers. At the end of the review, we summarize the current state of knowledge about barriers to the employment of welfare recipients and suggest several ways in which welfare-to-work programs might address these barriers.

Flight Envelope Information-Augmented Display for Enhanced Pilot Situation Awareness

This paper presents an interface system display which is conceived to improve pilot situation awareness with respect to a flight envelope protection system developed for a mid-sized transport aircraft. The new display is designed to complement existing cockpit displays, and to augment them with information that relates to both aircraft state and the control automation itself. In particular, the proposed display provides cues about the state of automation directly in terms of pilot control actions, in addition to flight parameters. The paper also describes a forthcoming evaluation test plan that is intended to validate the developed interface by assessing the relevance of the displayed information, as well as the adequacy of the display layout

A new analytical approach for the velocity field in rolling processes and its application in through-thickness texture prediction

A new analytical model is presented that expresses kinematically admissible velocity fields in rolling processes. Opposed to conventional streamline approaches, the current model does not force the material to flow along the prescribed lines, but introduces a new coordinate that is constant over these lines, to prescribe a fixed component of the velocity in the rolling direction as a function of that coordinate and the coordinate along the rolling direction. The interaction between the rolls and the surface is incorporated in the model via two scalar parameters which depend on the friction conditions between the roll and the sheet, and the properties of rolled material. The scalar parameters can be tuned with experimental observations of deformation flow across the thickness. The modelled material flow does not reveal significant deviation from the one calculated by streamlines. The obtained analytical expressions for the velocity gradient tensor components combined with polycrystal plasticity models enables the prediction of the through-thickness texture evolution for various friction conditions.status: publishe

Designing and evaluating an automation display for use with a flight envelope protection system

Complex control tasks involving human operators involve increasingly complex automation. Despite the advanced design of these systems, a disconnect between the pilot and the state of the automation can lead to confusion and potentially loss of control. Recognizing this shortcoming and its negative effects allows us to design systems which construct this channel of communication and increase overall awareness of system state. This thesis presents a display system designed for use with the Flight Envelope Protection system. We present our both our design, and initial results from a pilot study performed at the Illinois Simulator Laboratory

UPPER BODY SEGMENT LENGTHS AS A PROPORTION OF HEIGHT IN CHILDREN

Most research studies in biomechanics directly measure body segment lengths via anthropometry or digitization of joint markers. There are circumstances in which estimating segment lengths in relation to height is desirable, such as in biomechanical modelling or in the classroom. One commonly used model for this purpose is that by Drillis and Contini (1966; cited in Winter, 2005). One problem with this model is that the initial data was derived from adults, and thus has potentially limited applicability to the study of biomechanics in children. The purpose of the present study was to compare actual selected upper body segment lengths measured via anthropometry to those predicted by Drillis and Contini and also to derive regression equations for those segment lengths based on height and age (separately for males and females)

Guided play and free play in an enriched environment: impact on motor development

The purpose of this study was to investigate the effects of guided play and free play in an enriched environment intervention programs using motor skill development in kindergarten children. Seventy-one children attending kindergarten classes were assigned to two experimental groups and one control group. Participants performed the Test of Gross Motor Development-2 before and after the intervention period. Results revealed that both boys and girls in the guided play group showed motor skill improvement, whereas no changes were observed in motor development in the boys and girls assigned to the free play in enriched environment group, nor in those in the control group. These findings indicate that the teacher’s role in the guided play intervention was crucial to help preschool children to improve their performance.CIEC – Research Centre on Child Studies, UM (FCT R&D 317

A scoping study of interventions to increase the uptake of physical activity (PA) amongst individuals with mild-to-moderate depression (MMD)

Background - Depression is the largest contributor to disease burden globally. The evidence favouring physical activity as a treatment for mild-to-moderate depression is extensive and relatively uncontested. It is unclear, however, how to increase an uptake of physical activity amongst individuals experiencing mild-to-moderate depression. This leaves professionals with no guidance on how to help people experiencing mild-to-moderate depression to take up physical activity. The purpose of this study was to scope the evidence on interventions to increase the uptake of physical activity amongst individuals experiencing mild-to-moderate depression, and to develop a model of the mechanisms by which they are hypothesised to work. Methods - A scoping study was designed to include a review of primary studies, grey literature and six consultation exercises; two with individuals with experience of depression, two pre-project consultations with physical activity, mental health and literature review experts, one with public health experts, and one with community engagement experts. Results - Ten papers met the inclusion criteria and were included in the review. Consultation exercises provided insights into the mechanisms of an uptake of physical activity amongst individuals experiencing mild-to-moderate depression; evidence concerning those mechanisms is (a) fragmented in terms of design and purpose; (b) of varied quality; (c) rarely explicit about the mechanisms through which the interventions are thought to work. Physical, environmental and social factors that may represent mediating variables in the uptake of physical activity amongst people experiencing mild-to-moderate depression are largely absent from studies. Conclusions - An explanatory model was developed. This represents mild-to-moderate depression as interfering with (a) the motivation to take part in physical activity and (b) the volition that it is required to take part in physical activity. Therefore, both motivational and volitional elements are important in any intervention to increase physical activity in people with mild-to-moderate depression. Furthermore, mild-to-moderate depression-specific factors need to be tackled in any physical activity initiative, via psychological treatments such as Cognitive Behavioural Therapy. We argu