3,832 research outputs found
Variable elimination for building interpreters
In this paper, we build an interpreter by reusing host language functions
instead of recoding mechanisms of function application that are already
available in the host language (the language which is used to build the
interpreter). In order to transform user-defined functions into host language
functions we use combinatory logic : lambda-abstractions are transformed into a
composition of combinators. We provide a mechanically checked proof that this
step is correct for the call-by-value strategy with imperative features.Comment: 33 page
WIMP searches with gamma rays in the Fermi era: challenges, methods and results
The launch of the gamma-ray telescope Fermi Large Area Telescope (Fermi-LAT)
started a pivotal period in indirect detection of dark matter. By outperforming
expectations, for the first time a robust and stringent test of the paradigm of
weakly interacting massive particles (WIMPs) is within reach. In this paper, we
discuss astrophysical targets for WIMP detection and the challenges they
present, review the analysis tools which have been employed to tackle these
challenges, and summarize the status of constraints on and the claimed
detections in the WIMP parameter space. Methods and results will be discussed
in comparison to Imaging Air Cherenkov Telescopes. We also provide an outlook
on short term and longer term developments.Comment: 72 pages, 7 figures, Invited review for Journal of Experimental and
Theoretical Physics,v3: added a few references, addressed referee comment
The Approach: A Promise of Warmth Inside
Walking up those stairs is always a treat. The tacit knowledge that you are moving towards a hidden gem: a space most don’t know to find. Salt water, wood smoke, and roasted coffee perfume the air. But the best part of all is the intention. This is not a space to go to out of necessity or convenience. This is a space for slow sips and long reprieves.
This thesis explores many themes, but at the heart is the idea of The Approach: how we come to an object is just as important as the actual moment when we meet the object. The Approach pulls the outside world in, building opportunities for solace. Woven into the core of this research is the theme of tension in harmony: contrast that creates a sum greater than its parts. I seek to better understand how to harness balance in opposition. I search for moments on the stairs, when the promise of warmth beckons from just around the corner
Conceptions of headteachers concerning their role
The study is an exploration of the role conceptions of headteachers for various aspects of their work with pupils, teachers and parents, and the expectations that heads believe teachers and parents hold for the role of the head as school leader.
A Headteacher Role Definition Instrument (HRDI) was constructed with the assistance of headteachers and tested. It was completed by a national sample of Infant, Junior and Secondary school headteachers from schools throughout England and Wales.
In the first part of the study, the interpositional analysis, a number of hypotheses were tested in connection with the relationship between situational factors (the type, the size, and the location of schools) end personal factors (the age and the sex of their incumbents) and head teachers' role conceptions.
In the initial section of the second part of the study, the phenomenological analysis, each of eleven headteacher groups was examined separately on each item of the HRDI to ascertain the pattern of relationships between head teachers' role conceptions and their attributed expectations to teachers and to parents. A typology of nine perceived role type situations was deduced.
In the final section of the second part of the study, an adequate stimulus weighting criterion was introduced by which to identify 44 HRDI items on which headteachers—in-general held common phenomenological perceptions. Ihe head teacher's world was described by reference to the typology of role type situations and the 44 items of headteacher behaviour.
In the interpositional analysis, hypotheses which related the type and the size of the school to the role conceptions of their headteachÂers were supported. So, also, were hypotheses concerning relationships between age, sex, end headteachers' role conceptions. A null hypothesis in respect of the location of schools and the role conceptions of their headteachers was not rejected.
In the phenomenological analysis, the headteacher was described as the occupant of a boundary position which served as a point of articulaÂtion between the internal and external systems of the school.
Headteachers' mandatory role conceptions were directed primarily towards the internal system of the school and were marked by high consensual agreement among heads themselves and, so they believed, among teachers and parents.
Those items of headteacher behaviour which articulated the internal and external systems of the school were generally marked by less consensual agreement both actual and attributed, and were identified as potentially -
conflictful for headteachers.
The commonest source of such conflict was held to arise out of headteachers' perceptions of the incompatibility of teacher expectations for professional autonomy and boundary maintenance and parent expectations for representation and influence in specific aspects of the school's affairs.
The findings reported here are suggested as useful basic material content for lecture, seminar, and simulation techniques in connection with courses concerned with the in-service training of head teachers
A Biography of the Second Justice Harlan
A Review of John Marshall: Great Dissenter of the Warren Court by Tinsley E. Yarbroug
Democracy as Civic Conversation: Book Review Of: Talking It Through: Puzzles of American Democracy. by Robert W. Bennett
Book review of: Talking It Through: Puzzles of American Democracy. By Robert W. Bennett. Cornell University Press. Pp. 223. Reviewed by: Louis R. Cohen
Democracy as Civic Conversation: Book Review Of: Talking It Through: Puzzles of American Democracy. by Robert W. Bennett
Book review of: Talking It Through: Puzzles of American Democracy. By Robert W. Bennett. Cornell University Press. Pp. 223. Reviewed by: Louis R. Cohen
The Potential of Synergistic Static, Dynamic and Speculative Loop Nest Optimizations for Automatic Parallelization
Research in automatic parallelization of loop-centric programs started with
static analysis, then broadened its arsenal to include dynamic
inspection-execution and speculative execution, the best results involving
hybrid static-dynamic schemes. Beyond the detection of parallelism in a
sequential program, scalable parallelization on many-core processors involves
hard and interesting parallelism adaptation and mapping challenges. These
challenges include tailoring data locality to the memory hierarchy, structuring
independent tasks hierarchically to exploit multiple levels of parallelism,
tuning the synchronization grain, balancing the execution load, decoupling the
execution into thread-level pipelines, and leveraging heterogeneous hardware
with specialized accelerators. The polyhedral framework allows to model,
construct and apply very complex loop nest transformations addressing most of
the parallelism adaptation and mapping challenges. But apart from
hardware-specific, back-end oriented transformations (if-conversion, trace
scheduling, value prediction), loop nest optimization has essentially ignored
dynamic and speculative techniques. Research in polyhedral compilation recently
reached a significant milestone towards the support of dynamic, data-dependent
control flow. This opens a large avenue for blending dynamic analyses and
speculative techniques with advanced loop nest optimizations. Selecting
real-world examples from SPEC benchmarks and numerical kernels, we make a case
for the design of synergistic static, dynamic and speculative loop
transformation techniques. We also sketch the embedding of dynamic information,
including speculative assumptions, in the heart of affine transformation search
spaces
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