Energy-Efficient Approximate Computation in Topaz

We present Topaz, a new task-based language for computations that execute on approximate computing platforms that may occasionally produce arbitrarily inaccurate results. The Topaz implementation maps approximate tasks onto the approximate machine and integrates the approximate results into the main computation, deploying a novel outlier detection and reliable reexecution mechanism to prevent unacceptably inaccurate results from corrupting the overall computation. Topaz therefore provides the developers of approximate hardware with substantial freedom in producing designs with little or no precision or accuracy guarantees. Experimental results from our set of benchmark applications demonstrate the effectiveness of Topaz and the Topaz implementation in enabling developers to productively exploit emerging approximate hardware platforms

Hardware-Aware Static Optimization of Hyperdimensional Computations

Binary spatter code (BSC)-based hyperdimensional computing (HDC) is a highly error-resilient approximate computational paradigm suited for error-prone, emerging hardware platforms. In BSC HDC, the basic datatype is a hypervector, a typically large binary vector, where the size of the hypervector has a significant impact on the fidelity and resource usage of the computation. Typically, the hypervector size is dynamically tuned to deliver the desired accuracy; this process is time-consuming and often produces hypervector sizes that lack accuracy guarantees and produce poor results when reused for very similar workloads. We present Heim, a hardware-aware static analysis and optimization framework for BSC HD computations. Heim analytically derives the minimum hypervector size that minimizes resource usage and meets the target accuracy requirement. Heim guarantees the optimized computation converges to the user-provided accuracy target on expectation, even in the presence of hardware error. Heim deploys a novel static analysis procedure that unifies theoretical results from the neuroscience community to systematically optimize HD computations. We evaluate Heim against dynamic tuning-based optimization on 25 benchmark data structures. Given a 99% accuracy requirement, Heim-optimized computations achieve a 99.2%-100.0% median accuracy, up to 49.5% higher than dynamic tuning-based optimization, while achieving 1.15x-7.14x reductions in hypervector size compared to HD computations that achieve comparable query accuracy and finding parametrizations 30.0x-100167.4x faster than dynamic tuning-based approaches. We also use Heim to systematically evaluate the performance benefits of using analog CAMs and multiple-bit-per-cell ReRAM over conventional hardware, while maintaining iso-accuracy -- for both emerging technologies, we find usages where the emerging hardware imparts significant benefits

Executive Coaching In Morocco: Simple Trend Or A Really Impactful Process?

Nowadays, organizations present an environment leading people to greater competitiveness and individual performance in the workplace. In order to better serve its interests and objectives, business community use different forms of support of their managers, namely the executive coaching, object of our study. This approach is applied as a managers’ performance development strategy (Grant & Greene, 2004; Moën & Federici, 2012; Moën & Skaalvik, 2009). Since the last 90’s, executive coaching is gaining progressive popularity in Morocco, thanks to the emergence of different coaching programs and institutions. The aim of the present study is to highlight the main reasons explaining the resort to this strategy, and to bring valuable insights about its success factors and its impacts on managers’ performance. Is executive coaching in Morocco just an observable trend or a real difference making process? Through semi-structured interviews, conducted with Moroccan coaches, coachees and a HR Manager, we will analysis this research question.Nowadays, organizations present an environment leading people to greater competitiveness and individual performance in the workplace. In order to better serve its interests and objectives, business community use different forms of support of their managers, namely the executive coaching, object of our study. This approach is applied as a managers’ performance development strategy (Grant & Greene, 2004; Moën & Federici, 2012; Moën & Skaalvik, 2009). Since the last 90’s, executive coaching is gaining progressive popularity in Morocco, thanks to the emergence of different coaching programs and institutions. The aim of the present study is to highlight the main reasons explaining the resort to this strategy, and to bring valuable insights about its success factors and its impacts on managers’ performance. Is executive coaching in Morocco just an observable trend or a real difference making process? Through semi-structured interviews, conducted with Moroccan coaches, coachees and a HR Manager, we will analysis this research question

An Analysis of Patch Plausibility and Correctness for Generate-And-Validate Patch Generation Systems

We analyze reported patches for three existing generate-and-validate patch generation systems (GenProg, RSRepair, and AE). The basic principle behind generate-and-validate systems is to accept only plausible patches that produce correct outputs for all inputs in the test suite used to validate the patches. Because of errors in the patch evaluation infrastructure, the majority of the reported patches are not plausible --- they do not produce correct outputs even for the inputs in the validation test suite. The overwhelming majority of the reported patches are not correct and are equivalent to a single modification that simply deletes functionality. Observed negative effects include the introduction of security vulnerabilities and the elimination of desirable standard functionality. We also present Kali, a generate-and-validate patch generation system that only deletes functionality. Working with a simpler and more effectively focused search space, Kali generates at least as many correct patches as prior GenProg, RSRepair, and AE systems. Kali also generates at least as many patches that produce correct outputs for the inputs in the validation test suite as the three prior systems. We also discuss patches produced by ClearView, a generate-and-validate binary hot patching system that leverages learned invariants to produce patches that enable systems to survive otherwise fatal defects and security attacks. Our analysis indicates that ClearView successfully patches 9 of the 10 security vulnerabilities used to evaluate the system. At least 4 of these patches are correct

Automatic Program Repair with Condition Synthesis and Compound Mutations

We present PCR, a new automatic patch generation system. PCR uses a new condition synthesis technique to efficiently discover logical expressions that generate desired control- flow transfer patterns. Presented with a set of test cases, PCR deploys condition synthesis to find and repair incorrect if conditions that cause the application to produce the wrong result for one or more of the test cases. PCR also leverages condition synthesis to obtain a set of compound modifications that generate a rich, productive, and tractable search space of candidate patches. We evaluate PCR on a set of 105 defects from the GenProg benchmark set. For 40 of these defects, PCR generates plausible patches (patches that generate correct outputs for all inputs in the test suite used to validate the patch). For 12 of these defects, PCR generates correct patches that are functionally equivalent to developer patches that appear in subsequent versions. For comparison purposes, GenProg generates plausible patches for only 18 defects and correct patches for only 2 defects. AE generates plausible patches for only 27 defects and correct patches for only 3 defects

Design of Novel Analog Compute Paradigms with Ark

Previous efforts on reconfigurable analog circuits mostly focused on specialized analog circuits, produced through careful co-design, or on highly reconfigurable, but relatively resource inefficient, accelerators that implement analog compute paradigms. This work deals with an intermediate point in the design space: Specialized reconfigurable circuits for analog compute paradigms. This class of circuits requires new methodologies for performing co-design, as prior techniques are typically highly specialized to conventional circuit classes (e.g., filters, ADCs). In this context, we present Ark, a programming language for describing analog compute paradigms. Ark enables progressive incorporation of analog behaviors into computations, and deploys a validator and dynamical system compiler for verifying and simulating computations. We use Ark to codify the design space for three different exemplary circuit design problems, and demonstrate that Ark helps exploring design trade-offs and evaluating the impact of nonidealities to the computation

Reliability-Aware Optimization of Approximate Computational Kernels with Rely

Emerging high-performance architectures are anticipated to contain unreliable components (e.g., ALUs) that offer low power consumption at the expense of soft errors. Some applications (such as multimedia processing, machine learning, and big data analytics) can often naturally tolerate soft errors and can therefore trade accuracy of their results for reduced energy consumption by utilizing these unreliable hardware components. We present and evaluate a technique for reliability-aware optimization of approximate computational kernel implementations. Our technique takes a standard implementation of a computation and automatically replaces some of its arithmetic operations with unreliable versions that consume less power, but may produce incorrect results with some probability. Our technique works with a developer-provided specification of the required reliability of a computation -- the probability that it returns the correct result -- and produces an unreliable implementation that satisfies that specification. We evaluate our approach on five applications from the image processing, numerical analysis, and financial analysis domains and demonstrate how our technique enables automatic exploration of the trade-off between the reliability of a computation and its performance

Analyse de la pratique du coaching exécutif au Maroc

In the current context, the organizational climate presents an environment that leads managers to greater competitiveness and individual performance in order to better serve the interests and objectives of their organizations.  This leads them to resort to different forms of support, including coaching, considered as a strategy to develop the performance of managers. Since the end of the 90s, executive coaching has been gradually gaining popularity in Morocco, thanks to the emergence of various coaching programs and institutions. This article aims to analyze the practice of executive coaching in Morocco and to answer the following research question: Is executive coaching in Morocco just a fad or a real process with a real impact? The results of semi-structured interviews conducted with six coaches, three coachees and one HRD show that the practice of coaching in Morocco has gone beyond the stage of fashion, and that the characteristics of each of the participants have a direct impact on the effectiveness of the coaching process.   Keywods: Executive coaching Process Factors of success Effects JEL Classification: O15 Paper Type: Empircal ResearchDans le contexte actuel, le climat organisationnel présente un environnement conduisant les managers à une plus grande compétitivité et à une meilleure performance individuelle, afin de mieux servir les intérêts et les objectifs de leurs organisations.  Cela conduit ces dernières au recours à différentes formes d’accompagnement, dont le coaching, considéré comme étant une stratégie de développement de la performance des managers. Depuis la fin des années 90, le coaching exécutif gagne progressivement en popularité au Maroc, grâce notamment à l'émergence de différents programmes et institutions de coaching. Le présent article a pour objectif d’analyser la pratique du coaching exécutif au Maroc et de répondre à la question de recherche suivante : est-ce que le coaching exécutif au Maroc est juste un effet de mode ou bien un véritable processus avec un réel impact ? Les résultats d’entretiens semi-directifs menés auprès de six coachs, trois coachés et un DRH montrent que la pratique du coaching au Maroc a dépassé le stade de la mode, et que les caractéristiques liées à chacun des intervenants ont un impact direct sur l'efficacité du processus de coaching.   Mots clés : Coaching des cadres Processus Facteurs de réussite Effets Classification JEL : O15 Type de papier : Recherche empiriqu

Les enjeux communicationnels dans la gestion de la supply chain : Une étude exploratoire dans le secteur d'importation-distribution des produits informatiques au Maroc

In the context of a competitive economic environment, it is essential for any company to coordinate, cooperate, and collaborate with various stakeholders in the supply chain if it wishes to thrive in a fierce market. This article emphasizes the importance of communication throughout the supply chain process and highlights its impact on all aspects of a company. Reliable communication within the supply chain, supported by well-defined processes, a clear information flow, and an appropriate information system, can contribute to managing uncertainties related to unpredictable market changes. By establishing effective communication, companies can better anticipate demand fluctuations, optimize inventory levels, improve production planning, and respond more quickly to customer demands. To this end, we propose identifying commonly encountered communication issues within the supply chain, which helps to better understand the challenges of communication between different links in this chain. To reach these conclusions, we used an exploratory qualitative approach combined with thematic content analysis, based on semi-structured interviews with the five main importers and distributors of authorized computer products by manufacturers and publishers, who hold a near-monopoly in the Moroccan market. The results of this study have demonstrated that communication among supply chain actors can provide operational and tactical advantages to the stakeholders, although its strategic implementation is complex. By understanding these challenges and seeking appropriate solutions, companies can strengthen their competitive position and ensure their longevity in the market. Keywords: Communication, supply chain, stakeholders, information flow. JEL Classification : D83, R41, L2 Paper type : Empirical researchDans le contexte d'une conjoncture économique compétitive, il est essentiel pour toute entreprise de coordonner, coopérer et collaborer avec les différents acteurs de la supply chain si elle souhaite perdurer sur un marché acharné. Cet article souligne l'importance de la communication tout au long du processus de la supply chain et met en évidence son impact sur tous les aspects d'une entreprise. Une communication fiable au sein de la supply chain, soutenue par des processus bien définis, un circuit d'information claire et un système d'information adapté, peut contribuer à la gestion des incertitudes liées aux changements imprévisibles du marché. En établissant une communication efficace, les entreprises peuvent mieux anticiper les variations de la demande, optimiser leurs niveaux de stock, améliorer la planification de la production et répondre plus rapidement aux demandes des clients. À cet effet, nous proposons une identification des problèmes de communication couramment rencontrés au sein de la supply chain, ce qui permet de mieux comprendre les enjeux de la communication entre les différents maillons de cette chaîne. Pour parvenir à ces conclusions, nous avons utilisé une approche qualitative exploratoire combinée à une analyse de contenu thématique, basée sur des entretiens semi-directifs avec les cinq principaux importateurs-distributeurs de produits informatiques agréés par les constructeurs et éditeurs, qui détiennent un quasi-monopole sur le marché marocain. Les résultats de cette étude ont démontré que la communication entre les acteurs de la supply chain peut procurer des avantages opérationnels et tactiques aux acteurs, bien que sa mise en œuvre stratégique soit complexe. En comprenant ces enjeux et en cherchant des solutions appropriées, les entreprises peuvent renforcer leur position concurrentielle et assurer leur pérennité sur le marché. Mots clés : Communication, supply chain, acteurs, flux d’informations JEL Classification : D83, R41, L2 Type de l’article : Recherche empiriqu

Strong PUF Security Metrics: Sensitivity of Responses to Single Challenge Bit Flips

This paper belongs to a sequence of manuscripts that discuss generic and easy-to-apply security metrics for Strong Physical Unclonable Functions (PUFs). These metrics cannot and shall not fully replace in-depth machine learning (ML) studies in the security assessment of Strong PUF candidates. But they can complement the latter, serve in initial complexity analyses, and allow simple iterative design optimization. Moreover, they are computationally more efficient and far easier to standardize than typical ML-studies. This manuscript treats one very natural, but also very impactful metric, and investigates the effects that the alteration of single challenge bits has on the associated PUF-responses. We define several concrete metric scores based on this idea, and demonstrate their predictive power by applying them to various popular Strong PUF design families as test cases. This includes XOR Arbiter PUFs, XOR Bistable Ring PUFs, and Feed-Forward Arbiter PUFs, whose practical security is particularly well known after two decades of intense research. In passing, our manuscript also suggests techniques for representing our metric scores graphically, and for interpreting them in a meaningful manner. Our work demonstrates that if comparable methods had existed earlier, various Strong PUF candidates deemed secure and broken later could have been recognized and winnowed early on