Description:
The development of smart vehicles brings drivers and passengers a comfortable and safe environment. Various emerging applications are promising to enrich users' traveling experiences and daily life. However, how to execute computing-intensive applications on resource-constrained vehicles still faces huge challenges. In this article, we construct an intelligent offloading system for vehicular edge computing by leveraging deep reinforcement learning. First, both the communication and computation states are modelled by finite Markov chains. Moreover, the task scheduling and resource allocation strategy is formulated as a joint optimization problem to maximize users' Quality of Experience (QoE). Due to its complexity, the original problem is further divided into two sub-optimization problems. A two-sided matching scheme and a deep reinforcement learning approach are developed to schedule offloading requests and allocate network resources, respectively. Performance evaluations illustrate the effectiveness and superiority of our constructed system.
Description:
The development of smart vehicles brings drivers and passengers a comfortable and safe environment. Various emerging applications are promising to enrich users' traveling experiences and daily life. However, how to execute computing-intensive applications on resource-constrained vehicles still faces huge challenges. In this article, we construct an intelligent offloading system for vehicular edge computing by leveraging deep reinforcement learning. First, both the communication and computation states are modelled by finite Markov chains. Moreover, the task scheduling and resource allocation strategy is formulated as a joint optimization problem to maximize users' Quality of Experience (QoE). Due to its complexity, the original problem is further divided into two sub-optimization problems. A two-sided matching scheme and a deep reinforcement learning approach are developed to schedule offloading requests and allocate network resources, respectively. Performance evaluations illustrate the effectiveness and superiority of our constructed system.
Description:
Shuffle-exchange networks (SENs) have been widely considered as practical interconnection systems due to their size of its switching elements (SEs) and uncomplicated configuration. SEN is a network among a large class of topologically equivalent multistage interconnection networks (MINs) that includes omega, indirect binary n-cube, baseline, and generalized cube. In this paper, SEN with additional stages that provide more redundant paths are analyzed. A common network topology with a 2×2 basic building block in a SEN and its variants in terms of extra-stages is investigated. As an illustration, three types of SENs are compared: SEN, SEN with an additional stage (SEN+), and SEN with two additional stages (SEN+2). Finally, three measures of reliability: terminal, broadcast, and network reliability for the three SEN systems are analyzed.
Description:
We consider the problem of security in wireless multicasting for a multiple-input multiple-output (MIMO) relay-aided system. The network suffers from a group of adaptive eavesdroppers who can act as both simple eavesdroppers and hostile jammers. This paper formulates the impact of friendly jammers to improve secured communication. We derived the expressions for secrecy multicast capacities considering the absence and presence of friendly jammers. The best relay for transmission is chosen from a group of relays that aids to achieve the maximum secrecy capacity while the best jammer is selected based on competitive interference price. Numerical results show that the achievable secrecy multicast capacity increases significantly in the presence of jammer to nullify the effect of adversaries. Results under different scenarios of varying jamming and relay powers demonstrate the efficacy of friendly jammers in providing physical layer security.
Description:
We consider the problem of security in wireless multicasting for a
Description:
Education policies and practices developed for urban populations are not always effective when implemented in regional and remote locations. Despite government policy initiatives that may provide for collaboration across communities, a singular issue is that a diversity of solutions may be required rather than a 'one size fits all' approach. This article presents a potential solution to this problem through engaging collaboration and co-creation to optimise educational opportunities in initial teacher education in Australia. Qualitative analysis of a collaborative and co-created process of enhancement, lesson development and reflection brings together the every-day problem-solving processes used by pre-service teachers and classroom students with those used by research scientists and community experts. A consequence of such a process that benefits regional and remote communities is the development of collaborative networks founded in co-creation of educational opportunities and based on daily life in local communities.
Description:
Objectives: Higher levels of depression have been documented among older adults who reside in an assisted living facility, compared with those who remain in their own homes. The aims of the current study were to test whether the relationship between housing type and depressive symptoms was mediated by a sense of belonging and whether housing type and sense of belonging interact to influence the depressive symptoms among older adults (moderation model).Method: A sample of 257 older adults who lived in their own homes and 166 older adults who lived in an assisted living facility completed the psychological subscale of the Sense of Belonging Instrument and the Center for Epidemiologic Studies Depression Scale.Results: Results showed that a sense of belonging partially mediated the relationship between housing type and depressive symptoms, such that living in a nursing home was associated with lower levels of belonging, and lower levels of belonging were, in turn, associated with higher levels of depressive symptoms. Residing in an assisted living facility was associated with depressive symptoms at low and average levels of belonging.Conclusion: Results highlight the need for more research on the role of sense of belonging as an influencing factor on depressive symptoms among institutionalised older adults for both theoretical and treatment goals.
Description:
This paper discusses elements of inter-entrepreneurial trust in regional networks and clusters in terms of influencing business processes and economic viability in today’s economy. The message that can be extracted from the literature is that competitive advantage strongly depends on interfirm collaboration and that networks with a high degree of trust lead to entrepreneurship and innovation. The paper highlights two local Victorian network studies, one in the grains industry and one in the tourism industry, and explores trust based relations in these regional networks. Contrasting sectoral results indicate that social network cohesion and trust were found to be present in the grains community but were absent in the tourism community. Borrowing from the economics and leadership literature, it is proposed that trust fosters certain types of inter-entrepreneurial networks. A description of these networks and related policy implications conclude the paper.
Description:
This paper discusses elements of inter-entrepreneurial trust in regional networks and clusters in terms of influencing business processes and economic viability in today’s economy. The message that can be extracted from the literature is that competitive advantage strongly depends on interfirm collaboration and that networks with a high degree of trust lead to entrepreneurship and innovation. The paper highlights two local Victorian network studies, one in the grains industry and one in the tourism industry, and explores trust based relations in these regional networks. Contrasting sectoral results indicate that social network cohesion and trust were found to be present in the grains community but were absent in the tourism community. Borrowing from the economics and leadership literature, it is proposed that trust fosters certain types of inter-entrepreneurial networks. A description of these networks and related policy implications conclude the paper.
Description:
Summary Trophic cascade theory predicts that apex predators structure ecosystems by regulating mesopredator and herbivore abundance and behaviour. Studies on trophic cascades have typically focused on short linear chains of species interactions. A framework that integrates more realistic and complex interactions is needed to make broader predictions on ecosystem structuring. Network analysis is used to study food webs and other types of species interaction networks. These often comprise large numbers of species but rarely account for multiple interaction types and strengths. Here, we develop an intermediate complexity theoretical framework that allows specification of multiple interaction types and strengths for the study of trophic cascades. This ecological network is designed to suit data typically derived from field‐based studies. The trophic cascade network contains fewer nodes than food webs, but provides semi‐weighted directional links that enable different types of interactions to be included in a single model. We use this trophic cascade network model to explore how an apex predator shapes ecosystem structure in an Australian arid ecosystem. We compared two networks that contrasted in the dominance of an apex predator, the dingo (Canis dingo), using published results ranking the direction and strength of key interactions. Nodes and links interacted dynamically to shape these networks. We examined how changes to an apex predator population affect ecosystem structure through their direct and indirect influences on different components of this ecological community. Under strong apex predator influence, the network structure was denser and more complex, even and top‐down driven and dingo predation and soil commensalism formed denser interactive modules. Under weak apex predator influence (e.g. reflecting predator control), the resulting network structure was frayed, with mesopredator predation and grazing forming modules. Our study demonstrates that networks of intermediate complexity can provide a powerful tool for elucidating potential ecosystem‐wide effects of apex predators and predicting the consequences of management interventions such as predator control. Integrating trophic cascades, with their array of complex interactions, with the three‐dimensional structure of ecological networks, has the potential to reveal ‘ecological architecture’ that neither captures on its own.
Description:
Cloud-based High Definition (HD) video streaming is becoming popular day by day. On one hand, it is important for both end users and large storage servers to store their huge amount of data at different locations and servers. On the other hand, it is becoming a big challenge for network service providers to provide reliable connectivity to the network users. There have been many studies over cloud-based video streaming for Quality of Experience (QoE) for services like YouTube. Packet losses and bit errors are very common in transmission networks, which affect the user feedback over cloud-based media services. To cover up packet losses and bit errors, Error Concealment (EC) techniques are usually applied at the decoder/receiver side to estimate the lost information. This paper proposes a time-efficient and quality-oriented EC method. The proposed method considers H.265/HEVC based intra-encoded videos for the estimation of whole intra-frame loss. The main emphasis in the proposed approach is the recovery of Motion Vectors (MVs) of a lost frame in real-time. To boost-up the search process for the lost MVs, a bigger block size and searching in parallel are both considered. The simulation results clearly show that our proposed method outperforms the traditional Block Matching Algorithm (BMA) by approximately 2.5 dB and Frame Copy (FC) by up to 12 dB at a packet loss rate of 1%, 3%, and 5% with different Quantization Parameters (QPs). The computational time of the proposed approach outperforms the BMA by approximately 1788 seconds.
Description:
This paper discusses the role of tourism networks, clustering and destination value chains for micro and small and medium size tourism enterprises (SMEs) in freely assembled destinations. In discussing destination benefits and barriers surrounding SME clustering, SME positioning and performance are highlighted. It is proposed in this paper that SME clustering and value are not always naturally established. Successful destination clusters may be created by upgrading SME performance, analysing local value chains and matching both tangible and intangible sources of value, such as systems, leadership, relationships and brands with demand-side value segmentation.
Description:
This paper discusses the role of tourism networks, clustering and destination value chains for micro and small and medium size tourism enterprises (SMEs) in freely assembled destinations. In discussing destination benefits and barriers surrounding SME clustering, SME positioning and performance are highlighted. It is proposed in this paper that SME clustering and value are not always naturally established. Successful destination clusters may be created by upgrading SME performance, analysing local value chains and matching both tangible and intangible sources of value, such as systems, leadership, relationships and brands with demand-side value segmentation.
Description:
Due to the infrequent medium access in Wireless Sensor Networks (WSN), their MAC protocols are mostly based on CSMA. In this paper we present an efficient contention resolution scheme for CSMA based MAC protocols which is suitable for periodic data collection in WSNs. Taking into account that the number of nodes in a single cluster is fixed, this protocol uses successively decreasing contention window. It is characterized by non-overlapping contention window, that maintains a constant successful transmission rate. It significantly decreases data collection time by minimizing the time wastage due to collisions. At the same time, by using adaptive CW, it reduces the time wastage in empty slots. Experimental results demonstrate that in periodic data collection within a single hop cluster this scheme has performance superior to the recently proposed Synchronous Shared Contention Window (SSCW) based scheme in terms of time wastage and throughput.