7,978 research outputs found

    Robust Header Compression (ROHC) in Next-Generation Network Processors

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    Robust Header Compression (ROHC) provides for more efficient use of radio links for wireless communication in a packet switched network. Due to its potential advantages in the wireless access area andthe proliferation of network processors in access infrastructure, there exists a need to understand the resource requirements and architectural implications of implementing ROHC in this environment. We presentan analysis of the primary functional blocks of ROHC and extract the architectural implications on next-generation network processor design for wireless access. The discussion focuses on memory space andbandwidth dimensioning as well as processing resource budgets. We conclude with an examination of resource consumption and potential performance gains achievable by offloading computationally intensiveROHC functions to application specific hardware assists. We explore the design tradeoffs for hardware as-sists in the form of reconfigurable hardware, Application-Specific Instruction-set Processors (ASIPs), andApplication-Specific Integrated Circuits (ASICs)

    The sele sentence completion questionnaire: a new instrument for the assessment of personal meaning in research on aging

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    In this paper, the SELE-instrumenits presented. The SELE-instrument is a sentence completion test and an accompanying coding scheme, which is designed to study cognitions about self and life. The related theoretical construct is the personal meaning system, which encompasses different meaning domains, like "self", "activities" and "social relations", as well as evaluations and time perspectives. It is argued that especially in aging research. it is necessarv to use more oven instruments in studying self-and-life-cognitions. A short history of sentence completion instruments in psychology, is presented in order to better understand the specific contents of the SELE-instrument. The SELE provides sentence stems in the first form singular ("I") combination with verbal factors, which express different combinations of evaluation and time perspective, to which the respondents have to react in their own words. The SELE-instrumenits thus a semi-structured questionnaire, which can be used in large-scale research. The sentence completions are coded with an extensive coding scheme, which is hierarchially and dimensionally organized. Some figures on the coding reliability as well as on the validity and stability of the instrument are presented. The different uses to which the SELE-instrument as been put are described shortly.En este articulo se presenta el instrumento SELE. Este instrumento, que consta de un cuestionario de frases incompletas y un esquema de codificación de respuestas, está diseñado para el estudio de las cogniciones sobre el self y la vida. El constructo teórico al que se aproxima es el sistema de significado personal, sistema que comprende tanto diferentes dominios de significado (por ejemplo el "self", "actividades" o "relaciones sociales") como evaluaciones y perspectivas temporales. Se argumenta que, especialmente en la investigación en envejecimiento, es necesario utilizar instrurnentos de carácter más abierto para el estudio de cogniciones relacionadas con el self y la vida. Por otra parte, para entender mejor los contenidos específicos del SELE, se presenta una breve historia de los instrumentos de frases incompletas en Psicologia. El SELE proporciona estimulos en forma de frases incompletas a los que la persona tiene que contestar en sus propias palabras. Estos estímulos comienzan con un sujeto en primera persona del singular ("Yo") seguido por una forma verbal que expresa diferentes combinaciones de perspectiva temporal y evaluación. Debido a este formato, el SELE es un cuestionario semiestructurado que puede ser utilizado en investigaciones a gran escala. Las respuestas se categorizan mediante un exhaustivo sistema de codificación que está organizado tanto jerárquica como dimensionalmente. En el articulo se presentan algunos resultados en relación con la fiabilidad, la validez y la estabilidad del cuestionario, asi como también se describen brevemente los diferentes usos a los que ha estado dirigido el SELE

    The sele sentence completion questionnaire: a new instrument for the assessment of personal meaning in research on aging

    Get PDF
    In this paper, the SELE-instrumenits presented. The SELE-instrument is a sentence completion test and an accompanying coding scheme, which is designed to study cognitions about self and life. The related theoretical construct is the personal meaning system, which encompasses different meaning domains, like "self", "activities" and "social relations", as well as evaluations and time perspectives. It is argued that especially in aging research. it is necessarv to use more oven instruments in studying self-and-life-cognitions. A short history of sentence completion instruments in psychology, is presented in order to better understand the specific contents of the SELE-instrument. The SELE provides sentence stems in the first form singular ("I") combination with verbal factors, which express different combinations of evaluation and time perspective, to which the respondents have to react in their own words. The SELE-instrumenits thus a semi-structured questionnaire, which can be used in large-scale research. The sentence completions are coded with an extensive coding scheme, which is hierarchially and dimensionally organized. Some figures on the coding reliability as well as on the validity and stability of the instrument are presented. The different uses to which the SELE-instrument as been put are described shortly.En este articulo se presenta el instrumento SELE. Este instrumento, que consta de un cuestionario de frases incompletas y un esquema de codificación de respuestas, está diseñado para el estudio de las cogniciones sobre el self y la vida. El constructo teórico al que se aproxima es el sistema de significado personal, sistema que comprende tanto diferentes dominios de significado (por ejemplo el "self", "actividades" o "relaciones sociales") como evaluaciones y perspectivas temporales. Se argumenta que, especialmente en la investigación en envejecimiento, es necesario utilizar instrurnentos de carácter más abierto para el estudio de cogniciones relacionadas con el self y la vida. Por otra parte, para entender mejor los contenidos específicos del SELE, se presenta una breve historia de los instrumentos de frases incompletas en Psicologia. El SELE proporciona estimulos en forma de frases incompletas a los que la persona tiene que contestar en sus propias palabras. Estos estímulos comienzan con un sujeto en primera persona del singular ("Yo") seguido por una forma verbal que expresa diferentes combinaciones de perspectiva temporal y evaluación. Debido a este formato, el SELE es un cuestionario semiestructurado que puede ser utilizado en investigaciones a gran escala. Las respuestas se categorizan mediante un exhaustivo sistema de codificación que está organizado tanto jerárquica como dimensionalmente. En el articulo se presentan algunos resultados en relación con la fiabilidad, la validez y la estabilidad del cuestionario, asi como también se describen brevemente los diferentes usos a los que ha estado dirigido el SELE

    Antigens in human glioblastomas and meningiomas: Search for tumour and onco-foetal antigens. Estimation of S-100 and GFA protein.

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    Extracts of glioblastomas and meningiomas were analysed by quantitative immunoelectrophoresis for the presence of foetal brain antigens and tumour-associated antigens, and levels of 2 normal brain-specific proteins were also determined. The following antibodies were used: monospecific anti-S-100 (glia specific); monospecific anti-GFA (glial fibrillary acidic protein), (astroglia specific); polyspecific anti-foetal brain (12-16th week of gestation); a polyspecific anti-glioblastoma antiserum, absorbed with insolubilized serum, haemolysate and normal brain extract; polyspecific anti-alpha-foetoprotein; and monospecific anti-ferritin. Using the antibodies raised against the tumours, several antigens not present in foetal or adult normal brain were found in the glioblastomas and the meningiomas. These antigens cross-reacted with antigens present in normal liver and were therefore not tumour-associated. S-100 was found in glioblastomas in approximately one tenth the amount in whole brain homogenate, whereas GFA was found 2-4 times enriched. The 2 proteins were absent in meningiomas. The possible use of the GFA protein as a marker for astroglial neoplasia is discussed. Five foetal antigens were found in foetal brain, but none in the tumours. alpha-Foetoprotein could only be demonstrated in foetal tissue extracts, including foetal brain, but not in tumours. Ferritin was detected in all tumour extracts, although the amounts determined were unrelated to histological tumour type

    Covariance and Fisher information in quantum mechanics

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    Variance and Fisher information are ingredients of the Cramer-Rao inequality. We regard Fisher information as a Riemannian metric on a quantum statistical manifold and choose monotonicity under coarse graining as the fundamental property of variance and Fisher information. In this approach we show that there is a kind of dual one-to-one correspondence between the candidates of the two concepts. We emphasis that Fisher informations are obtained from relative entropies as contrast functions on the state space and argue that the scalar curvature might be interpreted as an uncertainty density on a statistical manifold.Comment: LATE

    Bures volume of the set of mixed quantum states

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    We compute the volume of the N^2-1 dimensional set M_N of density matrices of size N with respect to the Bures measure and show that it is equal to that of a N^2-1 dimensional hyper-halfsphere of radius 1/2. For N=2 we obtain the volume of the Uhlmann 3-D hemisphere, embedded in R^4. We find also the area of the boundary of the set M_N and obtain analogous results for the smaller set of all real density matrices. An explicit formula for the Bures-Hall normalization constants is derived for an arbitrary N.Comment: 15 revtex pages, 2 figures in .eps; ver. 3, Eq. (4.19) correcte
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