10 research outputs found
Wide-Supply-Range All-Digital Leakage Variation Sensor for On-Chip Process and Temperature Monitoring
Variation in process, voltage and temperature is a major obstacle in achieving energy-efficient operation of LSI. This paper proposes an all-digital on-chip circuit to monitor leakage current variations of both of the nMOSFET and pMOSFET independently. As leakage current is highly sensitive to threshold voltage and temperature, the circuit is suitable for tracking process and temperature variation. The circuit uses reconfigurable inhomogeneity to obtain statistical properties from a single monitor instance. A compact reconfigurable inverter topology is proposed to implement the monitor circuit. The compact and digital nature of the inverter enables cell-based design, which will reduce design costs. Measurement results from a 65 nm test chip show the validity of the proposed circuit. For a 124 sample size for both of the nMOSFET and pMOSFET, the monitor area is 4500 μm2 and active power consumption is 76 nW at 0.8 V operation. The proposed technique enables area-efficient and low-cost implementation thus can be used in product chips for applications such as dynamic energy and thermal management, testing and post-silicon tuning
Single-Conductor Transmission-Line Model for Bent Wire Structures
A bend in a single-conductor line is a primary cause of radiation associated with the antenna mode; conversely, the radiation is fed back, resulting in attenuation and distortion of the current waveform. Despite being a fundamental phenomenon, its dynamics have not been sufficiently characterized. Therefore, this study presents a single-conductor transmission-line model for bent wire structures comprising multiple straight elements by using the local variables of charge per-unit-length and current along a thin conductor. The proposed model is validated over a wide frequency range using the method of moments. The total charge and current distributions that an external field induces on a bent structure are classified into three components: the scattering source distribution, traveling wave corresponding to the Sommerfeld mode, and radiation reaction. These components suggest an overall field-line coupling process: initially, an external electromagnetic field induces a scattering current in the structure, which in turn drives traveling and radiation-reaction currents at the ends, resulting in propagation along the line accompanied by radiation losses. The presented model is advantageous for designing electromagnetic phenomena corresponding to antennas and metamaterials and for addressing electromagnetic interference problems using passive circuit elements. A case study that makes use of the precise and descriptive model is included to predict the field emissions associated with the antenna mode around a bend
Measuring Coverage in MNCH:A Prospective Validation Study in Pakistan and Bangladesh on Measuring Correct Treatment of Childhood Pneumonia
Antibiotic treatment for pneumonia as measured by Demographic and Health Surveys (DHS) and Multiple Indicator Cluster Surveys (MICS) is a key indicator for tracking progress in achieving Millennium Development Goal 4. Concerns about the validity of this indicator led us to perform an evaluation in urban and rural settings in Pakistan and Bangladesh.Caregivers of 950 children under 5 y with pneumonia and 980 with "no pneumonia" were identified in urban and rural settings and allocated for DHS/MICS questions 2 or 4 wk later. Study physicians assigned a diagnosis of pneumonia as reference standard; the predictive ability of DHS/MICS questions and additional measurement tools to identify pneumonia versus non-pneumonia cases was evaluated. Results at both sites showed suboptimal discriminative power, with no difference between 2- or 4-wk recall. Individual patterns of sensitivity and specificity varied substantially across study sites (sensitivity 66.9% and 45.5%, and specificity 68.8% and 69.5%, for DHS in Pakistan and Bangladesh, respectively). Prescribed antibiotics for pneumonia were correctly recalled by about two-thirds of caregivers using DHS questions, increasing to 72% and 82% in Pakistan and Bangladesh, respectively, using a drug chart and detailed enquiry.Monitoring antibiotic treatment of pneumonia is essential for national and global programs. Current (DHS/MICS questions) and proposed new (video and pneumonia score) methods of identifying pneumonia based on maternal recall discriminate poorly between pneumonia and children with cough. Furthermore, these methods have a low yield to identify children who have true pneumonia. Reported antibiotic treatment rates among these children are therefore not a valid proxy indicator of pneumonia treatment rates. These results have important implications for program monitoring and suggest that data in its current format from DHS/MICS surveys should not be used for the purpose of monitoring antibiotic treatment rates in children with pneumonia at the present time
Baseline characteristics of the study children.
<p>Data are given as number (percent) unless otherwise indicated.</p>a<p>There was only one child in the 0–2 age group at the Bangladesh rural site, hence a standard deviation value could not be calculated.</p><p>SD, standard deviation.</p
Discriminative power of DHS/MICS questions about suspected pneumonia and of video for identifying childhood pneumonia (based on 2-wk and 4-wk recall).
<p>Discriminative power of DHS/MICS questions about suspected pneumonia and of video for identifying childhood pneumonia (based on 2-wk and 4-wk recall).</p
Bangladesh urban site—flowchart of selection of pneumonia and no-pneumonia cases in Dhaka Shishu Hospital, Bangladesh.
<p>Bangladesh urban site—flowchart of selection of pneumonia and no-pneumonia cases in Dhaka Shishu Hospital, Bangladesh.</p
Bangladesh rural site—flowchart of selection of pneumonia and no-pneumonia cases in the rural setting.
<p>Bangladesh rural site—flowchart of selection of pneumonia and no-pneumonia cases in the rural setting.</p
Sensitivity and specificity of different tools (individually and in combination).
<p>Data are given as percent (95% CI). Results for both recall periods combined.</p>a<p>These variables from the pneumonia score were selected for this analysis because they had the strongest association with pneumonia in screening univariate analyses.</p><p>LCI, lower chest indrawing.</p