1,032 research outputs found
A Closing Lemma for a Class of Symplectic Diffeomorphisms
We prove a closing lemma for a class of partially hyperbolic symplectic
diffeomorphisms. We show that for a generic symplectic diffeomorphism, , with two dimensional center and close to a product map, the set
of all periodic points is dense
Discrete-time loop transfer recovery for systems with nonminimum phase zeros and time delays,
The purpose of this paper is to study what happens when the discrete-time loop transfer recovery (LTR) procedure is applied to plants with nonminimum phase zeros and with uniform time delay in all channels. Explicit expressions are given for the asymptotic behavior of the resulting sensitivity function and loop transfer function. These results yield a better understanding of the mechanism of the discrete-time loop transfer recovery procedure and the design limitations due to nonminimum phase zeros and time delays.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30951/1/0000623.pd
Undersampling and Cumulative Class Re-decision Methods to Improve Detection of Agitation in People with Dementia
Agitation is one of the most prevalent symptoms in people with dementia (PwD)
that can place themselves and the caregiver's safety at risk. Developing
objective agitation detection approaches is important to support health and
safety of PwD living in a residential setting. In a previous study, we
collected multimodal wearable sensor data from 17 participants for 600 days and
developed machine learning models for predicting agitation in one-minute
windows. However, there are significant limitations in the dataset, such as
imbalance problem and potential imprecise labels as the occurrence of agitation
is much rarer in comparison to the normal behaviours. In this paper, we first
implement different undersampling methods to eliminate the imbalance problem,
and come to the conclusion that only 20\% of normal behaviour data are adequate
to train a competitive agitation detection model. Then, we design a weighted
undersampling method to evaluate the manual labeling mechanism given the
ambiguous time interval (ATI) assumption. After that, the postprocessing method
of cumulative class re-decision (CCR) is proposed based on the historical
sequential information and continuity characteristic of agitation, improving
the decision-making performance for the potential application of agitation
detection system. The results show that a combination of undersampling and CCR
improves F1-score and other metrics to varying degrees with less training time
and data used, and inspires a way to find the potential range of optimal
threshold reference for clinical purpose.Comment: 19 pages, 8 figure
Determination of astrophysical 12N(p,g)13O reaction rate from the 2H(12N, 13O)n reaction and its astrophysical implications
The evolution of massive stars with very low-metallicities depends critically
on the amount of CNO nuclides which they produce. The
N(,\,)O reaction is an important branching point in
the rap-processes, which are believed to be alternative paths to the slow
3 process for producing CNO seed nuclei and thus could change the fate
of massive stars. In the present work, the angular distribution of the
H(N,\,O) proton transfer reaction at =
8.4 MeV has been measured for the first time. Based on the Johnson-Soper
approach, the square of the asymptotic normalization coefficient (ANC) for the
virtual decay of O N + was
extracted to be 3.92 1.47 fm from the measured angular
distribution and utilized to compute the direct component in the
N(,\,)O reaction. The direct astrophysical S-factor at
zero energy was then found to be 0.39 0.15 keV b. By considering the
direct capture into the ground state of O, the resonant capture via the
first excited state of O and their interference, we determined the total
astrophysical S-factors and rates of the N(,\,)O
reaction. The new rate is two orders of magnitude slower than that from the
REACLIB compilation. Our reaction network calculations with the present rate
imply that N()O will only compete successfully with
the decay of N at higher (two orders of magnitude)
densities than initially predicted.Comment: 8 figures, 2 tables, Submitted to Physical Review
Characterization of a p75NTR Apoptotic Signaling Pathway Using a Novel Cellular Model
The p75 neurotrophin receptor (p75(NTR)) belongs to the tumor necrosis factor receptor/nerve growth factor receptor superfamily. In some cells derived from neuronal tissues it causes cell death through a poorly characterized pathway. We developed a neuronal system using conditionally immortalized striatal neurons, in which the expression of p75(NTR) is inducibly controlled by the ecdysone receptor. In these cells p75(NTR) induces apoptosis through its death domain in a nerve growth factor-independent manner. Caspases 9, 6, and 3 are activated by receptor expression indicating the activation of the common effector pathway of apoptosis. Cell death is blocked by a dominant negative form of caspase 9 and Bcl-X(L) consistent with a pathway that involves mitochondria. Significantly, the viral flice inhibitory protein E8 protects from p75(NTR)-induced cell death indicating that death effector domains are involved. A p75(NTR) construct with a deleted death domain dominantly interferes with p75(NTR) signaling, implying that receptor multimerization is required. However, in contrast to the other receptors of the family, p75(NTR)-mediated apoptosis does not involve the adaptor proteins Fas-associated death domain protein or tumor necrosis factor-associated death domain protein, and the apical caspase 8 is not activated. We conclude that p75(NTR) signals apoptosis by similar mechanisms as other death receptors but uses different adaptors and apical caspases
Formal planning and the reshaping of public sector professional work
This paper deals with the ‘managerialization’ of public sector professional work. Specifically,
it will focus on the role of formal planning practices (as expressed in strategic planning,
project management and budgeting practices) in changing public sector professional work.
Planning and accounting are at the heart of public sector reforms, responding to a logic of
having public service professionals transparent on what they do, on how they pursue their
goals, and accountable on the use of resources and on results. Thus planning and accounting
practices have been transferred from private sector management models to public,
professional organizations. Yet public sector professional organizations can be conceived as a
pluralistic setting characterized by diffuse power, fragmented objectives and knowledgebased
and are deeply embedded in public administration regulatory logics: how can
management models deriving from private, hierarchical firms be applied to the specificities
and complexities of public, pluralistic settings? What is the specific meaning of formal
planning practices in such complex contexts?
Based on a qualitative, single case study design, this paper will show how the planning
system (in its manifestation of strategic planning, project management and budgeting) applied
in a public hospital apparently ‘fails’ when its deliberate role of serving as a tool for decisions
is considered. Yet it is widely in use and widely accepted by professionals as well.
Conclusions on the value of formal planning when other emergent roles are taken into account
will be discussed
Heterogeneous Multi-wavelength Optical Injection Locked System-on-chip: a Proposal & Proof-of-concept Experiment
We present proof-of-concept work towards an integrated multi-λ optical injection locked system-on-chip using just one master laser. Tremendous improvement of direct modulation (4→20 Gb/s) and single-mode operation on slave microring laser was achieved
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