빠른 성능조건 만족을 위한 임계경로를 고려하는 상위 수준 합성

학위논문 (박사)-- 서울대학교 대학원 : 전기·컴퓨터공학부, 2014. 2. 최기영.Rapid advancement of process technology enables designers to integrate various functions onto a single chip and to realize diverse requirements of customers, but productivity of system designers has improved too slowly to make optimal design in time-to-market. Since designing at higher levels of abstraction reduces the number of design instances to be considered to acquire an optimal design, it improves quality of system as well as reduces design time and cost. High-level synthesis, which maps behavioral description models to register-transfer models, can improve design productivity drastically, and thus, it has been one of the important issues in electronic system level design. Centralized controllers commonly used in high-level synthesis often require long wires and cause high load capacitance, and that is why critical paths typically occur on paths from controllers to data registers instead of paths from data registers to data registers. However, conventional high-level synthesis has focused on delays within a datapath, making it difficult to solve the timing closure problem during physical synthesis. This thesis presents hardware architecture with a distributed controller, which makes the timing closure problem much easier. A novel critical-path-aware high-level synthesis flow is also presented for synthesizing such hardware through datapath partitioning, register binding, and controller optimization. We explore the design space related to the number of partitions, which is an important design parameter for target architecture. According to our experiments, the proposed approach reduces the critical path delay excluding FUs by 29.3% and that including FUs by 10.0%, with 2.2% area overhead on average compared to centralized controller architecture. We also propose two approaches, clock gating and register constrained flow, to alleviate high peak current problem which is caused by the proposed approach. These approaches suppress the peak current overhead to keep it less than 3.6%.Chapter 1 Introduction 1 Chapter 2 Background 7 2.1 High-level Synthesis 7 2.2 Subtasks of High-level Synthesis 8 2.2.1 Operation Scheduling and FU Binding 8 2.2.2 Register Binding 10 2.2.3 Controller Synthesis 11 2.2.4 Functional Pipelining Technique for High-level Synthesis 11 2.3 Centralized Controller Architecture 12 2.4 Design Closure Problem in High-level Synthesis 15 2.5 Thesis Contribution 18 Chapter 3 Target Architecture and Overall flow 21 3.1 Target Architecture 21 3.2 Overall flow 23 Chapter 4 Critical-Path-Aware Datapath Partitioning 27 4.1 Introduction 27 4.2 Problem Formulation 30 4.3 Proposed Algorithm 32 4.4 Exploring Design Space for the Number of Partitions 36 Chapter 5 Critical-Path-Aware Register Binding 39 5.1 Introduction 39 5.2 Problem Formulation 40 5.3 Proposed Algorithm 43 Chapter 6 Critical-Path-Aware Controller Optimization 49 6.1 Introduction 49 6.2 Problem Formulation 50 6.3 Proposed Algorithm 55 Chapter 7 Evaluation 63 7.1 Experimental Setup 63 7.2 Design Parameters and Computation Time 66 7.3 Analysis Critical Path Delay on Distributed Controller Architecture 68 7.4 Analysis of Performance and Area 70 7.5 Energy Consumption 78 7.6 Analysis on Register Overhead 80 7.6.1 Clock Gating Approach 81 7.6.2 Register Constrained Approach 84 7.6.3 Combined Approach 86 7.7 Join to Conventional Optimization Techniques on HLS 87 7.8 Comparison with DRFM Binding Approach 87 Chapter 8 Conclusion and Future Work 89 8.1 Summary 89 8.2 Future Work 90 Bibliography 93 Abstract in Korean 103Docto

A Physiologically Based System Theory of Consciousness

A system which uses large numbers of devices to perform a complex functionality is forced to adopt a simple functional architecture by the needs to construct copies of, repair, and modify the system. A simple functional architecture means that functionality is partitioned into relatively equal sized components on many levels of detail down to device level, a mapping exists between the different levels, and exchange of information between components is minimized. In the instruction architecture functionality is partitioned on every level into instructions, which exchange unambiguous system information and therefore output system commands. The von Neumann architecture is a special case of the instruction architecture in which instructions are coded as unambiguous system information. In the recommendation (or pattern extraction) architecture functionality is partitioned on every level into repetition elements, which can freely exchange ambiguous information and therefore output only system action recommendations which must compete for control of system behavior. Partitioning is optimized to the best tradeoff between even partitioning and minimum cost of distributing data. Natural pressures deriving from the need to construct copies under DNA control, recover from errors, failures and damage, and add new functionality derived from random mutations has resulted in biological brains being constrained to adopt the recommendation architecture. The resultant hierarchy of functional separations can be the basis for understanding psychological phenomena in terms of physiology. A theory of consciousness is described based on the recommendation architecture model for biological brains. Consciousness is defined at a high level in terms of sensory independent image sequences including self images with the role of extending the search of records of individual experience for behavioral guidance in complex social situations. Functional components of this definition of consciousness are developed, and it is demonstrated that these components can be translated through subcomponents to descriptions in terms of known and postulated physiological mechanisms

What do people bring into the game? experiments in the field about cooperation in the commons

The study of collective action requires an understanding of the individual incentives and of the institutional constraints that guide people in making choices about cooperating or defecting on the group facing the dilemma. The use of local ecosystems by groups of individuals is just one example where individual extraction increases well-being, but aggregate extraction decreases it. The use of economic experiments has enhanced the already diverse knowledge from theoretical and field sources of when and how groups can solve the problem through selfgoverning mechanisms. These studies have identified several factors that promote and limit collective action, associated with the nature of the production system that allows groups to benefit from a joint-access local ecosystem, and associated with the institutional incentives and constraints from both self-governed and externally imposed rules. In general, there is widespread agreement that cooperation can happen and be chosen by individuals as a rational strategy, beyond the ?tragedy of the commons? prediction. A first step in this paper is to propose a set of layers of information that the individuals might be using to decide over their level of cooperation. The layers range from the material incentives that the specific production function imposes, to the dynamics of the game, to the composition of the group and the individual characteristics of the player. We next expand the experimental literature by analyzing data from a set of experiments conducted in the field with actual ecosystem users in three rural villages of Colombia using this framework. We find that repetition brings reciprocity motives into the decision making. Further, prior experience of the participants, their perception of external regulation, or the composition of the group in terms of their wealth and social position in the village, influence decisions to cooperate or defect in the experiment. The results suggest that understanding the multiple levels of the game, in terms of the incentives, the group and individual characteristics or the context, can help understand and therefore explore the potentials for solving the collective-action dilemma.collective action, cooperation, experimental economics, field experiments, local ecosystems

Searching Data: A Review of Observational Data Retrieval Practices in Selected Disciplines

A cross-disciplinary examination of the user behaviours involved in seeking and evaluating data is surprisingly absent from the research data discussion. This review explores the data retrieval literature to identify commonalities in how users search for and evaluate observational research data. Two analytical frameworks rooted in information retrieval and science technology studies are used to identify key similarities in practices as a first step toward developing a model describing data retrieval

Public engagement with carbon and climate change: To what extent is the public 'carbon capable'?

The relevance of climate change for society seems indisputable: scientific evidence points to a significant human contribution in causing climate change, and impacts which will increasingly affect human welfare. In order to meet national and international greenhouse gas (GHG) emissions reduction targets, there is an urgent need to understand and enable societal engagement inmitigation. Yet recent research indicates that this involvement is currently limited: although awareness of climate change is widespread, understanding and behavioral engagement are far lower. Proposals for mitigative ‘personal carbon budgets’ imply a need for public understanding of the causes and consequences of carbon emissions, as well as the ability to reduce emissions. However, little has been done to consider the situated meanings of carbon and energy in everyday life and decisions. This paper builds on the concept of ‘carbon capability’, a term which captures the contextual meanings associated with carbon and individuals’ abilities and motivations to reduce emissions. We present empirical findings from a UK survey of public engagement with climate change and carbon capability, focusing on both individual and institutional dimensions. These findings highlight the diverse public understandings about ‘carbon’, encompassing technical, social, and moral discourses; and provide further evidence for the environmental value-action gap in relation to adoption of low-carbon lifestyles. Implications of these findings for promoting public engagement with climate change and carbon capability are discussed

A Reconfigurable Processor for Heterogeneous Multi-Core Architectures

A reconfigurable processor is a general-purpose processor coupled with an FPGA-like reconfigurable fabric. By deploying application-specific accelerators, performance for a wide range of applications can be improved with such a system. In this work concepts are designed for the use of reconfigurable processors in multi-tasking scenarios and as part of multi-core systems

Design and application of reconfigurable circuits and systems

Open Acces

RBS and Promoter Strengths Determine the Cell-Growth-Dependent Protein Mass Fractions and Their Optimal Synthesis Rates

[EN] Models of gene expression considering host-circuit interactions are relevant for understanding both the strategies and associated trade-offs that cell endogenous genes have evolved and for the efficient design of heterologous protein expression systems and synthetic genetic circuits. Here, we consider a small-size model of gene expression dynamics in bacterial cells accounting for host-circuit interactions due to limited cellular resources. We define the cellular resources recruitment strength as a key functional coefficient that explains the distribution of resources among the host and the genes of interest and the relationship between the usage of resources and cell growth. This functional coefficient explicitly takes into account lab-accessible gene expression characteristics, such as promoter and ribosome binding site (RBS) strengths, capturing their interplay with the growth-dependent flux of available free cell resources. Despite its simplicity, the model captures the differential role of promoter and RBS strengths in the distribution of protein mass fractions as a function of growth rate and the optimal protein synthesis rate with remarkable fit to the experimental data from the literature for Escherichia coli. This allows us to explain why endogenous genes have evolved different strategies in the expression space and also makes the model suitable for model-based design of exogenous synthetic gene expression systems with desired characteristics.This work was partially supported by grants MINECO/AEI, EU DPI2017-82896-C2-1-R, and MCIN/AEI/10.13039/501100011033 grant number PID2020-117271RB-C21. F.N.S.-N. is grateful to grant PAID-01-2017 (Universitat Politecnica de Valencia). The authors are very grateful to the anonymous reviewers for their comprehensive and in-depth reviews.Santos-Navarro, FN.; Vignoni, A.; Boada-Acosta, YF.; Picó, J. (2021). RBS and Promoter Strengths Determine the Cell-Growth-Dependent Protein Mass Fractions and Their Optimal Synthesis Rates. ACS Synthetic Biology. 10(12):3290-3303. https://doi.org/10.1021/acssynbio.1c0013132903303101