484 research outputs found
Ce qui est abusif au sens de l'article 8 de la Charte canadienne lors de la recherche de preuves
In determining whether legislation permitting search and seizure properly meets the requirements of section 8 of the Canadian Charter of Rights and Freedoms, the courts have been obliged to balance the right of the individual to be secure against unreasonable search and seizure with the right of the state to ensure compliance with the law. In Hunter v. Southam, the Supreme Court of Canada established the minimum criteria of reasonable search and seizure for the purposes of section 8. The liberal approach adopted by the Supreme Court raises an important question : Should the same criteria apply to administrative statutes empowering bodies to conduct inquiries and inspections ? The author compares section 8 of the Charter with the American 4th Amendment, examining the requirement for search warrants in the light of Canadian cases. He then examines and discusses the case law concerning the applicability of section 8 to statutory provisions relating to the production of documents and the standard of reasonableness that should apply to these situations
EP-1732: Quantitative estimation of gamma passing rates from characteristics of respiratory motion
Detection of Multiple Human Papillomavirus Genotypes in Anal Carcinoma
Infection with human papillomavirus (HPV) is a major risk factor for development of anal squamous cell carcinoma. Despite over 100 genotypes of the virus, HPV 16 and 18 are considered pathogenic as they are seen in the majority of cervical and anal cancers. We have employed a custom microarray to examine DNA for several HPV genotypes. We aimed to determine the accuracy of our microarray in anal cancer DNA for HPV genotypes compared to the DNA sequencing gold standard
Immittance Matching for Multi-dimensional Open-system Photonic Crystals
An electromagnetic (EM) Bloch wave propagating in a photonic crystal (PC) is
characterized by the immittance (impedance and admittance) of the wave. The
immittance is used to investigate transmission and reflection at a surface or
an interface of the PC. In particular, the general properties of immittance are
useful for clarifying the wave propagation characteristics. We give a general
proof that the immittance of EM Bloch waves on a plane in infinite one- and
two-dimensional (2D) PCs is real when the plane is a reflection plane of the PC
and the Bloch wavevector is perpendicular to the plane. We also show that the
pure-real feature of immittance on a reflection plane for an infinite
three-dimensional PC is good approximation based on the numerical calculations.
The analytical proof indicates that the method used for immittance matching is
extremely simplified since only the real part of the immittance function is
needed for analysis without numerical verification. As an application of the
proof, we describe a method based on immittance matching for qualitatively
evaluating the reflection at the surface of a semi-infinite 2D PC, at the
interface between a semi-infinite slab waveguide (WG) and a semi-infinite 2D PC
line-defect WG, and at the interface between a semi-infinite channel WG and a
semi-infinite 2D PC slab line-defect WG.Comment: 8 pages, 6 figure
Theory of itinerant-electron ferromagnetism
A theory of Kondo lattices or a expansion theory, with spatial
dimensionality, is applied to studying itinerant-electron ferromagnetism. Two
relevant multi-band models are examined: a band-edge model where the chemical
potential is at one of band-edges, the top or bottom of bands, and a flat-band
model where one of bands is almost flat or dispersionless and the chemical
potential is at the flat band. In both the models, a novel ferromagnetic
exchange interaction arises from the virtual exchange of pair excitations of
quasiparticles; it has two novel properties such as its strength is in
proportion to the effective Fermi energy of quasiparticles and its temperature
dependence is responsible for the Curie-Weiss law. When the Hund coupling
is strong enough, the superexchange interaction, which arises from the virtual
exchange of pair excitations of electrons across the Mott-Hubbard gap, is
ferromagnetic. In particular, it is definitely ferromagnetic for any nonzero
in the large limit of band multiplicity. Ferromagnetic instability
occurs, when the sum of the two exchange interactions is ferromagnetic and it
overcomes the quenching of magnetic moments by the Kondo effect or local
quantum spin fluctuations and the suppression of magnetic instability by the
mode-mode coupling among intersite spin fluctuations.Comment: 14 pages, 4 figure
A working model of stroke recovery from rehabilitation robotics practitioners
We reviewed some of our initial insights about the process of upper-limb behavioral recovery following stroke. Evidence to date indicates that intensity, task specificity, active engagement, and focusing training on motor coordination are key factors enabling efficacious recovery. On modeling, experience with over 400 stroke patients has suggested a working model of recovery similar to implicit motor learning. Ultimately, we plan to apply these insights in the development of customized training paradigms to enhance recovery
Frustrated electron liquids in the Hubbard model
The ground state of the Hubbard model is studied within the constrained
Hilbert space where no order parameter exists. The self-energy of electrons is
decomposed into the single-site and multisite self-energies. The calculation of
the single-site self-energy is mapped to a problem of self-consistently
determining and solving the Anderson model. When an electron reservoir is
explicitly considered, it is proved that the single-site self-energy is that of
a normal Fermi liquid even if the multisite self-energy is anomalous. Thus, the
ground state is a normal Fermi liquid in the supreme single-site approximation
(S^3A). In the strong-coupling regime, the Fermi liquid is stabilized by the
Kondo effect in the S^3A and is further stabilized by the Fock-type term of the
superexchange interaction or the resonating-valence-bond (RVB) mechanism beyond
the S^3A. The stabilized Fermi liquid is frustrated as much as an RVB spin
liquid in the Heisenberg model. It is a relevant unperturbed state that can be
used to study a normal or anomalous Fermi liquid and an ordered state in the
whole Hilbert space by Kondo lattice theory. Even if higher-order multisite
terms than the Fock-type term are considered, the ground state cannot be a Mott
insulator. It can be merely a gapless semiconductor even if the multisite
self-energy is so anomalous that it is divergent at the chemical potential. A
Mott insulator is only possible as a high temperature phase.Comment: 11 pages, no figur
Electronic control of coherence in a two-dimensional array of photonic crystal surface emitting lasers
We demonstrate a semiconductor PCSEL array that uniquely combines an in-plane waveguide structure with nano-scale patterned PCSEL elements. This novel geometry allows two-dimensional electronically controllable coherent coupling of remote vertically emitting lasers. Mutual coherence of the PCSEL elements is verified through the demonstration of a two-dimensional Young’s Slits experiment. In addition to allowing the all-electronic control of the interference pattern, this type of device offers new routes to power and brightness scaling in semiconductor lasers, and opportunities for all-electronic beam steering
An Inverse-Problem Approach to Designing Photonic Crystals for Cavity QED Experiments
Photonic band gap (PBG) materials are attractive for cavity QED experiments
because they provide extremely small mode volumes and are monolithic,
integratable structures. As such, PBG cavities are a promising alternative to
Fabry-Perot resonators. However, the cavity requirements imposed by QED
experiments, such as the need for high Q (low cavity damping) and small mode
volumes, present significant design challenges for photonic band gap materials.
Here, we pose the PBG design problem as a mathematical inversion and provide an
analytical solution for a two-dimensional crystal. We then address a planar (2D
crystal with finite thickness) structure using numerical techniques.Comment: 12 pages, 8 figures, preprint available from
http://minty.caltech.edu/MabuchiLa
Cognitive loading affects motor awareness and movement kinematics but not locomotor trajectories during goal-directed walking in a virtual reality environment.
The primary purpose of this study was to investigate the effects of cognitive loading on movement kinematics and trajectory formation during goal-directed walking in a virtual reality (VR) environment. The secondary objective was to measure how participants corrected their trajectories for perturbed feedback and how participants' awareness of such perturbations changed under cognitive loading. We asked 14 healthy young adults to walk towards four different target locations in a VR environment while their movements were tracked and played back in real-time on a large projection screen. In 75% of all trials we introduced angular deviations of ±5° to ±30° between the veridical walking trajectory and the visual feedback. Participants performed a second experimental block under cognitive load (serial-7 subtraction, counter-balanced across participants). We measured walking kinematics (joint-angles, velocity profiles) and motor performance (end-point-compensation, trajectory-deviations). Motor awareness was determined by asking participants to rate the veracity of the feedback after every trial. In-line with previous findings in natural settings, participants displayed stereotypical walking trajectories in a VR environment. Our results extend these findings as they demonstrate that taxing cognitive resources did not affect trajectory formation and deviations although it interfered with the participants' movement kinematics, in particular walking velocity. Additionally, we report that motor awareness was selectively impaired by the secondary task in trials with high perceptual uncertainty. Compared with data on eye and arm movements our findings lend support to the hypothesis that the central nervous system (CNS) uses common mechanisms to govern goal-directed movements, including locomotion. We discuss our results with respect to the use of VR methods in gait control and rehabilitation
- …