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Mixed Mode Silicon-on-Insulator MMIC Technology for digitally controlled RF/Microwave Systems
Get PDFABSTRACT A high performance mixed mode Silicon-On-Insulator (SOI) IC process has been developed providing the ability to integrate digital, analog, RF and microwave circuitry on the same substrate. Standard functions such as microprocessor bus interface logic and microwave lumped/distributed circuits for 2.4/5.8GHz are described along with related system-on-a-chip implementations. Using this technology, digital microprocessor controlled system architectures can be developed quickly without the need for interfacing between control logic control, data and programming ports of the analog/microwave hardware. INTRODUCTION Advancements in a low cost SOI semiconductor process offers the ability to integrate digital CMOS functions with RF/microwave lumped and distributed circuit designs for applications spanning DC to 10GHz. This cost effective IC process provides an approach bridging between high performance RF front-ends and low power CMOS digital processing. This paper discusses the IC process, design examples and the advantages of systems with direct microprocessor control of RF/Microwave hardware
Transition-Aware Decoupling-Capacitor Allocation in Power Noise Reduction
Get PDFAbstract-Dynamic power noises may not only degrade the circuit performance but also reduce the noise margin which may result in the functional errors in integrated circuit. Decoupling capacitor (decap) allocation is one of the most effective way in reducing serious dynamic power noises (hotspots). To allocate decap bef ore placement, we observed that not only locations but also rising time of functional cells are required to accurately predict power noises. Compared to a previous work which only takes neighborhood relation into consideration, our method is more efficient in reducing hotspots. Furthermore, to reduce the hotspots af ter placement, instead of only using the empty space as proposed in the previous work, we move out cells in the area with serious power noise area (hot area). The obtained empty space can be used to accommodate decaps to further reduce the hotspots. The experimental result shows, compared to the previous work [1], our estimation function to allocate decap before placement is 23% better in reducing power noises. Moreover, compared to a method which fills decaps to all remaining empty space, our cell move algorithm can almost eliminate all the remaining hot grid nodes and hot cells. In summary, compared to the original circuits (without decap), about 60% of hotspots can be removed using our prediction function before placement, and most of the remaining hotspots are removed by our cell moving step after placement
Links Between Behavioral Regulation and Preschoolers' Literacy, Vocabulary, and Math Skills
Get PDFThis study investigated predictive relations between preschoolers' (N ϭ 310) behavioral regulation and emergent literacy, vocabulary, and math skills. Behavioral regulation was assessed using a direct measure called the Head-to-Toes Task, which taps inhibitory control, attention, and working memory, and requires children to perform the opposite of what is instructed verbally. Hierarchical linear modeling (HLM) was utilized because children were nested in 54 classrooms at 2 geographical sites. Results revealed that behavioral regulation significantly and positively predicted fall and spring emergent literacy, vocabulary, and math skills on the Woodcock Johnson Tests of Achievement (all ps Ͻ .05). Moreover, growth in behavioral regulation predicted growth in emergent literacy, vocabulary, and math skills over the prekindergarten year (all ps Ͻ .05), after controlling for site, child gender, and other background variables. Discussion focuses on the role of behavioral regulation in early academic achievement and preparedness for kindergarten. Keywords: self-regulation, academic achievement, school readiness, hierarchical linear modeling, executive function Each year, hundreds of thousands of American children make the transition from preschool to a more structured kindergarten environment. This transition can be particularly problematic for children who have not mastered basic skills involved in regulating behavior, including paying attention, following instructions, and inhibiting inappropriate actions. These skills, which we refer to as behavioral regulation, fall under the broader domain of selfregulation, which is important for functioning in all contexts There has been growing interest in and debate about the definition and components of self-regulation in early childhood (Cole, We used a recently developed direct measure of behavioral regulation (called the Head-to-Toes Task; Cameron et al., in press), which was adapted from work by McCabe and colleagues Succeeding at the Head-to-Toes Task requires attention, working memory, and inhibitory control, but inhibitory control is a main component. The task shares features of traditional measures of inhibitory control, including the Bear and Dragon Task Using a behavioral measure has advantages over teacher or parent ratings, which may be based on perceptions rather than actual child behavior RimmKaufman et al., 2000). A recent study found that the Head-to-Toes Task showed developmental differences in performance with two sites of children from distinct geographical regions and was a stable and valid measure of early behavioral regulation in diverse populations. Moreover, the greatest variability on Head-to-Toes Task performance was found in 4-and 5-year-olds (prior to kindergarten entry; Cameron et al., in press). Thus, the present study examined links between this direct measure of behavioral regulation and emergent literacy, vocabulary, and math skills in the prekindergarten year, when children were 4 and 5 years old. Behavioral Regulation and Academic Achievement in Elementary School Considerable research has demonstrated that behavioral aspects of self-regulation are important for achievement throughout elementary school. Acquiring behavioral regulation (including atten-948 MCCLELLAND ET AL. tion, working memory, and inhibitory control) provides a foundation for developing positive behavior in classroom contexts and making academic gains. Together, these three cognitive processes allow children to remember and follow teachers' directions and focus on a task without succumbing to distractions. Those who are unable to inhibit problematic behaviors, such as talking out of turn and failing to complete assignments, are less able to function effectively in the classroom There is also mounting evidence that young children's attention, working memory, and inhibitory control are each important for school performance and adaptation Behavioral Regulation and Early Achievement in Preschool Research supports the notion that strong behavioral regulation is associated with higher levels of academic achievement in elementary school. There is less work examining this relation before kindergarten, although researchers have argued that attention, working memory, and inhibitory control included in behavioral regulation are important for learning outcomes prior to formal school entry Taken together, findings demonstrate that the processes involved in behavioral regulation relate to children's early achievement. However, it is not known when during early childhood behavioral regulation emerges as being important for particular aspects of academic achievement. In addition, research has often relied on parent or teacher reports to assess children's skills or used laboratory-based tasks to measure the processes involved in behavioral regulation, which may not have practical utility in classrooms. We used an easy-to-administer, direct observational measure of behavioral regulation that focuses on inhibitory control and also taps attention and working memory. In contrast to previous studies that have not focused on early childhood or on overall behavioral regulation, we were interested in how behavioral regulation was related to early academic skills prior to formal schooling. We administered the measure to children in the fall and spring of the prekindergarten year along with three assessments of early academic achievement: emergent literacy, vocabulary, and math. This enabled us to examine whether level and growth (i.e., residualized change) in behavioral regulation predicted early academic skill gains. Classroom Influences In the current study, it was important to control for the influence of classroom-level variability because children enter formal education widely varying in their skills and knowledge, which may differ by the classroom or school in which they are placed (Christian, Goals of the Present Study The present study sought to examine whether performance and growth on the Head-to-Toes Task, a measure of behavioral regulation, were significantly related to level and growth in emergent literacy, vocabulary, and math skills over the prekindergarten year. The following two research questions guided this inquiry. First, what is the variability and growth over the prekindergarten year in behavioral regulation, using a measure that relies on direct observation of the child's behavior rather than teacher or parent report? Based on the extant literature, we anticipated substantial variability and growth in behavioral regulation. Second, we asked whether behavioral regulation would relate to three measures of early academic achievement, expecting that children with higher behavioral regulation would achieve academically at higher levels in fall 949 BEHAVIORAL REGULATION AND EARLY ACHIEVEMENT and spring of the prekindergarten year, compared to children with lower behavioral regulation. Finally, we hypothesized that growth in behavioral regulation over the school year would be significantly and positively related to gains in emergent literacy, vocabulary, and math skills. Method Participants Children were recruited from two sites: a predominantly middleto upper-middle-SES urban fringe area with a range of economic and ethnic diversity in Michigan, and a mixed-SES rural site in Oregon. Participants in Michigan were recruited through their preschool programs, housed in a public school district, to participate in a 5-year longitudinal study on early academic and social development. All 3-and 4-year-old children entering preschool were recruited through fall orientations at the district's six participating schools, as well as through backpack mailing during the first 2 years of the study. One of the preschools was a Title I and Head Start site, and all others were licensed by the state of Michigan. Children from the Title I school were overrecruited. Once the target sample size had been achieved, recruiting was stopped. Recruitment efforts in these locations enrolled approximately 38% of the districts' children who were entering preschool in the longitudinal study, with a final sample size of n ϭ 217 for the present investigation, including only 4-year-old children during their prekindergarten year. Participants were enrolled in 42 classrooms. In Oregon, children and parents were part of a study investigating factors related to self-regulation in preschool. Three preschools accredited by the National Association for the Education of Young Children and three Head Start preschools located in Oregon were invited to participate in the study and all agreed. Recruitment letters were sent home with approximately 165 children entering prekindergarten from the participating preschools, and 95 families (or 58%) agreed to participate. Two participants were excluded from the study analyses because neither English nor Spanish was their first language, making the final sample size n ϭ 93 children enrolled in 12 classrooms. For both sites, written informed consents, outlining the nature of the study and extent of participation, were obtained from preschools and parents prior to participation. At the Michigan site, the mean age of children at Time 1 (fall) was 4.43 years (SD ϭ 0.34 years) with a range between 3.12 and 5.11 years (see At the Oregon site, the mean age of children at Time 1 (fall) was 4.58 years (SD ϭ 0.27 years) with ages ranging from 4.08 to 5.17 years (see There were approximately equal numbers of girls (52%) and boys in the study. On average, children had spent about 22 months in child care prior to data collection at Time 1 (SD ϭ 18.07 months) and were attending full-day and part-day programs and spending an average of 21 hours per week in prekindergarten (SD ϭ 13.37 hours). Families demonstrated considerable educational and ethnic diversity. The average education level attained for mothers and fathers was approximately an associate's degree (M ϭ 14.63 years) and 24% of parents had a high-school education or less (n ϭ 22). Twenty-five percent (n ϭ 23) of children and families were Latino/a, of which 19 (83%) were primary Spanish speakers. The remaining sample was 48% Caucasian, 19% Asian, and 7% other ethnic group
Atmospheric Concentration of Trace Elements, Dry Deposition Fluxes and Source Apportionment Study in Mumbai
Get PDFPrecision Time Synchronization Using IEEE 1588 for Distributed Acoustic Measurement
No full textABSTRACT Distributed measurement based on Local Area Network (LAN) is popular in measuring machines' vibration, of which the timing requirement is becoming increasingly stringent. Traditional synchronal methods, such as Network Time Protocol (NTP), Simple Network Time Protocol (SNTP), can achieve accuracy of microseconds, but it doesn't meet the requirements. At the same time, the sync cable is not competent for long dsitance transmission. A synchronal device based on Precision Time Protocol (PTP, IEEE1588) is designed. A Field Programmable Gate Array (FPGA) is emplaced between Medium Independent Interface (MII) and PHY. Normal data packets pass by without modification, and IEEE 1588 packets are unpacked and stamped according to the accurate time. The FPGA, which also has a management unit to process IEEE1588 events, compensates the drift of crystal oscillator that is notable during the sync interval by using discrete linear Kalman filter. Trigger can be programmed, of which the output is used to driver the sample unit. Acoustic measurement equipments base on the design. Rough experiment shows that it satisfies the need
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No full textAbstract We investigated genetic diversity and structure of urban white-footed mouse, Peromyscus leucopus, populations in New York City (NYC) using variation at 18 microsatellite loci. White-footed mice are 'urban adapters' that occur at higher population densities as habitat fragments are reduced in area but have a limited ability to disperse through urbanized areas. We hypothesized that this combination of traits has produced substantial genetic structure but minimal loss of genetic variation over the last century in NYC. Allelic diversity and heterozygosity in 14 NYC populations were high, and nearly all of our NYC study sites contained genetically distinct populations of white-footed mice as measured by pairwise F ST , assignment tests, and Bayesian clustering analyses performed by Structure and BAPS. Analysis of molecular variance revealed that genetic differences between populations separated by a few kilometres are more significant than differences between prehistorically isolated landmasses (i.e. Bronx, Queens, and Manhattan). Allele size permutation tests and lack of isolation by distance indicated that mutation and migration are less important than drift as explanations for structure in urban, fragmented P. leucopus populations. Peromyscus often exhibit little genetic structure over even regional scales, prompting us to conclude that urbanization is a particularly potent driver of genetic differentiation compared to natural fragmentation
15+ MILLION TOP 1% MOST CITED SCIENTIST 12.2% AUTHORS AND EDITORS FROM TOP 500 UNIVERSITIES Chapter from the book Sustainable Development -Energy, Engineering and Technologies -Manufacturing and Environment Downloaded from: http://www.intechopen.com/books
No full text14+ MILLION TOP 1% MOST CITED SCIENTIST 12.2% AUTHORS AND EDITORS FROM TOP 500 UNIVERSITIES 21 Decision Support Systems used in Disaster Management
No full textWHAM OBSERVATIONS OF Ha FROM HIGH-VELOCITY CLOUDS: ARE THEY GALACTIC OR EXTRAGALACTIC?
No full textABSTRACT It has been suggested that high-velocity clouds may be distributed throughout the Local Group and are therefore not in general associated with the Milky Way. With the aim of testing this hypothesis, we have made observations in the Ha line of high-velocity clouds selected as the most likely candidates for being at larger than average distances. We have found Ha emission from four out of five of the observed clouds, suggesting that the clouds under study are being illuminated by a Lyman continuum flux greater than that of the metagalactic ionizing radiation. Therefore, it appears likely that these clouds are in the Galactic halo and not distributed throughout the Local Group
A Simplified Numerical Model for Assessing the Residual Strength and Deformation Capacity of Asymmetrically Damaged Ropes
No full textABSTRACT A simplified nonlinear mechanical model is proposed to estimate the residual strength and deformation capacity of ropes with asymmetric damage distribution. In this study, damage corresponds to the complete rupture of one or more rope components that belong to the outermost layer of a particular rope cross-section. In the proposed model, the damaged rope is assumed to behave as a nonlinear beam under biaxial bending and axial load with Bernoulli´s kinematic hypothesis REFERENCES [1] K. Hjelmstad, Fundamentals of structural mechanics. New York, USA: Springer, (2005). [2]C. MacDougall and F. Bartlett, "Mechanical model for unbonded seven-wire tendon with single broken wire", J Eng Mech,132,1345Mech,132, -1353Mech,132, (2006. [4] J.F.Beltran JF and D. Vargas, "Effect of broken rope components distribution throughout rope cross-section on polyester rope response: Numerical approach", Int J Mech Sci, 64,32-46 (2012). [5] J. Lanteigne, "Theoretical estimation of the response of helically armoured cables of tension, torsion, and bending" J Appl Mech, 52, 423-432(1985)