28,136 research outputs found
Talking About the Hidden in Architectural Education
No full textThe European Association of Architectural Education’s annual conference of 2019 was held at the Faculty of Architecture in Zagreb from August 28th to 31st. Titled ‘The Hidden School’, it aimed to open a discussion on the substance and quality of architectural education, an architecture school’s true character, the traits which – however explicitly or implicitly manifested – embody the school’s culture and identity. The conference explored the subliminal quality of architectural education less apparent just by reading the curricula or following evaluation procedures, yet which represent a substantial quality or the culture of a school, quite clearly legible to those engaging in it. The invitation to explore this topic proposed five aspects of a school as triggers, focusing on tacit meanings situated between the lines of the syllabus, the spirit generated by students contributing to it or the educators personifying it, informal learning modalities, spaces it inhabits: the Educator, the Content, the Process, the Place, the Student. The scientific committee placed a question to the participating schools: “If the hidden school exists in parallel or as a background process, a self-generated search for fundamental answers, and its interpretation, manifestation or legibility has a multitude of facets, how can these aspects be captured?” Is it possible to assess the ‘hidden’?Theory, Territories & Transition
On the dark side of the market: identifying and analyzing hidden order placements
No full textTrading under limited pre-trade transparency becomes increasingly popular on financial markets. We provide first evidence on traders’ use of (completely) hidden orders which might be placed even inside of the (displayed) bid-ask spread. Employing TotalView-ITCH data on order messages at NASDAQ, we propose a simple method to conduct statistical inference on the location of hidden depth and to test economic hypotheses. Analyzing a wide cross-section of stocks, we show that market conditions reflected by the (visible) bid-ask spread, (visible) depth, recent price movements and trading signals significantly affect the aggressiveness of ’dark’ liquidity supply and thus the ’hidden spread’. Our evidence suggests that traders balance hidden order placements to (i) compete for the provision of (hidden) liquidity and (ii) protect themselves against adverse selection, front-running as well as ’hidden order detection strategies’ used by high-frequency traders. Accordingly, our results show that hidden liquidity locations are predictable given the observable state of the market
On the Dark Side of the Market: Identifying and Analyzing Hidden Order Placements
No full textTrading under limited pre-trade transparency becomes increasingly popular on financial markets. We provide first evidence on traders’ use of (completely) hidden orders which might be placed even inside of the (displayed) bid-ask spread. Employing TotalView-ITCH data on order messages at NASDAQ, we propose a simple method to conduct statistical inference on the location of hidden depth and to test economic hypotheses. Analyzing a wide cross-section of stocks, we show that market conditions reflected by the (visible) bid-ask spread, (visible) depth, recent price movements and trading signals significantly affect the aggressiveness of ’dark’ liquidity supply and thus the ’hidden spread’. Our evidence suggests that traders balance hidden order placements to (i) compete for the provision of (hidden) liquidity and (ii) protect themselves against adverse selection, front-running as well as ’hidden order detection strategies’ used by high-frequency traders. Accordingly, our results show that hidden liquidity locations are predictable given the observable state of the market.limit order market, hidden liquidity, high-frequency trading, non-display order, iceberg orders
Coalgebra Semantics for Hidden Algebra: Parameterised Objects and Inheritance
No full textThe theory of hidden algebras combines standard algebraic techniques with coalgebraic techniques to provide a semantic foundation for the object paradigm. This paper focuses on the coalgebraic aspect of hidden algebra, concerned with signatures of destructors at the syntactic level and with finality and cofree constructions at the semantic level. Our main result shows the existence of cofree constructions induced by maps between coalgebraic hidden specifications. Their use in giving a semantics to parameterised objects and inheritance is then illustrated. The cofreeness result for hidden algebra is generalised to abstract coalgebra and a universal construction for building object systems over existing subsystems is obtained. Finally, existence of final/cofree constructions for arbitrary hidden specifications is discussed
Hidden Unemployment and Older Male Workers
No full textA number of policy reforms have recently been announced by the Commonwealth government to encourage greater labour force participation by older people in the context of an ageing society. These policy reforms are generally supply side in orientation such as the removal of the Mature Age Allowance, or restrictions to the Disability Support Pension. In this paper it is argued that these pensions have historically been used to accommodate otherwise unemployed older male workers. A number of methods are used to quantify the level of hidden unemployment within the older male population over recent decades. Estimates of adjusted unemployment rates, which include hidden as well as official unemployment, reveal a very dramatic picture of unutilised older male labour beneath relatively modest official unemployment rates. It is argued that without complementary employment policy addressing the labour demand side these policy reforms will achieve little except to reveal the previously high levels of hidden unemployment in official unemployment statistics.hidden unemployment, older male workers, employment policy
Semantic Constructions for Hidden Algebra
No full textHidden algebra is a behavioural algebraic specification formalism for objects. It captures their constructional aspect, concerned with the initialisation and evolution of their states, as well as their observational aspect, concerned with the observable behaviour of such states. When attention is restricted to the observational aspect, final/cofree constructions provide suitable denotations for the specification techniques involved. However, when the constructional aspect is integrated with the observational one, the presence of nondeterminism in specifications prevents the existence of final/cofree algebras. It is shown here that final/cofree families of algebras exist in this case, with each algebra in such a family resolving the nondeterminism in a particular way. Existence of final/cofree families yields a canonical way of constructing algebras of structured specifications from algebras of the component specifications. Finally, a layered approach to specifying complex objects in hidden algebra is presented, with the semantics still involving final/cofree families
A coupled hidden Markov model for disease interactions
No full textTo investigate interactions between parasite species in a host, a population of field voles was studied longitudinally, with presence or absence of six different parasites measured repeatedly. Although trapping sessions were regular, a different set of voles was caught at each session, leading to incomplete profiles for all subjects. We use a discrete time hidden Markov model for each disease with transition probabilities dependent on covariates via a set of logistic regressions. For each disease the hidden states for each of the other diseases at a given time point form part of the covariate set for the Markov transition probabilities from that time point. This allows us to gauge the influence of each parasite species on the transition probabilities for each of the other parasite species. Inference is performed via a Gibbs sampler, which cycles through each of the diseases, first using an adaptive Metropolis–Hastings step to sample from the conditional posterior of the covariate parameters for that particular disease given the hidden states for all other diseases and then sampling from the hidden states for that disease given the parameters. We find evidence for interactions between several pairs of parasites and of an acquired immune response for two of the parasites
Heisenberg (and Schroedinger, and Pauli) on Hidden Variables
No full textIn this paper, we discuss various aspects of Heisenberg’s thought on hidden variables in the period 1927–1935. We also compare Heisenberg’s approach to others current at the time, specifically that embodied by von Neumann’s impossibility proof, but also views expressed mainly in correspondence by Pauli and by Schroedinger. We shall base ourselves mostly on published and unpublished materials that are known but little-studied, among others Heisenberg’s own draft response to the EPR paper. Our aim will be not only to clarify Heisenberg’s thought on the hidden-variables question, but in part also to clarify how this question was understood more generally at the time
A statistical multiresolution approach for face recognition using structural hidden Markov models
No full textThis paper introduces a novel methodology that combines the multiresolution feature of the discrete wavelet transform (DWT) with the local interactions of the facial structures expressed through the structural hidden Markov model (SHMM). A range of wavelet filters such as Haar, biorthogonal 9/7, and Coiflet, as well as Gabor, have been implemented in order to search for the best performance. SHMMs perform a thorough probabilistic analysis of any sequential pattern by revealing both its inner and outer structures simultaneously. Unlike traditional HMMs, the SHMMs do not perform the state conditional independence of the visible observation sequence assumption. This is achieved via the concept of local structures introduced by the SHMMs. Therefore, the long-range dependency problem inherent to traditional HMMs has been drastically reduced. SHMMs have not previously been applied to the problem of face identification. The results reported in this application have shown that SHMM outperforms the traditional hidden Markov model with a 73% increase in accuracy
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