219 research outputs found
How Systems Analysts Can Provide More Effective Assistance to the Policy Maker
Policy makers do not benefit from advances in (a) systems analysis or (b) judgement and decision theory because neither of these disciplines recognize the incompleteness of its methodology. A complete methodology requires a synthesis of the two. This RM explains why such a synthesis is necessary, describes how it can be achieved, and provides a worked-out example of its application to the problem of changing sources of energy production in the US. The example also illustrates that the linkage of systems analysis and judgement theory provides information that neither discipline can provide separately. Finally, the RM shows that such information is policy relevant and that it provides more effective assistance to the policy maker than does either approach used separately
An energy vision for a planet under pressure
Worldwide, global energy systems face an array of challenges, from access for the poor to reliability and security. Meanwhile, the provision of energy creates local human and ecological health impacts as well as dangerous global climate change. Addressing these issues simultaneously will require a fundamental transformation of the energy system. Recent assessments show that such a transformation is achievable in technological and economic terms, but it will present formidable supply- and demand-side challenges as well as problems of governance, transparency and reliability across scales.
This policy brief presents a long-term vision for the energy system and describes the elements required for the transition towards this vision. To succeed, this transformation must integrate several key components, including a focus on high levels of energy efficiency and the scale up of investments in technology deployment as well as research, development and demonstration (RD&D)
Wavelets and graph -algebras
Here we give an overview on the connection between wavelet theory and
representation theory for graph -algebras, including the higher-rank
graph -algebras of A. Kumjian and D. Pask. Many authors have studied
different aspects of this connection over the last 20 years, and we begin this
paper with a survey of the known results. We then discuss several new ways to
generalize these results and obtain wavelets associated to representations of
higher-rank graphs. In \cite{FGKP}, we introduced the "cubical wavelets"
associated to a higher-rank graph. Here, we generalize this construction to
build wavelets of arbitrary shapes. We also present a different but related
construction of wavelets associated to a higher-rank graph, which we anticipate
will have applications to traffic analysis on networks. Finally, we generalize
the spectral graph wavelets of \cite{hammond} to higher-rank graphs, giving a
third family of wavelets associated to higher-rank graphs
The influence of individual cognitive style on performance in management education
This paper reports the outcomes of an empirical study undertaken to explore the possibility that cognitive style may be an important factor influencing performance on certain types of task in management education. Four hundred and twelve final-year undergraduate degree students studying management and business administration were tested using the Allinson-Hayes Cognitive Style Index. Their cognitive styles were then compared with assessment grades achieved for academic modules, the task categories of which were deemed to be consonant with either the wholist/intuitive or the analytic style of working. Overall ability defined by final degree grades was also tested against individuals’ cognitive styles. As expected, students whose dominant cognitive styles were analytic attained higher grades for long term solitary tasks involving careful planning and analysis of information. However, contrary to expectations, performance on tasks believed to be more suited to the wholist/intuitive style was also higher for analytic individuals, as was overall ability defined by final degree grades. The results were discussed in terms of the nature of the tasks and the need for methods of performance assessment that are independent of an orientation bias. Without this, it is argued, employment selection criteria may favour the wrong type of candidate in some circumstances
Outcome Feedback Effects on Risk Propensity in an MCPLP Task
In this experimental analysis, the effects of outcome feedback on risk propensity were assessed within the multiple-cue-probability-learning-paradigm (MCPLP). The individual decision maker in this task received outcome feedback on a decision-by-decision basis. It was hypothesized that information on his/her success or lack of success (outcome feedback) on each decision would influence the decision to risk (commit) resources. Hierarchical regression results revealed that after all other performance effects had been partialled out, current outcome feedback explained much of the commitment decision.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data
Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signal-to-noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars over a fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of 11 pulsars using data from Advanced LIGO's first observing run. Although we have found several initial outliers, further studies show no significant evidence for the presence of a gravitational wave signal. Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for the first time. For an additional 3 targets, the median upper limit across the search bands is below the spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried out so far. © 2017 American Physical Society
Search for intermediate mass black hole binaries in the first observing run of Advanced LIGO
During their first observational run, the two Advanced LIGO detectors attained an unprecedented sensitivity, resulting in the first direct detections of gravitational-wave signals produced by stellar-mass binary black hole systems. This paper reports on an all-sky search for gravitational waves (GWs) from merging intermediate mass black hole binaries (IMBHBs). The combined results from two independent search techniques were used in this study: the first employs a matched-filter algorithm that uses a bank of filters covering the GW signal parameter space, while the second is a generic search for GW transients (bursts). No GWs from IMBHBs were detected; therefore, we constrain the rate of several classes of IMBHB mergers. The most stringent limit is obtained for black holes of individual mass 100 M, with spins aligned with the binary orbital angular momentum. For such systems, the merger rate is constrained to be less than 0.93 Gpc-3 yr-1 in comoving units at the 90% confidence level, an improvement of nearly 2 orders of magnitude over previous upper limits. © 2017 American Physical Society
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