352 research outputs found

    Automatic synthesis and optimization of chip multiprocessors

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    The microprocessor technology has experienced an enormous growth during the last decades. Rapid downscale of the CMOS technology has led to higher operating frequencies and performance densities, facing the fundamental issue of power dissipation. Chip Multiprocessors (CMPs) have become the latest paradigm to improve the power-performance efficiency of computing systems by exploiting the parallelism inherent in applications. Industrial and prototype implementations have already demonstrated the benefits achieved by CMPs with hundreds of cores.CMP architects are challenged to take many complex design decisions. Only a few of them are:- What should be the ratio between the core and cache areas on a chip?- Which core architectures to select?- How many cache levels should the memory subsystem have?- Which interconnect topologies provide efficient on-chip communication?These and many other aspects create a complex multidimensional space for architectural exploration. Design Automation tools become essential to make the architectural exploration feasible under the hard time-to-market constraints. The exploration methods have to be efficient and scalable to handle future generation on-chip architectures with hundreds or thousands of cores.Furthermore, once a CMP has been fabricated, the need for efficient deployment of the many-core processor arises. Intelligent techniques for task mapping and scheduling onto CMPs are necessary to guarantee the full usage of the benefits brought by the many-core technology. These techniques have to consider the peculiarities of the modern architectures, such as availability of enhanced power saving techniques and presence of complex memory hierarchies.This thesis has several objectives. The first objective is to elaborate the methods for efficient analytical modeling and architectural design space exploration of CMPs. The efficiency is achieved by using analytical models instead of simulation, and replacing the exhaustive exploration with an intelligent search strategy. Additionally, these methods incorporate high-level models for physical planning. The related contributions are described in Chapters 3, 4 and 5 of the document.The second objective of this work is to propose a scalable task mapping algorithm onto general-purpose CMPs with power management techniques, for efficient deployment of many-core systems. This contribution is explained in Chapter 6 of this document.Finally, the third objective of this thesis is to address the issues of the on-chip interconnect design and exploration, by developing a model for simultaneous topology customization and deadlock-free routing in Networks-on-Chip. The developed methodology can be applied to various classes of the on-chip systems, ranging from general-purpose chip multiprocessors to application-specific solutions. Chapter 7 describes the proposed model.The presented methods have been thoroughly tested experimentally and the results are described in this dissertation. At the end of the document several possible directions for the future research are proposed

    Дослідження та вдосконалення алгоритмів адміністрування мережевої бази даних “Navi”

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    Робота публікується згідно наказу ректора від 29.12.2020 р. №580/од "Про розміщення кваліфікаційних робіт вищої освіти в репозиторії НАУ". Керівник проекту: к.т.н., доцент Проценко Микола МихайловичLong before the advent of computerized databases, humanity already then had a need to store information in a structured form. Since at a time when computers either did not exist at all, or they were just entering the market and were at the stage of their formation, peculiar databases existed in written or physical form, for example, data archives, reference centers, libraries, ledgers, telephone directories etc. And since now there is a need to store huge amounts of information, while taking up as little storage space and resources as possible, databases are an integral stage in the development of opportunities to simplify the life of mankind. The database is both a tool and the very subject of a collection of data, which shows the state of certain objects and their relationship in a certain subject area.Задовго до появи комп'ютеризованих баз даних людство вже тоді мало потребу зберігати інформацію у структурованому вигляді. Оскільки в той час, коли комп’ютери або взагалі не існували, або вони тільки виходили на ринок і були на стадії свого формування, своєрідні бази даних існували в письмовій або фізичній формі, наприклад, архіви даних, довідкові центри, бібліотеки, книги , телефонні довідники тощо. І оскільки зараз існує потреба зберігати величезні обсяги інформації, займаючи при цьому якомога менше місця для зберігання та ресурсів, бази даних є невід’ємним етапом у розвитку можливостей спрощення життя людства. База даних є одночасно інструментом і самим предметом збору даних, який показує стан певних об’єктів та їх взаємозв’язок у певній предметній області

    Philosophical perspectives on time in biology

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    Although time is a central topic in philosophy, within the philosophy of science discussions of time in biology have largely been neglected. This dissertation argues for the philosophical importance of paying closer attention to the vastly different timescales at which biological phenomenon can be investigated and explained. The importance of timescales for four themes in philosophy of biology is examined: abstractions and manipulations of time in biological practice, metaphysical debates between the mechanistic and process ontology frameworks, the problem of synchronizing molecular clocks and fossil clocks, and reductionism in biology. This dissertation provides the first sustained philosophical examination of the role of time in biology. The first chapter explores how researchers manage the complexities of multiple timescales by abstracting from time physically, procedurally, mathematically, and conceptually. Understanding how researchers abstract from time in their investigations is important for determining what phenomena might be obscured by such practices. Chapter two turns to the debate in philosophy of biology between traditional mechanistic accounts and the new process ontology. While process ontology is an advance, insofar as it has the potential to bring temporal issues to the fore, it is better understood as an epistemological—not metaphysical—framework. A careful consideration of timescales highlights how different metaphysical frameworks can be more epistemologically appropriate in different contexts. The third chapter examines how molecular and fossil clocks are used to measure time in biology. In both cases, researchers use phenomena occurring at one timescale (e.g. DNA mutations) to measure durations across another scale (e.g., the evolutionary occurrence of a last common ancestor). Attempts to synchronize these clocks for key biological events in the deep past pose interesting methodological problems—and suggest new solutions—for how to deal with discordant and interdependent lines of evidence. The final chapter considers the consequences of this analysis of time in biology for debates about reductionism. Reductionism has focused almost exclusively on spatial scales. This chapter shows how a consideration of temporal scales transforms philosophical debates about reductionism in biology and poses new challenges. This dissertation demonstrates the fertility of extending the philosophy of time into the philosophy of biology

    Applications

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    Volume 3 describes how resource-aware machine learning methods and techniques are used to successfully solve real-world problems. The book provides numerous specific application examples: in health and medicine for risk modelling, diagnosis, and treatment selection for diseases in electronics, steel production and milling for quality control during manufacturing processes in traffic, logistics for smart cities and for mobile communications

    Applications

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    Volume 3 describes how resource-aware machine learning methods and techniques are used to successfully solve real-world problems. The book provides numerous specific application examples: in health and medicine for risk modelling, diagnosis, and treatment selection for diseases in electronics, steel production and milling for quality control during manufacturing processes in traffic, logistics for smart cities and for mobile communications

    Conflict detection in software-defined networks

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    The SDN architecture facilitates the flexible deployment of network functions. While promoting innovation, this architecture induces yet a higher chance of conflicts compared to conventional networks. The detection of conflicts in SDN is the focus of this work. Restrictions of the formal analytical approach drive our choice of an experimental approach, in which we determine a parameter space and a methodology to perform experiments. We have created a dataset covering a number of situations occurring in SDN. The investigation of the dataset yields a conflict taxonomy composed of various classes organized in three broad types: local, distributed and hidden conflicts. Interestingly, hidden conflicts caused by side-effects of control applications‘ behaviour are completely new. We introduce the new concept of multi-property set, and the ·r (“dot r”) operator for the effective comparison of SDN rules. With these capable means, we present algorithms to detect conflicts and develop a conflict detection prototype. The evaluation of the prototype justifies the correctness and the realizability of our proposed concepts and methodologies for classifying as well as for detecting conflicts. Altogether, our work establishes a foundation for further conflict handling efforts in SDN, e.g., conflict resolution and avoidance. In addition, we point out challenges to be explored. Cuong Tran won the DAAD scholarship for his doctoral research at the Munich Network Management Team, Ludwig-Maximilians-Universität München, and achieved the degree in 2022. He loves to do research on policy conflicts in networked systems, IP multicast and alternatives, network security, and virtualized systems. Besides, teaching and sharing are also among his interests

    In/Compatible Research - Editorial

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