724 research outputs found
LA PERCEZIONE DEL RISCHIO AMBIENTALE NEI CONTESTI DI VALUTAZIONE IPOTETICA. IL CASO DELLE INFRASTRUTTURE URBANE PER LO SMALTIMENTO DEI RIFIUTI
This work highlights how, within the context of contingent valuation, supporting the assessment of monetary measures of mitigation of environmental damages, has not been sufficiently clarified the role played by the perception of environmental risk, particularly in an ex ante context, where the effect of psychological anchoring to the status quo and the amount / type of available information have an important role driving the individual preferences. The contribution to experimental economics - of which the contingent valuation takes share - of the theory of choice under uncertainty and of behavioural economics is briefly traced and, in order to provide empirical evidence, the results of a choice experiment implemented in Turin, in order to assess the effect of the disamenity due to the location of solid waste infrastructure, are showin
Rinascimento: Playing Splendor-Like Games with Event-Value Functions
In the realm of games research, artificial general intelligence algorithms often use score as the main reward signal for learning or playing actions. However, this has shown its limitations in scenarios where the rewards are very rare or absent until the end of the game. The problem is even more severe when the computational budget available is limited. This article proposes a new approach based on event logging: the game state triggers an event every time one of its features changes. These events are processed by an event-value function (EF) that assigns a value to a single action or a sequence. Experiments show that this approach can mitigate the problem of scarce rewards and improve the artificial intelligence performance compared with both the point-based heuristics and state-value functions. Furthermore, this represents a step forward in a finer control of the strategy adopted by the artificial agent, by describing a much richer and controllable behavioral space through EFs. Tuned EFs are able to neatly synthesize the relevance of the events in the game. Agents using an EF are also more robust when playing games with several opponents
La Conjoint Analysis nelle valutazioni immobiliari
Conjoint Analysis (CA) is probably the most known and
widely used tool in marketing research and demand forecasting.
The premise of CA is that every product, or service,
has multiple attributes, each with a different utility
value for the consumer and that individual utilities can be
quantified and assessed in a market simulation perspective.
In spite of its popularity and wide diffusion, there
has been little systematic research relating to the specific
market – like the real estate market. Our work starts from
this lack and it is organised in three sections: the first introduces
a short history of CA and compares the performances
of different interview designs: Adaptive Conjoint
Analysis (ACA) and Choice Based Conjoint (CBC). The second
section presents the case-study – the housing market of
Turin – and shows the results of a research experiment. We
compare ACA and CBC designs and discuss about the best
when the goal is valuation – in other hands, the price is
present between the attributes. The third section concludes
and focuses on the problem of real estate market simulation
and demand forecasting
Normality and smoothness of simple linear group compactifications
If G is a complex semisimple algebraic group, we characterize the normality
and the smoothness of its simple linear compactifications, namely those
equivariant GxG-compactifications which possess a unique closed orbit and which
arise in a projective space of the shape P(End(V)), where V is finite
dimensional rational G-module. Both the characterizations are purely
combinatorial and are expressed in terms of the highest weights of V. In
particular, we show that Sp(2r) (with r > 0) is the unique non-adjoint simple
group which admits a simple smooth compactification.Comment: v2: minor changes, final version. To appear in Math.
Primer genoma mitocondrial en restos humanos de la Costa de Santa Cruz, Argentina
En este trabajo se presenta la secuencia completa de ADN mitocondrial, obtenida a partir de restos óseos de un hombre adulto, hallado en el sitio Cañadón Misioneros (provincia de Santa Cruz, Argentina), con una antigüedad de 70 ± 30 años antes del presente. La secuencia corresponde al haplogrupo (hg) D4h3a5, nativo de América y exclusivo del sur de Patagonia, donde ha sido descripto tanto en muestras antiguas como actuales. Esta secuencia constituye el primer dato de ADN mitocondrial en la costa atlántica de Patagonia con la resolución suficiente para definir a nivel de subhaplogrupo.
Se discuten las implicancias en cuanto a los vínculos biológicos de las poblaciones que habitaron esa porción del espacio patagónico en el marco de la información genética y arqueológica disponible.We describe the complete mitochondrial genome sequence of an adult male skeleton, discovered at Cañadón Misioneros (Santa Cruz Province, Argentina), and dated 70 ± 30 years before present. The DNA sequence corresponded to haplogroup D4h3a5, native to the Americas and exclusive to the south of Patagonia, where it has been observed both in ancient and present-day individuals. This is the first mitochondrial DNA data of the Atlantic coast of Patagonia of sufficient resolution to permit classification at the subhaplogroup level. The implications for the genetic affinities of populations of this region of Patagonia will be discussed in the context of available genetic and archaeological information
Intrinsic surface depression of the order parameter under mixed (s+id)-wave pair symmetry and its effect on the critical current of high-Tc SIS Josephson junctions
An intrinsic gap depression at the Superconductor-Insulator interface due to
the very short value of the coherence length in High-Tc Superconductors [HTSs]
is considered, in the framework of a mixed (s+id)-wave pair symmetry for the
order parameter ranging from pure s to pure d-wave. This gap depression acts as
the main physical agent causing the relevant reduction of IcRn(T) values with
respect to BCS expectations in HTS SIS Josephson junctions. Good agreement with
various experimental data is obtained with both pure s-wave and pure d-wave
symmetries of the order parameter, but with amounts of gap depression depending
on the pair symmetry adopted. Regardless of the pair symmetry considered, these
results prove the importance of the surface order-parameter depression in the
correct interpretation of the Ic(T)Rn(T) data in HTS SIS junctions. In a case
of planar YBCO-based junction the use of the de Gennes condition allowed us to
tentatively obtain an upper limit for the amount of d-wave present in the order
parameter of YBCO.Comment: 11 pages REVTeX file, 6 PostScript figures, to be published in J.
Superconductivit
Mediterranean diet and outcomes of assisted reproduction: an Italian cohort study
Background: Detrimental lifestyle habits have been indicated as potential causes of reduced fertility. Recently studies have suggested an association between healthy diets and increased live birth rates after assisted reproduction techniques. However, the issue remains under debate, and evidence is still accumulating. Objective: The objective of the study was to study the relationship between a Mediterranean diet and outcomes of assisted reproduction techniques in subfertile couples in an Italian population. Study Design: This was a prospective cohort study, conducted in an Italian fertility clinic. Couples undergoing in vitro fertilization were interviewed on the day of oocyte retrieval to obtain information on personal and health history, lifestyle habits, and diet. Adherence to a Mediterranean diet was evaluated using a Mediterranean diet score. Relative risks and 95% confidence intervals for embryo transfer, clinical pregnancy, and live birth were calculated. Potential confounders were included in the equation model. Results: Among 474 women (mean age, 36.6 years, range, 27\u201345), 414 (87.3%) performed embryo transfer, 150 (31.6%) had clinical pregnancies, and 117 (24.7%) had live births. In a model including the potential confounders (age, leisure physical activity, body mass index, smoking, daily calorie intake, and previous failed in vitro fertilization cycles), findings showed that the Mediterranean diet score was not significantly associated with in vitro fertilization outcomes. Adjusted analyses were performed in strata of age, previous assisted reproduction technique cycles, and reasons for infertility, with consistent findings. The only exception was observed in women >35 years old with an intermediate Mediterranean diet score, who showed a lower risk of not achieving clinical pregnancy (adjusted relative risk, 0.84, 95% confidence interval, 0.71\u20131.00, P = .049). Conclusion: No clear association was observed between adherence to a Mediterranean diet and successful in vitro fertilization
Health effects of living near an incinerator: A systematic review of epidemiological studies, with focus on last generation plants
Huge reductions in incinerators' emissions occurred over time, and results of older studies cannot be directly generalized to modern plants. We conducted a systematic review of the epidemiologic evidence of the health
effects of incinerators, classifying plants in three generations, according to emission limits. A systematic search identified 63 epidemiologic studies, published in English, investigating health effects of incinerators on humans. We focused on cancer, cardio-cerebrovascular diseases (CVD) and respiratory diseases, pregnancy outcomes and congenital anomalies. Only six studies in the general population were on third generation incinerators providing data on pregnancy outcomes and congenital anomalies. Given the heterogeneity of methods, the abundance of ecological/semi-ecological studies and the lack of reliable quantitative measures of
exposure in several studies we did not perform any meta-analysis. No excesses emerged concerning all cancers and lung cancer. An excess of non-Hodgkin lymphoma was reported in some earlier studies, but not for second generation plants. Possible excesses of soft tissue sarcomas were confined to earlier incinerators and the areas closer to the plants. No clear association emerged for CVD and diseases of the respiratory system. Several different pregnancy outcomes were considered, and no consistent association emerged, in spite of a few positive results. Studies were negative for congenital anomalies as a whole. Sporadic excesses were reported in a few studies for specific types of anomalies, but no consistent pattern emerged. Evaluation of the evidence was hindered by heterogeneity in reporting and classification of outcomes across studies.
Direct evidence from third generation plants is scarce. Methodological issues in study design (mainly related to exposure assessment, confounding and ecological design) and analysis make interpretation of results complex. In spite of this, the overall evidence suggests that, if there were any excesses at all for older incinerators, they were modest at most. Additional monitoring of third generation plants needs to overcome methodological weakness
Inferring hidden states in Langevin dynamics on large networks: Average case performance
We present average performance results for dynamical inference problems in
large networks, where a set of nodes is hidden while the time trajectories of
the others are observed. Examples of this scenario can occur in signal
transduction and gene regulation networks. We focus on the linear stochastic
dynamics of continuous variables interacting via random Gaussian couplings of
generic symmetry. We analyze the inference error, given by the variance of the
posterior distribution over hidden paths, in the thermodynamic limit and as a
function of the system parameters and the ratio {\alpha} between the number of
hidden and observed nodes. By applying Kalman filter recursions we find that
the posterior dynamics is governed by an "effective" drift that incorporates
the effect of the observations. We present two approaches for characterizing
the posterior variance that allow us to tackle, respectively, equilibrium and
nonequilibrium dynamics. The first appeals to Random Matrix Theory and reveals
average spectral properties of the inference error and typical posterior
relaxation times, the second is based on dynamical functionals and yields the
inference error as the solution of an algebraic equation.Comment: 20 pages, 5 figure
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