2,503 research outputs found
Rebooting Content: Broadcasting Sport and Esports to Homes During COVID-19
Beginning in early March 2020, sport in the United States entered an unprecedented period of hiatus due to the COVID-19 pandemic. The postponement, suspension, and cancellation of live sporting events impacted every professional and amateur sport organization, from the National Basketball Association to the National Association for Stock Car Auto Racing, high school sports to college football, and even esports leagues. Although the abrupt cancellation of live sporting events was disruptive, it did create opportunities for the production of new media and consumption opportunities for sport leagues, teams, and their fans through different types of sport media broadcasts. This commentary examines how the U.S. sport industry developed media content strategies using new, mixed, and rebroadcasted content, across multiple broadcast and streaming platforms, to provide sport consumption opportunities to fans who were largely quarantined at home. This research contributes to the existing scholarship on live and rebroadcasted mediated content, while providing guidance to content owners and rights holders facing uncertainty in the marketplace
On Factor Universality in Symbolic Spaces
The study of factoring relations between subshifts or cellular automata is
central in symbolic dynamics. Besides, a notion of intrinsic universality for
cellular automata based on an operation of rescaling is receiving more and more
attention in the literature. In this paper, we propose to study the factoring
relation up to rescalings, and ask for the existence of universal objects for
that simulation relation. In classical simulations of a system S by a system T,
the simulation takes place on a specific subset of configurations of T
depending on S (this is the case for intrinsic universality). Our setting,
however, asks for every configurations of T to have a meaningful interpretation
in S. Despite this strong requirement, we show that there exists a cellular
automaton able to simulate any other in a large class containing arbitrarily
complex ones. We also consider the case of subshifts and, using arguments from
recursion theory, we give negative results about the existence of universal
objects in some classes
Cellular automata and Lyapunov exponents
In this article we give a new definition of some analog of Lyapunov exponents
for cellular automata . Then for a shift ergodic and cellular automaton
invariant probability measure we establish an inequality between the entropy of
the automaton, the entropy of the shift and the Lyapunov exponent
Compact, Deep-Penetrating Geothermal Heat Flow Instrumentation for Lunar Landers
Geothermal heat flow is obtained as a product of the two separate measurements of geothermal gradient in, and thermal conductivity of, the vertical soi/rock/regolith interval penetrated by the instrument. Heat flow measurements are a high priority for the geophysical network missions to the Moon recommended by the latest Decadal Survey [I] and previously the International Lunar Network [2]. The two lunar-landing missions planned later this decade by JAXA [3] and ESA [4] also consider geothermal measurements a priority
The organisational and human resource challenges facing primary care trusts : protocol of a multiple case study
BACKGROUND: The study is designed to assess the organisational and human resource challenges faced by Primary Care Trusts (PCTs). Its objectives are to: specify the organisational and human resources challenges faced by PCTs in fulfilling the roles envisaged in government and local policy; examine how PCTs are addressing these challenges, in particular, to describe the organisational forms they have adopted, and the OD/HR strategies and initiatives they have planned or in place; assess how effective these structures, strategies and initiatives have been in enabling the PCTs to meet the organisational and human resources challenges they face; identify the factors, both internal to the PCT and in the wider health community, which have contributed to the success or failure of different structures, strategies and initiatives. METHODS: The study will be undertaken in three stages. In Stage 1 the key literature on public sector and NHS organisational development and human resources management will be reviewed, and discussions will be held with key researchers and policy makers working in this area. Stage 2 will focus on detailed case studies in six PCTs designed to examine the organisational and human resources challenges they face. Data will be collected using semi-structured interviews, group discussion, site visits, observation of key meetings and examination of local documentation. The findings from the case study PCTs will be cross checked with a Reference Group of up to 20 other PCG/Ts, and key officers working in organisational development or primary care at local, regional and national level. In Stage 3 analysis of findings from the preparatory work, the case studies and the feedback from the Reference Group will be used to identify practical lessons for PCTs, key messages for policy makers, and contributions to further theoretical development
Applying causality principles to the axiomatization of probabilistic cellular automata
Cellular automata (CA) consist of an array of identical cells, each of which
may take one of a finite number of possible states. The entire array evolves in
discrete time steps by iterating a global evolution G. Further, this global
evolution G is required to be shift-invariant (it acts the same everywhere) and
causal (information cannot be transmitted faster than some fixed number of
cells per time step). At least in the classical, reversible and quantum cases,
these two top-down axiomatic conditions are sufficient to entail more
bottom-up, operational descriptions of G. We investigate whether the same is
true in the probabilistic case. Keywords: Characterization, noise, Markov
process, stochastic Einstein locality, screening-off, common cause principle,
non-signalling, Multi-party non-local box.Comment: 13 pages, 6 figures, LaTeX, v2: refs adde
Development of a Compact, Deep-Penetrating Heat Flow Instrument for Lunar Landers: In-Situ Thermal Conductivity System
Geothermal heat flow is obtained as a product of the geothermal gradient and the thermal conductivity of the vertical soil/rock/regolith interval penetrated by the instrument. Heat flow measurements are a high priority for the geophysical network missions to the Moon recommended by the latest Decadal Survey and previously the International Lunar Network. One of the difficulties associated with lunar heat flow measurement on a robotic mission is that it requires excavation of a relatively deep (approx 3 m) hole in order to avoid the long-term temporal changes in lunar surface thermal environment affecting the subsurface temperature measurements. Such changes may be due to the 18.6-year-cylcle lunar precession, or may be initiated by presence of the lander itself. Therefore, a key science requirement for heat flow instruments for future lunar missions is to penetrate 3 m into the regolith and to measure both thermal gradient and thermal conductivity. Engineering requirements are that the instrument itself has minimal impact on the subsurface thermal regime and that it must be a low-mass and low-power system like any other science instrumentation on planetary landers. It would be very difficult to meet the engineering requirements, if the instrument utilizes a long (> 3 m) probe driven into the ground by a rotary or percussive drill. Here we report progress in our efforts to develop a new, compact lunar heat flow instrumentation that meets all of these science and engineering requirements
Improved Data Reduction Algorithm for the Needle Probe Method Applied to In-Situ Thermal Conductivity Measurements of Lunar and Planetary Regoliths
The needle probe method (also known as the' hot wire' or 'line heat source' method) is widely used for in-situ thermal conductivity measurements on soils and marine sediments on the earth. Variants of this method have also been used (or planned) for measuring regolith on the surfaces of extra-terrestrial bodies (e.g., the Moon, Mars, and comets). In the near-vacuum condition on the lunar and planetary surfaces, the measurement method used on the earth cannot be simply duplicated, because thermal conductivity of the regolith can be approximately 2 orders of magnitude lower. In addition, the planetary probes have much greater diameters, due to engineering requirements associated with the robotic deployment on extra-terrestrial bodies. All of these factors contribute to the planetary probes requiring much longer time of measurement, several tens of (if not over a hundred) hours, while a conventional terrestrial needle probe needs only 1 to 2 minutes. The long measurement time complicates the surface operation logistics of the lander. It also negatively affects accuracy of the thermal conductivity measurement, because the cumulative heat loss along the probe is no longer negligible. The present study improves the data reduction algorithm of the needle probe method by shortening the measurement time on planetary surfaces by an order of magnitude. The main difference between the new scheme and the conventional one is that the former uses the exact mathematical solution to the thermal model on which the needle probe measurement theory is based, while the latter uses an approximate solution that is valid only for large times. The present study demonstrates the benefit of the new data reduction technique by applying it to data from a series of needle probe experiments carried out in a vacuum chamber on JSC-1A lunar regolith stimulant. The use of the exact solution has some disadvantage, however, in requiring three additional parameters, but two of them (the diameter and the volumetric heat capacity of the probe) can be measured and the other (the volumetric heat capacity of the regolith/stimulant) may be estimated from the surface geologic observation and temperature measurements. Therefore, overall, the new data reduction scheme would make in-situ thermal conductivity measurement more practical on planetary missions
Development of Compact, Modular Lunar Heat Flow Probes
Geothermal heat flow measurements are a high priority for the future lunar geophysical network missions recommended by the latest Decadal Survey and previously the International Lunar Network. Because the lander for such a mission will be relatively small, the heat flow instrumentation must be a low-mass and low-power system. The instrument needs to measure both thermal gradient and thermal conductivity of the regolith penetrated. It also needs to be capable of excavating a deep enough hole (approx. 3 m) to avoid the effect of potential long-term changes of the surface thermal environment. The recently developed pneumatic excavation system can largely meet the low-power, low-mass, and the depth requirements. The system utilizes a stem which winds out of a pneumatically driven reel and pushes its conical tip into the regolith. Simultaneously, gas jets, emitted from the cone tip, loosen and blow away the soil. The thermal sensors consist of resistance temperature detectors (RTDs) embedded on the stem and an insitu thermal conductivity probe attached to the cone tip. The thermal conductivity probe consists of a short 'needle' (2.4-mm diam. and 15- to 20-mm length) that contains a platinum RTD wrapped in a coil of heater wire. During a deployment, when the penetrating cone reaches a desired depth, it stops blowing gas, and the stem pushes the needle into the yet-to-be excavated, undisturbed bottom soil. Then, it begins heating and monitors the temperature. Thermal conductivity of the soil can determined from the rate of temperature increase with time. When the measurement is complete, the system resumes excavation until it reaches the next targeted depth
Limiting modular symbols and their fractal geometry
In this paper we use fractal geometry to investigate boundary aspects of the
first homology group for finite coverings of the modular surface. We obtain a
complete description of algebraically invisible parts of this homology group.
More precisely, we first show that for any modular subgroup the geodesic
forward dynamic on the associated surface admits a canonical symbolic
representation by a finitely irreducible shift space. We then use this
representation to derive an `almost complete' multifractal description of the
higher--dimensional level sets arising from Manin--Marcolli's limiting modular
symbols.Comment: 20 pages, 1 figur
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