Search results for "edicta"
showing 10 items of 112 documents
«I molteplici casi della sorte». Disastri della guerra e della natura in Tucidide
2018
Il capitolo 23 del primo libro di Tucidide conclude il proemio e ricapitola gli elementi chiave della visione storiografica dello storico ateniese. Sopo aver connesso il primato della guerra alla sua durata e ad un impressionante elenco di sofferenze (pathemata) Tucidide aggiunge un secondo elenco di disastri naturali (terremoti, eclissi, la peste). Questo contributo si propone di indagare il rapporto tra le due serie di disastri nel quadro della più ampia visione tucididea sulla guerra e sulla condotta umana. Accostando ai pathemata l’elenco dei disastri naturali, lungi dal volere individuare nella straordinaria sovversione dell’ambiente naturale un effetto delle decisioni umane o un annun…
Designed for unanticipated use
2003
Common artefacts have been identified as fundamental characteristics for framing activities in workplaces. Mike Robinson's article 'Design for unanticipated use...' conceptualised and defined the dimensions of common artefacts as consisting of predictability, peripheral awareness, implicit communication, double level language and overview. These dimensions have often been used in explaining unexpected uses of different applications and systems. In this paper, experiences from common artefacts as CSCW application design principles, indicating that unanticipated uses are expected and further supported, are discussed. Two distinct cases, a physical room and a software application, are presente…
Stochastic modeling of Supramax spot and forward freight rates
2015
We conducted an empirical analysis of Supramax spot rates and propose a continuous time process to model the dynamics. The model incorporates features relevant for shipping freight rates, freight rate volatility that varies over time, sudden, big freight rate movements, and short-term, mean-reverting price trends. This suggests some degree of short-term predictability of Supramax spot rates, making shipping different from traditional asset markets, like stocks and currencies, and also most commodity markets. However, this does not imply that arbitrage profits are easily picked up in this market, as, financially speaking, spot freight rates are not traded assets. We instead focus on the rela…
The adaptive nature of liquidity taking in limit order books
2014
In financial markets, the order flow, defined as the process assuming value one for buy market orders and minus one for sell market orders, displays a very slowly decaying autocorrelation function. Since orders impact prices, reconciling the persistence of the order flow with market efficiency is a subtle issue. A possible solution is provided by asymmetric liquidity, which states that the impact of a buy or sell order is inversely related to the probability of its occurrence. We empirically find that when the order flow predictability increases in one direction, the liquidity in the opposite side decreases, but the probability that a trade moves the price decreases significantly. While the…
Diagnosis and predictability of intraseasonal characteristics of wet and dry spells over equatorial east Africa
2010
Most of Eastern Africa has arid and semi-arid climate with high space-time variability in rainfall. The droughts are very common in this region, and often persist for several years, preceded or followed by extreme floods. Most of the livelihoods and socio-economic activities however remain rain-dependent leading to severe negative impacts during the periods of occurrence of climate extremes. It has been noted that one extreme event was capable of reversing national economic growth made over a period of several years. Thus no sustainable development can be attained in eastern Africa without effective mainstreaming of climate information in the development policies, plans and programmes. Many…
A method for the time-varying nonlinear prediction of complex nonstationary biomedical signals
2009
A method to perform time-varying (TV) nonlinear prediction of biomedical signals in the presence of nonstationarity is presented in this paper. The method is based on identification of TV autoregressive models through expansion of the TV coefficients onto a set of basis functions and on k -nearest neighbor local linear approximation to perform nonlinear prediction. The approach provides reasonable nonlinear prediction even for TV deterministic chaotic signals, which has been a daunting task to date. Moreover, the method is used in conjunction with a TV surrogate method to provide statistical validation that the presence of nonlinearity is not due to nonstationarity itself. The approach is t…
Definition and predictability of an OLR based West African monsoon onset
2008
The monsoon onset is documented in terms of latitudinal shift of deep convection areas within the ITCZ using an interpolated version of the National Oceanic and Atmospheric Administration (NOAA) Outgoing Longwave Radiation (OLR) at a 5-day time-step over West Africa for the period 1979–2004. Signals in moist convection derived from OLR values lower than 180 W/m2 allow better determination of onset dates (ODs) than the use of other thresholds or of the raw values of OLR. Such ODs are defined without any time filtering or spatial averaging along the meridional plane. They are also significantly correlated with ODs based on other datasets such as the CMAP and Global Precipitation Climatology P…
Analysis of the unpredictable migration of impacted mandibular third molars: A pilot study
2020
Background Eruption of an impacted mandibular third molar (3MM) is often unpredictable. The objective of this study was to establish the radiographic parameters of migration in patients whose 3MMs evolved unpredictably. Material and Methods This was a retrospective observational study. Patients with unusual 3MM migration (away from their physiological eruption position with changes in the longitudinal and horizontal axes) and with at least two panoramic radiographs were included. To evaluate the radiographic parameters, images were superimposed, using mandibular angle and ipsilateral condyle as references. Results Of a total of 2851 patients, four were included in our study. The average age…
Extracting subseasonal scenarios: an alternative method to analyze seasonal predictability of regional-scale tropical rainfall.
2013
Abstract Current seasonal prediction of rainfall typically focuses on 3-month rainfall totals at regional scale. This temporal summation reduces the noise related to smaller-scale weather variability but also implicitly emphasizes the peak of the climatological seasonal cycle of rainfall. This approach may hide potentially predictable signals when rainfall is lower: for example, near the onset or cessation of the rainy season. The authors illustrate such a case for the East African long rains (March–May) on a network of 36 stations in Kenya and north Tanzania from 1961 to 2001. Spatial coherence and potential predictability of seasonal rainfall anomalies associated with tropical sea surface…
Spatial coherence of monsoon onset over Western and Central Sahel (1950-2000)
2009
Abstract The spatial coherence of boreal monsoon onset over the western and central Sahel (Senegal, Mali, Burkina Faso) is studied through the analysis of daily rainfall data for 103 stations from 1950 to 2000. Onset date is defined using a local agronomic definition, that is, the first wet day (>1 mm) of 1 or 2 consecutive days receiving at least 20 mm without a 7-day dry spell receiving less than 5 mm in the following 20 days. Changing either the length or the amplitude of the initial wet spell, or both, or the length of the following dry spell modifies the long-term mean of local-scale onset date but has only a weak impact either on its interannual variability or its spatial coher…