Assumption Of Knowledge Research Articles

Constraining neutrino properties with a Euclid-like galaxy cluster survey

We perform a forecast analysis on how well a Euclid-like photometric galaxy cluster survey will constrain the total neutrino mass and effective number of neutrino species. We base our analysis on the Monte Carlo Markov Chains technique by combining information from cluster number counts and cluster power spectrum. We find that combining cluster data with Cosmic Microwave Background (CMB) measurements from Planck improves by more than an order of magnitude the constraint on neutrino masses compared to each probe used independently. For the ΛCDM+mν model the 2σ upper limit on total neutrino mass shifts from ∑mν < 0.35 eV using cluster data alone to ∑mν < 0.031 eV when combined with Planck data. When a non-standard scenario with Neff≠3.046 number of neutrino species is considered, we estimate an upper limit of Neff < 3.14 (95%CL), while the bounds on neutrino mass are relaxed to ∑mν < 0.040 eV. This accuracy would be sufficient for a 2σ detection of neutrino mass even in the minimal normal hierarchy scenario (∑mν ≃ 0.05 eV). In addition to the extended ΛCDM+mν+Neff model we also consider scenarios with a constant dark energy equation of state and a non-vanishing curvature. When these models are considered the error on ∑mν is only slightly affected, while there is a larger impact of the order of ∼ 15% and ∼ 20% respectively on the 2σ error bar of Neff with respect to the standard case. To assess the effect of an uncertain knowledge of the relation between cluster mass and optical richness, we also treat the ΛCDM+mν+Neff case with free nuisance parameters, which parameterize the uncertainties on the cluster mass determination. Adopting the over-conservative assumption of no prior knowledge on the nuisance parameter the loss of information from cluster number counts leads to a large degradation of neutrino constraints. In particular, the upper bounds for ∑mν are relaxed by a factor larger than two, ∑mν < 0.083 eV (95%CL), hence compromising the possibility of detecting the total neutrino mass with good significance. We thus confirm the potential that a large optical/near-IR cluster survey, like that to be carried out by Euclid, could have in constraining neutrino properties, and we stress the importance of a robust measurement of masses, e.g. from weak lensing within the Euclid survey, in order to full exploit the cosmological information carried by such survey.

Toll Competition and Dynamic Toll-Setting Strategies

ABSTRACT Private toll operators generally seek to maximize their profit while accounting for the re-routing and demand response of the road users and, in the case of competitive toll operation, the response of other toll operators. Traditionally, the literature assumes that toll operators act under perfect information or set up a game-theoretic approach to find the competitive equilibrium. This article takes a different approach. A system-dynamics approach is used to model both the users' route choice and demand response to changes in generalized cost and to model the toll operators' decision rules or toll-update strategies. Simple examples are used to demonstrate that the approach can lead to the traditional equilibrium solution under the assumption of perfect knowledge, but that other solutions may occur when operators use estimates of elasticities based on observed data. The solutions are shown to depend upon the frequency of the decision or change in toll level, and errors are related to the disequilibrium which is present as users respond to changes in toll levels. Finally, alternative toll-setting strategies are investigated whereby one operator may act aggressively to increase its share of the market while maximizing profit. This tactic is compared to the traditional Nash and Stackelberg solutions.

Performing POZ: Irish Theatre, HIV Stigma, and ‘Post-AIDS’ Identities

This essay interrogates how the theatre of Queer monologist Neil Watkins challenges HIV-stigma, while simultaneously reconciling his Queerness and HIV-positivity with a sense of Irishness. The development of life-saving drugs for the treatment of HIV means that, in certain parts of the world, including Ireland, people are no longer dying from AIDS, but living with HIV. This has given rise to what cultural commentators call a ‘Post-AIDS’ discourse, whereby a discourse of crisis and death has evolved into one of health and typical life expectancy. In terms of being ‘post-AIDS’, Ireland bifurcates into two paradoxical socio-cultural discourses: that of HIV as a medical event, and that of AIDS as a cultural narrative. And while the discourse surrounding HIV the medical event is progressive and democratic, the cultural narrative of AIDS in Ireland is steeped in stigma, ignorance, and contagion paranoia. This damaging narrative is mirrored and embodied in Irish theatre. Interrogating Irish theatre's contentious relationship with the HIV-positive body reveals persistent themes of absence, hiddenness, illness, and death. Neil Watkins disrupts this dramaturgy of shame by mobilizing HIV-stigma to political effect, disrupting received knowledge and cultural assumptions about the HIV-positive body and its current theatrical placement within an anachronistic discourse of crisis. In earlier monologues such as A Cure for Homosexuality (2005) Watkins blurs the lines between the fictional HIV-positive character and the living performer, engendering a troubling tension for the spectator. With his latest work, The Year of Magical Wanking (2010) Watkins further evolves this space whereby the boundaries between character and performer are completely negated. By journeying through Watkins's ‘magical’ year of quotidian HIV-stigma and sexual shame, the spectator discovers the roots of such shame and stigma are not only embedded in Irish socio-political structures, but also in a limiting and narrow heteronormative sexual imaginary.

Degrees of Freedom for the Two-Cell Two-Hop MIMO Interference Channel: Interference-Free Relay Transmission and Spectrally Efficient Relaying Protocol

This paper considers the two-cell two-hop multiple-input-multiple-output (MIMO) interference channel, where two source groups consisting of multiple users with a single antenna wish to communicate with two multiantenna destinations by sharing two multiantenna relays. For such a channel, an inner bound on the degrees of freedom is derived for different channel knowledge assumptions and relay operations. Assuming global channel knowledge at the relays and full-duplex relay operation, it is shown that two cascaded interfering links can be decomposed into two independent parallel relay channels while sharing the spectrum. The key to showing this result is a novel amplify-and-forward interference-free relay transmission method, which performs interference-shaping during reception and interference neutralization during transmission. Assuming that the relays have global channel knowledge only for the first hop, a spectrally efficient relaying protocol is proposed that overcomes the loss due to half-duplex relaying constraint. The proposed protocol improves performance compared to a trivial time-division-multiple access method for the two-cell two-hop MIMO interference channel.

On the structure of rationalizability for arbitrary spaces of uncertainty

Weinstein and Yildiz (2007) show that only very weak predictions are robust to misspecifications of higher order beliefs. Whenever a type has multiple rationalizable actions, any of these actions is uniquely rationalizable for some arbitrarily close type. Hence, refinements of rationalizability are not robust. This negative result is obtained under a richness condition, which essentially means that all common knowledge assumptions on payoffs are relaxed. In many settings, this condition entails an unnecessarily demanding robustness test. It is, therefore, natural to explore the structure of rationalizability when arbitrary common knowledge assumptions are relaxed (i.e., without assuming richness). For arbitrary spaces of uncertainty and for every player i, I construct a set A ∞ of actions that are uniquely rationalizable for some hierarchy of beliefs. The main result shows that for any type ti and any action ai rationalizable for ti ,i fai belongs to A ∞ and is justified by conjectures concentrated on A ∞ , then there exists a sequence of types converging to ti for which ai is uniquely rationalizable. This result significantly generalizes Weinstein and Yildiz’s. Some of its implications are discussed in the context of auctions and equilibrium refinements, and in connection with the literature on global games.

Low‐complexity symbol timing error detection for quasi‐orthogonal space–time block codes

The author presents the design and analysis of low-complexity symbol timing error detectors (TEDs) for timing synchronisation in quasi-orthogonal space-time block code (QOSTBC) receivers. The estimators operate on data symbols and approximate decision variables, producing timing error measurements which are shown to be robust to channel fading. In evaluating the detector S-curve for the general form of the estimator, the author shows that the result is independent of the constellation rotation angle employed by the code. The expressions for the estimation error variance and TED signal-to-noise ratio are also obtained, with the analysis carried out under the assumptions of perfect data and channel knowledge at the receiver. Through system simulations, the effects of decision errors on the detector characteristics are examined, and the overall system performance is evaluated, where the proposed TEDs are incorporated into the receiver timing loop. Receivers with perfect channel knowledge and pilot-based channel estimation are considered. Symbol error rate results show timing synchronisation loss of less than 0.5 dB for a receiver with perfect channel information. In addition, it is shown that the receiver is able to track the timing variations two orders of magnitude faster than required by the present-day hardware oscillators.

Spectral Correlation Based Blind Automatic Modulation Classification Using Symbol Rate Estimation

Automatic modulation classification (AMC) is an important function of radio surveillance systems in order to identify unknown signals. Many previous works on AMC have utilized signal cyclostationarity, particularly spectral correlation density (SCD), but many of them fail to address several implementation issues, such as the assumption of perfect knowledge of the symbol rate. In this paper, we discuss several practical issues, e.g. cyclic frequency mismatch, which may affect the SCD, and propose compensation techniques to overcome those issues. We also propose a novel feature extraction technique from the SCD, which utilizes the SCD of not only the original received signal, but also the squared received signal. A symbol rate estimation technique which complements the feature extraction is also proposed. Finally, the classification performance of the system is evaluated through Monte Carlo simulations using a wide variety of modulated signals, and simulation results show that the proposed technique can estimate the symbol rate and classify modulation with a probability of above 0.9 down to SNRs of 5dB.

Multiobjective Control of PEM Fuel Cell System With Improved Durability

A critical design goal of a fuel-cell-based renewable energy system in a smart grid scenario is to enable high efficiency while extending durability. This is particularly emphasized when the fuel-cell system becomes widely used. Towards this goal, the effort in this research paper is to develop multiobjective controllers to simultaneously realize both output tracking and durability improvement. More specifically, two types of controller are developed. With assumptions of knowledge of system parameters, the first controller enables exponentially stability of the closed-loop system. Then, with practical considerations of robustness, an adaptive extension of the first controller is developed, which is capable of handling possible mismatch between real parameters and parameters obtained from the manufacturer or system identification methods. The performance and stability is theoretically guaranteed by a Lyapunov-based proof. Together with theoretical analysis, several scenarios are considered and tested via Matlab/simulink-based simulation.

Asymmetric information and rationalizability

We study how asymmetric information affects the set of rationalizable solutions in a linear setup where the outcome is determined by forecasts about this same outcome. The unique rational expectations equilibrium is also the unique rationalizable solution when the sensitivity of the outcome to agents’ forecasts is less than one, provided that this sensitivity is common knowledge. Relaxing this common knowledge assumption, multiple rationalizable solutions arise when the proportion of agents who know the sensitivity is large, and the uninformed agents believe it is possible that the sensitivity is greater than one. Instability is equivalent to existence of some kind of sunspot equilibria.

Bartlett's schema theory: The unreplicated “portrait d'homme” series from 1932

In 1932, Frederic Bartlett laid the foundation for the later schema theory. His key assumption of previous knowledge affecting the processing of new stimuli was illustrated in the famous "portrait d'homme" series. Sequenced reproductions of ambiguous stimuli showed progressive object-likeness. As Bartlett pointed out, activation of specific schemata, for instance "the face schema", biases memory retrieval towards such schemata. In five experiments (Experiment 1, n = 53; Experiment 2, n = 177; Experiment 3, n = 36; Experiment 4, n = 6; Experiment 5, n = 2), we tested several factors potentially influencing retrieval biases-for example, by varying the general procedure of reproduction (repeated vs. serial) and by omitting versus providing visual or semantic cues for activating face schemata. Participants inspected face-like stimuli with the caption "portrait of the human" and reproduced them repeatedly under specific conditions. None of the experiments revealed a systematic tendency towards Bartlett's described case, even when the participants were explicitly instructed to draw "a face" like the previously inspected one. In one of the "serial reproduction" experiments, we even obtained contrary effects with decreasing face-likeness over the reproduction generations. A close analysis of the original findings raises questions about the replicability of Bartlett's findings, qualifying the "portrait d'homme" series more or less as an illustrative example of the main idea of reconstructive memory.

Developing an Organizational Perspective to Management Accounting

B eing asked to make a short speech as part of accepting the award inevitably leads to some introspection and reflection on major factors that have influenced one’s career, be they events or individuals. Past recipients of the award have been very influential in putting management accounting on the map. Some have been instrumental in developing the way we think about management accounting and teach the subject; some have developed important perspectives such as information economics, combining economics with psychology, the importance of national culture, activity-based cost management, and balanced scorecards. The way these recipients developed their thoughts is well told in their acceptance speeches and collectively provides a wealth of ideas and a historical perspective on the development of our discipline. I commenced my studies in economics, and I maintain a keen interest in economic approaches to management accounting. However, early in my academic career, I was pressed into considering an organizational approach to management accounting, not because it was an easier option; rather it addressed the world of management accounting within which I found myself. In this address, I will share with you some personal reflections on the process of my discoveries in the area of organizational approaches to management accounting from the mid-1960s. The backdrop to this address is that research is something of a growth model. Stage 1: starting from a baseline of skills and knowledge gained at undergraduate studies; stage 2: progressing through refinement of skills with more graduate study; and stage 3: consolidating through work toward publications and other academic outputs. Stages 1 and 2 are somewhat planned and incremental, while stage 3 is more often associated with less ordered processes, often stumbling across potential research areas by way of reading and personal interactions. Research projects can be focused around existing ideas, sometimes being somewhat formulaic, sometimes highly innovative. Often ideas can be serendipitous and develop in unpredictable ways. The key is to recognize when there is a management accounting angle that will relate to an important organizational or social issue.

Can probability theory deal with entrepreneurship?

The Austrian theory of entrepreneurship emphasizes the importance of epistemic heterogeneity and the unlistability of the set of all possibilities. A similar concern with what has been called “the art of choosing the space of possibilities” is an important part of Bayesian model selection. Both Austrian and Bayesian authors view the common knowledge assumption as an unrealistic and unnecessary restriction. This coincidence of concerns leads to a joint theory of entrepreneurship. Three important benefits result from this merger: (1) the ability to use Itti & Baldi’s Bayesian theory of surprise to empirically measure radical surprise and improve the Betrand competition model as a consequence, (2) dealing with the unlistability problem, and (3) better understanding why the emergence of common knowledge is always the outcome of a social process rather than an inherent consequence of “rationality”.

On-line Support Vector Regression of the transition model for the Kalman filter

Recursive Bayesian Estimation (RBE) is a widespread solution for visual tracking as well as for applications in other domains where a hidden state is estimated recursively from noisy measurements. From a practical point of view, deployment of RBE filters is limited by the assumption of complete knowledge on the process and measurement statistics. These missing tokens of information lead to an approximate or even uninformed assignment of filter parameters. Unfortunately, the use of the wrong transition or measurement model may lead to large estimation errors or to divergence, even when the otherwise optimal filter is deployed. In this paper on-line learning of the transition model via Support Vector Regression is proposed. The specialization of this general framework for linear/Gaussian filters, which we dub Support Vector Kalman (SVK), is then introduced and shown to outperform a standard, non adaptive Kalman filter as well as a widespread solution to cope with unknown transition models such as the Interacting Multiple Models (IMM) filter.

Consent and the Use of the Bodies of the Dead

Gametes, tissue, and organs can be taken from the dying or dead for reproduction, transplantation, and research. Whole bodies as well as parts can be used for teaching anatomy. While these uses are diverse, they have an ethical consideration in common: the claims of the people whose bodies are used. Is some use permissible only when people have consented to the use, actually wanted the use, would have wanted the use, not opposed the use, or what? The aim of this article is to make progress in answering these questions. Initially I assume knowledge of people's desires in order to test whether consent is directly required by their rights without worrying about mistaken uses against their wishes. I claim consent is not directly required by people's rights. If we know people wanted or would want a use, their rights permit the use, but if we know they wanted or would want not to be used, their rights do not permit the use. The knowledge assumption is then dropped and the question becomes how to decide what to do when the wishes of rightholders are not known. I suggest working out what to do when wishes are known and then adjusting, on the basis of whatever evidence there is, for probability and strength of desire. There are other considerations too, for instance about default rules. The key general comment here is that, in setting rules, the costs to rightholders in not getting what they want needs to be taken into account. The final section tries to show that, in setting these rules, mistaken uses are not to be taken as worse than mistaken failure to use.

Preliminary Assessment of Knowledge Management in Universities

PurposeThis current study carried to the knowledge management, emphasizes in universities to create a dynamic work climate, and that will promotes further creation, assumption, storage and use of knowledge. Design/methodology/approachThe clearly and for uncertainty management of knowledge through distribution and warehouse truck of knowledge in different academic ways, promote the continuous update and development of ability and skills competences. That is to say, promotes learning. Further, the dynamics of knowledge management in universities stimulates students to exchange their experiences and knowledge in universities. That can be reached through conveyance each other in formal structured activities or informally stimulating the harmonization and diffusion of day to day tacit and explicit knowledge. The authors formulate reviews based on workplace realities, professional insights and personal experience in knowledge sharing and collaborative learning. FindingsMoreover, knowledge management in universities must encourage the creation of a knowledge base regarding the environment and will create conditions for abilities and skills training development of the Higher Education. Practical implicationsThe preliminary knowledge integration and exploitation can also contribute to the development of the new organizational knowledge through the accumulation of the experience. Originality/valueThe preliminary study of assessment of knowledge management in universities focuses on practical applications of skills purchased in universities. The methods for implementing a knowledge management, to connect and share this knowledge in universities, can be a challenge, if is well understanding how we can benefit from information.

Can Consortial Reference Partners Answer Your Local Users' Library Questions?

The purpose of this article is to explore location-based questions as a weakness of virtual reference consortia and discuss how to mitigate related issues. Content analysis of how both local and non-local academic librarians responded to location-based questions provides insight into considerations academic libraries must make when participating in a virtual reference consortia. Unobtrusive testing analyzed the local knowledge assumption that non-local librarians have difficulty answering questions about libraries beyond their own. The results from these two methods indicate academic librarians have some difficulties providing responses to library location-based questions and a discussion on overcoming this weakness is included.

Link Adaptation for Throughput Optimization of Parallel Channels with Application to Hybrid FSO/RF Systems

Hybrid free space optical (FSO)/radio frequency (RF) communication systems provide an attractive solution for high-throughput wireless connectivity. Such systems promise high data rates (Gbps) due to the FSO channel, weather permitting. The reliability of these systems is enhanced by the more robust RF channel. A critical question is how to efficiently transmit data using hybrid systems with highly variable channel conditions. In this paper, a hybrid FSO/RF communication system is modeled as two independent parallel channels. Under the assumptions of quasi-static channels and perfect channel knowledge at the transceivers, we propose an adaptive design resulting in a capacity-approaching and seamless joint system. In our design, information bits are jointly encoded and decoded. The encoder rate, modem transmission rate, and modulation scheme of each channel are dynamically adjusted according to the channel state. Analytical and simulation results give insight into the relationship between the adaptive parameters and the performance of the hybrid system.

Language and Perceptions of Member Contribution in Globally Dispersed Teams

Communication and coordination of individual expertise among members of globally dispersed teams is critically dependent upon assumptions of mutual knowledge – the knowledge known to be held in com...

Receive Antenna Selection for Time-Varying Channels Using Discrete Prolate Spheroidal Sequences

Receive antenna selection (AS) has been shown to maintain the diversity benefits of multiple antennas while potentially reducing hardware costs. However, the promised diversity gains of receive AS depend on the assumptions of perfect channel knowledge at the receiver and slowly time-varying fading. By explicitly accounting for practical constraints imposed by the next-generation wireless standards such as training, packetization and antenna switching time, we propose a single receive AS method for time-varying fading channels. The method exploits the low training overhead and accuracy possible from the use of discrete prolate spheroidal (DPS) sequences based reduced rank subspace projection techniques. It only requires knowledge of the Doppler bandwidth, and does not require detailed correlation knowledge. Closed-form expressions for the channel prediction and estimation error as well as symbol error probability (SEP) of M-ary phase-shift keying (MPSK) for symbol-by-symbol receive AS are also derived. It is shown that the proposed AS scheme, after accounting for the practical limitations mentioned above, outperforms the ideal conventional single-input single-output (SISO) system with perfect CSI and no AS at the receiver and AS with conventional estimation based on complex exponential basis functions.

On the estimation of characteristic S–N curves with confidence

When fatigue test data for the number of cycles N to failure are limited, the estimation of the characteristic S–N curve, defined as the curve corresponding to the mean value of logN minus two standard deviations of logN, becomes uncertain. A study has been carried out to establish which confidence level in the estimation of the characteristic S–N curve from limited data is required in order to maintain the safety level equal to the safety level which is achieved under an assumption of perfect knowledge (infinitely many fatigue tests).Probability calculations for the situation with perfect knowledge as well as for the situation with limited fatigue test data are based on a first-order reliability method (FORM). Tolerance bound theory is used to calibrate the required confidence level from the results obtained from the FORM analyses.Calculations are carried out for assumptions of no uncertainty in the loading and unknown standard deviation of logN. Results are presented for a 10−2 requirement for the failure probability over the design life as well as for a 10−4 requirement for the failure probability in the last year of a 20-year design life that is typically used for design of marine structures. Variation cases are carried out to study the influence of uncertainty in the loading and to study the effect of assuming the standard deviation in logN to be known.The purpose of the paper is to demonstrate why and how to estimate characteristic S–N curves with confidence when the amount of data is limited. The results of the study provide a new way to optimize fatigue design whenever it is costly or time-consuming to achieve many reliable test data.