The computing capability of the embedded systems and bandwidth of the home network increase rapidly due to the rapid development of information and communication technologies. Many home appliances such as TVs, refrigerators, or air conditioners are now connected to the internet, then, the controlling firmware modules are automatically updatable via the network. TR-069 is a widely adopted standard for automatic appliance management and firmware update. Maintaining a TR-069 network usually involves the design and deployment of the overall security and trust infrastructure, the update file repository and the update audit mechanisms. Thus, maintaining a dedicated TR-069 network is a heavy burden for the vendors of home appliances. Blockchain is an emerging technology that provides a secure and trust infrastructure based on distributed consensus. This paper reports the results of our initial attempt to design a prototype of a multitenant TR-069 platform based on the blockchain. The core idea is to reify each automatic deployment task as a smart contract instance whose transactions are recorded in the append-only distributed ledger and verified by the peers. Also, the overall design should be transparent to the original TR-069 entities. We have built a prototype based on the proposed architecture to verify the feasibility in three key scenarios. The experimental results show that the proposed approach is feasible and is able to scale linearly in proportion to the number of managed devices.

The W3C organization has recently continued to propose recommendation for WoT (Web of Things). In order for BLE, which has a high market share in IoT application, to comply with the WoT recommendation, this paper propose a proprietary application-level gateway and WeBLE (Web of BLE) device that allow clients to treat BLE devices as WoT node and increase the interoperability of BLE devices.

Because of the worldwide aging population, more and more elders suffer from dementia problem. Nowadays, it is an inconvenient and time-consuming process for medical doctors to diagnose elders who live independently with possible dementia because the process imposes a large quantity of diagnostic questions from a checklist that needs to be answered by elders themselves or their caregivers either directly or after a long-term observation. In order to help doctors to make this diagnostic process easier, this article proposes a supporting system that can quickly estimate the likelihood for an elder of having dementia based on 2 to 4 hours monitoring of a behavioral test done by the elder. During the test, the elder only needs to perform certain activities selected from the so-called instrumental activities of daily living (IADL) in a smart home environment, and their movement trajectories will be extracted from motion sensors deployed in the smart home environment and be analyzed to find a potential correlation with the indoor wandering patterns. A machine learning algorithm is selected to carry out the classification task, namely, into dementia and nondementia groups, based on our proposed features of the aforementioned wandering patterns. Two data sets are employed for performance evaluation, where the first one is 232 elders including seven dementia, whereas the second one is collected by ourselves from a senior center, which is 30 elders including nine dementia. It turns out that the average precision and recall for the first data set are both up to 98.3% with area under the ROC curve (AUC-ROC) being 0.846, and those for the second data set are 89.9% and 90.0% with AUC-ROC being 0.921. Note to Practitioners-We proposed a supporting system which can classify the elders as either dementia or nondementia with high accuracy. The trajectories of the elders will be extracted from motion sensors that deployed in the smart home environment. The indoor wandering patterns according to repetitive movements are analyzed and classified using the machine learning technique. The proposed system used ambient sensors instead of wearable sensors or cameras to let the elders feel more comfortable when they are being monitored. In addition, the proposed system only required a short period of time to screen the elders and easier for medical doctors to diagnose the elders without wasting time for asking the large quantity of diagnostic questions from a checklist that needs to be answered by the elders themselves or their caregivers.

The use of message-oriented middleware (MOM) in pervasive systems has increased noticeably because of its flexible and failure-tolerant nature. Meanwhile, decentralized service management protocols such as UPnP are believed to be more suitable for administrating applications in small-scale pervasive environments such as smart homes. However, administering MOM-based pervasive systems by UPnP often suffers from network flood problems due to the replications of too many unnecessary messages. This paper presents several traffic reduction schemes, namely, decomposing the multicast traffic, service-based node searching, heartbeat by decomposing the multicast traffic, and on-demand heartbeat, which reduce the replications of unnecessary messages in MOM-based UPnP networks. The analytical predictions agree well with the simulated and experimental results, which show that the message counts of presence and leave announcements, node searching, and heartbeat can be greatly reduced.

In software as a service (SaaS) environments, designing a multi-tenant data architecture that supports shared database with custom extension is a non-trivial task. A general approach to support such an architecture is a middleware-level facility that supports the mapping of multiple single-tenant logical schemas in the application to one multi-tenant physical schema in the database. In this paper we follow this approach and report our preliminary results on the design and analysis of a query rewriting engine that can transparently transform tenant-specific logical queries into corresponding physical queries for Universal Table, a widely adopted and industry verified schema-mapping technique. A prototype and a sample SaaS application are implemented to verify the feasibility of the design of the query rewriting engine. Besides, performance analysis results that can be used to predict the overhead of schema-mapping in the engine are also reported.

Composing services in a pervasive environment usually involves user-in-the-loop adaption which is absent in most of the traditional enterprise service composition mechanisms. In such environment, the criteria for selecting and ranking services are usually specified by users, which tend to be vague and subjective. The criteria can be contradictory and the activated services can interfere with one another. This paper addresses these issues by defining a unifiable and negotiable expression language called the Preference Expression that is capable of specifying both enumerative/numeric as well as mandatory/negotiable user preferences. A set of unification rules for possible conflicting preferences is also derived. Experimental results show that the proposed approach is able to achieve high composition precision and maintains reasonable success rate at the same time.

Reliability is one of the key challenges of pervasive systems. Numerous message-oriented architectures and service discovery protocols have been proposed to support service management in pervasive systems. Nevertheless, few researches have been done to improve the reliability of pervasive systems. This paper attempts to propose a reliable service management framework by formally defining a message-oriented service application model and protocols that facilitate autonomous composition, failure detection, and recovery of services. Proposed approaches are realized by constructing a developer's toolkit that enables rapid-prototyping of services. We evaluate the proposed approach by first proving the reliability property and then conducting experiments on recovery rate and performance. The results show that the recovery rate can be greatly improved by the proposed approach. Furthermore, the services developed by using the proposed approach are capable of integrating heterogeneous software/hardware, and can be deployed in dissimilar sites with little efforts.

Current trends suggest that the smart home systems should be adaptive and robust. Many service-oriented architectures and discovery protocols for the smart home environments have been proposed to support on-line re-composition of home services in reaction to changing environments. Nevertheless, few researches have been done to improve the robustness of smart home systems. This paper attempts to propose a service management protocol that supports fast self-healing and self-organizing of home services by enhancing SSDP/UPnP with two protocol extensions and a lightweight heartbeat mechanism. Experiment results show that for average scale of services (less than 10 service components), the proposed protocol is capable of activating a service and recovering a failed service within 1200 ms and 2000 ms, respectively.

Service Discovery is an interesting challenge in highly dynamic Pervasive Environments such as smart living spaces. In addition to adaptation to varied environments, autonomous failure recovery and activation of services are two fundamental issues of a Service Discovery protocol in order to achieve high service availability. In [1], we have introduced an enhanced version of UPnP's Simple Service Discovery Protocol (SSDP), which aims to fulfill these two fundamental issues. However, our experiences in the previous work show that the failure recovery performance is not desirable due to the multicast mechanism used by SSDP. In this paper, we propose a supporting data structure, Mapped Eviction SND Tree, composed of a set of specialized mapped-trees to speed up the failure recovery process. The system with this structure is aware of existing service nodes and need not to perform the discovery procedure again when failure is detected. Hence, the time for restoring the failed service is minimized. Experiment results show that the proposed approach helps reducing the failure recovery time up to 90 percent in average. Issues concerning maintenance and collaboration between the sets of internal data structures are also discussed in this paper.

The architecture of a conventional smart home is usually server-centric and thus causes many problems. Mobile devices and dynamic services affect a dynamically changing environment, which can result in very difficult interaction. In addition, how to provide services efficiently and appropriately is always an important issue for a smart home. To solve the problems caused by traditional architectures, to deal with the dynamic environment, and to provide appropriate services, we propose a service-oriented architecture (SOA) for smart-home environments, based on Open Services Gateway Initiative (OSGi) and mobile-agent (MA) technology. This architecture is a peer-to-peer (P2P) model based on multiple OSGi platforms, in which service-oriented mechanisms are used for system components to interact with one another, and MA technology is applied to augment the interaction mechanisms

Character animations on most virtual environment systems are canned motions created off-line through motion capture techniques. The motions are then encoded and transmitted with a fixed format and played at the client side. In this paper, we have proposed an XML-based scripting language, called eXtensible Animation Markup Language (XAML), to describe interactive dialog-based animations. The language is designed to describe character animations at various command levels and to compose a new animation from existing animation clips. In addition, the language is extended to incorporate other dialog-based scripting language such as VoiceXML. We have implemented such a system in Java that can interpret the language and render 3D animations based on the user's interactive voice commands.