Non-systematic Information Research Articles

Expanding information for flood frequency analysis using a weather generator: Application in a Spanish Mediterranean catchment

Study regionThe proposed methodology has been applied in the Segura River basin (south-eastern Spain) whose hydrological regime has a high anthropic alteration and catastrophic floods have occurred at different times for centuries. The climate is generally semi-arid, with frequent droughts but also floods caused mainly by rainfall associated with mesoscale convective systems. Study focusWe present a methodology that exploits all available information to obtain reliable low-frequency flood quantiles through the integration of different methods. First, a Weather Generator (WG) was implemented with the results from a regional study of annual maximum precipitation. Second, a rainfall temporal disaggregation procedure was carried out to capture the sub-daily behavior of flood generating storms. Third, a fully-distributed Hydrological Model (HM) was implemented including the role of sediments in extreme events. Finally, the estimation of flood quantiles using plotting positions was validated with systematic and non-systematic information. New Hydrological Insights for the regionThe use of this process-based approach allows to reproduce the main hydrometeorological mechanisms associated with floods in the region studied. Accurate flood quantiles up to 200 years have been possible to obtain, which represents an important advance in the knowledge of the basin since reliable flood quantiles of only 20 years were adequately captured with the current observations. Finally, sediment yield has been proven to be an important factor for the region hydrographs’ reconstruction.

Digital design of new products: accounting for output correlation via a novel algebraic formulation of the latent-variable model inversion problem

Product design problems often require finding the raw materials and/or operating conditions (inputs) that are needed to achieve some pre-assigned quality specifications on the product (outputs). The problem can be tackled by first building a latent-variable model (e.g., partial least-squares regression) on historical manufacturing data of products similar to the new one, and then using model inversion to find the input conditions required to obtain the target product. However, in most practical cases, the variables characterizing product quality are correlated, and this may raise singularity issues upon algebraic model inversion. The most popular approach to cope with this relies on removing a priori some of the correlated quality variables from the model output matrix, and on building the latent-variable model in such a way that the inputs be related to the remaining outputs only. However, in this case the inputs obtained upon model inversion may not be able to ensure that the quality variables that were not included in the output matrix will be close enough to their targets. We propose a novel algebraic formulation of the latent-variable model inversion problem, named regularized direct inversion, which can cope with output correlation by design. The proposed formulation enables one to retain in the model output matrix all quality variables, and addresses output correlation by removing a posteriori only the non-systematic information that would cause singularity issues. Therefore, no structural information about the relation between inputs and outputs is left out of the model by design, which in turn improves the performance of model inversion. The superiority of regularized direct inversion over the standard approach, and its ability to cope with model uncertainty, are proved using two simulated batch processes: a generic fermentation process, and a process for the manufacturing of penicillin.

Backbone or Helping Hand? On the Role of Information Systems and Non-systematic Information in Managers’ Work

An international association advancing the multidisciplinary study of informing systems. Founded in 1998, the Informing Science Institute (ISI) is a global community of academics shaping the future of informing science.

Estimation of high return period flood quantiles using additional non-systematic information with upper bounded statistical models

Abstract. This paper proposes the estimation of high return period quantiles using upper bounded distribution functions with Systematic and additional Non-Systematic information. The aim of the developed methodology is to reduce the estimation uncertainty of these quantiles, assuming the upper bound parameter of these distribution functions as a statistical estimator of the Probable Maximum Flood (PMF). Three upper bounded distribution functions, firstly used in Hydrology in the 90's (referred to in this work as TDF, LN4 and EV4), were applied at the Jucar River in Spain. Different methods to estimate the upper limit of these distribution functions have been merged with the Maximum Likelihood (ML) method. Results show that it is possible to obtain a statistical estimate of the PMF value and to establish its associated uncertainty. The behaviour for high return period quantiles is different for the three evaluated distributions and, for the case study, the EV4 gave better descriptive results. With enough information, the associated estimation uncertainty for very high return period quantiles is considered acceptable, even for the PMF estimate. From the robustness analysis, the EV4 distribution function appears to be more robust than the GEV and TCEV unbounded distribution functions in a typical Mediterranean river and Non-Systematic information availability scenario. In this scenario and if there is an upper limit, the GEV quantile estimates are clearly unacceptable.

A contribution to improved flood magnitude estimation in base of palaeoflood record and climatic implications – Guadiana River (Iberian Peninsula)

Abstract. The Guadiana River has a significant record of historical floods, but the systematic data record is only 59 years. From layers left by ancient floods we know about we can add new data to the record, and we can estimate maximum discharges of other floods only known by the moment of occurrence and by the damages caused. A hydraulic model has been performed in the area of Pulo de Lobo and calibrated by means of the rating curve of Pulo do Lobo Station. The palaeofloods have been dated by means of 14C y 137Cs. As non-systematic information has been used in order to calculate distribution functions, the quantiles have changed with respect to the same function when using systematic information. The results show a variation in the curves that can be blamed on the human transformations responsible for changing the hydrologic conditions as well as on the latest climate changes. High magnitude floods are related to cold periods, especially at transitional moments of change from cold to warm periods. This tendency has changed from the last medium-high magnitude flood, which took place in a systematic period. Both reasons seem to justify a change in the frequency curves indicating a recent decrease in the return period of big floods over 8000 m3 s−1. The palaeofloods indicate a bigger return period for the same water level discharge thus showing the river basin reference values in its natural condition previous to the transformation of the basin caused by anthropic action.

Publicações de B. F. Skinner: de 1930 a 2004

Skinner publicou sistematicamente desde 1930 até sua morte em 1990. Diferentes autores em distintos contextos compilaram sua produção e publicaram listas de referências. A partir de um conjunto destes trabalhos que listaram as publicações de Skinner e de outras informações assistemáticas de seu trabalho, construiu-se a lista aqui apresentada. Nela estão listados artigos, livros, resenhas, resumos, cartas a editor e entrevistas e estão indicadas as fontes (listas já publicadas) que também indicam a referência. Estão listadas também republicações, especialmente em português. A lista de publicações apresentada traz as referências de 295 itens publicados, dos quais 269 foram diretamente verificados.

Dietary effects of partial or total substitution of sucrose for starch on glucose and lipid metabolism in dyslipidemic rats

Rats fed on a sucrose-rich diet (SRD) (63 % w w ) up to 30 weeks develop stable hypertriglyceridemia, impaired glucose tolerance and insulin insensitivity. At present only scarce and non-systematic information is available concerning the possible reversion of these metabolic derangements by nutritional or metabolic interventions. The present study was designed to investigate the effect of the isocaloric substitution of sucrose for starch (during 15 weeks) on lipid and glucose metabolisms in rats in which a well-established hypertriglyceridemia and glucose intolerance were present before the amount of sucrose (63% w w ) was partially (33% w w ) or totally (0% w w ) replaced by an isocaloric amount of starch. Our findings show that: i) when the amount of fructose (sucrose moieties) is partially replaced by starch (from 33 to 18% of the total calories) most of its undesirable effects on lipid metabolism are still present and no significant improvement in glucose regulation is noticed; ii) hypertriglyceridemia and glucose intolerance can be completely reversed, without detectable changes in circulating insulin levels, by shifting completely to starch as the source of carbohydrate in the diet. Moreover, when sucrose was removed from the diet, it took 7 weeks for plasma triglyceride levels to become completely normal while plasma free fatty acids and glucose levels needed twice that time. These findings suggest that manipulation of dietary fructose may play a role in the management of lipid disorders associated with glucose intolerance and insulin resistance.

Using the TCEV distribution function with systematic and non-systematic data in a regional flood frequency analysis

Due to the social and economic implications, flood frequency analysis must be done with the highest precision. For this reason, the most suitable statistical model must be selected, and the maximum amount of information must be used. Floods in Mediterranean rivers can be produced by two different mechanisms, which forces the use of a non-traditional distribution like the TCEV. The information can be increased by using additional non-systematic data, or with a regional analysis, or both. Through the statistical gain concept, it has been shown that in most cases the use of additional non-systematic information can decrease the quantile estimation error in about 50%. In a regional analysis, the␣benefit of additional information in one station, is propagated to the rest of␣the␣stations with only a small decrease with respect to the at-site equivalent analysis.

Increasing awareness of and behaviour towards periconceptional folic acid consumption in The Netherlands from 1994 to 1995.

In November 1993, Dutch health authorities advised that women planning a pregnancy should take folic acid in the periconceptional period to reduce the risk of fetal neural tube defects. In the autumn of 1995 a national campaign was organized to inform women and health care professionals in a systematic way. We assessed the awareness and behaviour of women at their first or second antenatal visit in two surveys in the spring of 1994 and the autumn of 1995, in order to evaluate the impact of non-systematic information during that period, and to collect baseline data to evaluate the effect of the national folic acid campaign. The two surveys were carried out in the north and the west of The Netherlands. The proportion of women who had heard of folic acid increased from 28% to 78%. The proportion that used folic acid during any period in pregnancy increased from 7.8% to 26%. The proportion that took folic acid tablets during the whole of the recommended period increased from 0.8 to 4.4%. In the group of women who did not take folic acid, the proportion who did "not like to use anything during pregnancy" decreased, as did the proportion who did "not think it is useful". In the Netherlands, non-systemic information about periconceptional folic acid use has already led to significant changes in awareness and behaviour before the start of the national folic acid campaign.