1,347 research outputs found

    A fast passivity test for descriptor systems via structure-preserving transformations of Skew-Hamiltonian/Hamiltonian matrix pencils

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    Passivity in a VLSI model is an important property to guarantee stable global simulation. Most VLSI models are naturally described as descriptor systems (DSs) or singular state spaces. Passivity tests for DSs, however, are much less developed compared to their non-singular state space counterparts. For large-scale DSs, the existing test based on linear matrix inequality (LMI) is computationally prohibitive. Other system decoupling techniques involve complicated coding and sometimes ill-conditioned transformations. This paper proposes a simple DS passivity test based on the key insight that the sum of a passive system and its adjoint must be impulse-free. A sidetrack shows that the proper (non-impulsive) part of a passive DS can be easily decoupled along the test flow. Numerical examples confirm the effectiveness of the proposed DS passivity test over conventional approaches. Copyright 2006 ACM.published_or_final_versio

    Formation and Dissociation of Phosphorylated Peptide Radical Cations

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    Emphysematous pyelonephritis: an eight-year retrospective review across four hospitals in a single cluster

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    香港泌尿外科學會Moderated Poster (Free Paper) Session II - Upper Tract and Robotic Surgery: MP.2-1OBJECTIVE: Emphysematous pyelonephritis (EPN) is a rare but life-threatening infection. We aim to review our cluster’s experience of managing this urologic emergency. PATIENTS & METHODS: Case notes of patients with EPN in four acute hospitals in the KWC (PMH, CMC, KWH and YCH) were retrospectively reviewed. The patients’ demographic data, clinical presentation, investigation findings, treatment and outcome were studied. OBJECTIVE: Emphysematous pyelonephritis (EPN) is a rare but life-threatening infection. We aim to review our cluster’s experience of managing this urologic emergency. PATIENTS & METHODS: Case notes of patients with EPN in four acute hospitals in the KWC (PMH, CMC, KWH and YCH) were retrospectively reviewed. The patients’ demographic data, clinical presentation, investigation findings, treatment and outcome were studied.published_or_final_versionThe 17th Annual Scientific Meeting of the Hong Kong Urological Association, Hong Kong, 6 November 2011. In Program Book, 2011, p. 6

    An evaluative study on the effectiveness of a parent-child parallel group model

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    Objective; To examine the effectiveness of a parent-child parallel group model that attempted to reduce parent-adolescent conflict. Method: A single group research design with pretest, posttest, and follow-up assessments was employed. Results: Results showed that the level of mother-adolescent conflict at posttest was lower than the level at pretest. The findings, based on the target problem rating, indicated that after the group intervention, both the mothers and adolescents perceived that the problems they had identified in the mother-child relationship had become less severe. The findings, based on subjective outcome measures, were also positive. Conclusion: The present study provides some evidence to support the effectiveness of the parallel group intervention for social work practice.preprin

    吸烟的成本和代价 : 社会成本与对财政预算的影响计算方式的比较

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    Title in Traditional Chinese: 吸煙的成本和代價:社會成本與對財政預算的影響計算方式的比較Journal title in Traditional Chinese: 中國藥物濫用防治雜誌2004-2005 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Nucleophilic substitution by amide nitrogen in the aromatic rings of [zn − H]˙+ ions; the structures of the [b2 − H − 17]˙+ and [c1 − 17]+ ions

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    Peptide radical cations that contain an aromatic amino acid residue cleave to give [zn − H]˙+ ions with [b2 − H − 17]˙+ and [c1 − 17]+ ions, the dominant products in the dissociation of [zn − H]˙+, also present in lower abundance in the CID spectra. Isotopic labeling in the aromatic ring of [Yπ˙GG]+ establishes that in the formation of [b2 − H − 17]˙+ ions a hydrogen from the δ-position of the Y residue is lost, indicating that nucleophilic substitution on the aromatic ring has occurred. A preliminary DFT investigation of nine plausible structures for the [c1 − 17]+ ion derived from [Yπ˙GG]+ shows that two structures resulting from attack on the aromatic ring by oxygen and nitrogen atoms from the peptide backbone have significantly better energies than other isomers. A detailed study of [Yπ˙GG]+ using two density functionals, B3LYP and M06-2X, with a 6-31++G(d,p) basis set gives a higher barrier for attack on the aromatic ring of the [zn − H]˙+ ion by nitrogen than by the carbonyl oxygen. However, subsequent rearrangements involving proton transfers are much higher in energy for the oxygen-substituted isomer leading to the conclusion that the [c1 − 17]+ ions are the products of nucleophilic attack by nitrogen, protonated 2,7-dihydroxyquinoline ions. The [b2 − H − 17]˙+ ions are formed by loss of glycine from the same intermediates involved in the formation of the [c1 − 17]+ ions.postprin

    A Mobile App Platform for Discovering Learning Profiles and Analytics

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    Inferring Influenza Infection Attack Rate from Seroprevalence Data

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    Exploring Characteristics of Fine-Grained Behaviors of Learning Mathematics in Tablet-Based E-Learning Activities

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    Attributes of teaching and learning contexts provide rich information about how students participate in learning activities. By tracking and analyzing snapshots of these attributes captured continuously throughout the duration of the learning activities, teachers can identify individual students who need special attention and apply different pedagogical actions to them. This paper describes the results of the work-in-progress study in exploring characteristics of fine-grained behaviors of learning mathematics in tablet-based e-learning activities. An experimental platform called SkyApp is built. Through SkyApp, teachers can create e-learning activities and track learning records of students after the delivery of the activities. SkyApp supports capturing, storing and analyzing of fine-grained behaviors of students. Pilot tests have been done in two primary schools for eight months. The review of the tests demonstrates the potential in performing learning analytics. By applying clustering algorithms on multiple learning metrics of marks, time and number of attempts for students in solving mathematics questions, classification of students by learning characteristics of performance and engagement can be formulated. [For the complete proceedings, see ED579335.]published_or_final_versio
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