Fully Decou pled Controller Models for Voltage Source Converter based High Voltage DC Transmission

VSC-HVDC has two distinct advantages over its earlier generation thyristor based High Voltage DC transmission. Synchronous voltage source is not required to commutate against, for its operation and it does not suffer from commutation failures under adverse conditions in interfacing ac system. These two properties make it amenable to wider application areas. To make it adapt to operational conditions imposed on it in various applications, its controller parameters need to be assessed and tuned through extensive simulation studies. To facilitate this, two alternative controllers viz. a fully decoupled controller model and also an instantaneous theory based fully decoupled hybrid controller model are developed in the thesis. The decoupling is achieved by exploiting similarity transformation in both the controllers. In the first controller model, the Park's currents and voltages are directly obtained from the measured network variables and the reference park's currents for the inner current loop are obtained from the instantaneous measured power. In the second one, both the feedback as well as reference Park's currents for the inner current loop are obtained from the Clarke's variables. An AC system interfacing electronics based power transmission or distribution network experiences non-sinusoidal voltage and current waveforms. Instantaneous power theory being suitable for steady as well as transient states, is used for handling measured inputs. The performance of the models is assessed through SIMULINK Power system Blockset aided simulations on a VSC-HVDC link interfacing an ac system, having normal fault level, low fault level and also witnessing a single line to ground fault on its rectifier transformer primary side

Understanding of the logic of nesting of the different realities of architectural space: pedagogical approach

Ponencia presentada a Session 6: Los procesos de diseño como conocimiento / Design processes and knowledg

Understanding of the logic of nesting of the different realities of architectural space: pedagogical approach

Education of architecture in the first year at the national school of architecture and urbanism of Tunis is subject to different experiences drawing their theoretical foundations in several disciplinary fields. Considering the work of several scientists dealing with the perception of space, geometry, as well as effects of sense and the anthropological dimension of architecture, we have introduced a pedagogical approach to deal with architectural space according to the geometric tripartition: topological structures, projective structures and metric structures. The object of this article relate to the pedagogical approach of an exercise registering upstream from the last chapter ‘an introduction to architectural design’. This exercise is the accompaniment of the students in the understanding of the different types of apprehended spaces and the mechanisms underlying their relationship development.Peer Reviewe

A Stochastic Hybrid Framework for Driver Behavior Modeling Based on Hierarchical Dirichlet Process

Scalability is one of the major issues for real-world Vehicle-to-Vehicle network realization. To tackle this challenge, a stochastic hybrid modeling framework based on a non-parametric Bayesian inference method, i.e., hierarchical Dirichlet process (HDP), is investigated in this paper. This framework is able to jointly model driver/vehicle behavior through forecasting the vehicle dynamical time-series. This modeling framework could be merged with the notion of model-based information networking, which is recently proposed in the vehicular literature, to overcome the scalability challenges in dense vehicular networks via broadcasting the behavioral models instead of raw information dissemination. This modeling approach has been applied on several scenarios from the realistic Safety Pilot Model Deployment (SPMD) driving data set and the results show a higher performance of this model in comparison with the zero-hold method as the baseline.Comment: This is the accepted version of the paper in 2018 IEEE 88th Vehicular Technology Conference (VTC2018-Fall) (references added, title and abstract modified

Study and assessment of compost of different organic mixtures and effect of organic compost tea on plant diseases

Four compost treatments representing different organic mixtures were studied: - Treatment T1: 100% cattle manure - Treatment T2: 80% cattle manure and 20% sheep manure - Treatment T3: 70% cattle manure, 20% sheep manure and 10% poultry manure. - Treatment T4: 50% cattle manure, 20% sheep manure, 20% poultry manure and 10% crushed wheat straw. The results showed that the temperature was higher for the 4th treatment which was richer in carbon than the other treatments. The initial alkaline pH decreases for all treatments and approaches neutrality at the end of composting process, essentially for the first treatment. There is also a decrease in the carbon / nitrogen ratio. At the maturity stage, a compost tea was prepared from different composts after five days extraction period. The four compost teas were tested on different plant pathogens: Fusarium roseum var sambucinum, Fusarium oxysporum, Fusarium oxysporum, Fusarium solani var coeruleum, Phytophtora erythroseptica and Rhizoctonia solani. All the treatments were efficient against these pathogens and especially the 4th treatment which considerably reduces also the dry rot of Fusarium solani in potato tubers during storage. This is considered an important result since Fusarium solani seems to be the most important pathogen in Tunisian soils. Our studies should be carried out in order to determine the better combination of organic mixtures, the better method of compost tea extraction (aerobic or anaerobic), the optimal period of extraction and doses to be used

Modeling Pharmaceutical Risk-Sharing Agreements

Many new and expensive drugs have been introduced in the past 10 years. However, at the time of introduction, the effectiveness of these drugs outside of clinical trials is often unknown. This creates a risk to third-party payers, as the outcome of these drugs in real-world practice is uncertain at the time of introduction. A pay-for-performance risk-sharing agreement is a type of contract that shares part of this risk with the manufacturer by linking the performance of a drug to the manufacturer’s revenue. This dissertation consists of three essays to examine the performance of two types of pharmaceutical pay-for-performance risk-sharing agreements. In my first essay I examine the performance of a pay-for-performance risk-sharing agreement in which patients are assessed at some evaluation time to determine their response to the drug. The manufacturer rebates to the payer a proportion of the sales from all patients excluding the sales from those responding at the evaluation time. I model disease progression using a continuous time Markov chain with uncertain transition rates. I address the following questions regarding the performance of this agreement: What is the optimum evaluation time and under what conditions will the manufacturer make a profit? What is the distribution of the manufacturer’s profit resulting from different sources of uncertainty? In the second essay I extend the model developed in the first essay to calculate the net monetary benefits of the payer and identify the conditions under which both parties have incentives to introduce the new drug. The third essay focuses on the analysis of a risk-sharing agreement in which patients are prescribed a drug only if their probability of response lies within a range of success probabilities. The payer determines this range such that the use of the drug is cost-effective. I generalize from the existing literature by allowing the rebate to be different from the price of the drug and incorporating two types of administrative costs. I seek to answer two important policy questions: First, under what conditions does the payer benefit from the agreement? Second, under what conditions does the agreement become welfare-improving