Papers by Jean-pierre Ottoy
ABSTRACT KEYWORDS INTRODUCTION CASE STUDY RESULTS AND DISCUSSION CONCLUSIONS ACKNOWLEDGMENT REFER... more ABSTRACT KEYWORDS INTRODUCTION CASE STUDY RESULTS AND DISCUSSION CONCLUSIONS ACKNOWLEDGMENT REFERENCES ABSTRACT Model-based scenario analysis with the ASM1 model was used to evaluate the effect of different process modifications on the biological nitrogen removal process for a specific case study (municipal wastewater treatment plant). Simulations showed that the construction of extra tank volume was needed to obtain the effluent standard of 15 mg N/l. However, the renovation scenarios resulting from a model-based analysis resulted in lower construction costs (less extra tank volume to be constructed and better reuse of existing treatment plant components) compared to a rule-of-thumb design as often applied. KEYWORDS ASM1, biological N removal, denitrification, modelling, nitrification, renovation INTRODUCTION Activated sludge models were developed as a tool to study the complex interactions that occur between the different microbial communities in an activated sludge plant. The Act...
Communications in Statistics - Simulation and Computation, Jan 2, 2004
ABSTRACT In this paper, a class of nonparametric tests for independence between two continuous ra... more ABSTRACT In this paper, a class of nonparametric tests for independence between two continuous random variables is proposed. The members of the class are characterized by the size of the partitions of the sample space on which the test statistics are based. The test statistic that corresponds to the smallest partition size may be seen as an extension of Hoeffding's statistic with an Anderson-Darling-type weight function. In this simplest case, we have proven its asymptotic null distribution as well as its omnibus consistency. In a simulation study, the powers of the new tests are compared to those of some other tests for independence. It is concluded that overall high powers are obtained with these new tests.
IFAC Proceedings Volumes, May 1, 1998
Statistics & Probability Letters, Sep 1, 2003
Statistics in Medicine, Feb 25, 2013
Journal of Statistical Computation and Simulation, Sep 1, 2004
In this paper we first show that the k-sample Anderson–Darling test is basically an average of Pe... more In this paper we first show that the k-sample Anderson–Darling test is basically an average of Pearson statistics in 2 × k contingency tables that are induced by observation-based partitions of the sample space. As an extension, we construct a family of rank test statistics, indexed by c ∈ ℕ, which is based on similarly constructed c × k partitions. An extensive simulation study, in which
International Journal of Control, Sep 1, 1980
ABSTRACT
The disturbance the sludge is subjected to is most often in the form of a substrate addition (org... more The disturbance the sludge is subjected to is most often in the form of a substrate addition (organic carbon, nitrogen, mixtures, wastewater, etc.). The measurement typically takes place in a small reactor filled with activated sludge that was previously sampled from a treatment plant. ...
We present a semiparametric statistical model for the probabilistic index which is defined as P (... more We present a semiparametric statistical model for the probabilistic index which is defined as P (Y< Y*), where Y and Y* are independent random response variables associated with covariate patterns X and X*, respectively. In particular, we consider the model P (Y< Y*)= ...
Recently the authors have proposed tests for the one-sample and the ksample problem, and a test f... more Recently the authors have proposed tests for the one-sample and the ksample problem, and a test for independence. All three tests are based on sample space partitions, but they were originally developed in different papers. Here we give an overview of the construction of these tests, stressing the common underlying concept of "sample space partitions."
A general method is proposed for detecting differential genes in high density oligonucleotide mic... more A general method is proposed for detecting differential genes in high density oligonucleotide microarrays. It is a unified approach in the sense that it integrates the three preprocessing steps and the statistical testing methods into one semiparametric model. An important characteristic is that no stringent assumptions are imposed on the background correction and normalization steps. Instead of focusing on mean differences in gene expression, we formulate the model in terms of stochastic ordering. In particular, probabilities $P(Y_1 < Y_2 )$, with $Y_i$ the intensity of a gene in group $i$ ($i = 1, 2$), are modeled in terms of predictor variables. We present some theoretical results and spike-in studies are considered for comparing the performance of this new method with existing methods. Finally we apply the new method to a publicly available data set.
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Papers by Jean-pierre Ottoy