Evaluation of HTTP/DASH Adaptation Algorithms on Vehicular Networks

Video streaming currently accounts for the majority of Internet traffic. One factor that enables video streaming is HTTP Adaptive Streaming (HAS), that allows the users to stream video using a bit rate that closely matches the available bandwidth from the server to the client. MPEG Dynamic Adaptive Streaming over HTTP (DASH) is a widely used standard, that allows the clients to select the resolution to download based on their own estimations. The algorithm for determining the next segment in a DASH stream is not partof the standard, but it is an important factor in the resulting playback quality. Nowadays vehicles are increasingly equipped with mobile communication devices, and in-vehicle multimedia entertainment systems. In this paper, we evaluate the performance of various DASH adaptation algorithms over a vehicular network. We present detailed simulation results highlighting the advantages and disadvantages of various adaptation algorithms in delivering video content to vehicular users, and we show how the different adaptation algorithms perform in terms of throughput, playback interruption time, and number of interruptions

A Load Balancing Algorithm for Resource Allocation in IEEE 802.15.4e Networks

The recently created IETF 6TiSCH working group combines the high reliability and low-energy consumption of IEEE 802.15.4e Time Slotted Channel Hopping with IPv6 for industrial Internet of Things. We propose a distributed link scheduling algorithm, called Local Voting, for 6TiSCH networks that adapts the schedule to the network conditions. The algorithm tries to equalize the link load (defined as the ratio of the queue length over the number of allocated cells) through cell reallocation. Local Voting calculates the number of cells to be added or released by the 6TiSCH Operation Sublayer (6top). Compared to a representative algorithm from the literature, Local Voting provides simultaneously high reliability and low end-to-end latency while consuming significantly less energy. Its performance has been examined and compared to On-the-fly algorithm in 6TiSCH simulator by modeling an industrial environment with 50 sensors

Towards Optimal Distributed Node Scheduling in a Multihop Wireless Network through Local Voting

In a multihop wireless network, it is crucial but challenging to schedule transmissions in an efficient and fair manner. In this paper, a novel distributed node scheduling algorithm, called Local Voting, is proposed. This algorithm tries to semi-equalize the load (defined as the ratio of the queue length over the number of allocated slots) through slot reallocation based on local information exchange. The algorithm stems from the finding that the shortest delivery time or delay is obtained when the load is semi-equalized throughout the network. In addition, we prove that, with Local Voting, the network system converges asymptotically towards the optimal scheduling. Moreover, through extensive simulations, the performance of Local Voting is further investigated in comparison with several representative scheduling algorithms from the literature. Simulation results show that the proposed algorithm achieves better performance than the other distributed algorithms in terms of average delay, maximum delay, and fairness. Despite being distributed, the performance of Local Voting is also found to be very close to a centralized algorithm that is deemed to have the optimal performance

Emerging Technologies, Evolving Threats: Next-Generation Security Challenges

Security is a fundamental human requirement. We desire the security of our person against injury, security of our capability to provide for our families, security of income linked to needs (food, water, clothing, and shelter), and much more. Most also hope for security of a way of life that is fulfilling and pleasant and peaceful [1] . In 2003, Alkire [2] defined “human security” as: “[t]he objective … to safeguard the vital core of all human lives from critical pervasive threats, in a way that is consistent with long-term human fulfillment.” Today most of the world’s population is highly dependent, even for basic needs, on large technological systems. According to the Oxford Dictionary , dependence can be defined as: “the state of relying on or being controlled by someone or something else.” In the context of technological systems, dependence may imply an unwanted consequence of nonavailability. Dependence may also be deliberately misapplied to create some level of coercion toward some other action [3] . For instance, in drug abuse, we can say that there is an overreliance on a dependency that leads to addiction. In the realm of technology systems, as they are increasingly becoming a part of everyday life, dependencies can have major consequences. Thus, an emphasis on “security” seems highly relevant for a journal devoted to considering the effects of technology on society in all its facets

The Ten-Year Road: Joys and Challenges on the Road to Tenure

This paper explores the pre-tenure experiences of five assistant professors employed in the faculty of education of a research-intensive university. Acting as co-researchers, the authors researched their experiences through a critical narrative approach. The analysis, informed by critically-oriented writing that extends Wenger\u27s Communities of Practice, takes as axiomatic the notion that globalized processes of economic restructuring are mediating work in the academy and examines its local manifestations. Discussions explore issues of power, equity, shifting identities, and the need for improved navigational resources. The authors found that the process of critically and collaboratively researching their pre-tenure experiences offered insight into sites of personal and professional agency and also served as the impetus to form the social semiotic spaces that encouraged a sense of community. The Dean, a tenured member, but also a newcomer, serves in the role of critical friend

Dynamic texture perception in plant-based yogurt alternatives: Identifying temporal drivers of liking by TDS

As texture properties in novel food categories have a crucial role in consumer acceptance, mouthfeel profile of different plant-based yogurt-like semi-solid products were studied and compared to dairy yogurts. Mouthfeel properties of five plant-based yogurt-like products and two dairy yogurts were analyzed using temporal dominance of sensations (TDS) with consumers (n = 87). The attributes evaluated were thick, thin, creamy, watery, sticky, and foamy. Following TDS, overall liking and mouthfeel liking were evaluated using a 7-point hedonic scale. Temporal drivers of mouthfeel liking were studied using correspondence analysis and penalty-lift analysis with different time points during mastication. For penalty-lift analysis TDS data was analyzed as check-all-that-apply (CATA) data. Results from the present work show that mouthfeel perception in non-dairy yogurt alternatives is a dynamic process. Attributes typically used to describe dairy yogurts are also relevant for describing non-dairy yogurt alternatives. Yogurt alternatives and dairy yogurts can be similar and equally liked by their mouthfeel profile. Temporal drivers of liking in plant-based products are thickness and creaminess and temporal drivers of disliking are thinness and wateriness. In this study, the first dominant attributes were found to have a stronger impact on mouthfeel liking than the dominant attributes perceived later during mastication

Challenges for Developing Complex System Governance

This paper examines the challenges and practice implications for Complex System Governance (CSG). CSG is presented as an emerging field focused on the design, execution, and evolution of the higher order (metasystem) functions necessary to provide control, communication, coordination, and integration of a complex system. This paper is focused on three primary objectives. First, we introduce the complex system problem domain that the CSG field is being designed to address. The pervasiveness of this problem domain is demonstrated by a short examination of the water utilities sector. Second, we expound the nature of CSG and an emerging reference model that defines the functions of CSG. These functions must be performed by any system that maintains viability (continued existence). The CSG reference model rests on the underlying conceptual foundations built from Systems Theory (axioms and propositions governing system integration and coordination) and Management Cybernetics (communication and control for effective system organization). Third, we explore the particular challenges that must be addressed if the potential of the emerging CSG field is to be realized. The paper concludes by suggesting the potential that the CSG field brings for enhancing practitioner capabilities to more effectively deal with complex systems and their associated problems

Physicochemical Properties and Mouthfeel in Commercial Plant-Based Yogurts

There is a growing need for plant-based yogurts that meet consumer demands in terms of texture. However, more research is needed to understand the relationship between physicochemical and mouthfeel properties in plant-based yogurts. The purpose of the study was to determine the physicochemical properties of five commercial plant-based yogurt alternatives with different chemical compositions, making comparisons to dairy yogurts and mouthfeel sensations such as thick, creamy, thin, and watery. The physicochemical parameters studied included large and small deformation rheology, particle size, soluble solids, acidity, and chemical composition. Significant differences in flow behavior and small deformation rheology were found between dairy and plant-based yogurts. Among plant-based yogurts, mouthfeel sensations such as thick, creamy, thin, and watery were strongly associated with steady shear rates and apparent viscosity. The results highlight the importance of large deformation rheology in advancing the use of plant-based ingredients in the development of yogurt alternatives. Furthermore, the study demonstrates that dairy and plant-based yogurts with a similar mouthfeel profile may have different viscoelastic properties, which indicates that instrumental and sensory methods should not be considered substitutes but complementary methods when developing plant-based yogurts in a cost-effective and timely manner

Grounding Evaluation Capacity Development in Systems Theory

While “systemic thinking” is popular in the context of capacity development and evaluation, there is currently a lack of understanding about the benefits to employing systems theory in evaluation capacity development. Systems theory provides a useful orientation to the work involved in complex systems (e.g. national evaluation systems). This article illustrates how evaluation capacity development practitioners can use systems theory as a conceptual tool to gain a better understanding of the functional aspects and interrelationships present within a given evaluation system. Specifically, the systems theory perspective can help elucidate the reasons for the success or failure of a given evaluation capacity development program or activity. With the goal of motivating evaluation capacity development practitioners to use systems theory in their work, this article presents a systems theory framework for evaluation capacity development and offers practical examples of how it can be adopted