129 research outputs found
Flexible Bus Media Redundancy
DETIThis paper proposes a flexible approach to bus media
redundancy in Controller Area Network (CAN) fieldbuses,
both to improve the bandwidth by transmitting different
traffic in different channels or to promote redundancy by
transmitting the same message in more than one channel.
Specifically the proposed solution is discussed in the context
of Flexible Time-Triggered protocol over CAN (FTTCAN)
and inherits the online scheduling flexibility of FTTCAN,
enabling on-the-fly modifications of the traffic conveyed
in the replicated buses. Flexible bus media redundancy
is useful to fulfill application requirements in terms
of additional bandwidth or to react to bus failures leading
the system to a degraded operational mode, without compromising
safety. The arguments for and against flexible
bus media redundancy in the context of FTT-CAN are also
discussed in detail
Using FTT-CAN to the Flexible Control of Bus Redundancy and Bandwidth Usage
DETIController Area Network (CAN) is a popular and very well-known bus system, both in
academia and in industry, initially targeted to automotive applications as a single
digital bus to replace the wiring that were growing complexity, weight and cost with
the advent of new automotive appliances. However, requirements have evolved and
CAN’s dependability and bandwidth limitations led to the emergence of alternative
networks such as FlexRay and TTP/C. Nevertheless, we believe that it is possible to
improve CAN so it could fulfill contemporary requirements. This paper proposes the
use of Flexible Time-Triggered CAN (FTT-CAN) to increase the available bandwidth
while providing fault tolerance in CAN based systems with multiple buses. The
architecture and flexibility of FTT based systems enables a tight yet flexible control of
redundancy and bandwidth usage without increasing the complexity of the nodes. In
this novel solution, a FTT-CAN Master controls the dispatching of messages among a
set of independent buses. The Master can react online to bus failures switching the
transmission of critical messages to a non-faulty bus, always keeping a predetermined
redundancy level
Controller Area Network
Controller Area Network (CAN) is a popular and very well-known bus system, both in academia and in industry. CAN protocol was introduced in the mid eighties by Robert Bosch GmbH [7] and it was internationally standardized in 1993 as ISO 11898-1 [24]. It was initially designed to distributed automotive control systems, as a single digital bus to replace traditional point-to-point cables that were growing in complexity, weight and cost with the introduction of new electrical and electronic systems. Nowadays CAN is still used extensively in automotive applications, with an excess of 400 million CAN enabled microcontrollers manufactured each year [14].
The widespread and successful use of CAN in the automotive industry, the low cost asso- ciated with high volume production of controllers and CAN's inherent technical merit, have driven to CAN adoption in other application domains such as: industrial communications,
medical equipment, machine tool, robotics and in distributed embedded systems in general.
CAN provides two layers of the stack of the Open Systems Interconnection (OSI) reference model: the physical layer and the data link layer. Optionally, it could also provide an additional application layer, not included on the CAN standard. Notice that CAN physical layer was not dened in Bosch original specication, only the data link layer was dened. However, the CAN ISO specication lled this gap and the physical layer was then fully specied. CAN is a message-oriented transmission protocol, i.e., it denes message contents rather than nodes and node addresses. Every message has an associated message identier, which is unique within the whole network, dening both the content and the priority of the message. Transmission rates are dened up to 1 Mbps.
The large installed base of CAN nodes with low failure rates over almost two decades, led to the use of CAN in some critical applications such as Anti-locking Brake Systems (ABS) and Electronic Stability Program (ESP) in cars. In parallel with the wide dissemination of CAN in industry, the academia also devoted a large eort to CAN analysis and research, making CAN one of the must studied eldbuses. That is why a large number of books or book chapters describing CAN were published. The rst CAN book, written in French by D. Paret, was published in 1997 and presents the CAN basics [32]. More implementation oriented approaches, including CAN node implementation and application examples, can be found in Lorenz [28] and in Etschberger [16], while more compact descriptions of CAN can be found in [11] and in some chapters of [31].
Despite its success story, CAN application designers would be happier if CAN could be made faster, cover longer distances, be more deterministic and more dependable [34]. Over the years, several protocols based in CAN were presented, taking advantage of some CAN properties and trying to improve some known CAN drawbacks. This chapter, besides presenting an overview of CAN, describes also some other relevant higher level protocols based on CAN, such as CANopen [13], DeviceNet [6], FTT-CAN [1] and TTCAN [25]
Tolerância a falhas em sistemas de comunicação de tempo-real flexÃveis
Nas últimas décadas, os sistemas embutidos distribuÃdos, têm sido usados em
variados domÃnios de aplicação, desde o controlo de processos industriais até
ao controlo de aviões e automóveis, sendo expectável que esta tendência se
mantenha e até se intensifique durante os próximos anos.
Os requisitos de confiabilidade de algumas destas aplicações são
extremamente importantes, visto que o não cumprimento de serviços de uma
forma previsÃvel e pontual pode causar graves danos económicos ou até pôr
em risco vidas humanas.
A adopção das melhores práticas de projecto no desenvolvimento destes
sistemas não elimina, por si só, a ocorrência de falhas causadas pelo
comportamento não determinÃstico do ambiente onde o sistema embutido
distribuÃdo operará. Desta forma, é necessário incluir mecanismos de
tolerância a falhas que impeçam que eventuais falhas possam comprometer
todo o sistema.
Contudo, para serem eficazes, os mecanismos de tolerância a falhas
necessitam ter conhecimento a priori do comportamento correcto do sistema
de modo a poderem ser capazes de distinguir os modos correctos de
funcionamento dos incorrectos.
Tradicionalmente, quando se projectam mecanismos de tolerância a falhas, o
conhecimento a priori significa que todos os possÃveis modos de
funcionamento são conhecidos na fase de projecto, não os podendo adaptar
nem fazer evoluir durante a operação do sistema. Como consequência, os
sistemas projectados de acordo com este princÃpio ou são completamente
estáticos ou permitem apenas um pequeno número de modos de operação.
Contudo, é desejável que os sistemas disponham de alguma flexibilidade de
modo a suportarem a evolução dos requisitos durante a fase de operação,
simplificar a manutenção e reparação, bem como melhorar a eficiência usando
apenas os recursos do sistema que são efectivamente necessários em cada
instante. Além disto, esta eficiência pode ter um impacto positivo no custo do
sistema, em virtude deste poder disponibilizar mais funcionalidades com o
mesmo custo ou a mesma funcionalidade a um menor custo.
Porém, flexibilidade e confiabilidade têm sido encarados como conceitos
conflituais.
Isto deve-se ao facto de flexibilidade implicar a capacidade de permitir a
evolução dos requisitos que, por sua vez, podem levar a cenários de operação
imprevisÃveis e possivelmente inseguros. Desta fora, é comummente aceite
que apenas um sistema completamente estático pode ser tornado confiável, o
que significa que todos os aspectos operacionais têm de ser completamente
definidos durante a fase de projecto.
Num sentido lato, esta constatação é verdadeira. Contudo, se os modos como
o sistema se adapta a requisitos evolutivos puderem ser restringidos e
controlados, então talvez seja possÃvel garantir a confiabilidade permanente
apesar das alterações aos requisitos durante a fase de operação.
A tese suportada por esta dissertação defende que é possÃvel flexibilizar um
sistema, dentro de limites bem definidos, sem comprometer a sua
confiabilidade e propõe alguns mecanismos que permitem a construção de
sistemas de segurança crÃtica baseados no protocolo Controller Area Network
(CAN). Mais concretamente, o foco principal deste trabalho incide sobre o
protocolo Flexible Time-Triggered CAN (FTT-CAN), que foi especialmente
desenvolvido para disponibilizar um grande nÃvel de flexibilidade operacional
combinando, não só as vantagens dos paradigmas de transmissão de
mensagens baseados em eventos e em tempo, mas também a flexibilidade
associada ao escalonamento dinâmico do tráfego cuja transmissão é
despoletada apenas pela evolução do tempo.
Este facto condiciona e torna mais complexo o desenvolvimento de
mecanismos de tolerância a falhas para FTT-CAN do que para outros
protocolos como por exemplo, TTCAN ou FlexRay, nos quais existe um
conhecimento estático, antecipado e comum a todos os nodos, do
escalonamento de mensagens cuja transmissão é despoletada pela evolução
do tempo.
Contudo, e apesar desta complexidade adicional, este trabalho demonstra que
é possÃvel construir mecanismos de tolerância a falhas para FTT-CAN
preservando a sua flexibilidade operacional.
É também defendido nesta dissertação que um sistema baseado no protocolo
FTT-CAN e equipado com os mecanismos de tolerância a falhas propostos é
passÃvel de ser usado em aplicações de segurança crÃtica.
Esta afirmação é suportada, no âmbito do protocolo FTT-CAN, através da
definição de uma arquitectura tolerante a falhas integrando nodos com modos
de falha tipo falha-silêncio e nodos mestre replicados.
Os vários problemas resultantes da replicação dos nodos mestre são, também
eles, analisados e várias soluções são propostas para os obviar.
Concretamente, é proposto um protocolo que garante a consistência das
estruturas de dados replicadas a quando da sua actualização e um outro
protocolo que permite a transferência dessas estruturas de dados para um
nodo mestre que se encontre não sincronizado com os restantes depois de
inicializado ou reinicializado de modo assÃncrono.
Além disto, esta dissertação também discute o projecto de nodos FTT-CAN
que exibam um modo de falha do tipo falha-silêncio e propõe duas soluções
baseadas em componentes de hardware localizados no interface de rede de
cada nodo, para resolver este problema. Uma das soluções propostas baseiase
em bus guardians que permitem a imposição de comportamento falhasilêncio
nos nodos escravos e suportam o escalonamento dinâmico de tráfego
na rede. A outra solução baseia-se num interface de rede que arbitra o acesso
de dois microprocessadores ao barramento. Este interface permite que a
replicação interna de um nodo seja efectuada de forma transparente e
assegura um comportamento falha-silêncio quer no domÃnio temporal quer no
domÃnio do valor ao permitir transmissões do nodo apenas quando ambas as
réplicas coincidam no conteúdo das mensagens e nos instantes de
transmissão. Esta última solução está mais adaptada para ser usada nos
nodos mestre, contudo também poderá ser usada nos nodos escravo, sempre
que tal se revele fundamental.Distributed embedded systems (DES) have been widely used in the last few
decades in several application fields, ranging from industrial process control to
avionics and automotive systems. In fact, it is expectable that this trend will
continue over the years to come.
In some of these application domains the dependability requirements are of
utmost importance since failing to provide services in a timely and predictable
manner may cause important economic losses or even put human life in risk.
The adoption of the best practices in the design of distributed embedded
systems does not fully avoid the occurrence of faults, arising from the nondeterministic
behavior of the environment where each particular DES operates.
Thus, fault-tolerance mechanisms need to be included in the DES to prevent
possible faults leading to system failure.
To be effective, fault-tolerance mechanisms require an a priori knowledge of
the correct system behavior to be capable of distinguishing them from the
erroneous ones.
Traditionally, when designing fault-tolerance mechanisms, the a priori
knowledge means that all possible operational modes are known at system
design time and cannot adapt nor evolve during runtime. As a consequence,
systems designed according to this principle are either fully static or allow a
small number of operational modes only. Flexibility, however, is a desired
property in a system in order to support evolving requirements, simplify
maintenance and repair, and improve the efficiency in using system resources
by using only the resources that are effectively required at each instant. This
efficiency might impact positively on the system cost because with the same
resources one can add more functionality or one can offer the same
functionality with fewer resources.
However, flexibility and dependability are often regarded as conflicting
concepts. This is so because flexibility implies the ability to deal with evolving
requirements that, in turn, can lead to unpredictable and possibly unsafe
operating scenarios. Therefore, it is commonly accepted that only a fully static
system can be made dependable, meaning that all operating conditions are
completely defined at pre-runtime.
In the broad sense and assuming unbounded flexibility this assessment is true,
but if one restricts and controls the ways the system could adapt to evolving
requirements, then it might be possible to enforce continuous dependability.
This thesis claims that it is possible to provide a bounded degree of flexibility
without compromising dependability and proposes some mechanisms to build
safety-critical systems based on the Controller Area Network (CAN).
In particular, the main focus of this work is the Flexible Time-Triggered CAN
protocol (FTT-CAN), which was specifically developed to provide such high
level of operational flexibility, not only combining the advantages of time- and
event-triggered paradigms but also providing flexibility to the time-triggered
traffic. This fact makes the development of fault-tolerant mechanisms more
complex in FTT-CAN than in other protocols, such as TTCAN or FlexRay, in
which there is a priori static common knowledge of the time-triggered message
schedule shared by all nodes. Nevertheless, as it is demonstrated in this work,
it is possible to build fault-tolerant mechanisms for FTT-CAN that preserve its
high level of operational flexibility, particularly concerning the time-triggered
traffic. With such mechanisms it is argued that FTT-CAN is suitable for safetycritical
applications, too.
This claim was validated in the scope of the FTT-CAN protocol by presenting a
fault-tolerant system architecture with replicated masters and fail-silent nodes.
The specific problems and mechanisms related with master replication,
particularly a protocol to enforce consistency during updates of replicated data
structures and another protocol to transfer these data structures to an
unsynchronized node upon asynchronous startup or restart, are also
addressed.
Moreover, this thesis also discusses the implementations of fail-silence in FTTCAN
nodes and proposes two solutions, both based on hardware components
that are attached to the node network interface. One solution relies on bus
guardians that allow enforcing fail-silence in the time domain. These bus
guardians are adapted to support dynamic traffic scheduling and are fit for use
in FTT-CAN slave nodes, only. The other solution relies on a special network
interface, with duplicated microprocessor interface, that supports internal
replication of the node, transparently. In this case, fail-silence can be assured
both in the time and value domain since transmissions are carried out only if
both internal nodes agree on the transmission instant and message contents.
This solution is well adapted for use in the masters but it can also be used, if
desired, in slave nodes
In-vehicle communication networks : a literature survey
The increasing use of electronic systems in automobiles instead of mechanical and hydraulic parts brings about advantages by decreasing their weight and cost and providing more safety and comfort. There are many electronic systems in modern automobiles like antilock braking system (ABS) and electronic brakeforce distribution (EBD), electronic stability program (ESP) and adaptive cruise control (ACC). Such systems assist the driver by providing better control, more comfort and safety. In addition, future x-by-wire applications aim to replace existing braking, steering and driving systems. The developments in automotive electronics reveal the need for dependable, efficient, high-speed and low cost in-vehicle communication. This report presents the summary of a literature survey on in-vehicle communication networks. Different in-vehicle system domains and their requirements are described and main invehicle communication networks that have been used in automobiles or are likely to be used in the near future are discussed and compared with key references
Using CAN to retrofit houses for quadriplegic people
DETIThis paper describes the B-Live® system targetted to automate house appliances for
severely impaired people, in particular quadriplegic. This system has been developed
at Micro I/O for enhancing the quality of life and the independence of its potential
users. The envisaged application is the retrofitting of common dwellings.
The B-Live system is described and details on its software, hardware and CAN-based
communications architecture are provided. A survey of the supported appliances and
interfaces is presented as well as a description of the B-live configuration and
operation procedures. The adequacy of the B-Live system to improve the autonomy of
the envisaged users was informally evaluated by C5 and C6 patients at a
demonstration house located in the CMRRC Rovisco Pais, a rehabilitation center near
Aveiro, in Portugal. The conclusion is that the system has a short learning curve and
can cope with the requirements of its potential users. The use of CAN in this
application opens the possibility to include safety critical real-time systems in the BLive system. This is the case of the monitoring of the ventilator used for quadriplegic people that require breath assistance
Flexible management of bandwidth and redundancy in fieldbuses
Doutoramento em Engenharia ElectrotécnicaOs sistemas distribuÃdos embarcados (Distributed Embedded Systems – DES) têm sido usados ao longo dos últimos anos em muitos domÃnios de aplicação, da robótica, ao controlo de processos industriais passando pela aviónica e pelas aplicações veiculares, esperando-se que esta tendência continue nos próximos anos.
A confiança no funcionamento é uma propriedade importante nestes domÃnios de aplicação, visto que os serviços têm de ser executados em tempo útil e de forma previsÃvel, caso contrário, podem ocorrer danos económicos ou a vida de seres humanos poderá ser posta em causa.
Na fase de projecto destes sistemas é impossÃvel prever todos os cenários de falhas devido ao não determinismo do ambiente envolvente, sendo necessária a inclusão de mecanismos de tolerância a falhas.
Adicionalmente, algumas destas aplicações requerem muita largura de banda, que também poderá ser usada para a evolução dos sistemas, adicionandolhes novas funcionalidades.
A flexibilidade de um sistema é uma propriedade importante, pois permite a sua adaptação às condições e requisitos envolventes, contribuindo também para a simplicidade de manutenção e reparação. Adicionalmente, nos sistemas
embarcados, a flexibilidade também é importante por potenciar uma melhor utilização dos, muitas vezes escassos, recursos existentes.
Uma forma evidente de aumentar a largura de banda e a tolerância a falhas dos sistemas embarcados distribuÃdos é a replicação dos barramentos do sistema. Algumas soluções existentes, quer comerciais quer académicas,
propõem a replicação dos barramentos para aumento da largura de banda ou para aumento da tolerância a falhas. No entanto e quase invariavelmente, o propósito é apenas um, sendo raras as soluções que disponibilizam uma maior
largura de banda e um aumento da tolerância a falhas. Um destes raros exemplos é o FlexRay, com a limitação de apenas ser permitido o uso de dois
barramentos.
Esta tese apresentada e discute uma proposta para usar a replicação de barramentos de uma forma flexÃvel com o objectivo duplo de aumentar a
largura de banda e a tolerância a falhas. A flexibilidade dos protocolos propostos também permite a gestão dinâmica da topologia da rede, sendo o número de barramentos apenas limitado pelo hardware/software.
As propostas desta tese foram validadas recorrendo ao barramento de campo
CAN – Controller Area Network, escolhido devido à sua grande implantação no mercado. Mais especificamente, as soluções propostas foram implementadas e validadas usando um paradigma que combina flexibilidade com comunicações event-triggered e time-triggered: o FTT – Flexible Time- Triggered. No entanto, uma generalização para CAN nativo é também apresentada e discutida.
A inclusão de mecanismos de replicação do barramento impõe a alteração dos antigos protocolos de replicação e substituição do nó mestre, bem como a definição de novos protocolos para esta finalidade. Este trabalho tira partido da
arquitectura centralizada e da replicação do nó mestre para suportar de forma eficiente e flexÃvel a replicação de barramentos. Em caso de ocorrência de uma falta num barramento (ou barramentos) que poderia provocar uma falha no sistema, os protocolos e componentes propostos nesta tese fazem com que o sistema reaja, mudando para um modo de funcionamento degradado. As
mensagens que estavam a ser transmitidas nos barramentos onde ocorreu a falta são reencaminhadas para os outros barramentos.
A replicação do nó mestre baseia-se numa estratégia lÃder-seguidores (leaderfollowers),
onde o lÃder (leader) controla todo o sistema enquanto os seguidores (followers) servem como nós de reserva. Se um erro ocorrer no nó
lÃder, um dos nós seguidores passará a controlar o sistema de uma forma transparente e mantendo as mesmas funcionalidades.
As propostas desta tese foram também generalizadas para CAN nativo, tendo sido para tal propostos dois componentes adicionais. É, desta forma possÃvel ter as mesmas capacidades de tolerância a falhas ao nÃvel dos barramentos
juntamente com a gestão dinâmica da topologia de rede.
Todas as propostas desta tese foram implementadas e avaliadas. Uma
implementação inicial, apenas com um barramento foi avaliada recorrendo a uma aplicação real, uma equipa de futebol robótico onde o protocolo FTT-CAN foi usado no controlo de movimento e da odometria.
A avaliação do sistema com múltiplos barramentos foi feita numa plataforma de teste em laboratório. Para tal foi desenvolvido um sistema de injecção de faltas que permite impor faltas nos barramentos e nos nós mestre, e um sistema de medida de atrasos destinado a medir o tempo de resposta após a ocorrência de uma falta.Distributed embedded systems (DES) have been widely used in the last few decades in several application domains, from robotics, industrial process control, avionics and automotive. In fact, it is expectable that this trend will continue in the next years.
In some of these application fields the dependability requirements are very important since the fail to provide services in a timely and predictable manner
may cause important economic losses or even put humans in risk.
In the design phase it is impossible to predict all the possible scenarios of faults, due to the non deterministic behaviour of the surrounding environment.
In that way, the fault tolerance mechanisms must be included in the distributed embedded system to prevent failures occurrence.
Also, many application domains require a high available bandwidth to perform the desired functions, or to turn possible the scaling with the addition of new features.
The flexibility of a system also plays an important role, since it improves the capability to adapt to the surrounding world, and to the simplicity of the repair
and maintenance. The flexibility improves the efficiency of all the system by providing a way to efficiently manage the available resources. This is very important in embedded systems due to the limited resources often available.
A natural way to improve the bandwidth and the fault tolerance in distributed systems is to use replicated buses. Commercial and academic solutions propose the use of replicated fieldbuses for a single purpose only, either to improve the fault tolerance or to improve the available bandwidth, being the first the most common. One illustrative exception is FlexRay where the bus replica
can be used to improve the bandwidth of the overall system, besides enabling redundant communications. However, only one bus replica can be used.
In this thesis, a flexible bus replication scheme to improve both the dependability and the throughput of fieldbuses is presented and studied. It can
be applied to any number of replicated buses, provided the required hardware support is available. The flexible use of the replicated buses can achieve an also flexible management of the network topology.
This claim has been validated using the Controller Area Network (CAN) fieldbus, which has been chosen because it is widely spread in millions of
systems. In fact, the proposed solution uses a paradigm that combines flexibility, time and event triggered communication, that is the Flexible Time-
Triggered over CAN network (FTT-CAN). However, a generalization to native CAN is also presented and studied.
The inclusion of bus replication in FTT-CAN imposes not only new mechanisms but also changes of the mechanisms associated with the master replication, which has been already studied in previous research work. In this work, these
mechanisms were combined and take advantage of the centralized architecture and of the redundant masters to support an efficient and flexible bus
replication.
When considering the system operation, if a fault in the bus (or buses) occurs, and the consequent error leads to a system failure, the system reacts,
switching to a degraded mode, where the message flows that were transmitted in the faulty bus (or buses) change to the non-faulty ones.
The central node replication uses a leader-follower strategy, where the leader controls the system while the followers serve as backups. If an error occurs in
the leader, a backup will take the system control maintaining the system with the same functionalities.
The system has been generalized for native CAN, using two additional components that provide the same fault tolerance capabilities at the bus level,
and also enable the dynamic management of the network topology.
All the referred proposals were implemented and assessed in the scope of this work. The single bus version of FTT-CAN was assessed using a real
application, a robotic soccer team, which has obtained excellent results in international competitions. There, the FTT-CAN based embedded system has been applied in the low level control, where, mainly it is responsible for the
motion control and odometry.
For the case of the multiple buses system, the assessment was performed in a laboratory test bed. For this, a fault injector was developed in order to impose faults in the buses and in the central nodes. To measure the time reaction of the system, a special hardware has been developed: a delay measurement system. It is able to measure delays between two important time marks for posterior offline analysis of the obtained values
Coordinating distributed autonomous agents with a real-time database: the CAMBADA project
DETIInterest on using mobile autonomous agents has been growing,
recently, due to their capacity to cooperate for diverse purposes, from rescue to
demining and security. However, such cooperation requires the exchange of
state data that is time sensitive and thus, applications should be aware of data
temporal coherency. In this paper we describe the architecture of the agents that
constitute the CAMBADA robotic soccer team developed at the University of
Aveiro, Portugal. This architecture is built around a real-time database that is
partially replicated in all team members and contains both local and remote state
variables. The temporal coherency of the data is enforced by an adequate
management system that refreshes each database item transparently at a rate
specified by the application. The application software accesses the state
variables of all agents with local operations, only, delivering both value and
temporal coherency
Identity Theft Prevention Measures for State Unemployment Benefits Offices: A Case Study of Workforce West Virginia
Identity theft continues to pose an increasingly complex problem for government benefits offices. The purpose of this study was to explore the environmental factors that affected a state unemployment benefits office’s ability to reduce identity theft. Current research focused on protecting information systems’ hardware, software, and related infrastructure, focusing on cyberattacks such as phishing, Trojan horses, or illegal access. The U.S. government focuses on informing the consumer and assisting small businesses through risk assessments, strategic plans, and regulations for cybersecurity. Researchers have not conducted a thorough investigation of the environment that makes state government benefit offices susceptible to identity theft. The theoretical framework for this study was open systems theory using the six dimensions of digital governance. The research question involved the identification of the barriers to a state unemployment benefits office’s ability to reduce identity theft. A qualitative case study approach concentrated on the external environmental factors that affect the system. Data collection included documents, archival records, and artifacts from multiple sources. The outcome of this research may help to inform state governments to improve policies and procedures by providing administrative, operational, and technical controls. This study has implications for positive social change to inform efforts to reduce human costs (identity theft) and financial costs (government program fraud and individual recovery)
Challenges in health smart homes
This paper presents an overview of the challenges in developing Health Smart Homes targeting, in particular, elderly and impaired people. As such, it identifies the current endeavors as well as the main areas of research
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