The evaluation of the companies’ performance at University Science Parks (SPs) becomes essential in identifying the needs of the companies and the feasibility of the University-Business Collaboration (ubc). The companies’ real needs are also of interest for universities and SPs, since they face the challenge of designing strategies that best help them to transfer knowledge more effectively. This research article focuses on Key Performance Indicators (kpis) in ubc, needs and business objectives of companies co-located at SPs in Spain and Mexico. This article (i) aims to identify the kpis in ubc used by co-located companies at SPs, and (ii) explore the kpis in ubc and critical success factors of SPs. This article focuses on the perspective of companies, with a secondary focus on the perspectives of SPs and universities. For this study, data was collected through online company surveys in Spain and Mexico. Moreover, the empirical analysis uses fourteen semi-structured interviews addressed to SPs directors to explore kpis in ubc and success factors of SPs in both countries. In addition, two frameworks were developed with the main kpis in ubc, taking into account university and company perspectives. They show the objectives, strategies and long-term kpis as well as progress kpis, and they are a useful guide to evaluate the accomplishments and the alignment of goals in ubc.
High-performance single-threaded processors achieve their performance goal partly by relying, among other architectural techniques, on speculation and large on-chip caches. The hardware to support these techniques is usually a large portion of the overall processor real state area, and therefore it consumes a significant amount of power that sometimes is not optimally used toward doing useful work. In this work, we study the intuitive fact that architectures with hardware support for threads are more power efficient than a more traditional single-threaded superscalar architecture. Toward this goal, we have created a model of the power, performance and area of several parallel architectures. This model shows that a parallel architecture can be designed so that (a) it requires less area and power (to reach the same performance), or (b) it achieves better power efficiency and less area (for the same power budget), or (c) it has higher performance and better power efficiency (for the same area constraint), when compared to a single-threaded superscalar architecture.
Widespread deployment of autonomous vehicles (AVs) presents formidable challenges in terms on handling scalability and complexity, particularly regarding vehicular reaction in the face of unforeseen corner cases. Hierarchical Emergent Behaviors (HEB) is a scalable architecture based on the concepts of emergent behaviors and hierarchical decomposition. It relies on a few simple but powerful rules to govern local vehicular interactions. Rather than requiring prescriptive programming of every possible scenario, HEB's approach relies on global behaviors induced by the application of these local, well-understood rules. Our first two papers on HEB focused on a primal set of rules applied at the first hierarchical level. On the path to systematize a solid design methodology, this paper proposes additional rules for the second level, studies through simulations the resultant richer set of emergent behaviors, and discusses the communication mechanisms between the different levels.
Estimating available network resources is fundamental when adapting the sending rate both at the application and transport layer. Traditional approaches either rely on active probing techniques or iteratively adapting the average sending rate, as is the case for modern TCP congestion control algorithms. In this paper, we propose a statistical method based on the inter-packet arrival time analysis of TCP acknowledgments to estimate a path available bandwidth. SABES first estimates the bottleneck link capacity exploiting the TCP flow slow start traffic patterns. Then, an heuristic based on the capacity estimation, provides an approximation of the end-to-end available bandwidth. Exhaustive experimentation on both simulations and real-world scenarios were conducted to validate our technique, and our results are promising. Furthermore, we train an artificial neural network to improve the estimation accuracy.
Over the years, different techniques have been proposed to detect bottleneck bandwidth and available bandwidth of an end-to-end path. However, to the author's knowledge, no work has been conducted on detecting which link or node on the path could be the narrow link. In this paper, we present a novel technique based on packet pairs dispersion analysis, whose objective is twofold: first, it allows to estimate the narrow link capacity using a new approach which takes into account both inter-packet time and packet propagation delay. Its second objective is to induce the specific hop in the end-to-end path which represents the narrow link. This is achieved by injecting packets trains with intermediate TTL-expiring packets which decrease the train rate when they cross the narrow link (red-shift effect). We validate our approach in simulations showing the tool robustness in very complex scenarios.
Disaggregated data centers propose a modular architecture where memory and compute resources are utilized in a finer granularity, aiming for a better optimized capacity and power consumption. In contrast to a classic compute node in a data center, memory is not required to be co-located with the processor, disaggregation can enhance hardware elasticity, improve virtual machine (VM) migration, and reduce the total cost of ownership (TCO), when compared to current data center solutions. This paper presents an evaluation of a disaggregated memory system prototype implemented on two modern FPGA SoC boards; one as a compute node and the second one as memory node. Using the PARSEC and Splash2x benchmark suites, we characterize our disaggregated prototype running on a remote memory node. In order to understand the design trade-offs, we utilize data collected from AXI Performance Monitors and break down the executions into three principal stages: (i) disaggregated memory address translation, (ii) network and (iii) memory access. This helps us to better evaluate the trade-offs of our prototype and to give better insight towards the next generation of disaggregated data centers.
We present a control module for software edge routers called Receive Window Modulation - RWM. Its main objective is to mitigate what we define as self-induced congestion: the result of traffic emission patterns at the source that cause buffering and packet losses in any of the intermediate routers along the path between the connection's endpoints. The controller modifies the receiver's TCP advertised window to match the computed bandwidth-delay product, based on the connection round-trip time estimation and the bandwidth locally available at the edge router. The implemented controller does not need any endpoint modification, allowing it to be deployed in corporate edge routers, increasing visibility and control capabilities. This scheme, when used in real-world experiments with loss-based congestion control algorithms such as CUBIC, is shown to optimize access link utilization and per-connection goodput, and to reduce latency variability and packet losses.
Science and Technology Parks (STPs) facilitate the flow of knowledge and technology among universities, R&D institutions, companies and markets, and foster the creation and growth of innovation-based companies. Among the diversity of STPs, it is possible to identify two types: Science Parks (SPs), which involves university shareholding and Technology Parks (TPs), which are not owned by universities. This study will take into account just SPs due they are closely linked to the university, and they are the bridge between University and companies in the process of Knowledge and Technology Transfer (KTT). The evaluation of the firm’s performance in SPs results in determinant to identify the needs of the companies and the feasibility of the University-Business Collaboration (UBC). Firm’s real needs also are of interest of Universities, since they face the challenge of designing strategies that best help them to transfer the knowledge more effectively. While previous studies have been focused on tenants’ innovation performance on-Park and off-Park, very little research has taken into account the Parks heterogeneity that may affect the firm’s performance. This research focuses on SPs in Spain and México due to data availability. This paper (1) aims to identify the Key Performance Indicators (KPI’s) used by Companies co-located at SPs, and (2) explore the performance measure and critical success factors of SPs. For this study, data was collected through 71 online company surveys in Spain and 19 online company surveys in México. This empirical analysis uses ten semi-structured interviews to explore (KPI’s) and success factors of SPs in both countries.
The resurgence of machine learning since the late 1990s has been enabled by significant advances in computing performance and the growth of big data. The ability of these algorithms to detect complex patterns in data which are extremely difficult to achieve manually, helps to produce effective predictive models. Whilst computer architects have been accelerating the performance of machine learning algorithms with GPUs and custom hardware, there have been few implementations leveraging these algorithms to improve the computer system performance. The work that has been conducted, however, has produced considerably promising results. The purpose of this paper is to serve as a foundational base and guide to future computer architecture research seeking to make use of machine learning models for improving system efficiency. We describe a method that highlights when, why, and how to utilize machine learning models for improving system performance and provide a relevant example showcasing the effectiveness of applying machine learning in computer architecture. We describe a process of data generation every execution quantum and parameter engineering. This is followed by a survey of a set of popular machine learning models. We discuss their strengths and weaknesses and provide an evaluation of implementations for the purpose of creating a workload performance predictor for different core types in an x86 processor. The predictions can then be exploited by a scheduler for heterogeneous processors to improve the system throughput. The algorithms of focus are stochastic gradient descent based linear regression, decision trees, random forests, artificial neural networks, and $k$-nearest neighbors.
As heterogeneous systems become more ubiquitous, computer architects will need to develop novel CPU scheduling techniques capable of exploiting the diversity of computational resources. Accurately estimating the performance of applications on different heterogeneous resources can provide a significant advantage to heterogeneous schedulers seeking to improve system performance. Recent advances in machine learning techniques including artificial neural network models have led to the development of powerful and practical prediction models for a variety of fields. As of yet, however, no significant leaps have been taken towards employing machine learning for heterogeneous scheduling in order to maximize system throughput. In this paper we propose a unique throughput maximizing heterogeneous CPU scheduling model that uses machine learning to predict the performance of multiple threads on diverse system resources at the scheduling quantum granularity. We demonstrate how lightweight artificial neural networks (ANNs) can provide highly accurate performance predictions for a diverse set of applications thereby helping to improve heterogeneous scheduling efficiency. We show that online training is capable of increasing prediction accuracy but deepening the complexity of the ANNs can result in diminishing returns. Notably, our approach yields 25% to 31% throughput improvements over conventional heterogeneous schedulers for CPU and memory intensive applications.
As heterogeneous systems become more ubiquitous, computer architects will need to develop new CPU scheduling approaches capable of exploiting the diversity of computational resources. Advances in deep learning have unlocked an exceptional opportunity of using these techniques for estimating system performance. However, as of yet no significant leaps have been taken in applying deep learning for scheduling on heterogeneous systems. In this paper we describe a scheduling model that decouples thread selection and mapping routines. We use a conventional scheduler to select threads for execution and propose a deep learning mapper to map the threads onto a heterogeneous hardware. The validation of our preliminary study shows how a simple deep learning based mapper can effectively improve system performance for state-of-the-art schedulers by 8
In this chapter, we explain NEMsCAM cell, a new content-addressable memory (CAM) cell, which is designed based on both CMOS technologies and nanoelectromechanical (NEM) switches. The memory part of NEMsCAM is designed with two complementary nonvolatile NEM switches and located on top of the CMOS-based comparison component. As a use case, we evaluate first-level instruction and data translation lookaside buffers (TLBs) with 16 nm CMOS technology at 2 GHz. The simulation results demonstrate that the NEMsCAM TLB reduces the energy consumption per search operation (by 27%), standby mode (by 53.9%), write operation (by 41.9%), and the area (by 40.5%) compared to a CMOS-only TLB with minimal performance overhead.
Next generation data centers will likely be based on the emerging paradigm of disaggregated function-blocks-as-a-unit departing from the current state of mainboard-as-a-unit. Multiple functional blocks or bricks such as compute, memory and peripheral will be spread through the entire system and interconnected together via one or multiple high speed networks. The amount of memory available will be very large distributed among multiple bricks. This new architecture brings various benefits that are desirable in today’s data centers such as fine-grained technology upgrade cycles, fine-grained resource allocation, and access to a larger amount of memory and accelerators. An analysis of the impact and benefits of memory disaggregation is presented in this paper. One of the biggest challenges when analyzing these architectures is that memory accesses should be modeled correctly in order to obtain accurate results. However, modeling every memory access would generate a high overhead that can make the simulation unfeasible for real data center applications. A model to represent and analyze memory disaggregation has been designed and a statistics-based queuing-based full system simulator was developed to rapidly and accurately analyze applications performance in disaggregated systems. With a mean error of 10%, simulation results pointed out that the network layers may introduce overheads that degrade applications’ performance up to 66%. Initial results also suggest that low memory access bandwidth may degrade up to 20% applications’ performance.
Conventional system simulators are readily used by computer architects to design and evaluate their processor designs. These simulators provide reasonable levels of accuracy and execution detail but suffer from long simulation latencies and increased implementation complexity. In this work we propose iQ, a queue-based modeling technique that targets design space exploration and optimization studies at the core component level. iQ emulates processor elements by abstracting the implementation details into modular components composed of queue structures, delay parameters, probabilistic driven message generation and event control. Its easy reconfigurability makes iQ a highly flexible and powerful processor simulator. We have used iQ to build an Ivy Bridge and a Core 2 Duo processor model and have validated them against real hardware running SPEC CPU2006 Int achieving average error rates of 9.55% and 8.93%.
The Internet of Things (IoT) marks a phase transition in the evolution of the Internet, distinguished by a massive connectivity and the interaction with the physical world. The organic evolution of IoT requires the consideration of three dimensions: scale, organization, and context. These dimensions are particularly relevant in Ultra Large Scale Systems (ULSS), of which autonomous vehicles is a prime example. Fog Computing is well positioned to support contextual awareness and communication, critical for ULSS. The design and orchestration of ULSS require fresh approaches, new organizing principles. A recent paper proposed Hierarchical Emergent Behaviors (HEB), an architecture that builds on established concepts of emergent behaviors and hierarchical decomposition and organization. HEB’s local rules induce emergent behaviors, i.e., useful behaviors not explicitly programmed. In this chapter we take a first step to validate HEB concepts through the study of two basic self-driven car “primitives”: exiting a platoon formation, and maneuvering in anticipation of obstacles beyond the range of on-board sensors. Fog nodes provide the critical contextual information required.
The Internet of Things applications must carefully assess certain crucial factors such as the real-time and largely distributed nature of the "things".Fog Computing provides an architecture to satisfy those requirements through nodes located from near the "things" till the edge.The problem comes with the integration of the Fog nodes into current infrastructures.This process requires the development of complex software solutions and prevents Fog growth.In this paper we propose three innovations to enhance Fog: (i) a new orchestration policy, (ii) the creation of constellations of nodes, and (iii) Fog Function Virtualization (FFV).All together will complement Fog to reach its true potential as a generic scalable platform, running multiple IoT applications simultaneously.Deploying a new service is reduced to the development of the application code, fact that brings the democratization of the Fog Computing paradigm through ease of deployment and cost reduction.
Address translation is fundamental to processor performance. Prior work focused on reducing Translation Lookaside Buffer (TLB) misses to improve performance and energy, whereas we show that even TLB hits consume a significant amount of dynamic energy. To reduce the energy cost of address translation, we first propose Lite, a mechanism that monitors the performance and utility of L1 TLBs, and adaptively changes their sizes with way-disabling. The resulting TLBLite organization opportunistically reduces the dynamic energy spent in address translation by 23% on average with minimal impact on TLB miss cycles. To further reduce the energy and performance overheads of L1 TLBs, we also propose RMMLite that targets the recently proposed Redundant Memory Mappings (RMM) address-translation mechanism. RMM maps most of a process's address space with arbitrarily large ranges of contiguous pages in both virtual and physical address space using a modest number of entries in a range TLB. RMMLite adds to RMM an L1-range TLB and the Lite mechanism. The high hit ratio of the L1-range TLB allows Lite to downsize the L1-page TLBs more aggressively. RMMLite reduces the dynamic energy spent in address translation by 71% on average. Above the near-zero L2 TLB misses from RMM, RMMLite further reduces the overhead from L1 TLB misses by 99%. These proposed designs target current and future energy-efficient memory system design to meet the ever increasing memory demands of applications.
Computing systems servers -low-or high-end ones have been traditionally designed and built using a main-board and its hardware components as a "hard" monolithic building block; this formed the base unit on which the system hardware and software stack design build upon.This hard deployment and management border on compute, memory, network and storage resources is either fixed or quite limited in expandability during design time and in practice remains so throughout machine lifetime as subsystem upgrades are seldomely employed.The impact of this rigidity has well known ramifications in terms of lower system resource utilization, costly upgrade cycles and degraded energy proportionality.In the dReDBox project we take on the challenge of breaking the server boundaries through materialization of the concept of disaggregation.The basic idea of the dReDBox architecture is to use a core of high-speed, low-latency opto-electronic fabric that will bring physically distant components more closely in terms of latency and bandwidth.We envision a powerful software-defined control plane that will match the flexibility of the system to the resource needs of the applications (or VMs) running in the system.Together the hardware, interconnect, and software architectures will enable the creation of a modular, vertically-integrated system that will form a datacenter-in-a-box.
Modern workloads suffer high execution-time overhead due to page-based virtual memory. The authors introduce range translations that map arbitrary-sized virtual memory ranges to contiguous physical memory pages while retaining the flexibility of paging. A range translation reduces address translation to a range lookup that delivers near zero virtual memory overhead.
Networks-on-Chip (NoCs) are currently the paradigm of choice to interconnect the cores of a chip multiprocessor. However, conventional NoCs may not suffice to fulfill the on-chip communication requirements of processors with hundreds or thousands of cores. The main reason is that the performance of such networks drops as the number of cores grows, especially in the presence of multicast and broadcast traffic. This not only limits the scalability of current multiprocessor architectures, but also sets a performance wall that prevents the development of architectures that generate moderate-to-high levels of multicast. In this paper, a Wireless Network-on-Chip (WNoC) where all cores share a single broadband channel is presented. Such design is conceived to provide low latency and ordered delivery for multicast/broadcast traffic, in an attempt to complement a wireline NoC that will transport the rest of communication flows. To assess the feasibility of this approach, the network performance of WNoC is analyzed as a function of the system size and the channel capacity, and then compared to that of wireline NoCs with embedded multicast support. Based on this evaluation, preliminary results on the potential performance of the proposed hybrid scheme are provided, together with guidelines for the design of MAC protocols for WNoC.
Osman Unsal合作论文数Barcelona Supercomputing Center10