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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
281

Energy Measurements of High Performance Computing Systems: From Instrumentation to Analysis

Ilsche, Thomas 31 July 2020 (has links)
Energy efficiency is a major criterion for computing in general and High Performance Computing in particular. When optimizing for energy efficiency, it is essential to measure the underlying metric: energy consumption. To fully leverage energy measurements, their quality needs to be well-understood. To that end, this thesis provides a rigorous evaluation of various energy measurement techniques. I demonstrate how the deliberate selection of instrumentation points, sensors, and analog processing schemes can enhance the temporal and spatial resolution while preserving a well-known accuracy. Further, I evaluate a scalable energy measurement solution for production HPC systems and address its shortcomings. Such high-resolution and large-scale measurements present challenges regarding the management of large volumes of generated metric data. I address these challenges with a scalable infrastructure for collecting, storing, and analyzing metric data. With this infrastructure, I also introduce a novel persistent storage scheme for metric time series data, which allows efficient queries for aggregate timelines. To ensure that it satisfies the demanding requirements for scalable power measurements, I conduct an extensive performance evaluation and describe a productive deployment of the infrastructure. Finally, I describe different approaches and practical examples of analyses based on energy measurement data. In particular, I focus on the combination of energy measurements and application performance traces. However, interweaving fine-grained power recordings and application events requires accurately synchronized timestamps on both sides. To overcome this obstacle, I develop a resilient and automated technique for time synchronization, which utilizes crosscorrelation of a specifically influenced power measurement signal. Ultimately, this careful combination of sophisticated energy measurements and application performance traces yields a detailed insight into application and system energy efficiency at full-scale HPC systems and down to millisecond-range regions.:1 Introduction 2 Background and Related Work 2.1 Basic Concepts of Energy Measurements 2.1.1 Basics of Metrology 2.1.2 Measuring Voltage, Current, and Power 2.1.3 Measurement Signal Conditioning and Analog-to-Digital Conversion 2.2 Power Measurements for Computing Systems 2.2.1 Measuring Compute Nodes using External Power Meters 2.2.2 Custom Solutions for Measuring Compute Node Power 2.2.3 Measurement Solutions of System Integrators 2.2.4 CPU Energy Counters 2.2.5 Using Models to Determine Energy Consumption 2.3 Processing of Power Measurement Data 2.3.1 Time Series Databases 2.3.2 Data Center Monitoring Systems 2.4 Influences on the Energy Consumption of Computing Systems 2.4.1 Processor Power Consumption Breakdown 2.4.2 Energy-Efficient Hardware Configuration 2.5 HPC Performance and Energy Analysis 2.5.1 Performance Analysis Techniques 2.5.2 HPC Performance Analysis Tools 2.5.3 Combining Application and Power Measurements 2.6 Conclusion 3 Evaluating and Improving Energy Measurements 3.1 Description of the Systems Under Test 3.2 Instrumentation Points and Measurement Sensors 3.2.1 Analog Measurement at Voltage Regulators 3.2.2 Instrumentation with Hall Effect Transducers 3.2.3 Modular Instrumentation of DC Consumers 3.2.4 Optimal Wiring for Shunt-Based Measurements 3.2.5 Node-Level Instrumentation for HPC Systems 3.3 Analog Signal Conditioning and Analog-to-Digital Conversion 3.3.1 Signal Amplification 3.3.2 Analog Filtering and Analog-To-Digital Conversion 3.3.3 Integrated Solutions for High-Resolution Measurement 3.4 Accuracy Evaluation and Calibration 3.4.1 Synthetic Workloads for Evaluating Power Measurements 3.4.2 Improving and Evaluating the Accuracy of a Single-Node Measuring System 3.4.3 Absolute Accuracy Evaluation of a Many-Node Measuring System 3.5 Evaluating Temporal Granularity and Energy Correctness 3.5.1 Measurement Signal Bandwidth at Different Instrumentation Points 3.5.2 Retaining Energy Correctness During Digital Processing 3.6 Evaluating CPU Energy Counters 3.6.1 Energy Readouts with RAPL 3.6.2 Methodology 3.6.3 RAPL on Intel Sandy Bridge-EP 3.6.4 RAPL on Intel Haswell-EP and Skylake-SP 3.7 Conclusion 4 A Scalable Infrastructure for Processing Power Measurement Data 4.1 Requirements for Power Measurement Data Processing 4.2 Concepts and Implementation of Measurement Data Management 4.2.1 Message-Based Communication between Agents 4.2.2 Protocols 4.2.3 Application Programming Interfaces 4.2.4 Efficient Metric Time Series Storage and Retrieval 4.2.5 Hierarchical Timeline Aggregation 4.3 Performance Evaluation 4.3.1 Benchmark Hardware Specifications 4.3.2 Throughput in Symmetric Configuration with Replication 4.3.3 Throughput with Many Data Sources and Single Consumers 4.3.4 Temporary Storage in Message Queues 4.3.5 Persistent Metric Time Series Request Performance 4.3.6 Performance Comparison with Contemporary Time Series Storage Solutions 4.3.7 Practical Usage of MetricQ 4.4 Conclusion 5 Energy Efficiency Analysis 5.1 General Energy Efficiency Analysis Scenarios 5.1.1 Live Visualization of Power Measurements 5.1.2 Visualization of Long-Term Measurements 5.1.3 Integration in Application Performance Traces 5.1.4 Graphical Analysis of Application Power Traces 5.2 Correlating Power Measurements with Application Events 5.2.1 Challenges for Time Synchronization of Power Measurements 5.2.2 Reliable Automatic Time Synchronization with Correlation Sequences 5.2.3 Creating a Correlation Signal on a Power Measurement Channel 5.2.4 Processing the Correlation Signal and Measured Power Values 5.2.5 Common Oversampling of the Correlation Signals at Different Rates 5.2.6 Evaluation of Correlation and Time Synchronization 5.3 Use Cases for Application Power Traces 5.3.1 Analyzing Complex Power Anomalies 5.3.2 Quantifying C-State Transitions 5.3.3 Measuring the Dynamic Power Consumption of HPC Applications 5.4 Conclusion 6 Summary and Outlook
282

Architektonický výraz obytných staveb energeticky efektivní výstavby / Architectural expression of residential buildings in energy-efficient housing

Gerö, Jiří January 2013 (has links)
These days create an enormous pressure on energy savings because of their high prices. For future it is obvious that their prices will grow. Not only the representatives of European Union realize this fact, but basicaly common people who run their houses and pay the bills. For this reason low - energy houses respectively passive houses are in the limelight. Reasons of economy should not be the only criterion of quality, but its integral part, one of several components. Energy efficient housing is a response in architecture and building to turbulent global warming. The aim of the work is try to specify how to conceive an efficient building with respect to its architectural quality in the contect of directions coming from European Union and which should be implemented soon in the Czech republic. Will zero house become driving force of architecture in Europe in 21st century? The result of the work will be useful in orientation how to conceive an efficient house with respect to its aesthetical quality.
283

Energeticky úsporná budova penzionu / Low-energy building of boarding house

Rainochová, Anna-Marie Unknown Date (has links)
The aim of the master project is to design a building of an energy-efficient boarding house. It is a three-storey building made of sand-lime masonry with a combination of a saddle roof and a flat green roof. The capacity of the building is 20 visitors. The basement contains a small wellness centre, kitchen storage, general storage, and a utility room. The first floor contains main entrance, a canteen, staff premises, and an accessible guest room. The second floor contains 7 guest rooms and a cleaning room. The third floor contains a meeting room with a kitchenette and toilets, one guest room and entrance to the green roof terrace. Whole building is ventilated by four air conditioning units. The building is heated by floor heating and radiators supplied with a geothermal heat pump and solar thermal panels. Solar thermal panels were analysed.
284

Balancing of Network Energy using Observer Approach

Patharlapati, Sai Ram Charan 01 September 2016 (has links)
Efficient energy use is primarily for any sensor networks to function for a longer time period. There have been many efficient schemes with various progress levels proposed by many researchers. Yet, there still more improvements are needed. This thesis is an attempt to make wireless sensor networks with further efficient on energy usage in the network with respect to rate of delivery of the messages. In sensor network architecture radio, sensing and actuators have influence over the power consumption in the entire network. While listening as well as transmitting, energy is consumed by the radio. However, if by reducing listening times or by reducing the number of messages transmitting would reduce the energy consumption. But, in real time scenario with critical information sensing network leads to information loss. To overcome this an adaptive routing technique should be considered. So, that it focuses on saving energy in a much more sophisticated way without reducing the performance of the sensing network transmitting and receiving functionalities. This thesis tackles on parts of the energy efficiency problem in a wireless sensor network and improving delivery rate of messages. To achieve this a routing technique is proposed. In this method, switching between two routing paths are considered and the switching decision taken by the server based on messages delivered comparative previous time intervals. The goal is to get maximum network life time without degrading the number of messages at the server. In this work some conventional routing methods are considered for implementing an approach. This approach is by implementing a shortest path, Gradient based energy routing algorithm and an observer component to control switching between paths. Further, controlled switching done by observer compared to normal initial switch rule. Evaluations are done in a simulation environment and results show improvement in network lifetime in a much more balanced way.
285

Energieeffiziente Anpassung des Arbeitszyklus in drahtlosen Sensornetzen

Neugebauer, Mario 29 January 2007 (has links)
Drahtlose Sensornetze können Zustände physikalischer Größen messen und an eine Basisstation (Datensenke) melden. Durch die geographische Verteilung der Sensorknoten und die Bedingungen bei der Mehrwegeausbreitung kann die Situation auftreten, dass nicht alle Sensorknoten direkten Kontakt zur Basisstation aufbauen können. Sie müssen andere Sensorknoten als Vermittlungsstation in Anspruch nehmen, um die Nachrichten an die Basisstation zu befördern. Um den Energieverbrauch zu verringern, werden Nachrichten zum einen ereignisbasiert generiert und zum anderen zeitbasiert vermittelt. Dabei beschreibt der Arbeitszyklus den Anteil der Vermittlungsaktivität am Gesamtzyklus. Derzeit verfügbare Methoden berücksichtigen allerdings nicht die Verknüpfung zwischen dem von der Anwendung generierten Verkehr und der Vermittlungshäufigkeit. In der vorliegenden Arbeit wird ein Verfahren vorgeschlagen, mit dem der Arbeitszyklus zur Laufzeit automatisch eingestellt werden kann. Dafür wird in der Vermittlungsstation die Verkehrscharakteristik gemessen und für die Einstellung des Arbeitszyklus benutzt. Die Leistungsfähigkeit der Anpassung des Arbeitszyklus wird mit Simulationen untersucht. Sie zeigen, wie sich der Ansatz bei verschiedener Parametrierung in statischen und dynamischen Szenarien verhält. Um dem späteren Anwender der Anpassung eine Abschätzung des Verhaltens zu ermöglichen, werden zusätzlich analytische Modelle für die Analyse des statischen und dynamischen Verhaltens entwickelt. Ferner wird gezeigt, dass der entwickelte Ansatz für etablierte Standardtechniken (z. B. IEEE 802.15.4) eingesetzt werden kann. / Wireless Sensor Networks support flexible measuring of physical values. Due to the geographical distribution and multipath scattering the base station in such a network might not be reached by all sensors. Hence, other sensor nodes have to work as relay stations. At the same time, each sensor node is forced to consume as low energy as possible. In order to save energy the messages are generated event based in each sensor node and forwarded with a time triggered approach. Thereby, the duty cycle describes the portion of the relay activities in relation to the overall cycle. Currently available approaches do not properly adapt these two paradigms, event and time triggered, to each other. In this work a method to adapt the duty cycle according to the traffic is proposed. Therefore, the traffic is monitored and evaluated for traffic adaptation. Furthermore, the performance of the duty cycle adaptation is assessed using simulations. They show the behavior of the adaptation algorithm in static and dynamic scenarios with different parametrizations. The supplemental analytical models enable to easily estimate the behavior of the adaptation, in static as well as in dynamic scenarios. Also, it is shown how the duty cycle adaptation can be deployed for standard technologies like IEEE 802.15.4.
286

Energy-Efficient In-Memory Database Computing

Lehner, Wolfgang January 2013 (has links)
The efficient and flexible management of large datasets is one of the core requirements of modern business applications. Having access to consistent and up-to-date information is the foundation for operational, tactical, and strategic decision making. Within the last few years, the database community sparked a large number of extremely innovative research projects to push the envelope in the context of modern database system architectures. In this paper, we outline requirements and influencing factors to identify some of the hot research topics in database management systems. We argue that—even after 30 years of active database research—the time is right to rethink some of the core architectural principles and come up with novel approaches to meet the requirements of the next decades in data management. The sheer number of diverse and novel (e.g., scientific) application areas, the existence of modern hardware capabilities, and the need of large data centers to become more energy-efficient will be the drivers for database research in the years to come.
287

Wireless Interconnect for Board and Chip Level

Fettweis, Gerhard P., ul Hassan, Najeeb, Landau, Lukas, Fischer, Erik January 2013 (has links)
Electronic systems of the future require a very high bandwidth communications infrastructure within the system. This way the massive amount of compute power which will be available can be inter-connected to realize future powerful advanced electronic systems. Today, electronic inter-connects between 3D chip-stacks, as well as intra-connects within 3D chip-stacks are approaching data rates of 100 Gbit/s soon. Hence, the question to be answered is how to efficiently design the communications infrastructure which will be within electronic systems. Within this paper approaches and results for building this infrastructure for future electronics are addressed.
288

Waiting for Locks: How Long Does It Usually Take?

Baier, Christel, Daum, Marcus, Engel, Benjamin, Härtig, Hermann, Klein, Joachim, Klüppelholz, Sascha, Märcker, Steffen, Tews, Hendrik, Völp, Marcus January 2012 (has links)
Reliability of low-level operating-system (OS) code is an indispensable requirement. This includes functional properties from the safety-liveness spectrum, but also quantitative properties stating, e.g., that the average waiting time on locks is sufficiently small or that the energy requirement of a certain system call is below a given threshold with a high probability. This paper reports on our experiences made in a running project where the goal is to apply probabilistic model checking techniques and to align the results of the model checker with measurements to predict quantitative properties of low-level OS code.
289

Chiefly Symmetric: Results on the Scalability of Probabilistic Model Checking for Operating-System Code

Baier, Christel, Daum, Marcus, Engel, Benjamin, Härtig, Hermann, Klein, Joachim, Klüppelholz, Sascha, Märcker, Steffen, Tews, Hendrik, Völp, Marcus January 2012 (has links)
Reliability in terms of functional properties from the safety-liveness spectrum is an indispensable requirement of low-level operating-system (OS) code. However, with evermore complex and thus less predictable hardware, quantitative and probabilistic guarantees become more and more important. Probabilistic model checking is one technique to automatically obtain these guarantees. First experiences with the automated quantitative analysis of low-level operating-system code confirm the expectation that the naive probabilistic model checking approach rapidly reaches its limits when increasing the numbers of processes. This paper reports on our work-in-progress to tackle the state explosion problem for low-level OS-code caused by the exponential blow-up of the model size when the number of processes grows. We studied the symmetry reduction approach and carried out our experiments with a simple test-and-test-and-set lock case study as a representative example for a wide range of protocols with natural inter-process dependencies and long-run properties. We quickly see a state-space explosion for scenarios where inter-process dependencies are insignificant. However, once inter-process dependencies dominate the picture models with hundred and more processes can be constructed and analysed.
290

Secure degrees of freedom on widely linear instantaneous relay-assisted interference channel

Ho, Zuleita K.-M., Jorswieck, Eduard January 2013 (has links)
The number of secure data streams a relay-assisted interference channel can support has been an intriguing problem. The problem is not solved even for a fundamental scenario with a single antenna at each transmitter, receiver and relay. In this paper, we study the achievable secure degrees of freedom of instantaneous relay-assisted interference channels with real and complex coefficients. The study of secure degrees of freedom with complex coefficients is not a trivial multiuser extension of the scenarios with real channel coefficients as in the case for the degrees of freedom, due to secrecy constraints. We tackle this challenge by jointly designing the improper transmit signals and widely-linear relay processing strategies.

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