diff --git a/exa-ma-d7.1.tex b/exa-ma-d7.1.tex index 92c08fe..99eb9d0 100644 --- a/exa-ma-d7.1.tex +++ b/exa-ma-d7.1.tex @@ -53,7 +53,7 @@ \definecolor{CustomBlue}{rgb}{0.25, 0.41, 0.88} % RoyalBlue \hypersetup{ pdftitle={Benchmarking analysis report}, - pdfauthor={[Names of co-authors (partners short names)]}, + pdfauthor={[Christophe Prud'homme (UNISTRA), Pierre Alliez (INRIA), Vincent Chabannes (UNISTRA), Rudy Chocat (CEA), Emmanuel Franck (INRIA), Vincent Fraucher (CEA), Floriant Faucher (INRIA), Clément Gauchy (CEA), Christos Georgiadis (INRIA), Luc Giraud (INRIA), Frédéric Hecht (SU), Pierre Jolivet (CNRS), Pierre Ledac (CEA), Gilles Marait (INRIA), Victor Michel-Dansac (INRIA), Frédéric Nataf (SU), Lucas Palazzolo (INRIA), Yannick Privat (UL), Thomas Saigre-Tardif (UNISTRA), Christophe Trophime (CNRS), Pierre Henri Tournier (SU), Céline Van Landeghem (UNISTRA), Raphael Zanella (SU)]}, pdfkeywords={HPC, Exascale, Benchmarking}, bookmarksnumbered,linktocpage, colorlinks=true, @@ -122,17 +122,17 @@ \delivResponsible{UNISTRA} % Deliverable Version, Contractual and Actual Date, Dissemination Level, Type -\delivVersion{v0.0.6} +\delivVersion{v0.2.0} \ContractualDate{15/10/2024} \ActualDate{\today} \delivDissLevel{PU} % PU, PP, RE, CO \delivType{Report} % List of Main Authors (usually from the responsible partner) -\delivAuthor{[Names of co-authors (partners short names)]} +\delivAuthor{[Christophe Prud'homme (UNISTRA)]} % List of Co-Authors (all other co-authors should be listed here) -\delivFPAuthor{[Names of co-authors (partners short names)]} +\delivFPAuthor{[Pierre Alliez (INRIA), Vincent Chabannes (UNISTRA), Rudy Chocat (CEA), Emmanuel Franck (INRIA), Vincent Fraucher (CEA), Floriant Faucher (INRIA), Clément Gauchy (CEA), Christos Georgiadis (INRIA), Luc Giraud (INRIA), Frédéric Hecht (SU), Pierre Jolivet (CNRS), Pierre Ledac (CEA), Gilles Marait (INRIA), Victor Michel-Dansac (INRIA), Frédéric Nataf (SU), Lucas Palazzolo (INRIA), Yannick Privat (UL), Thomas Saigre-Tardif (UNISTRA), Christophe Trophime (CNRS), Pierre Henri Tournier (SU), Céline Van Landeghem (UNISTRA), Raphael Zanella (SU) ]} % Provision of Keywords (about 5-10) \delivKeywords{HPC, Exascale, Benchmarking, Software} @@ -144,7 +144,7 @@ %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%% Change Log %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\istChange{08/10/2024}{v0.2.0}{Prud'homme Christophe (UNISTRA), Thomas Saigre (UNISTRA), Vincent Chabannes(UNISTRA), Céline Van Landeghem (UNISTRA), Victor Dansac(UNISTRA,INRIA),Christos Georgiadis (INRIA), Pierre Alliez(INRIA), Clément Gauchy (CEA), Rudy Rochat(CEA), Florent Faucher (INRIA)}{Initial contributions} +\istChange{11/10/2024}{v0.2.0}{\href{https://github.com/numpex/exa-ma-d7.1/graphs/contributors}{+14 Contributors}}{Initial contributions} \istChange{30/09/2024}{v0.1.0}{Prud'homme Christophe (UNISTRA)}{setup architecture of D7.1, update profiling tools in toc, updates in methodology chapter, add information store in excel sheet in the report,update benchmark methodology} \istChange{27/09/2024}{v0.0.6}{Prud'homme Christophe (UNISTRA)}{In the methodology chapter, link the deliverable to the bottlenecks identified in Exa-MA scientific document. Add resilience stats and methdology, benchmark mmg and parmmg indirectly.} \istChange{26/09/2024}{v0.0.6}{Pierre Jolivet (CNRS)}{Review of the document} @@ -152,7 +152,7 @@ \istChange{02/09/2024}{v0.0.4}{Prud'homme Christophe (UNISTRA)}{ToC: add profiling tools in methodology chapter and udated the chapter overall} \istChange{30/08/2024}{v0.0.3}{Prud'homme Christophe (UNISTRA)}{ToC: setup architecture of D7.1;add benchmarking methodology chapter;add samurai software to be benchmarked} \istChange{20/08/2024}{v0.0.1}{Prud'homme Christophe (UNISTRA)}{Draft report template} -\istChange{}{}{}{} +%%\istChange{}{}{}{} \begin{document} diff --git a/gitHeadLocal.gin b/gitHeadLocal.gin index 70a2f4f..63810ba 100644 --- a/gitHeadLocal.gin +++ b/gitHeadLocal.gin @@ -1,17 +1,17 @@ \usepackage[% - shash={b26bd7c}, - lhash={b26bd7c5389f87390796c7310db5829e332eb9b6}, + shash={33226e4}, + lhash={33226e4c3c8eb1f0f7aafc37af995d5e65515962}, authname={Christophe Prud'homme}, authemail={christophe.prudhomme@cemosis.fr}, - authsdate={2024-09-27}, - authidate={2024-09-27 13:21:07 +0200}, - authudate={1727436067}, + authsdate={2024-10-11}, + authidate={2024-10-11 09:05:41 +0200}, + authudate={1728630341}, commname={Christophe Prud'homme}, commemail={christophe.prudhomme@cemosis.fr}, - commsdate={2024-09-27}, - commidate={2024-09-27 13:21:07 +0200}, - commudate={1727436067}, - refnames={ (HEAD -> main, tag: v0.1.0, origin/main, origin/HEAD)}, - firsttagdescribe={v0.1.0}, - reltag={v0.1.0-0-gb26bd7c} + commsdate={2024-10-11}, + commidate={2024-10-11 09:05:41 +0200}, + commudate={1728630341}, + refnames={ (HEAD -> main, tag: v0.2.0, origin/main, origin/HEAD)}, + firsttagdescribe={v0.2.0}, + reltag={v0.2.0-0-g33226e4} ]{gitexinfo} \ No newline at end of file diff --git a/sections/conclusions.tex b/sections/conclusions.tex index 5e0185f..0d3a3d4 100644 --- a/sections/conclusions.tex +++ b/sections/conclusions.tex @@ -31,6 +31,11 @@ \section{Conclusions} The initial benchmarking results present the initial state in developing exascale-ready numerical methods and software tools. The challenges identified during this process have informed our future work. +Depending on the software, the presentation of the results vary and we have in general an unbalanced presentation not only within each workpackage but also across the workpackages. +We do not feel that this is a problem, as the various software are in different stages of development and benchamarking and the benchmarking results are not yet all readily available. +However, during the coming months we should strive to setup the methodology for all software and be able any moment to present current results. +The next release of this documentation should have a more balanced systematic presentation of the results within and across the workpackages. + \section*{Future Work} @@ -38,12 +43,13 @@ \section*{Future Work} Our future efforts will focus on: \begin{itemize} + \item \textbf{Incorporating new methods and algorithms}: Developing and integrating novel numerical methods and algorithms optimized for exascale architectures. \item \textbf{Enhancing Scalability and Performance}: Further optimizing numerical methods and software tools to fully leverage emerging exascale platforms, ensuring efficient utilization of computational resources. \item \textbf{Extending Benchmarking Metrics}: Incorporating new metrics and evaluation criteria relevant to exascale computing, such as energy consumption, resilience, and data movement efficiency. \item \textbf{Fault Tolerance Mechanisms}: Implementing fault tolerance strategies to maintain resilience in the face of hardware and software failures common in exascale environments. \item \textbf{Strengthening Community Collaboration}: Engaging with the broader HPC community to share insights, tools, and best practices, fostering a collaborative ecosystem that accelerates progress. - \item \textbf{Addressing Identified Challenges}: Focusing research and development efforts on overcoming the specific bottlenecks and challenges identified in the initial benchmarking phase. + \item \textbf{Addressing Identified Challenges}: Focusing research and development efforts on overcoming the specific bottlenecks and challenges identified in this initial benchmarking phase. \end{itemize} \section*{Final Remarks} diff --git a/software/freefempp/freefempp.tex b/software/freefempp/freefempp.tex index 8913f40..74b6394 100644 --- a/software/freefempp/freefempp.tex +++ b/software/freefempp/freefempp.tex @@ -164,29 +164,29 @@ \subsection{Relevant Publications} \begin{description} \item[\fullcite{hecht_new_2012}] This is a short presentation of the capabilities of the software. The documentation is available online at \url{https://doc.freefem.org}. -{TOCITE Mathematics and Finite Element Discretizations of Incompressible Navier-Stokes Flows} This self-contained book provides a thorough theoretical study of finite element methods for solving incompressible Navier-Stokes equations. It focuses on efficient and widely used finite element methods that are well adapted to large-scale simulations. In this revised and expanded edition of Girault and Raviart's 1986 textbook Finite Element Methods for Navier-Stokes Equations, readers will find rigorous proof of stability and convergence, analysis of practical algorithms, and a stand-alone chapter on finite element methods that is applicable to a large range of PDEs. The book also covers a variety of numerical algorithms used in the computer implementation of Navier-Stokes equations and numerical experiments. +\item[\fullcite{bernardi_mathematics_2024}] This self-contained book provides a thorough theoretical study of finite element methods for solving incompressible Navier-Stokes equations. It focuses on efficient and widely used finite element methods that are well adapted to large-scale simulations. In this revised and expanded edition of Girault and Raviart's 1986 textbook Finite Element Methods for Navier-Stokes Equations, readers will find rigorous proof of stability and convergence, analysis of practical algorithms, and a stand-alone chapter on finite element methods that is applicable to a large range of PDEs. The book also covers a variety of numerical algorithms used in the computer implementation of Navier-Stokes equations and numerical experiments. -{TOCITE An Introduction to Domain Decomposition Methods: Algorithms, Theory, and Parallel Implementation} The purpose of this book is to offer an overview of the most popular domain decomposition methods for partial differential equations (PDEs). The authors present all popular algorithms, both at the PDE level and at the discrete level in terms of matrices, along with systematic FreeFEM scripts for sequential implementation as well as some parallel scripts. +\item[\fullcite{dolean_introduction_2015}] The purpose of this book is to offer an overview of the most popular domain decomposition methods for partial differential equations (PDEs). The authors present all popular algorithms, both at the PDE level and at the discrete level in terms of matrices, along with systematic FreeFEM scripts for sequential implementation as well as some parallel scripts. -{TOCITE A GenEO Domain Decomposition method for Saddle Point problems} This paper introduces an adaptive element-based domain decomposition (DD) method for solving saddle point problems defined as a block two by two matrix. The algorithm does not require any knowledge of the constrained space. The design of the adaptive coarse space extends the GenEO theory to saddle point problems. Numerical results on three dimensional elasticity problems for steel-rubber structures are shown for up to one billion degrees of freedom. +\item[\fullcite{nataf_geneo_2024}] This paper introduces an adaptive element-based domain decomposition (DD) method for solving saddle point problems defined as a block two by two matrix. The algorithm does not require any knowledge of the constrained space. The design of the adaptive coarse space extends the GenEO theory to saddle point problems. Numerical results on three dimensional elasticity problems for steel-rubber structures are shown for up to one billion degrees of freedom. -{TOCITE An 89-line code for geometrically nonlinear topology optimization written in FreeFEM} This paper presents an 89-line code for nonlinear topology optimization written in FreeFEM based on the popular SIMP (solid isotropic material with penalization) method. Excluding thirteen lines which are used for explanation, only 76 lines are needed for the initialization of the design parameters, nonlinear finite element analysis, sensitivity calculation, and updated design variables. Different design problems can be solved by modifying several lines in the proposed program. +\item[\fullcite{zhu_89-line_2021}] This paper presents an 89-line code for nonlinear topology optimization written in FreeFEM based on the popular SIMP (solid isotropic material with penalization) method. Excluding thirteen lines which are used for explanation, only 76 lines are needed for the initialization of the design parameters, nonlinear finite element analysis, sensitivity calculation, and updated design variables. Different design problems can be solved by modifying several lines in the proposed program. -{TOCITE PDE-constrained optimization within FreeFEM} This book is aimed at students and researchers who want to learn how to efficiently solve constrained optimization problems involving partial differential equations (PDE) using the FreeFEM software. +\item[\fullcite{hecht_pde-constrained_2024}] This book is aimed at students and researchers who want to learn how to efficiently solve constrained optimization problems involving partial differential equations (PDE) using the FreeFEM software. -{TOCITE Numerical Modeling and High-Speed Parallel Computing: New Perspectives on Tomographic Microwave Imaging for Brain Stroke Detection and Monitoring} This paper deals with microwave tomography for brain stroke imaging using state-of-the-art numerical modeling and massively parallel computing. It includes the accurate modeling of a whole-microwave measurement system. The inverse problem is solved by a gradient based L-BFGS minimization algorithm. The successive solution of the direct problem in the optimization loop is accelerated using an Optimized Restricted Additive Schwarz (ORAS) preconditioner. +\item[\fullcite{tournier_numerical_2017}] This paper deals with microwave tomography for brain stroke imaging using state-of-the-art numerical modeling and massively parallel computing. It includes the accurate modeling of a whole-microwave measurement system. The inverse problem is solved by a gradient based L-BFGS minimization algorithm. The successive solution of the direct problem in the optimization loop is accelerated using an Optimized Restricted Additive Schwarz (ORAS) preconditioner. -{TOCITE Parallel finite-element codes for the simulation of two-dimensional and three-dimensional solid-liquid phase-change systems with natural convection} This work presents a FreeFEM Toolbox for the parallel computing of two- or three-dimensional liquid-solid phase-change systems involving natural convection. Parallel 2D and 3D computations of benchmark cases of increasing difficulty are presented: natural convection of air, natural convection of water, melting or solidification of a phase-change material, water freezing. For each case, careful validations are provided and the performance of the code is assessed. +\item[\fullcite{sadaka_parallel_2020}] This work presents a FreeFEM Toolbox for the parallel computing of two- or three-dimensional liquid-solid phase-change systems involving natural convection. Parallel 2D and 3D computations of benchmark cases of increasing difficulty are presented: natural convection of air, natural convection of water, melting or solidification of a phase-change material, water freezing. For each case, careful validations are provided and the performance of the code is assessed. -{TOCITE Three-dimensional finite-difference finite-element frequency-domain wave simulation with multi-level optimized additive Schwarz domain-decomposition preconditioner: A tool for FWI of sparse node datasets} In seismic imaging, efficient frequency-domain full-waveform inversion (FWI) of long-offset node data can be designed with a few discrete frequencies, which lead to modest data volumes to be managed during the inversion process. This requires the solution of large and sparse linear indefinite systems for each frequency with multiple right-hand sides (RHSs). Here we investigate Optimized Restricted Additive Schwarz (ORAS) preconditioners with Robin or Perfectly Matched Layer (PML) interface conditions. Multiple sources are processed in groups with a pseudo-block method. The accuracy, computational cost and scalability of the solver are assessed against several realistic benchmarks. +\item[\fullcite{tournier_three-dimensional_2022}] In seismic imaging, efficient frequency-domain full-waveform inversion (FWI) of long-offset node data can be designed with a few discrete frequencies, which lead to modest data volumes to be managed during the inversion process. This requires the solution of large and sparse linear indefinite systems for each frequency with multiple right-hand sides (RHSs). Here we investigate Optimized Restricted Additive Schwarz (ORAS) preconditioners with Robin or Perfectly Matched Layer (PML) interface conditions. Multiple sources are processed in groups with a pseudo-block method. The accuracy, computational cost and scalability of the solver are assessed against several realistic benchmarks. -{TOCITE Three-dimensional topology optimization of a fluid-structure system using body-fitted mesh adaption based on the level-set method} This paper presents a new framework for the two- and three-dimensional topology optimization of the weakly-coupled fluid-structure system. The proposed design methodology uses a reaction-diffusion equation for updating the level-set function based on the topological sensitivity. The performance of the methodology is demonstrated by solving three different optimization problems: compliance, power dissipation, and fluid-structure interaction. For comparison and for assessing the various techniques, the designs are benchmarked against state-of-the-art works followed by showcasing a variety of practical engineering design examples. +\item[\fullcite{li_three-dimensional_2022}] This paper presents a new framework for the two- and three-dimensional topology optimization of the weakly-coupled fluid-structure system. The proposed design methodology uses a reaction-diffusion equation for updating the level-set function based on the topological sensitivity. The performance of the methodology is demonstrated by solving three different optimization problems: compliance, power dissipation, and fluid-structure interaction. For comparison and for assessing the various techniques, the designs are benchmarked against state-of-the-art works followed by showcasing a variety of practical engineering design examples. -{TOCITE Geometrical shape optimization in fluid mechanics using FreeFem++} This paper presents simple and robust numerical methods for two-dimensional geometrical shape optimization problems, in the context of viscous flows driven by the stationary Navier-Stokes equations at low Reynolds number. Several pedagogical examples are discussed. The corresponding program is written in the FreeFem++ environment, and it is freely available. Its chief features are carefully presented, so that it can easily be handled and elaborated upon to deal with different, or more complex physical situations. +\item[\fullcite{dapogny_geometrical_2018}] This paper presents simple and robust numerical methods for two-dimensional geometrical shape optimization problems, in the context of viscous flows driven by the stationary Navier-Stokes equations at low Reynolds number. Several pedagogical examples are discussed. The corresponding program is written in the FreeFem++ environment, and it is freely available. Its chief features are carefully presented, so that it can easily be handled and elaborated upon to deal with different, or more complex physical situations. -{TOCITE Radiative transfer for variable three-dimensional atmospheres} To study the temperature in a gas subjected to electromagnetic radiations, one may use the Radiative Transfer equations coupled with the Navier-Stokes equations. The problem has 7 dimensions but can be simplified to a small number of integro-differential equations in 3 dimensions. This work presents the method and its numerical implementation using a Hierarchical matrix compression scheme, using FreeFEM and HTOOL. Applications to the temperature in the French Chamonix valley are presented with and without snow or cloud and with a variable absorption coefficient taken from the Gemini measurements. The software is precise enough to assert temperature differences due to increased absorption in the vibrational frequency subrange of greenhouse gases. +\item[\fullcite{golse_radiative_2023}] To study the temperature in a gas subjected to electromagnetic radiations, one may use the Radiative Transfer equations coupled with the Navier-Stokes equations. The problem has 7 dimensions but can be simplified to a small number of integro-differential equations in 3 dimensions. This work presents the method and its numerical implementation using a Hierarchical matrix compression scheme, using FreeFEM and HTOOL. Applications to the temperature in the French Chamonix valley are presented with and without snow or cloud and with a variable absorption coefficient taken from the Gemini measurements. The software is precise enough to assert temperature differences due to increased absorption in the vibrational frequency subrange of greenhouse gases. -{TOCITE A finite element toolbox for the Bogoliubov-de Gennes stability analysis of Bose-Einstein condensates} This work presents a FreeFEM finite element toolbox for the computation of Bogoliubov-de Gennes modes used to assess the linear stability of stationary solutions of the Gross-Pitaevskii (GP) equation. Applications concern one (single GP equation) or two-component (a system of coupled GP equations) Bose-Einstein condensates in one, two and three dimensions of space. Programs are validated through comparisons with known theoretical results for simple cases and numerical results reported in the literature. +\item[\fullcite{sadaka_finite_2024}] This work presents a FreeFEM finite element toolbox for the computation of Bogoliubov-de Gennes modes used to assess the linear stability of stationary solutions of the Gross-Pitaevskii (GP) equation. Applications concern one (single GP equation) or two-component (a system of coupled GP equations) Bose-Einstein condensates in one, two and three dimensions of space. Programs are validated through comparisons with known theoretical results for simple cases and numerical results reported in the literature. \end{description} \subsection{Acknowledgements} diff --git a/software/pbb/pbb.tex b/software/pbb/pbb.tex index 23ecd52..7da062b 100644 --- a/software/pbb/pbb.tex +++ b/software/pbb/pbb.tex @@ -21,7 +21,11 @@ \section{Software: pBB} \rowcolor{numpexlightergray}\textbf{Supported Architectures} & \begin{tabular}{l} CPU or GPU\\ \end{tabular} \\ - \rowcolor{white}\textbf{Repository} & \href{https://gitlab.inria.fr/jgmys/permutationbb}{https://gitlab.inria.fr/jgmys/permutationbb} \\ + \rowcolor{white}\textbf{Repository} & + \begin{tabular}{l} + \href{https://gitlab.inria.fr/jgmys/permutationbb}{https://gitlab.inria.fr/jgmys/permutationbb}\\ + \href{https://github.com/Guillaume-Helbecque/P3D-DFS}{https://github.com/Guillaume-Helbecque/P3D-DFS} \\ + \end{tabular} \\ \rowcolor{numpexlightergray}\textbf{License} & \begin{tabular}{l} OSS: Cecill-*\\ \end{tabular} \\ @@ -40,18 +44,25 @@ \section{Software: pBB} \subsection{Software summary} \label{sec:pBB:summary} -%Detailed overview not available. -pBB is initially an implementation of a massively parallel Branch\&Bound algorithm for the exact resolution of permutation-based optimization problems, like Permutation Flow-shop Scheduling (see https://gitlab.inria.fr/jgmys/permutationbb). pBB is designed using the bare-metal MPI+X approach. First, pBB has been extended to improve its genericity w.r.t optimization problems than can be solved, going beyond the permutation ones. A new data structure named distBag-DFS is proposed for that purpose. In addition, a PGAS-guided design approach is used to improve its software productivity-awareness (see https://github.com/Guillaume-Helbecque). The Chapel language is used for the implementation of pBB meeting these genericity and productivity objectives. +pBB is initially an implementation of a massively parallel Branch-and-Bound (B\&B) algorithm for the exact resolution of permutation-based optimization problems, like Permutation Flow-shop Scheduling (see \url{https://gitlab.inria.fr/jgmys/permutationbb}). pBB is designed using the bare-metal MPI+X approach. +First, pBB has been extended to improve its genericity w.r.t optimization problems than can be solved, going beyond the permutation ones, like Knapsack problems. A new data structure named distBag-DFS is proposed for that purpose. +In addition, a PGAS-guided design approach is used to improve its software productivity-awareness (see \url{https://github.com/Guillaume-Helbecque/P3D-DFS}). The Chapel language is used for this implementation of pBB meeting these genericity and productivity objectives. \subsection{Purpose} \label{sec:pBB:purpose} -Purpose not available. +Three main properties characterize pBB: +\begin{itemize} + \item \textbf{Generalization}: our goal is to build a framework which unifies and generalizes various popular fractal decomposition-based algorithms from different communities (e.g. global optimization, reinforcement learning, computational intelligence). + + \item + + \item \textbf{Massively parallel}: a transparent and efficient parallel implementation of the algorithms on various architectures (e.g. multicores, GPUs) is carried out. The main challenge is the parallelization of the tree search component of the framework. Many parallel tree search algorithms can be considered. +\end{itemize} \subsection{Programming and Computational Environment} \label{sec::pBB:environment_capabilities} - The following table summarizes these aspects for pBB, providing a view of its programming and computational capabilities. \begin{table}[h!] @@ -102,9 +113,8 @@ \subsection{Programming and Computational Environment} \subsection{Mathematics} \label{sec:pBB:mathematics} -Mathematics not available. -In this section, provide a summary the mathematics used in the software. +Combinatorial Optimization Problems (COP) consist in finding an object within a finite (or countably infinite) set which is optimal according to a given criterion. Formally, a COP can be defined as a couple $(X, f)$, where $X$ is the search space and $f:X\rightarrow \mathbb{R}$ the objective function to be minimized or maximized. Constraints that must be fulfilled by a feasible solution $x\in X$ can be incorporated in the definition of the search space $X$ or the objective function $f$. The objective function $f$ takes its values in a totally ordered set, usually the set of real numbers or integers. The value $f(x)$ measures the cost (e.g., quality, time, benefit) of solution $x\in X$. The goal is to find one or multiple solution(s) $x^*\in X$ that are feasible and satisfy $f(x^*)\leq f(x), \forall x\in X$ in the case of minimization, or $f(x^*)\geq f(x), \forall x\in X$ in the case of maximization. \subsection{Relevant Publications} \label{sec:pBB:publications}