One Mean Can’t Rule Them All

Academic mentoring programming is a powerful tool used for supporting, engaging, and retaining students in their fields of study. Researchers have long known the positive effects of academic mentoring, particularly for students from underrepresented and marginalized backgrounds. The computer architecture community currently hosts an assortment of mentoring programs geared toward women, underrepresented students, junior graduate students, and undergraduates alike.In this work, we describe the current state of mentoring opportunities for students in computer architecture. In addition to summarizing various mentoring programs (e.g., CWWMCA, YArch, and uArch), this work details the organization and feedback from two programs (MaSA and MaSS) that the authors currently run and organize. Based on feedback from these short-term mentoring programs, along with relevant mentoring research literature, we identify opportunities for developing more productive longer-term mentoring programming for the computer architecture community. Following mentoring literature, this work makes a strong case for offering both short-term and long-term mentoring programs in the future; in particular, mentoring literature show the need for time in forming mentoring relationships for mentees to receive the multifaceted benefits of mentoring.ACM Reference Format:Elba Garza, Gururaj Saileshwar, Udit Gupta, Tianyi Liu, Abdulrahman Mahmoud, Saugata Ghose, and Joel Emer. 2021. Mentoring Opportunities in Computer Architecture: Analyzing the Past to Develop the Future. In WCAE '21: Workshop on Computer Architecture Education, June 17,2021, Online. ACM, New York, NY, USA, 9 pages. https://doi.org/10.1145/nnnnnnn.nnnnnnn

Many of the trends that have dominated recent evolution and advancement within the computer architecture community have complicated the analysis of task execution times. Most of the difficulties result from two particular emphases: (1) Instruction-level parallelism, and (2) Optimization of average-case behavior rather than worst-case latencies. Both of these trends have resulted in increased nondeterminism in the time required to execute particular code sequences. And since the analysis required to determine worst-case task execution times on modern processors is so complicated, it is not practical for programmers to perform all of the necessary analyses by hand. Tools must aid them. This paper describes ongoing research on a collection of tools intended to automate the analyses that must be performed in order to build reliable real-time software for modern computing environments. Emphasis is given to the interplay between components of the development environment.

Several benchmark suites, which provide a wide spectrum of applications in relevant domains, have been proposed and widely used in the computer architecture community. In the majority of them, a shared-memory based communication model is assumed for communication among tasks/threads of an application. Yet, most of the works in the context of Network-on-Chip (NoC) architectures use these benchmarks as a basis for their experiments. Nevertheless, NoC architectures enable message passing communication that is not exploited by the applications in current benchmark suites. In this paper, we propose a technique for converting the trace of memory references generated by the execution of a shared memory based multi-threaded program to the trace of communication messages that would be obtained if the same program would have been designed to use message passing. The proposed technique is applied to a set of representative benchmarks belonging to SPLASH-2 and PARSEC benchmark suites.

In this paper, we take a MIPS-based open-source uniprocessor soft core, Plasma, and extend it to obtain the Beefarm infrastructure for FPGA-based multiprocessor emulation, a popular research topic of the last few years both in the FPGA and the computer architecture communities. We discuss various design tradeoffs and we demonstrate superior scalability through experimental results compared to traditional software instruction set simulators. Based on our experience of designing and building a complete FPGA-based multiprocessor emulation system that supports run-time and compiler infrastructure and on the actual executions of our experiments running Software Transactional Memory (STM) benchmarks, we comment on the pros, cons and future trends of using hardware-based emulation for research.

This paper shows how thermal constraints affect the multidimensional design space for chip multiprocessors, considering the inter-related variables of CPU count, pipeline depth, superscalar width, L2 cache size, and operating voltage and frequency. The results show the importance of thermal modeling and the need for new thermal modeling capabilities and hence the need for collaboration between the thermal engineering and computer architecture communities. Thermal constraints both shift the optimal intra- and inter-core organization, and dominate other physical constraints such as pin-bandwidth and power delivery. Different thermal constraints also require different optimization strategies. For aggressive cooling solutions, reducing power density is at least as important as reducing total power, while for low-cost cooling solutions, reducing total power is more important.

It is a common belief that computer performance growth is over 50% annually, or that performance doubles every 18-20 months. By analyzing publicly available results from the SPEC integer (CINT) benchmark suites, we conclude that this was true between 1985 and 1996 -- the early years of the RISC paradigm.During the last 7.5 years (1996-2004), however, performance growth has slowed down to 41%, with signs of a continuing decline. Meanwhile, clock frequency has improved with about 29% annually. The improvement in clock frequency was enabled both by an annual device speed scaling of 20% as well as by longer pipelines with a lower gate-depth in each stage. This paper takes a fresh look at -- and tries to remove the confusion about -- performance scaling that exists in the computer architecture community.

Organized flight in birds

<p>Data produced within marine and terrestrial biodiversity research projects that evaluate and monitor Good Environmental Status, have a high potential for use by stakeholders involved in environmental management. However, environmental data, especially in ecology, are not readily accessible to various users. The specific scientific goals and the logics of project organization and information gathering lead to a decentralized data distribution. In such a heterogeneous system across different organizations and data formats, it is difficult to efficiently harmonize the outputs. Few tools are available to assist. For instance standards and specific protocols can be applied to interconnect databases. Such semantic approaches greatly increase data interoperability.</p> <p>This communication present the recent results and the consortium IndexMEED (Indexing for Mining Ecological and Environmental Data) activity that aims to build new approaches to investigate complex research questions, and support the emergence of new scientific hypotheses based on graph theory Auber et al. 2014). Current developments in data mining based on graphs, as well as the potential for relevant contributions to environmental research, particularly about strategic decision-making, and new ways of organizing data will be presented (David et al. 2015). In particular, the consortium makes decisions on how i) to analyze heterogeneous distributed data spread throughout different databases combining molecular and habitat characteristics data [3], ii) to create matches and incorporate some approximations, iii) to identify statistical relationships between observed data and the emergence of contextual patterns using a calculation library and distributed calculation center at the European level, iv) to encourage openness and sharing data while complying with the general principles of FAIR (Findable, Accessible, Interoperable, Re-usable and citable) in order to enhance data value and their utilization. IndexMEED participants are now exploring the ability of two scientific communities (ecology sensu lato and computer sciences) to work together, using several studies cases. The ECOSCOPE project aims to meet the need to access structured and complementary omics-datasets to better understand biodiversity state and its dynamics. Indeed, the ECOSCOPE case study targets to visualize, through the graph approach, links between datasets and databases from genetics to ecosystems. Another case study, displaying anthropology fossils and omics on the same graph, will also be presented. DEVOTES (DEVelopment Of innovative Tools for understanding marine biodiversity and assessing good Environmental Status) and CIGESMED (Coralligenous based Indicators to evaluate and monitor the "Good Environmental Status" of the MEDiterranean coastal water) European projects, conducted by IMBE, are focused on photo quadrats, cartography and omics data of the marine hard bottom in order to discover context patterns helpful to build decision support system building. Study case "65 Millions d'observateurs" French project is testing AskOmics to provide a graph-based querying interface using RDF (Resource Description Framework) and SPARQL technologies.</p> <p>Scientific questions can be resolved by the new data mining approaches that offer new ways to investigate heterogeneous environmental data with graph mining (Muñoz et al. 2017). The uses of data from biodiversity research demonstrate the prototype functionalities (<em>David et al. 2016</em>) and introduce new perspectives to analyze environmental and societal responses including decision-making at large scale, both at the information system level and the observing system level than at the observed system level.</p>

The spirit of these papers is that the topics should be presented in an historical context with emphasis on unsolved problems/conjectures. My personal background is a mixture of mathematics and computer science, with a year as a National Research Council/National Bureau of Standards postdoctoral fellow working in the Operations Research Division of NBS headed by Alan Goldman. To put this in context, the mathematician asks if a graph is graceful, the computer scientist asks how efficiently one can find a graceful labeling, and the operations researcher asks if it is not graceful, then how close to graceful is it? I believe the latter outlook actually provides a great source of interesting mathematics/computer science questions.

This reader provides an introduction to the gendering of science and the impact women are making in laboratories around the world. The republished essays included in this collection are both personal tales from women scientists and essays on the nature of science itself, covering such controversial issues like the under-representation of women in science, reproductive technology, sociobiology, evolutionary theory, and the notion of objective science.

It is our great pleasure and honor to welcome you to the program of the 49th IEEE/ACM International Symposium on Computer Architecture (ISCA), the flagship conference of the computer architecture community. After two years in a virtual format, the conference will be held physically in New York. There is an excellent program that has been selected for the conference.

The exponent of matrix multiplication is the smallest constant ω such that two n × n matrices may be multiplied by performing O ( n ω + ε ) arithmetic operations for every ε > 0 . Determining the constant ω is a central question in both computer science and mathematics. Strassen [Linear Algebra Appl. 52/53 (1983) 645–685] showed that ω is also governed by the tensor rank of the matrix multiplication tensor. We define certain symmetric tensors, that is, cubic polynomials, and our main result is that their symmetric rank also grows with the same exponent ω, so that ω can be computed in the symmetric setting, where it may be easier to determine. In particular, we study the symmetrized matrix multiplication tensor s M ⟨ n ⟩ defined on an n × n matrix A by s M ⟨ n ⟩ ( A ) = trace ( A 3 ) . The use of polynomials enables the introduction of additional techniques from algebraic geometry in the study of the matrix multiplication exponent ω.

The scalability of massively parallel algorithms is a fundamental question in computer science. We study the scalability and the efficiency of a conservative massively parallel algorithm for discrete-event simulations where the discrete events are Poisson arrivals. The parallel algorithm is applicable to a wide range of problems, including dynamic Monte Carlo simulations for large asynchronous systems with short-range interactions. The evolution of the simulated time horizon is analogous to a growing and fluctuating surface, and the efficiency of the algorithm corresponds to the density of local minima of this surface. In one dimension we find that the steady state of the macroscopic landscape is governed by the Edwards-Wilkinson Hamiltonian, which implies that the algorithm is scalable. Preliminary results for higher-dimensional logical topologies are discussed.

The P versus NP problem is a fundamental question in computer science. It asks whether problems whose solutions can be quickly verified can also be quickly solved. Here, "quickly" refers to computational time that grows proportionally to the size of the input (polynomial time). While the problem's roots trace back to a 1955 letter from John Nash, its formalization is attributed to Stephen Cook and Leonid Levin. Despite extensive research, a definitive answer remains elusive. Closely tied to this is the concept of NP-completeness. If a single NP-complete problem could be solved efficiently, it would imply that all problems in NP can be solved efficiently, proving that P equals NP. Garey and Johnson defined K-CLOSURE such that for any edge $(u, v)$ in the directed graph, either node $u$ is in the set $V'$ or node $v$ is not in $V'$. This implies that either both nodes are in $V'$ or both are not in $V'$. Our previous work in IPI Letters presented a polynomial-time algorithm for K-CLOSURE. While no errors have been identified in this work, many believe that Garey and Johnson's original definition was incorrect, and their citation of Queyranne was a misunderstanding. Many argue that the empty set serves as a simple counterexample to Garey and Johnson's definition of K-CLOSURE. This paper proposes that K-CLOSURE is actually an NP-complete problem, which would imply that P equals NP.

Perfect hash functions, superimposed codes as well as some other fashionable questions in computer science and random-access communication are special cases of early-day information theoretic models in the zero-error case.