946 research outputs found
Reversible codes
A code is defined to be reversible if its code-word set is invariant under a reversal of the digits in each code word. Such codes may have application in certain data storage and retrieval systems. It is shown that cyclic codes and convolutional codes are reversible when and only when their code-generating polynomials are self-reciprocal. Reversible codes are quite rare therefore, but it is shown that an important subclass of the Bose-Chaudhuri codes consists entirely of reversible codes. Techniques are developed by which any nonreversible cyclic code can be converted into a reversible cyclic code with at least as much error-correcting power, but at the cost of increased code redundancy. The redundancy of the derived code is at most twice that of the original code, and the derived code can be decoded by a decoder constructed for the original code. Similarly, it is shown how any nonreversible convolutional code can be converted into a reversible convolutional code with at least as much error-correcting power, but at the cost of increased code constraint length. Again the derived code can be decoded by substantially the same decoder as for the original code
HLAD 325 Health Care Organization
Course syllabus for HLAD 325 Health Care Organization
Course description: Provides an understanding of how health care is organized in the United States and the way it is provided to consumers
HLAD 325 Health Care Organization
Course syllabus for HLAD 325 Health Care Organization
Course description: Provides an understanding of how health care is organized in the United States and the way it is provided to consumers
The Origins of State Intervention in the Control of Juvenile Delinquency: The Nebraska Experience
The pages that follow trace the origins of Nebraska\u27s experience in official state intervention in the control of juvenile delinquency. The focus is on the developmental stages of the Nebraska juvenile justice system, and is designed to inform the reader about the foundation upon which this system has been built, as well as the assumptions that were implicit in this activity. The early chapters provide a brief overview of efforts to define and prevent juvenile delinquency from colonial times to just prior to the onset of the American Civil War. It was in this period that some forms of youthful misbehavior gradually came to be dealt with by a state supported system of control and ceased to fall exclusively under the auspices of traditional family discipline. After the Civil War a movement began which consolidated on a national scale correctional efforts which had previously been the concern of individual states acting in relative isolation. This movement will be traced through the activities of the National Conference of Charities and Correction, which during the last quarter of the nineteenth century was unquestionably an organization of prime influence in virtually all areas of child-saving
HLAD 325 Health Care Organization
Course syllabus for HLAD 325 Health Care Organization
Course description: Provides an understanding of how health care is organized in the United States and the way it is provided to consumers
An upper bound on decoding bit-error probability with linear coding on extremely noisy channels
When concatenated coding schemes operate near channel capacity their component encoders may operate above capacity. The decoding bit-error performance of binary convolutional codes near and above capacity is investigate
Tris(pentafluorophenyl)borane and beyond: modern advances in borylation chemistry
As main-group chemistry, in particular boron chemistry, has expanded and developed over the past 20 years, one reagent has risen to prominence as well. Tris(pentafluorophenyl)borane, B(C6F5)3 (commonly known as BCF), has demonstrated extensive applications in a wide variety of reactions, including borylation, hydrogenation, hydrosilylation, frustrated Lewis pair (FLP) chemistry, Lewis acid catalysis, and more. The high Lewis acidity of B(C6F5)3 is derived from the electronic effects of its three C6F5 rings, rendering it a versatile reagent for a great number of reactions. In addition, the steric bulk of these rings also allows it to function as the Lewis acid in a FLP, granting this reagent yet another synthetically useful application. However, as main-group chemistry continues to evolve as a field, new reagents are required that go beyond BCF, increasing not only the range of reactions available but also the breadth of compounds attainable. Great strides have already been made in order to accomplish this task, and this review will highlight modern advances in boron chemistry relating to borylation reactions. Herein, we will show the recent uses of B(C6F5)3 in borylation reactions while also focusing on current advances in novel borane and borocation usage that eclipses that of the stalwart B(C6F5)3
A Subaru Weak Lensing Survey I: Cluster Candidates and Spectroscopic Verification
We present the results of an ongoing weak lensing survey conducted with the
Subaru telescope whose initial goal is to locate and study the distribution of
shear-selected structures or halos. Using a Suprime-cam imaging survey spanning
21.82 square degree, we present a catalog of 100 candidate halos located from
lensing convergence maps. Our sample is reliably drawn from that subset of our
survey area, (totaling 16.72 square degree) uncontaminated by bright stars and
edge effects and limited at a convergence signal to noise ratio of 3.69. To
validate the sample detailed spectroscopic measures have been made for 26
candidates using the Subaru multi-object spectrograph, FOCAS. All are confirmed
as clusters of galaxies but two arise as the superposition of multiple clusters
viewed along the line of sight. Including data available in the literature and
an ongoing Keck spectroscopic campaign, a total of 41 halos now have reliable
redshifts. For one of our survey fields, the XMM LSS (Pierre et al. 2004)
field, we compare our lensing-selected halo catalog with its X-ray equivalent.
Of 15 halos detected in the XMM-LSS field, 10 match with published X-ray
selected clusters and a further 2 are newly-detected and spectroscopically
confirmed in this work. Although three halos have not yet been confirmed, the
high success rate within the XMM-LSS field (12/15) confirms that weak lensing
provides a reliable method for constructing cluster catalogs, irrespective of
the nature of the constituent galaxies or the intracluster medium.Comment: To appear in ApJ, High resolution preprint available at
http://anela.mtk.nao.ac.jp/suprime33/papers/p1.ps.g
A new perspective when examining maize fertilizer nitrogen use efficiency, incrementally
For maize (Zea mays L.), nitrogen (N) fertilizer use is often summarized from field to global scales using average N use efficiency (NUE). But expressing NUE as averages is misleading because grain increase to added N diminishes near optimal yield. Thus, environmental risks increase as economic benefits decrease. Here, we use empirical datasets obtained in North America of maize grain yield response to N fertilizer (n = 189) to create and interpret incremental NUE (iNUE), or the change in NUE with change in N fertilization. We show for those last units of N applied to reach economic optimal N rate (EONR) iNUE for N removed with the grain is only about 6%. Conversely stated, for those last units of N applied over 90% is either lost to the environment during the growing season, remains as inorganic soil N that too may be lost after the growing season, or has been captured within maize stover and roots or soil organic matter pools. Results also showed iNUE decrease averaged 0.63% for medium-textured soils and 0.37% for fine-textured soils, attributable to fine-textured soils being more predisposed to denitrification and/or lower mineralization. Further analysis demonstrated the critical nature growing season water amount and distribution has on iNUE. Conditions with too much rainfall and/or uneven rainfall produced low iNUE. Producers realize this from experience, and it is uncertain weather that largely drives insurance fertilizer additions. Nitrogen fertilization creating low iNUE is environmentally problematic. Our results show that with modest sub-EONR fertilization and minor forgone profit, average NUE improvements of ~10% can be realized. Further, examining iNUE creates unique perspective and ideas for how to improve N fertilizer management tools, educational programs, and public policies and regulations
Dimension- and Context-Specific Expression of Preschoolers’ Disruptive Behaviors Associated with Prenatal Tobacco Exposure
Objective—Precise phenotypic characterization of prenatal tobacco exposure (PTE) −related disruptive behavior (DB) that integrates nuanced measures of both exposures and outcomes is optimal for elucidating underlying mechanisms. Using this approach, our goals were to identify dimensions of DB most sensitive to PTE prior to school entry and assess contextual variation in these dimensions.
Methods—A community obstetric sample of N=369 women (79.2% lifetime smokers; 70.2% pregnancy smokers) from two Midwestern cities were assessed for PTE using cotinine-calibrated interview-based reports at 16, 28, and 40 weeks of gestation. A subset of n=244 who completed observational assessments with their 5-year-old children in a subsequent preschool follow-up study constitute the analytic sample. Using two developmentally-meaningful dimensions previously associated with emergent clinical risk for DB—irritability and noncompliance—we assessed children with 2 parent-report scales: the Multidimensional Assessment Profile of Disruptive Behavior (MAP-DB) and the Early Childhood Inventory (ECI). We also assessed children by direct observation across 3 interactional contexts with the Disruptive Behavior Diagnostic Observation Schedule (DB-DOS). We used generalized linear models to examine between-child variability across behavioral dimensions, and mixed effects models to examine directly observed within-child variability by interactional context.
Results—Increasing PTE predicted increasing impairment in preschoolers’ modulation of negative affect (irritability), but not negative behavior (noncompliance) across reported (MAP-DB) and observed (DB-DOS) dimensional measures. Moreover, children’s PTE-related irritability was more pronounced when observed with parents than with the examiner. The ECI did not detect PTE-related irritability nor noncompliance.
Conclusions—Nuanced, dimension- and context-specific characterization of PTE-related DB described can optimize early identification of at-risk children
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