Papers by Edmond Jonckheere
The purpose of this relatively new EE364 course (developed in 1998) is to expose Electrical Engin... more The purpose of this relatively new EE364 course (developed in 1998) is to expose Electrical Engineering students to uncertain phenomena during Junior year. The distinguishing feature between EE464 and EE364 is that the latter course deals with probability AND STATISTICS, while the former course deals with probability only.
The Journal of Alternative and Complementary Medicine, 2009
There has been much debate about the objective basis of Network Spinal Analysis (NSA) and Network... more There has been much debate about the objective basis of Network Spinal Analysis (NSA) and Network Spinal Analysis Care. 1-4 I and a number of my colleagues set out to study this. Our work during the last 10 years 5-10 has revealed some significant objective, repeatable, reliable, and measurable changes, which are the subject of a full paper being submitted for publication.* We believe that these findings have far-reaching implications for the future of health care development and for the development of Network Spinal Analysis Care as a discipline. For this reason, we believe it is
The Journal of Alternative and Complementary Medicine, 2009
There has been much debate about the objective basis of Network Spinal Analysis (NSA) and Network... more There has been much debate about the objective basis of Network Spinal Analysis (NSA) and Network Spinal Analysis Care. 1-4 I and a number of my colleagues set out to study this. Our work during the last 10 years 5-10 has revealed some significant objective, repeatable, reliable, and measurable changes, which are the subject of a full paper being submitted for publication.* We believe that these findings have far-reaching implications for the future of health care development and for the development of Network Spinal Analysis Care as a discipline. For this reason, we believe it is
Scientific Reports
Cellular biological networks represent the molecular interactions that shape function of living c... more Cellular biological networks represent the molecular interactions that shape function of living cells. Uncovering the organization of a biological network requires efficient and accurate algorithms to determine the components, termed communities, underlying specific processes. Detecting functional communities is challenging because reconstructed biological networks are always incomplete due to technical bias and biological complexity, and the evaluation of putative communities is further complicated by a lack of known ground truth. To address these challenges, we developed a geometric-based detection framework based on Ollivier-Ricci curvature to exploit information about network topology to perform community detection from partially observed biological networks. We further improved this approach by integrating knowledge of gene function, termed side information, into the Ollivier-Ricci curvature algorithm to aid in community detection. This approach identified essential conserved a...
2019 IEEE Conference on Control Technology and Applications (CCTA), 2019
This work develops a congestion management method for the power grid utilizing the notion of curv... more This work develops a congestion management method for the power grid utilizing the notion of curvature. It initially uses the curvature concept to detect areas prompt to congestion (negative curvature areas) and it subsequently applies load balancing techniques (through FACTS devices) and load (storage devices) deployment to maximize curvature (grid decongestion) and cost-effectively minimize the generated energy throughout the grid, while at the same time guaranteeing stability under phase angle and voltage constraints. Two different curvature definitions are compared (Ollivier-Ricci Curvature and Effective Resistance Curvature), and an entropy concept suitable to power grid is introduced as a new measure to analyze grid congestion.
Synthetic data. This folder contains the synthetic data used for Fig. 3 and Additional file 4. A... more Synthetic data. This folder contains the synthetic data used for Fig. 3 and Additional file 4. Additionally, it contains the python scripts that were used to make the synthetic data, Fig. 3, and Additional file 4: Figure S9-1. (ZIP 890 kb)
Growth rate estimates versus sampling frequency. This file contains an alternative representation... more Growth rate estimates versus sampling frequency. This file contains an alternative representation of the same data from Fig. 1. In this representation, the x-axis is the sampling interval (instead of the log 10 of the number of samples). (PDF 239 kb)
Windows and OSX distributions of CellPD. This file contains simple instructions and links to down... more Windows and OSX distributions of CellPD. This file contains simple instructions and links to download CellPD and use it on a Windows or an OSX computer. (PDF 119Â kb)
Quantum Information Processing, 2015
Spin networks are endowed with an information transfer fidelity (ITF), which defines an absolute ... more Spin networks are endowed with an information transfer fidelity (ITF), which defines an absolute upper bound on the probability of transmission of an excitation from one spin to another. The ITF is easily computable, but the bound can be reached asymptotically in time only under certain conditions. General conditions for attainability of the bound are established, and the process of achieving the maximum transfer probability is given a dynamical model, the translation on the torus. The time to reach the maximum probability is estimated using the simultaneous Diophantine approximation, implemented using a variant of the Lenstra-Lenstra-Lovász (LLL) algorithm. For a ring with uniform couplings, the network can be made into a metric space by defining a distance (satisfying the triangle inequality) that quantifies the lack of transmission fidelity between two nodes. It is shown that transfer fidelities and transfer times can be improved significantly by means of simple controls taking the form of nondynamic, spatially localized bias fields, opening up the possibility for intelligent design of spin networks and dynamic routing of information encoded in them, while being more flexible than engineering fixed couplings to favor some transfers, and less demanding than control schemes requiring fast dynamic controls.
2015 54th IEEE Conference on Decision and Control (CDC), 2015
Propagation of information encoded in spin degrees of freedom through networks of coupled spins e... more Propagation of information encoded in spin degrees of freedom through networks of coupled spins enables important applications in spintronics and quantum information processing. We study control of information propagation in networks of spin-1 2 particles with uniform nearest neighbor couplings forming a ring with a single excitation in the network as simple prototype of a router for spin-based information. Specifically optimizing spatially distributed potentials, which remain constant during information transfer, simplifies the implementation of the routing scheme. However, the limited degrees of freedom makes finding a control that maximizes the transfer probability in a short time difficult. We show that the structure of the eigenvalues and eigenvectors must fulfill a specific condition to be able to maximize the transfer fidelity, and demonstrate that a specific choice among the many potential structures that fulfill this condition significantly improves the solutions found by optimal control.
1977 IEEE Conference on Decision and Control including the 16th Symposium on Adaptive Processes and A Special Symposium on Fuzzy Set Theory and Applications, 1977
The General Discrete-Time Linear-Quadratic Control Problem, together with the classical time-doma... more The General Discrete-Time Linear-Quadratic Control Problem, together with the classical time-domain and frequency-domain conditions, is reviewed and treated from a novel point of view. When the quadratic cost is allowed to be non positive semi-definite, an important problem is to determine whether or not the cost admits a lower bound. We show that this can be related to the positivity of a self-adjoint Hilbert space operator. This point of view clarifies many features that have remained obscure in the literature. A new frequency-domain technique and a fast algorithm to check the positivity of the operator in question are outlined.
Applied Mathematics and Computation, 1998
The so called simplicial algorithms are put into use to compute the stationary probability distri... more The so called simplicial algorithms are put into use to compute the stationary probability distributions of stochastic matrices. This is a typical exampie of application of sinlplicia~ algorithms to compute the fixed points of a continuous map (Brouwer's theorem). We further demonstrate the variable grid refinement approach involved in the simpljcia~ algorithms. The variable grid refinement scheme gives good accuracy and acceptable average con~putati~~n~~i complexity. 0 199X Elsevier Science Inc. All rights reserved. uctin roblems such as: ~o~~putatiou of zero points [I]. j'(x) = 0; computation of x; com~utat;on of equiti riui~ prices in a free ex-somput~!tion of neutral stability region in uncertain ave received a computational solution firmly rooted gy and usually referred to as .si~t~~li~i(t~ ~~g~trit~tttt.s.
IEEE Transactions on Automatic Control, 2018
Information encoded in networks of stationary, interacting spin-1/2 particles is central for many... more Information encoded in networks of stationary, interacting spin-1/2 particles is central for many applications ranging from quantum spintronics to quantum information processing. Without control, however, information transfer through such networks is generally inefficient. Currently available control methods to maximize the transfer fidelities and speeds mainly rely on dynamic control using time-varying fields and often assume instantaneous readout. We present an alternative approach to achieving efficient, high-fidelity transfer of excitations by shaping the energy landscape via the design of time-invariant feedback control laws without recourse to dynamic control. Both instantaneous readout and the more realistic case of finite readout windows are considered. The technique can also be used to freeze information by designing energy landscapes that achieve Anderson localization. Perfect state or super-optimal transfer and localization are enabled by conditions on the eigenstructure of the system and signature properties for the eigenvectors. Given the eigenstructure enabled by super-optimality, it is shown that feedback controllers that achieve perfect state transfer are, surprisingly, also the most robust with regard to uncertainties in the system and control parameters.
arXiv: Optimization and Control, 2020
The robustness of quantum control in the presence of uncertainties is important for practical app... more The robustness of quantum control in the presence of uncertainties is important for practical applications but their quantum nature poses many challenges for traditional robust control. In addition to uncertainties in the system and control Hamiltonians and initial state preparation, there is uncertainty about interactions with the environment leading to decoherence. This paper investigates the robust performance of control schemes for open quantum systems subject to such uncertainties. A general formalism is developed, where performance is measured based on the transmission of a dynamic perturbation or initial state preparation error to a final density operator error. This formulation makes it possible to apply tools from classical robust control, especially structured singular value analysis, to assess robust performance of controlled, open quantum systems. However, there are additional difficulties that must be overcome, especially at low frequency ($s\approx0$). For example, at ...
2018 Clemson University Power Systems Conference (PSC)
Installing Phasor Measurement Units (PMUs) in the smart grid has played an important role in havi... more Installing Phasor Measurement Units (PMUs) in the smart grid has played an important role in having more reliable and secure grid. Due to the high sampling rate (50 samples/s), PMU generates massive amount of data compared to the conventional SCADA system. Understanding the mathematical and statistical characteristics of the PMU data is a very crucial step to perform accurate modeling and estimation of the power system variables (Voltage (V), frequency (f), and phase angle (θ)). In this paper, we show the non-stationarity of the PMU data by applying Augmented Dickey-Fuller and Kwiatkowski-Phillips-Schmidt-Shin tests on a large data set from the EPFL campus grid. Then, we study the fractality of the PMU data by estimating the differencing parameter (d) in the Autoregressive Fractionally Integrated Moving Average (ARFIMA) model. Our results call for adoption of ARFIMA models to model the PMU data in the smart grid.
Abstract—Traffic properties relevant to Active Queue Management (AQM) and the resulting pole/zero... more Abstract—Traffic properties relevant to Active Queue Management (AQM) and the resulting pole/zero and Bode limitations are examined. ARX models of TCP are derived from data collectedinafixed "dumbbell " simulation environment. The pole dynamics at short time scales can be traced to the RTT, which serves as a confirmation of the relevance of the models. It is shown that the weighted sensitivity function is a reasonable metric for AQM performance. However, � � design shows that the sensitivity can only be slightly reduced. The conclusion of this work is that the goal of smoothing TCP’s oscillations (a principle design goal of AQM) will likely not be met in general. I.
Networks of spins, or spintronic networks, are given an Information Transfer Fidelity (ITF) deriv... more Networks of spins, or spintronic networks, are given an Information Transfer Fidelity (ITF) derived from an upper bound on the probability of transmission of the excitation from one spin to another. It is shown that this theoretical bound can be reached asymptotically in time under certain conditions. The process of achieving maximum transfer probability is given a dynamical model, the translation on the torus, and the time to reach the maximum probability is estimated using the simultaneous Diophantine approximation computationally implemented using a variant of the Lenstra-Lenstra-Lovász (LLL) algorithm. The ITF induces a prametric on the network. For a ring with homogeneous couplings, it is shown that this prametric satisfies the triangle inequality, opening up the road to an ITF geometry, which turns out to be completely different from the geometry of the physical arrangement of the spin in the spintronic device. It is shown that transfer fidelities and transfer times can be im...
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Papers by Edmond Jonckheere