13,289 research outputs found
BRAMAC: Compute-in-BRAM Architectures for Multiply-Accumulate on FPGAs
Deep neural network (DNN) inference using reduced integer precision has been
shown to achieve significant improvements in memory utilization and compute
throughput with little or no accuracy loss compared to full-precision
floating-point. Modern FPGA-based DNN inference relies heavily on the on-chip
block RAM (BRAM) for model storage and the digital signal processing (DSP) unit
for implementing the multiply-accumulate (MAC) operation, a fundamental DNN
primitive. In this paper, we enhance the existing BRAM to also compute MAC by
proposing BRAMAC (Compute-in-AM
rchitectures for
ultiply-cumulate). BRAMAC supports
2's complement 2- to 8-bit MAC in a small dummy BRAM array using a hybrid
bit-serial & bit-parallel data flow. Unlike previous compute-in-BRAM
architectures, BRAMAC allows read/write access to the main BRAM array while
computing in the dummy BRAM array, enabling both persistent and tiling-based
DNN inference. We explore two BRAMAC variants: BRAMAC-2SA (with 2 synchronous
dummy arrays) and BRAMAC-1DA (with 1 double-pumped dummy array).
BRAMAC-2SA/BRAMAC-1DA can boost the peak MAC throughput of a large Arria-10
FPGA by 2.6/2.1, 2.3/2.0, and
1.9/1.7 for 2-bit, 4-bit, and 8-bit precisions, respectively at
the cost of 6.8%/3.4% increase in the FPGA core area. By adding
BRAMAC-2SA/BRAMAC-1DA to a state-of-the-art tiling-based DNN accelerator, an
average speedup of 2.05/1.7 and 1.33/1.52 can
be achieved for AlexNet and ResNet-34, respectively across different model
precisions.Comment: 11 pages, 13 figures, 3 tables, FCCM conference 202
CFLIT: Coexisting Federated Learning and Information Transfer
Future wireless networks are expected to support diverse mobile services,
including artificial intelligence (AI) services and ubiquitous data
transmissions. Federated learning (FL), as a revolutionary learning approach,
enables collaborative AI model training across distributed mobile edge devices.
By exploiting the superposition property of multiple-access channels,
over-the-air computation allows concurrent model uploading from massive devices
over the same radio resources, and thus significantly reduces the communication
cost of FL. In this paper, we study the coexistence of over-the-air FL and
traditional information transfer (IT) in a mobile edge network. We propose a
coexisting federated learning and information transfer (CFLIT) communication
framework, where the FL and IT devices share the wireless spectrum in an OFDM
system. Under this framework, we aim to maximize the IT data rate and guarantee
a given FL convergence performance by optimizing the long-term radio resource
allocation. A key challenge that limits the spectrum efficiency of the
coexisting system lies in the large overhead incurred by frequent communication
between the server and edge devices for FL model aggregation. To address the
challenge, we rigorously analyze the impact of the computation-to-communication
ratio on the convergence of over-the-air FL in wireless fading channels. The
analysis reveals the existence of an optimal computation-to-communication ratio
that minimizes the amount of radio resources needed for over-the-air FL to
converge to a given error tolerance. Based on the analysis, we propose a
low-complexity online algorithm to jointly optimize the radio resource
allocation for both the FL devices and IT devices. Extensive numerical
simulations verify the superior performance of the proposed design for the
coexistence of FL and IT devices in wireless cellular systems.Comment: The paper has been accepted for publication by IEEE Transactions on
Wireless Communications (March 2023
Deep Transfer Learning Applications in Intrusion Detection Systems: A Comprehensive Review
Globally, the external Internet is increasingly being connected to the
contemporary industrial control system. As a result, there is an immediate need
to protect the network from several threats. The key infrastructure of
industrial activity may be protected from harm by using an intrusion detection
system (IDS), a preventive measure mechanism, to recognize new kinds of
dangerous threats and hostile activities. The most recent artificial
intelligence (AI) techniques used to create IDS in many kinds of industrial
control networks are examined in this study, with a particular emphasis on
IDS-based deep transfer learning (DTL). This latter can be seen as a type of
information fusion that merge, and/or adapt knowledge from multiple domains to
enhance the performance of the target task, particularly when the labeled data
in the target domain is scarce. Publications issued after 2015 were taken into
account. These selected publications were divided into three categories:
DTL-only and IDS-only are involved in the introduction and background, and
DTL-based IDS papers are involved in the core papers of this review.
Researchers will be able to have a better grasp of the current state of DTL
approaches used in IDS in many different types of networks by reading this
review paper. Other useful information, such as the datasets used, the sort of
DTL employed, the pre-trained network, IDS techniques, the evaluation metrics
including accuracy/F-score and false alarm rate (FAR), and the improvement
gained, were also covered. The algorithms, and methods used in several studies,
or illustrate deeply and clearly the principle in any DTL-based IDS subcategory
are presented to the reader
A Decision Support System for Economic Viability and Environmental Impact Assessment of Vertical Farms
Vertical farming (VF) is the practice of growing crops or animals using the vertical dimension via multi-tier racks or vertically inclined surfaces. In this thesis, I focus on the emerging industry of plant-specific VF. Vertical plant farming (VPF) is a promising and relatively novel practice that can be conducted in buildings with environmental control and artificial lighting. However, the nascent sector has experienced challenges in economic viability, standardisation, and environmental sustainability. Practitioners and academics call for a comprehensive financial analysis of VPF, but efforts are stifled by a lack of valid and available data.
A review of economic estimation and horticultural software identifies a need for a decision support system (DSS) that facilitates risk-empowered business planning for vertical farmers. This thesis proposes an open-source DSS framework to evaluate business sustainability through financial risk and environmental impact assessments. Data from the literature, alongside lessons learned from industry practitioners, would be centralised in the proposed DSS using imprecise data techniques. These techniques have been applied in engineering but are seldom used in financial forecasting. This could benefit complex sectors which only have scarce data to predict business viability.
To begin the execution of the DSS framework, VPF practitioners were interviewed using a mixed-methods approach. Learnings from over 19 shuttered and operational VPF projects provide insights into the barriers inhibiting scalability and identifying risks to form a risk taxonomy. Labour was the most commonly reported top challenge. Therefore, research was conducted to explore lean principles to improve productivity.
A probabilistic model representing a spectrum of variables and their associated uncertainty was built according to the DSS framework to evaluate the financial risk for VF projects. This enabled flexible computation without precise production or financial data to improve economic estimation accuracy. The model assessed two VPF cases (one in the UK and another in Japan), demonstrating the first risk and uncertainty quantification of VPF business models in the literature. The results highlighted measures to improve economic viability and the viability of the UK and Japan case.
The environmental impact assessment model was developed, allowing VPF operators to evaluate their carbon footprint compared to traditional agriculture using life-cycle assessment. I explore strategies for net-zero carbon production through sensitivity analysis. Renewable energies, especially solar, geothermal, and tidal power, show promise for reducing the carbon emissions of indoor VPF. Results show that renewably-powered VPF can reduce carbon emissions compared to field-based agriculture when considering the land-use change.
The drivers for DSS adoption have been researched, showing a pathway of compliance and design thinking to overcome the ‘problem of implementation’ and enable commercialisation. Further work is suggested to standardise VF equipment, collect benchmarking data, and characterise risks. This work will reduce risk and uncertainty and accelerate the sector’s emergence
TOWARDS AN UNDERSTANDING OF EFFORTFUL FUNDRAISING EXPERIENCES: USING INTERPRETATIVE PHENOMENOLOGICAL ANALYSIS IN FUNDRAISING RESEARCH
Physical-activity oriented community fundraising has experienced an exponential growth in popularity over the past 15 years. The aim of this study was to explore the value of effortful fundraising experiences, from the point of view of participants, and explore the impact that these experiences have on people’s lives. This study used an IPA approach to interview 23 individuals, recognising the role of participants as proxy (nonprofessional) fundraisers for charitable organisations, and the unique organisation donor dynamic that this creates. It also bought together relevant psychological theory related to physical activity fundraising experiences (through a narrative literature review) and used primary interview data to substantiate these. Effortful fundraising experiences are examined in detail to understand their significance to participants, and how such experiences influence their connection with a charity or cause. This was done with an idiographic focus at first, before examining convergences and divergences across the sample. This study found that effortful fundraising experiences can have a profound positive impact upon community fundraisers in both the short and the long term. Additionally, it found that these experiences can be opportunities for charitable organisations to create lasting meaningful relationships with participants, and foster mutually beneficial lifetime relationships with them. Further research is needed to test specific psychological theory in this context, including self-esteem theory, self determination theory, and the martyrdom effect (among others)
Códigos convolucionais para codificação em rede com múltiplos envios
In this thesis, we aim to provide a general overview of the area of multi-shot
codes for network coding. We will review the approaches and results proposed
so far and present slightly more general definitions of rank metric block and
convolutional codes that allows a wider set of rates than the definitions of rank
metric codes that exist in the literature. We also present, within this new
framework, the notion of column rank distance of a rank metric convolutional
code. We investigate it properties and derive an upper-bound that allows us to
extend the notions of Maximum Distance Profile and Strongly-Maximum
Distance Separable convolutional codes to some rank metric codes analogues.
We focused on the development of channel encoders as a mechanism that
allows the recovery of the data lost during the transmission. We also
concentrate on the construction of novel classes of MRD convolutional codes.
In particular we aim at extending the constructions presented by Napp, Pinto,
Rosenthal and Vettori, in order to increase the degree of the code and
consequently it error correction capability.
As alternative to rank metric convolutional codes, we present a novel scheme
by concatenation of a Hamming metric convolutional code (as outer code) and
a rank metric block code (as a inner code). The proposed concatenated code
is defined over the base finite field instead of over several extension finite fields
and pretend to reduce the complexity of encoding and decoding process and
moreover use the more general definition of rank metric code in order to be
more natural.Nesta tese, pretendemos mostrar uma visão geral da área de códigos multishot
na codificação em redes. Para o efeito, iremos rever as abordagens e
resultados propostos até agora e apresentar definições um pouco mais gerais
de códigos a blocos e códigos convolucionais que permitem uma ampliação
das definições de códigos de métrica rank que já existem na literatura.
Também apresentamos, dentro desta nova estrutura, a noção de distância de
coluna de um código convolucional de métrica rank. Investigamos as suas
propriedades e derivamos um limite superior para o valor da mesma, que nos
permite estender as noções de MDP e Strongly MDS para os códigos de
métrica rank.
Iremos também focar-nos no desenvolvimento de codificadores de canal como
mecanismo que permite uma melhor recuperação dos dados perdidos durante
o processo de transmissão. Também nos concentramos na construção de
novas classes de códigos convolucionais MRD. Em particular, pretendemos
estender as construções apresentadas por Napp, Pinto, Rosenthal e Vettori,
com o intuito de incrementar o grau do código e, consequentemente, melhorar
a sua capacidade corretora.
Como alternativa aos códigos convolucionais de métrica rank, apresentamos
um novo esquema usando concatenação de um código convolucional de
métrica Hamming (como código externo) e um código a bloco de métrica rank
(como um código interno). O código concatenado proposto é definido sobre o
corpo finito base, com o intuito de reduzir a complexidade do processo de
codificação e decodificação e, além disso, usa a definição mais geral de código
de métrica rank, tornando o processo mais natural.Programa Doutoral em Matemátic
Foundations for programming and implementing effect handlers
First-class control operators provide programmers with an expressive and efficient
means for manipulating control through reification of the current control state as a first-class object, enabling programmers to implement their own computational effects and
control idioms as shareable libraries. Effect handlers provide a particularly structured
approach to programming with first-class control by naming control reifying operations
and separating from their handling.
This thesis is composed of three strands of work in which I develop operational
foundations for programming and implementing effect handlers as well as exploring
the expressive power of effect handlers.
The first strand develops a fine-grain call-by-value core calculus of a statically
typed programming language with a structural notion of effect types, as opposed to the
nominal notion of effect types that dominates the literature. With the structural approach,
effects need not be declared before use. The usual safety properties of statically typed
programming are retained by making crucial use of row polymorphism to build and
track effect signatures. The calculus features three forms of handlers: deep, shallow,
and parameterised. They each offer a different approach to manipulate the control state
of programs. Traditional deep handlers are defined by folds over computation trees,
and are the original con-struct proposed by Plotkin and Pretnar. Shallow handlers are
defined by case splits (rather than folds) over computation trees. Parameterised handlers
are deep handlers extended with a state value that is threaded through the folds over
computation trees. To demonstrate the usefulness of effects and handlers as a practical
programming abstraction I implement the essence of a small UNIX-style operating
system complete with multi-user environment, time-sharing, and file I/O.
The second strand studies continuation passing style (CPS) and abstract machine
semantics, which are foundational techniques that admit a unified basis for implementing deep, shallow, and parameterised effect handlers in the same environment. The
CPS translation is obtained through a series of refinements of a basic first-order CPS
translation for a fine-grain call-by-value language into an untyped language. Each refinement moves toward a more intensional representation of continuations eventually
arriving at the notion of generalised continuation, which admit simultaneous support for
deep, shallow, and parameterised handlers. The initial refinement adds support for deep
handlers by representing stacks of continuations and handlers as a curried sequence of
arguments. The image of the resulting translation is not properly tail-recursive, meaning some function application terms do not appear in tail position. To rectify this the
CPS translation is refined once more to obtain an uncurried representation of stacks
of continuations and handlers. Finally, the translation is made higher-order in order to
contract administrative redexes at translation time. The generalised continuation representation is used to construct an abstract machine that provide simultaneous support for
deep, shallow, and parameterised effect handlers. kinds of effect handlers.
The third strand explores the expressiveness of effect handlers. First, I show that
deep, shallow, and parameterised notions of handlers are interdefinable by way of typed
macro-expressiveness, which provides a syntactic notion of expressiveness that affirms
the existence of encodings between handlers, but it provides no information about the
computational content of the encodings. Second, using the semantic notion of expressiveness I show that for a class of programs a programming language with first-class
control (e.g. effect handlers) admits asymptotically faster implementations than possible in a language without first-class control
How to Be a God
When it comes to questions concerning the nature of Reality, Philosophers and Theologians have the answers.
Philosophers have the answers that can’t be proven right. Theologians have the answers that can’t be proven wrong.
Today’s designers of Massively-Multiplayer Online Role-Playing Games create realities for a living. They can’t spend centuries mulling over the issues: they have to face them head-on. Their practical experiences can indicate which theoretical proposals actually work in practice.
That’s today’s designers. Tomorrow’s will have a whole new set of questions to answer.
The designers of virtual worlds are the literal gods of those realities. Suppose Artificial Intelligence comes through and allows us to create non-player characters as smart as us. What are our responsibilities as gods? How should we, as gods, conduct ourselves?
How should we be gods
Chinese Benteng Women’s Participation in Local Development Affairs in Indonesia: Appropriate means for struggle and a pathway to claim citizen’ right?
It had been more than two decades passing by aftermath the devastating Asia’s Financial Crisis in 1997, subsequently followed by Suharto’s step down from his presidential throne which he occupied for more than three decades. The financial turmoil turned to a political disaster furthermore has led to massive looting that severely impacted Indonesians of Chinese descendant, including unresolved mystery of the most atrocious sexual violation against women and covert killings of students and democracy activists in this country. Since then, precisely aftermath May 1998, which publicly known as “Reformasi”1, Indonesia underwent political reform that eventually corresponded positively to its macroeconomic growth. Twenty years later, in 2018, Indonesia captured worldwide attention because it has successfully hosted two internationally renowned events, namely the Asian Games 2018 – the most prestigious sport events in Asia – conducted in Jakarta and Palembang; and the IMF/World Bank Annual Meeting 2018 in Bali. Particularly in the IMF/World Bank Annual Meeting, this event has significantly elevated Indonesia’s credibility and international prestige in the global economic powerplay as one of the nations with promising growth and openness. However, the narrative about poverty and inequality, including increasing racial tension, religious conservatism, and sexual violation against women are superseded by friendly climate for foreign investment and eventually excessive glorification of the nation’s economic growth. By portraying the image of promising new economic power, as rhetorically promised by President Joko Widodo during his presidential terms, Indonesia has swept the growing inequality in this highly stratified society that historically compounded with religious and racial tension under the carpet of digital economy.Arte y Humanidade
Towards a Low-SWaP 1024-beam Digital Array: A 32-beam Sub-system at 5.8 GHz
Millimeter wave communications require multibeam beamforming in order to
utilize wireless channels that suffer from obstructions, path loss, and
multi-path effects. Digital multibeam beamforming has maximum degrees of
freedom compared to analog phased arrays. However, circuit complexity and power
consumption are important constraints for digital multibeam systems. A
low-complexity digital computing architecture is proposed for a
multiplication-free 32-point linear transform that approximates multiple
simultaneous RF beams similar to a discrete Fourier transform (DFT). Arithmetic
complexity due to multiplication is reduced from the FFT complexity of
for DFT realizations, down to zero, thus yielding a
46% and 55% reduction in chip area and dynamic power consumption, respectively,
for the case considered. The paper describes the proposed 32-point DFT
approximation targeting a 1024-beams using a 2D array, and shows the
multiplierless approximation and its mapping to a 32-beam sub-system consisting
of 5.8 GHz antennas that can be used for generating 1024 digital beams without
multiplications. Real-time beam computation is achieved using a Xilinx FPGA at
120 MHz bandwidth per beam. Theoretical beam performance is compared with
measured RF patterns from both a fixed-point FFT as well as the proposed
multiplier-free algorithm and are in good agreement.Comment: 19 pages, 8 figures, 4 tables. This version corrects a typo in the
matrix equations from Section
- …