5,324 research outputs found
The ultra-sensitive electrical detection of spin Rabi oscillation at paramagnetic defects
A short review of the pulsed electrically detected magnetic resonance (pEDMR)
experiment is presented. PEDMR allows the highly sensitive observation of
coherent electron spin motion of charge carriers and defects in semiconductors
by means of transient current measurements. The theoretical foundations, the
experimental implementation, its sensitivity and its potential with regard to
the investigation of electronic transitions in semiconductors are discussed.
For the example of the P_b center at the crystalline silicon (111) to silicon
dioxide interface it is shown experimentally how one can detect spin
Rabi-oscillation, its dephasing, coherence decays and spin-coupling effects.Comment: The manuscript has been submitted for journal publicatio
The monopoly benchmark on two-sided markets
The literature on the effects of market concentration in platform industries or two-sided markets often compares the competitive outcome against a benchmark. This benchmark is either the âjoint managementâ solution in which one decision maker runs all platforms or a âpureâ monopoly with just one platform. Literature has not generally discussed, which benchmark is the appropriate one. We show that the appropriate benchmark, i.e. how many platforms the monopolist will operate, depends on whether agents multi- or singlehome, whether the externalities are positive or negative, and in some cases on the properties of the demand functions. Different situations require different benchmarks. Our results also help to anticipate the effects of proposed platform mergers, where the assessment might crucially depend on the number of platforms after a merger.two-sided markets; market concentration; monopoly
The sound of trustworthiness: acoustic-based modulation of perceived voice personality
When we hear a new voice we automatically form a "first impression" of the voice ownerâs
personality; a single word is sufficient to yield ratings highly consistent across listeners. Past
studies have shown correlations between personality ratings and acoustical parameters of
voice, suggesting a potential acoustical basis for voice personality impressions, but its
nature and extent remain unclear. Here we used data-driven voice computational modelling
to investigate the link between acoustics and perceived trustworthiness in the single word
"hello". Two prototypical voice stimuli were generated based on the acoustical features of
voices rated low or high in perceived trustworthiness, respectively, as well as a continuum
of stimuli inter- and extrapolated between these two prototypes. Five hundred listeners
provided trustworthiness ratings on the stimuli via an online interface. We observed an
extremely tight relationship between trustworthiness ratings and position along the trustworthiness
continuum (r = 0.99). Not only were trustworthiness ratings higher for the high- than
the low-prototypes, but the difference could be modulated quasi-linearly by reducing or
exaggerating the acoustical difference between the prototypes, resulting in a strong
caricaturing effect. The f0 trajectory, or intonation, appeared a parameter of particular relevance:
hellos rated high in trustworthiness were characterized by a high starting f0 then a
marked decrease at mid-utterance to finish on a strong rise. These results demonstrate a
strong acoustical basis for voice personality impressions, opening the door to multiple
potential applications
APPR Teacher Appeals Process Report
[Excerpt] The Annual Professional Performance Review (APPR) is the new teacher evaluation system adopted by New York State in 2012. Through APPR, each New York State teacherâs performance is evaluated annually. If a teacher is rated Ineffective, he or she must take part in a Teacher Improvement Plan (TIP). If a teacher is rated Ineffective for two consecutive years, the teacher may be dismissed even if that teacher has tenure. Given these potential consequences, the ability to appeal APPR ratings and how those ratings are conducted has been a major issue for teachers and their unions. Under New York Education Law 3012-c, which establishes APPR, each school district negotiates its own APPR procedure with its local teachers union, including any procedures for appealing the performance review. This report examines the APPR appeals procedures established by school districts in order to investigate the following: Which aspects of the APPR process can teachers appeal? Who has the fi nal say in that appeals process? How much time do appeals processes take? Can teachers appeal APPR issues through the regular contractual grievance-arbitration procedure? This report addresses these questions by analyzing APPR appeal procedures for all New York State school districts. The data analyzed was gathered by coding the provisions of the APPR appeal procedures, which are publicly available on the New York State Department of Education website (1)
Electrical rotary joint apparatus for large space structures
A structural array and electrical rotary joint for transmitting an electrical power between large space structures having relative rotational movement is disclosed which includes large support framework structures which rotate relative to one another about a common axis of rotation. A rotary interface joint is defined between the structures. A cylindrical hub member is carried by one structure and a cylindrical hub member is carried by a support structure with a third hub member being concentrically within a fourth hub member for relative rotation. Tension connecting cables connect hub members with their associated outer structures whereby relative rotational movement between the structures is transmitted to the cylindrical hub members for unitary motion therewith. Electrical conductor brush members are carried by one hub and electrical contact rings are carried by another hub member in sliding electrical contact with the brushes for transmission of electrical power during relative rotational movement between the two support structures
Transport and recombination through weakly coupled localized spin pairs in semiconductors during coherent spin excitation
Semi-analytical predictions for the transients of spin-dependent transport
and recombination rates through localized states in semiconductors during
coherent electron spin excitation are made for the case of weakly spin-coupled
charge carrier ensembles. The results show that the on-resonant Rabi frequency
of electrically or optically detected spin-oscillation doubles abruptly as the
strength of the resonant microwave field gamma B_1 exceeds the Larmor frequency
separation within the pair of charge carrier states between which the transport
or recombination transition takes place. For the case of a Larmor frequency
separation of the order of gamma B_1 and arbitrary excitation frequencies, the
charge carrier pairs exhibit four different nutation frequencies. From the
calculations, a simple set of equations for the prediction of these frequencies
is derived
Fishing for drifts : detecting buoyancy changes of a top marine predator using a step-wise filtering method
This research was partly funded by a Natural Environment Research Council grant [NE/E018289/1]. Further, a PhD studentship in Marine Biology partially funded by the Natural Environment Research Council [NE/L501852/1] and the University of St Andrews 600th Scholarship supported this work.In southern elephant seals (Mirounga leonina), fasting and foraging related fluctuations in body composition are reflected by buoyancy changes which can be monitored by changes in drift rate. Here, we present an improved knowledge-based method for detecting buoyancy changes from compressed and abstracted dive profiles received through telemetry. We applied this step-wise filtering method to the dive records of 11 southern elephant seals, which identified 0.8% to 2.2% of all dives as drift dives. At the beginning of the migration, all individuals were strongly negatively buoyant. Over the following 75 to 150 days, the buoyancy reached a peak close to or at neutral buoyancy, indicative of a sealâs foraging success. Ground-truthing confirmed that this new knowledge-based method is capable to reliably detect buoyancy changes in the dive records of drift diving species using abstracted dive profiles. This affirms that the abstraction algorithm conveys sufficient detail of the geometric shape of drift dives for them to be identified. It also suggest that using this step-wise filtering method, buoyancy changes could be detected even in old datasets with compressed dive information, for which conventional drift dive classification previously failed.Publisher PDFPeer reviewe
New York State Teacher Salary Report
Teachers are central to the success of any education system and the salaries paid to teachers are among the most important issues for both school districts and the unions that represent teachers. For school districts, teacher salaries are a major com- ponent of district budgets. Teacher salary levels are also a crucial factor in attracting and retaining quality educators. This report presents data on teacher salary levels based on teacher contracts throughout New York State. In addition to reporting overall statewide salary levels, it also documents the wide variation in teacher salary levels across New York State.
This New York State Teacher Salary Report was prepared by the Bargaining for Better Schools (BBS) project, which is an initiative of the ILR School at Cornell University through the Scheinman Institute on Conflict Resolution and the Worker Institute.
The data provided in this report comes from an analysis of the teacher contracts from every school district in the State of New York. The database of information came from two sources, both of which are publicly available on websites: DigitalCommons at ILR and SeeThroughNY, each of which contain the full text of teacher contracts, i.e. collective bargaining agreements and asso- ciated memoranda of understanding. The most recent contract from either website was selected for inclusion in this data
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