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Energy minimization is an important design goal in wireless video transmission. We examine how the RF energy and the analog circuit energy, which account for a large part of the energy consumption for wireless video transmission, can be controlled with physical-layer parameters (e.g., modulation level, bit rate, bit error rate, and multiple access interference) and link-layer specifications (e.g., the buffer status, idle time, and active time). Building on these insights, we develop three energy-efficient video transmission schemes for the single-user system, i.e., frame-by-frame transmission, group of pictures (GOP)-by-GOP transmission, and client-buffer-related energy-efficient video transmission (CBEVT). Our simulations indicate that energy savings of up to 85% is achievable in the radio frequency (RF) front end using the CBEVT algorithm. We also present an energy-efficient optimal smoothing algorithm for reducing the RF front-end energy consumption and the peak data rate. For CDMA-based multiuser systems, we propose an RF front-end energy model that assumes perfect power control. We find the signal-to-interference-noise ratio (SINR) for the entire system that minimizes the total energy consumption. We propose the multiuser-based energy-efficient video transmission (MBEVT) algorithm, which can achieve energy savings of up to 38% for a six-user CDMA system with an independent 16-MB buffer for every uplink. [ABSTRACT FROM AUTHOR]

The recently developed H.264/AVC video codec with Scalable Video Coding (SVC) extension, compresses non-scalable (single-layer) and scalable video significantly more efficiently than MPEG-4 Part 2. Since the traffic characteristics of encoded video have a significant impact on its network transport, we examine the bit rate-distortion and bit rate variability-distortion performance of single-layer video traffic of the H.264/AVC codec and SVC extension using long CIF resolution videos. We also compare the traffic characteristics of the hierarchical B frames (SVC) versus classical B frames. In addition, we examine the impact of frame size smoothing on the video traffic to mitigate the effect of bit rate variabilities. We find that compared to MPEG-4 Part 2, the H.264/AVC codec and SVC extension achieve lower average bit rates at the expense of significantly increased traffic variabilities that remain at a high level even with smoothing. Through simulations we investigate the implications of this increase in rate variability on (i) frame losses when transmitting a single video, and (ii) on a bufferless statistical multiplexing scenario with restricted link capacity and information loss. We find increased frame losses, and rate-distortion/rate-variability/encoding complexity tradeoffs. We conclude that solely assessing bit rate-distortion improvements of video encoder technologies is not sufficient to predict the performance in specific networked application scenarios. [ABSTRACT FROM AUTHOR]

The real-time streaming of bursty continuous media, such as variable-bit rate encoded video, to buffered clients over networks can be made more efficient by collaboratively prefetching parts of the ongoing streams into the client buffers. The existing collaborative prefetching schemes have been developed for discrete time models, where scheduling decisions for all ongoing streams are typically made for one frame period at a time. This leads to inefficiencies as the network bandwidth is not utilized for some duration at the end of the frame period when no video frame "fits" into the remaining transmission capacity in the schedule. To overcome this inefficiency, we conduct in this paper an extensive study of collaborative prefetching in a continuous-time model. In the continuous-time model, video frames are transmitted continuously across frame periods, while making sure that frames are only transmitted if they meet their discrete playout deadlines. We specify a generic framework for continuous-time collaborative prefetching and a wide array of priority functions to be used for making scheduling decisions within the framework. We conduct an algorithm-theoretic study of the resulting continuous-time prefetching algorithms and evaluate their fairness and starvation probability performance through simulations. We find that the continuous-time prefetching algorithms give favorable fairness and starvation probability performance. [ABSTRACT FROM AUTHOR]

We examine and model the bit rate variability-distortion (VD) curve of -4 Part 2 variable bit rate (VBR) video encodings. The VD curve has important applications for evaluating the statistical multiplexing of streaming video. We show that the concave VD curve shape at high compression ratios, or equivalently large quantization scales, is influenced by both the texture and the motion information. Based on this insight, we first develop a general VD curve model by analytically expressing the VD curve in terms of elementary statistics (mean, variance, covariance) of the numbers of motion and texture coding bits. In a second step we develop and validate linear and quadratic models for the elementary texture and motion bit statistics, whereby the model parameters are obtained from only two sample encodings. The texture and motion bit models are then employed in our general VD curve model. This work extends our previous work on piecewise models of the VD curve. The texture and motion based VD model obtained from two sample encodings has comparable accuracy to a piece- wise model based on three sample encodings. In addition, the texture and motion based VD model provides fundamental insights into how texture and motion affect traffic variability. [ABSTRACT FROM AUTHOR]

WDM EPONs are rapidly becoming mature. In this article we briefly review the state of the art of cost reduction, colorless ONUs, and WDM PONs. We then lift the veil of future WDM EPONs, and elaborate on evolutionary cost-effective upgrades of WDM EPONs and their all-optical WDM integration with Ethernet-based metropolitan area networks to provide transparent connections at the wavelength and sub-wavelength granularity on demand between ONUs residing in different WDM EPONs. [ABSTRACT FROM AUTHOR]

A variety of error resilience and scalable coding techniques have recently been proposed to facilitate the delivery of video over best-effort networks; a common drawback of these techniques is reduced compression efficiency. Also, MPEG-7 descriptors have recently been developed for the purpose of indexing. In this paper, we propose to employ MPEG-7 descriptors to improve the quality of the video delivered over best-effort networks. In particular, we propose a video transmission system that uses the motion activity descriptors to ensure robust video transmission. A novel motion activity extraction technique is proposed, which relies on a neural network approach. By considering several low-level visual features, our proposed extraction approach achieves high consistency with subjective evaluations of motion activities. In order to demonstrate the benefits of the proposed transmission system, we develop a selective packet dropping scheme that can be applied in case of network congestion. Simulations demonstrate that the reconstruction quality of the proposed congestion scheme can surpass conventional schemes by 1.2 dB. The network performance of the proposed transmission system when video sequences are coded into single layer or scalable layers is presented. We also present a transcoding scheme that achieves the optimal reconstructed quality by exploiting the motion activities of the underlying video sequence. [ABSTRACT FROM AUTHOR]

Routing algorithms with time and message complexities that are provably low and independent of the total number of nodes in the network are essential for the design and operation of very large scale wireless mobile ad hoc networks (MANET5). In this paper, we develop and analyze Cluster Overlay Broadcast (COB), a low-complexity routing algorithm for MANETs. COB runs on top of a one-hop cluster cover of the network, which can be created and maintained using, for instance, the Least Cluster Change (LCC) algorithm. We formally prove that the LCC algorithm maintains a cluster cover with a constant density of cluster leaders with minimal update cost. COB discovers routes by flooding (broadcasting) route requests through the network of cluster leaders with a doubling radius technique. Building on the constant density property of the network of cluster leaders, we formally prove that, if there exists a route from a source to a destination node with a minimum hop count of Δ, then COB discovers a route with at most O(Δ) hops from the source to the destination node in at most O(Δ) time and by sending at most Q(Δ²) messages. We prove this result for arbitrary node distributions and mobility patterns and also show that COB adapts asymptotically optimally to the mobility of the nodes. In our simulation experiments, we examine the network layer performance of COB, compare it with Dynamic Source Routing, and investigate the impact of the MAC layer on COB routing. [ABSTRACT FROM AUTHOR]

Encoded video is expected to contribute a significant portion of the load on future communication systems and networks, which often employ statistical multiplexing. In such systems, the number of video streams that can be supported depends both on the mean bit rate as well as bit rate variability of the video streams. At the same time, the utility (revenue) earned from video streaming depends both on the number of supported video streams as well as their quality level. In this paper we examine the interplay between video quality, traffic variability, and utility for open-loop encoded video. We introduce the rate variability-distortion (VD) curve which relates the bit rate variability to the quality level of an encoded video. We find that the VD curve generally exhibits a characteristic "hump" behavior of first increasing, peaking, and subsequently decreasing variability for increasing quality. We examine the impact of video content characteristics, encoding parameters, and traffic smoothing on the VD behavior. We describe a methodology for assessing (i) the set of the video streams that can be supported with a statistical quality of service requirement, and (ii) the utility earned from video streaming over a link. This methodology is based on the rate-distortion and rate variability-distortion characteristics of the videos. We find that the statistical multiplexing gain and the utility as a function of the video quality level typically exhibit a "hump" similar to the VD curve. [ABSTRACT FROM AUTHOR]

Research has shown that providing instructional prompts in computer-based learning environments designed to support example-based learning fosters learning. In computer-based environments, where learners interact only with a computer and do not have access to direct support from a teacher, learners need to be provided with instructional prompts or just-in-time help intended to encourage more active example processing during learning. This study investigated whether it was more beneficial to provide the learners access to on-demand (self-regulated) help after they committed an error in problem solving or for the learning environment to regulate the presentation of instructional help externally. Furthermore, two different presentational formats-textual and pictorial-of instructional prompts were examined. This study was conducted with a computer-based learning environment that introduced high school students without any prior content-specific knowledge to the principles of parallel and series circuit analysis. Textual prompts facilitated practice problem solving notably better than pictorial prompts. Overall, textual-based prompts produced a large effect on near transfer. A significant format of prompts by academic ability interaction was discovered on near transfer. In particular, lower-ability learners scored significantly better when given textual prompts; whereas, their higher-ability counterparts performed equally well with both formats. Moreover, learners provided with externally regulated prompts reported significantly more positive attitudes toward the prompts in general compared to learners in the self-regulated conditions. Finally, continuous motivation was significantly stronger in learners who viewed textual prompts than in their counterparts in the pictorial prompt groups. [ABSTRACT FROM AUTHOR]

Multimedia networking has been emerging in recent years as a strong driving force behind the expansion of the Internet. However, this topic is not commonly covered in the already content-intensive introductory networking courses. To facilitate student self-study of this novel topic the authors have developed a computer-based instructional module on the fundamentals of multimedia networking. In this paper, they describe the design and development of the module, which is aligned with Gagne's theory of instruction. They have developed two versions of the module—one with equation-based representation of the learning content and one with graph-based representation of the learning content. They have evaluated the two versions of the module with a total of 75 undergraduate, senior-level electrical engineering students, of which half were randomly assigned to the equational representation, and the other half to the graphical representation. They found that the graphical representation results in statistically significantly higher student performance on practice and post-test problems, shorter learning time, and more positive attitudes toward the computer-based instructional module. [ABSTRACT FROM AUTHOR]

Bursty continuous media streams with periodic playout deadlines (e.g., VBR-encoded video) are expected to account for a large portion of the traffic in the future Internet. By prefetching parts of ongoing streams into client buffers these bursty streams can be more efficiently accommodated in packet-switched networks. In this paper we develop a modular algorithm-theoretic framework for the fair and efficient transmission of continuous media over a bottleneck link. We divide the problem into the two subproblems of (i) assuring fairness, and (ii) efficiently utilizing the available link capacity. We develop and analyze algorithm modules for these two subproblems. Specifically, we devise a bin packing algorithm for subproblem (i), and a "layered prefetching" algorithm for subproblem (ii). Our simulation results indicate that the combination of these two algorithm modules compares favorably with existing monolithic solutions. This demonstrates the competitiveness of the decoupled modular algorithm framework, which provides a foundation for the development of refined algorithms for fair and efficient prefetching. [ABSTRACT FROM AUTHOR]

Fine granularity scalability (FGS) is a new development in the area of video coding, which is designed to facilitate video streaming over communication networks. With FGS coding, the video stream can be flexibly truncated at very fine granularity to adapt to the available network resources. In this article we introduce the communications generalist to the basic properties of FGS video coding to provide background for the design of video streaming mechanisms for FGS video. We then outline a methodology for evaluating streaming mechanisms for FOS encoded video. The methodology relies On traces of the rate-distortion characteristics of FOS encoded video and enables networking researchers and practitioners without access to video codecs and video sequences to develop and evaluate rate-distortion optimized streaming mechanisms for FGS encoded video. [ABSTRACT FROM AUTHOR]

Both wavelength-division-multiplexing (WDM) networks with a ring architecture and WDM networks with a star architecture have been extensively studied as solutions to the ever increasing amount of traffic in the metropolitan area. Studies typically focus on either the ring or the star and significant advances have been made in the protocol design and performance optimization for the WDM ring find the WDM star, respectively. However, very little is known about the relative performance comparisons of ring and star networks. In this paper, we conduct a comprehensive comparison of a state-of-the-art WDM ring network with a state-of-the-art WDM star network. In particular, we compare time-slotted WDM ring networks (both single-fiber and dual-fiber) with tunable-transmitter and fixed-receiver (TT-FR) nodes and an arrayed-waveguide grating-based single-hop star network with tunable-transmitter and tunable-receiver (TT-TR) nodes. We evaluate mean aggregate throughput, relative packet loss, and mean delay by means of simulation for Bernoulli and self-similar traffic models for unicast traffic with uniform and hot-spot traffic matrices, as well as for multicast traffic. Our results quantify the fundamental performance characteristics of ring networks versus star networks and vice versa, as well as their respective performance limiting bottlenecks and, thus, provide guidance for directing future research efforts. [ABSTRACT FROM AUTHOR]

Stabilizing the throughput over wireless links is one of the key challenges in providing high-quality wireless multimedia services. Wireless links are typically stabilized by a combination of link-layer automatic repeat request (ARQ) mechanisms in conjunction with forward error correction and other physical layer techniques. In this paper, we focus on the ARQ component and study a novel class of ARQ mechanisms, referred to as simultaneous MAC packet transmission (SMPT). In contrast to the conventional ARQ mechanisms that transmit one packet at a time over the wireless air interface, SMPT exploits the parallel code channels provided by multicode code-division multiple access. SMPT stabilizes the wireless link by transmitting multiple packets in parallel in response to packet drops due to wireless link errors. While these parallel packet transmissions stabilize the link layer throughput, they also increase the interference level in a given cell of a cellular network or cluster of an ad hoc network. This increased interference reduces the number of traffic flows that can be simultaneously supported in a cell/cluster. We develop an analytical framework for the class of SMPT mechanisms and analyze the link-layer buffer occupancy and the code usage in a wireless system running some form of SMPT. Our analysis quantifies the tradeoff between increased link-layer quality of service and reduced number of supported flows in SMPT with good accuracy, as verified by simulations. In a typical scenario, SMPT reduces the probability of link-layer buffer overflow by over two orders of magnitude (thus enabling high-quality multimedia services, such as real-time video streaming) while supporting roughly 20% fewer flows than conventional ARQ. Our analytical framework provides a basis for resource management in wireless systems running some form of SMPT and optimizing SMPT mechanisms. [ABSTRACT FROM AUTHOR]

Research on multicasting in single-hop wavelength-division-multiplexing (WDM) networks has so far focused on networks based on the passive star coupler (PSC), a broadcast device. It has been shown that the multicasting performance is improved by partitioning multicast transmissions into multiple multicast copies. However, the channel bottleneck of the PSC, which does not allow for spatial wavelength reuse, restricts the multicast performance. In this paper, we investigate multicasting in a single-hop WDM network that is based on an arrayed-waveguide grating (AWG), a wavelength routing device that allows for spatial wavelength reuse. In our network, optical multicasting is enabled by wavelength-insensitive splitters that are attached to the AWG output ports. Multicasts are partitioned among the splitters and each multicast copy is routed to a different splitter by sending it on a different wavelength. We demonstrate that the spatial wavelength reuse in our network significantly improves the throughput-delay performance for multicast traffic. By means of analysis and simulations, we also demonstrate that for a typical mix of unicast and multicast traffic the throughput-delay performance is dramatically increased by transmitting multicast packets concurrently with control information in the reservation medium access control protocol of our AWG-based network. [ABSTRACT FROM AUTHOR]

Investigates the delivery of layered encoded video through caches. Development of a model of layered video streaming with proxy; Examination of optical caching strategies; Numerical results.

Develops a high-performance streaming protocol for the real-time delivery of prerecorded continuous media over wireless links. Description of the architecture for the streaming of prerecorded continuous media with focus on code division multiple access; Components of join-the-shortest-queue prefetching protocol; Evaluation of the prefetching protocol both without and with channel probing through extensive simulations.

Communications for IoT sensor networks in Smart City applications are demanding new technologies to avoid the radio frequency spectrum saturation and support the massive nodes situation required in this kind of network. Visible Light Communications are gaining interest as an alternative scheme for solving this problem. In particular, Optical Camera Communication (OCC) takes advantage of the presence of cameras in a wide range of devices (smartphones, surveillance systems). Several transmission and modulation schemes, specifically developed for OCC, have been proposed but they present different problems as the communication range, the flickering effects in the transmitted signal, or the system complexity. In this work, an Optical Camera Communication modulation scheme that addresses the considerable variability of the transmitter–receiver distance is proposed. As will be shown, the modulation scheme works properly independently of this separation for a wide range of distances. Additionally, it performs a flickering free transmission to avoid undesired blinking effects for humans and uses a simplified transmission and reception scheme, reducing the system complexity and cost. Results of the modulation's performance for short (<20 m), medium (20–60 m), and long (>60 m) ranges are presented in the paper, showing a 16 bps transmission rate with Bit Error Rate below the Forward Error Correction (FEC) limit (3.8 · 10−3). [ABSTRACT FROM AUTHOR]

The wearable textile antenna plays a decisive role in the currently increasingly wireless communication network area. To realize the miniaturization and electromagnetic reliability, a slotted full-textile microstrip antenna was designed and fabricated using the screen printing method. The measured return loss and radiation pattern were tested and compared with the simulated results. Additionally, the adhesion between the silver paste coating as the radiation element and the textile substrate was detected using sticking tape as well as observation by the microscope. To develop the designed antenna in the on-body application, the artificial magnetic conductor (AMC) was designed, optimized and fabricated. The antenna performance results showed that the existence of the AMC had a significant effect in reducing the body coupling and antenna backward radiation. [ABSTRACT FROM AUTHOR]

By bringing together advances in computer vision, embedded computing, image sensors, and networks, researchers are working toward more automated analysis of large-scale camera networks' data. [ABSTRACT FROM PUBLISHER]

We propose a novel emergency alert broadcast mechanism for mobile phone users, which is based on the convergence of 5G and ATSC 3.0. Cellular networks including 5G adopt a broadcast technique for emergency alert. This technique just delivers a text-based message. Moreover, the message only includes a limited number of characters. Therefore, cellular networks cannot afford to provide abundant information in emergency cases. Broadcast networks such as ATSC 3.0 also offer an emergency alert broadcast service. This service can deliver a multimedia-based message in emergency cases. Therefore, the ATSC 3.0 supports more abundant information in the cases of emergency alert broadcasts. Especially, the ATSC 3.0 employs wake-up functionality and location information, which enables the delivery of emergency alerts to idle-state receivers in emergency areas. However, it is unlikely that the wake-up functionality and the location information are directly applicable to mobile phone users due to some practical issues. In order to improve the emergency alert broadcast service in mobile environments, we converge the 5G and the ATSC 3.0 networks, which effectively exploits the advantages of the networks. For the convergence network, we suggest a modified table, which associates the 5G message with the ATSC 3.0 message in the cases of emergency alerts. We also present a novel scenario for delivery of the emergency alert messages. Simulation results show that the convergence significantly enhances the receiver performance for emergency alert broadcast. [ABSTRACT FROM AUTHOR]

The Tactile Internet will require ultra-low latencies for combining machines and humans in systems where humans are in the control loop. Real-time and perceptual coding in these systems commonly require content-specific approaches. We present a generic approach based on deliberately reduced number accuracy and evaluate the trade-off between savings achieved and errors introduced with real-world data for kinesthetic movement and tele-surgery. Our combination of bitplane-level accuracy adaptability with perceptual threshold-based limits allows for great flexibility in broad application scenarios. Combining the attainable savings with the relatively small introduced errors enables the optimal selection of a working point for the method in actual implementations. [ABSTRACT FROM AUTHOR]

The ubiquitous nature of Internet of Things (IoT) devices has posited many challenges that need innovative solutions in the 5G era. Software defined networks (SDNs) are becoming indispensable in managing several aspects of next-generation IoT networking that arise from the need to control highly heterogeneous, geographically dispersed, mobile IoT devices. One such aspect is cache management at the edge. Recently, multiple forms of edge resources, including mobile device clouds and micro-edge data centers have emerged to provide scalable cache placement locations that reduce the costs for the mobile network operator (MNO). As all of these service locations are registered with the MNO (or links established after registration with the 5G base station, BS), content should be placed according to the user's demand and the cost the user is willing to pay to receive the desired level of QoS. To this end, it is important to understand the future popularity of the content for its optimal placement considering the highly dynamic user mobility. In this article, we address two key aspects of a mobile IoT network: security and seamless connectivity for data delivery. We rely on the federated learning (FL) architecture, which enables harnessing data and computational capabilities at end-user devices to train machine learning models. We study FL concepts in the domain of edge computing for IoT use cases, such as caching. We draw conclusions from various state-of-the-art models and posit several challenges that can be overcome via a novel proposed control algorithm. [ABSTRACT FROM AUTHOR]

This study examined the association between elementary students' (N = 1627; 51.3% girls, ages 4–12) engineering‐related ability beliefs (competence), task‐value beliefs (interest, importance), and career aspirations. Findings suggest that mean levels of children's engineering‐related beliefs did not vary by gender. High levels of competence, interest, and importance beliefs were related to higher engineering‐related career aspirations. Findings also revealed that the association of competence and interest with career aspirations was stronger for girls than boys; whereas, the association of importance with career aspirations was stronger for boys than girls. Last, results provide evidence of importance as a moderator of the link between competence and career aspirations, suggesting that there was a stronger positive association between competence and career aspirations under high levels of importance. Against the backdrop of the increasing urgency to teach engineering in elementary schools, this study highlighted the salience of examining children's engineering‐related motivational beliefs. The study has practical implications for teachers and school psychologists on promoting inclusive instruction in elementary schools. Specifically, the implications of the results for instructional strategies as well as assessments and interventions in elementary schools are discussed. Practitioner points: Children's beliefs about engineering‐related activities and skills did not vary by gender, suggesting that engineering should be taught through activities and skills so as to reduce the gender differences that typically exist in children's general beliefs about the discipline of engineering.Results suggest that curricula should focus on increasing students' engineering competence, interest, and importance beliefs.Engineering lessons with children should teach about the importance of developing skills in engineering as high levels of importance play a key role in children developing engineering‐related career aspirations. [ABSTRACT FROM AUTHOR]

In the interest of understanding choices related to achievement, persistence, and performance that inform pursuit of careers in science, technology, engineering, and math, the current research pursued a novel approach to asking young children about their beliefs related to engineering. The Engineering-Related Activities and Skills (ERAS) items were developed to use instead of the term 'engineering' to measure children's achievement-related ability beliefs (competence) and subjective task values (importance, interest). A range of methods across three studies were implemented in the development and assessment of evidence related to the internal structure of the ERAS items across the domains of ability beliefs and subjective task values (N = 949 students). Results suggest initial evidence for the ERAS items being valid in measuring children's perceptions of engineering-related competence, importance, and interest. Theoretical and practical implications related to the factors that influence the academic and career choices in the science, technology, engineering, and math (STEM) fields, as well as future directions are outlined. [ABSTRACT FROM AUTHOR]

The U.S. Federal Communications Commission (FCC) defines white space as the channels that are unused at a specific location or time. For futuristic cognitive radio (CR) based applications and communication networks, white space detection plays an important role. In fact, the proper white space understanding is a prerequisite for effective communication in support of a wide range of information technology systems. Moreover, by clearly defining the white space, the business and technical scenarios for white space usage can be clearly defined and their implementation will be simplified. Also, the decisions of regulatory bodies and telecommunications policy makers for auctions of particular spectrum bands can be facilitated by a thorough white space understanding. White space detection is a critical aspect of Dynamic Spectrum Access (DSA) which ultimately can help in overcoming bandwidth shortages. A major portion of the DSA research to date has been limited to the dimensions of time, frequency, and geographical location while neglecting other perspectives for the detection of white spaces. Generally, what exactly is a white space and how do white spaces differ in various modern contexts of wireless networks? This paper strives to answer these questions by reviewing the conventional white space definitions and exploring advanced perspectives on white spaces that can be used for CR communications. We propose a novel classification of white spaces based on the combination of three perspectives, namely signal dimension, licence, and transmission strategy, and outline open areas for future research on exploiting white spaces for CR communication. [ABSTRACT FROM AUTHOR]

Feedback has a strong influence on effective learning from computer-based instruction. Prior research on feedback in computer-based instruction has mainly focused on static feedback schedules that employ the same feedback schedule throughout an instructional session. This study examined transitional feedback schedules in computer-based multimedia instruction on procedural problem-solving in electrical circuit analysis. Specifically, we compared two transitional feedback schedules: the TFS-P schedule switched from initial feedback after each problem step to feedback after a complete problem at later learning states; the TFP-S schedule transitioned from feedback after a complete problem to feedback after each problem step. As control conditions, we also considered two static feedback schedules, namely providing feedback after each practice problem-solving step (SFS) or providing feedback after attempting a complete multi-step practice problem (SFP). Results indicate that the static stepwise (SFS) and transitional stepwise to problem (TFS-P) feedback produce higher problem solving near-transfer post-test performance than static problem (SFP) and transitional problem to step (TFP-S) feedback. Also, TFS-P resulted in higher ratings of program liking and feedback helpfulness than TFP-S. Overall, the study results indicate benefits of maintaining high feedback frequency (SFS) and reducing feedback frequency (TFS-P) compared to low feedback frequency (SFP) or increasing feedback frequency (TFP-S) as novice learners acquire engineering problem solving skills. [ABSTRACT FROM AUTHOR]

Multimedia engineering instruction typically includes verbal descriptions and diagrams, which can be presented in a contextualized format, using descriptions and illustrations of real-life elements (e.g., light bulb and battery), or in an abstract format, using conventional electrical engineering symbols. How the sequencing of these representation formats influences learning of conceptual knowledge has been examined in prior research. The present study examines how the representation sequencing impacts procedural learning of engineering problem solving. The study compared four sequences of representation (abstract → abstract, contextualized → contextualized, contextualized → abstract, or abstract → contextualized) during computer-based learning to determine which of the four sequences best promotes student learning. Learning outcomes were measured with a problem-solving posttest and learner perceptions were assessed using a learner questionnaire. The study results indicated that the abstract → contextualized condition resulted in significantly higher near- and far-transfer posttest scores than the contextualized → contextualized condition and in significantly higher near-transfer posttest scores than the contextualized → abstract condition. Computer-based instruction in engineering problem solving for novice learners should initially employ abstract representations that convey the conceptually-relevant solution procedures shared across similar problems. Providing a variety of problem contexts in later stages of learning can assist learners in transfer of key procedural problem solving principles to novel problem settings with different superficial features. [Copyright &y& Elsevier]

Highlights: [•] Preferred characteristics of animated agents teaching engineering were studied. [•] Preferences of elementary, middle, and high school students were examined. [•] Students preferred agent characteristics that were close to their own. [•] Provides support for the similarity–attraction hypothesis in computer interactions. [•] Animated agents in engineering domain should be designed to match the learner. [Copyright &y& Elsevier]

Highlights: [•] Examined impact of representation type and guidance on integrating representations. [•] Learning module presented abstract or contextualized representations of electric circuits. [•] Verbal guidance denoted correspondences among representations. [•] Without guidance, abstract representations led to better learning outcomes. [•] Contextualized representations were more effective when guidance was provided. [Copyright &y& Elsevier]

Abstract: The similarity attraction hypothesis posits that humans are drawn toward others who behave and appear similar to themselves. Two experiments examined this hypothesis with middle-school students learning electrical circuit analysis in a computer-based environment with an Animated Pedagogical Agent (APA). Experiment 1 was designed to determine whether matching the gender of the APA to the student has a positive impact on learning outcomes or student perceptions. One hundred ninety-seven middle-school students learned with the computer-based environment using an APA that matched their gender or one which was opposite in gender. Female students reported higher program ratings when the APA matched their gender. Male students, on the other hand, reported higher program ratings than females when the APA did not match their gender. Experiment 2 systematically tested the impact of providing learners the choice among four APAs on learning outcomes and student perceptions. Three hundred thirty-four middle-school students received either a pre-assigned random APA or were free to choose from four APA options: young male agent, older male agent, young female agent, or older female agent. Learners had higher far transfer scores when provided a choice of animated agent, but student perceptions were not impacted by having the ability to make this choice. We suggest that offering students learner control positively impacts student motivation and learning by increasing student perceptions of autonomy, responsibility for the success of the instructional materials, and global satisfaction with the design of materials. [Copyright &y& Elsevier]

While the Internet is ubiquitous in most parts of the world today, the dominant network access technology is gradually shifting from wired to wireless connections. Notably, the ever increasing bandwidth, together with reduced latency in mobile networks, enables a multitude of new use cases for a wide range of industries. These new use cases have typically increased quality requirements for the wireless connection. Accordingly, the Internet architecture needs to keep pace with the recent developments, particularly in light of the holistic approach of the new fifth generation (5G) mobile communication standard. In this study, we shed light on the effects of 5G on the Internet's core, i.e., on the Internet interdomain traffic. The interdomain traffic between distinct autonomous systems (ASs) is exchanged by transit networks as well as through peerings at private network interconnects (PNIs) and public Internet Exchange Points (IXPs). 5G interdomain traffic estimation is especially important for IXPs as these are focal points that aggregate high traffic volumes. We coherently derive twelve 5G use case groups and present an overview of their individual associated 5G use cases. We characterize the communication networking (connection) requirements and the resulting implications of these use cases. Further, we develop and apply a methodology to assess the 5G use cases, so as to rank them in terms of their projected impact on the overall internet traffic growth. Based on this systematic approach, we conclude that the traffic for the use case groups Video in 5G, Health, and Virtual & Augmented Reality will have the largest impact. We identify a large number of other use case groups, e.g., Live Events, Tactile Internet, and Manufacturing, that will contribute rather small individual fractions to the overall growth of Internet traffic. However, their aggregated contribution to the internet traffic growth will be significant. Our traffic estimation can inform interdomain infrastructure providers, such as IXPs, and policy makers about the likely impact of the introduction of 5G on the interdomain traffic in the Internet. • Based on important vertical industries, twelve 5G use case groups are identified. • Impact of 5G use case groups on Internet interdomain traffic is estimated. • Traffic is modeled based on traffic characteristics (number of nodes, bandwidth, and latency). • Impact model is based on traffic characteristics as well as computation and storage locations. • Video in 5G, Health, and Virtual & Augmented Reality have highest traffic impact. [ABSTRACT FROM AUTHOR]