In this task, you are given a paper review. Based on the review, your job is to identify language and generate "en" if the review is in English or generate "es" if the review is in Spanish. Note that URLs in the text have been replaced with [Link].

Q: This paper discusses Hyperband, an extension of successive halving by Jamieson & Talwalkar (AISTATS 2016). Successive halving is a very nice algorithm that starts evaluating many configurations and repeatedly cuts off the current worst half to explore many configuration for a limited budget.  Having read the paper for the question period and just rereading it again, I am now not entirely sure what its contribution is meant to be: the only improvement of Hyperband vs. successive halving is in the theoretical worst case bounds (not more than 5x worse than random search), but you can (a) trivially obtain that bound by using a fifth of your time for running random configurations to completion and (b) the theoretical analysis to show this is said to be beyond the scope of the paper. That makes me wonder whether the theoretical results are the contribution of this paper, or whether they are the subject of a different paper and the current paper is mostly an empirical study of the method? I hope to get a response by the authors and see this made clearer in an updated version of the paper.  In terms of experiments, the paper fails to show a case where Hyperband actually performs better than the authors' previous algorithm successive halving with its most agressive setting of bracket b=4. Literally, in every figure, bracket b=4 is at least as good (and sometimes substantially better) than Hyperband. That makes me think that in practice I would prefer successive halving with b=4 over Hyperband. (And if I really want Hyperband's guarantee of not being more than 5x worse than random search I can run random search on a fifth of my machines.)  The experiments also compare to some Bayesian optimization methods, but not to the most relevant very closely related Multi-Task Bayesian Optimization methods that have been dominating effective methods for deep learning in that area in the last 3 years: "Multi-Task Bayesian Optimization" by Swersky, Snoek, and Adams (2013) already showed 5x speedups for deep learning by starting with smaller datasets, and there have been several follow-up papers showing even larger speedups.   Given that this prominent work on multitask Bayesian optimization exists, I also think the introduction, which sells Hyperband as a very new approach to hyperparameter optimization is misleading. I would've much preferred a more down-to-earth pitch that says "configuration evaluation" has been becoming a very important feature in hyperparameter optimization, including Bayesian optimization, that sometimes yields very large speedups (this can be quantified by examples from existing papers) and this paper adds some much-needed theoretical understanding to this and demonstrates how important configuration evaluation is even in the simplest case of being used with random search. I think this could be done easily and locally by adding a paragraph to the intro.  As another point regarding novelty, I think the authors should make clear that approaches for adaptively deciding how many resources to use for which evaluation have been studied for (at least) 23 years in the ML community -- see Maron & Moore, NIPS 1993: "Hoeffding Races: Accelerating Model Selection Search for Classification and Function Approximation" (

A: en
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Q: The primary point made by this paper is that given certain architectural characteristics of multi-GPU systems, namely the use of bi-directional PCI-E for communication and the integration of two independent DMA engines on recent GPU devices (providing support for simultaneous independent communications), and given the characteristics of the communications patterns required by synchronous SGD trainers for deep neural networks, namely that the messages are large, dense, and have a fixed length, it makes sense to design communication collectives such as broadcast, reduce, and allreduce specifically for the use case of synchronous SGD training on a multi-GPU system.  The paper describes the implementation of these three collectives (broadcast, reduce, and allreduce) using a linear pipelining (LP) scheme on a (logical) ring topology.  The paper compares the LP collectives to two alternatives:  collectives based on a minimal spanning tree (MST) topology and collectives based on bidirectional exchange (BE).  First, a theoretical comparison is made using a standard cost model used in the high performance computing community.  When assumptions based on multi-GPU system architecture (very low latency for messages) and on the communication characteristics of synchronous SGD training (very large messages) are integrated into the model, the paper finds that the LP collectives should be less costly than BE collectives by a factor of 2 and less costly than MST collectives by a factor of log(p), where p is the number of GPUs being used.  Second, an empirical comparison is performed in which (1) the time required to perform each of the different collectives on a 4-device (k40m) system is measured as a function of message size and (2) the time required to perform each of the different collectives with a 200 MB message length is measured as a function of the number of devices in the system.  These measurements show that the LP-based collectives are consistently the fastest.  Third, DNN training experiments with AlexNet and GoogLeNet are performed on a 4-device system using three different synchronous SGD algorithms with the different implementations of the collectives (a total of 6 different algorithms in all).  Measurements of the communication and computation costs show that the LP collectives reduce communication costs without affecting computation costs (as expected).  Measurements of the convergence of the training loss as a function of time for the two DNN architectures show that use of the LP collectives leads to faster training.  While the theory says that the costs of LP collectives should be invariant to the number of devices in a multi-GPU system, the empirical work shows that in practice this does not hold going from 4 to 5 devices (in the tested configuration) because in a 5-device system messages must traverse the QPI.  Are there other practical considerations that the authors are aware of that affect the scaling of the LP collectives?  If so, these should be mentioned in the paper.  In the sentence "Worringen (2003) proposed a pipeline collective model in shared memory environment for CPU data, but communications of different MPI processes sharing the same CPU memory bus within the same CPU socket." I really can't figure out what the words after "but communications of different MPI processes" are trying to convey.  This sentence is not comprehensible.  "Please note the latency term is log pα, which is the smallest among algorithms in Table.1. Therefore, MST only suits for high frequent short messages."  The claim that MST collectives are only suitable for high-frequency, short messages does not follow from the statement that MST collectives have the smallest latency term.  You also need to consider the way the cost scales with message size (the bandwidth term).  If the MST collectives had a better bandwidth term than the other collectives, then they would also be superior for large messages.  "Let’s take an appropriate block size b to ensure n/b ≪ α."  This looks wrong, since n > b.  Should it be b/n ≪ α?  "However, the parameters are not consistent after several iterations due to the precision issues of float multiplications in Gradient Update."  Are you sure the inconsistency in weight estimates across devices is due to multiplication?  I would expect that it would be due to gradients being accumulated in different orders; that is, because floating point addition is not commutative.  I recommend replacing the term "sub-gradients" in this paper with "partial gradients."  In the optimization literature, the term "sub-gradient" has a very specific meaning that differs from this paper's use of the term (see

A: en
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Q: El tema de la participación ciudadana es hoy uno de los temas a nivel de gobierno  que interesa a los gobiernos y a los ciudadanos. Los autores presentan una aplicación que aplica estos conceptos en ámbito de gobierno local.  El objetivo del artículo no es claro. Los autores declaran que el proyecto asociado a este artículo tiene como objetivo desarrollar métodos que den soporte social a la participación de los ciudadanos de Monteria en los procesos y/o decisiones de gobierno.... Por otro lado ellos declaran que el objetivo  es proporcionar una arquitectura de apoyo  a la toma de decisiones grupales y de comunicaciones, que facilite la participación ciudadana en aquellos proceso públicos relacionados con la toma de decisiones , promover su empleo en decisiones importantes y explorar los aspectos políticos-legales asociados al mismo.  Sin embargo estos objetivos se refieren al proyecto ya que ellos no se desarrollan en el artículo. Los autores deben dejar claro el objetivo del artículo y este debe estar circunscrito a lo que se presenta en él.  El artículo también presenta aspectos negativos relacionados fundamentalmente con la revisión del estado del arte o de la literatura en el tema y en el desarrollo metodológico.  En relación a la revisión de la literatura los autores no presentan los principales estudios en el ámbito de la participación  ciudadana en el mundo. Existe un importante número de publicaciones que abordan este tema en los Estados Unidos y en Europa. Los modelos de madurez del gobierno electrónico abordan claramente este ámbito. Los autores deben  revisar en forma exhaustiva la literatura referente al tema.  El aspecto metodológico del artículo es incompleto ya que no establece un diseño de la investigación que identifique con claridad las herramientas a utilizar en cada etapa y la justificación de las mismas (comparativamente), solo se mencionan dos alternativas pero se desconoce las razones de su eliminación.   Dado que el trabajo se encuentra aún en su etapa de implementación es difícil determinar los beneficios finales de la implementación por lo cual los autores deben destacar esta limitación.

A:
es
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