The poor interfacial stability not only deteriorates fibre lithium-ion batteries(FLBs)performance but also impacts their scalable applications.To efficiently address these challenges,Prof.Huisheng Peng team proposed a...The poor interfacial stability not only deteriorates fibre lithium-ion batteries(FLBs)performance but also impacts their scalable applications.To efficiently address these challenges,Prof.Huisheng Peng team proposed a generalized channel structures strategy with optimized in situ polymerization technology in their recent study.The resultant FLBs can be woven into different-sized powering textiles,providing a high energy density output of 128 Wh kg^(-1) and simultaneously demonstrating good durability even under harsh conditions.Such a promising strategy expands the horizon in developing FLB with particular polymer gel electrolytes,and significantly ever-deepening understanding of the scaled wearable energy textile system toward a sustainable future.展开更多
The number of students demanding computer science(CS)education is rapidly rising,and while faculty sizes are also growing,the traditional pipeline consisting of a CS major,a CS master’s,and then a move to industry or...The number of students demanding computer science(CS)education is rapidly rising,and while faculty sizes are also growing,the traditional pipeline consisting of a CS major,a CS master’s,and then a move to industry or a Ph.D.program is simply not scalable.To address this problem,the Department of Computing at the University of Illinois has introduced a multidisciplinary approach to computing,which is a scalable and collaborative approach to capitalize on the tremendous demand for computer science education.The key component of the approach is the blended major,also referred to as“CS+X”,where CS denotes computer science and X denotes a non-computing field.These CS+X blended degrees enable win-win partnerships among multiple subject areas,distributing the educational responsibilities while growing the entire university.To meet the demand from non-CS majors,another pathway that is offered is a graduate certificate program in addition to the traditional minor program.To accommodate the large number of students,scalable teaching tools,such as automatic graders,have also been developed.展开更多
Over the last decade,remarkable progress has been made in metal halide perovskite solar cells(PSCs),which have been a focus of emerging photovoltaic techniques and show great potential for commercialization.However,th...Over the last decade,remarkable progress has been made in metal halide perovskite solar cells(PSCs),which have been a focus of emerging photovoltaic techniques and show great potential for commercialization.However,the upscaling of small-area PSCs to large-area solar modules to meet the demands of practical applications remains a significant challenge.The scalable production of high-quality perovskite films by a simple,reproducible process is crucial for resolving this issue.Furthermore,the crystallization behavior in the solution-processed fabrication of perovskite films can be strongly influenced by the physicochemical properties of the precursor inks,which are significantly affected by the employed solvents and their interactions with the solutes.Thus,a comprehensive understanding of solvent engineering for fabricating perovskite films over large areas is urgently required.In this paper,we first analyze the role of solvents in the solution-processed fabrication of large-area perovskite films based on the classical crystal nucleation and growth mechanism.Recent efforts in solvent engineering to improve the quality of perovskite films for solar modules are discussed.Finally,the basic principles and future challenges of solvent system design for scalable fabrication of high-quality perovskite films for efficient solar modules are proposed.展开更多
Ubiquitous data monitoring and processing with minimal latency is one of the crucial challenges in real-time and scalable applications.Internet of Things(IoT),fog computing,edge computing,cloud computing,and the edge ...Ubiquitous data monitoring and processing with minimal latency is one of the crucial challenges in real-time and scalable applications.Internet of Things(IoT),fog computing,edge computing,cloud computing,and the edge of things are the spine of all real-time and scalable applications.Conspicuously,this study proposed a novel framework for a real-time and scalable application that changes dynamically with time.In this study,IoT deployment is recommended for data acquisition.The Pre-Processing of data with local edge and fog nodes is implemented in this study.The thresholdoriented data classification method is deployed to improve the intrusion detection mechanism’s performance.The employment of machine learningempowered intelligent algorithms in a distributed manner is implemented to enhance the overall response rate of the layered framework.The placement of respondent nodes near the framework’s IoT layer minimizes the network’s latency.For economic evaluation of the proposed framework with minimal efforts,EdgeCloudSim and FogNetSim++simulation environments are deployed in this study.The experimental results confirm the robustness of the proposed system by its improvised threshold-oriented data classification and intrusion detection approach,improved response rate,and prediction mechanism.Moreover,the proposed layered framework provides a robust solution for real-time and scalable applications that changes dynamically with time.展开更多
The emerging new services in the sixth generation(6G)communication system impose increasingly stringent requirements and challenges on video transmission.Semantic communications are envisioned as a promising solution ...The emerging new services in the sixth generation(6G)communication system impose increasingly stringent requirements and challenges on video transmission.Semantic communications are envisioned as a promising solution to these challenges.This paper provides a highly-efficient solution to video transmission by proposing a scalable semantic transmission algorithm,named scalable semantic transmission framework for video(SST-V),which jointly considers the semantic importance and channel conditions.Specifically,a semantic importance evaluation module is designed to extract more informative semantic features according to the estimated importance level,facilitating high-efficiency semantic coding.By further considering the channel condition,a cascaded learning based scalable joint semanticchannel coding algorithm is proposed,which autonomously adapts the semantic coding and channel coding strategies to the specific signalto-noise ratio(SNR).Simulation results show that SST-V achieves better video reconstruction performance,while significantly reducing the transmission overhead.展开更多
Data center networks may comprise tens or hundreds of thousands of nodes,and,naturally,suffer from frequent software and hardware failures as well as link congestions.Packets are routed along the shortest paths with s...Data center networks may comprise tens or hundreds of thousands of nodes,and,naturally,suffer from frequent software and hardware failures as well as link congestions.Packets are routed along the shortest paths with sufficient resources to facilitate efficient network utilization and minimize delays.In such dynamic networks,links frequently fail or get congested,making the recalculation of the shortest paths a computationally intensive problem.Various routing protocols were proposed to overcome this problem by focusing on network utilization rather than speed.Surprisingly,the design of fast shortest-path algorithms for data centers was largely neglected,though they are universal components of routing protocols.Moreover,parallelization techniques were mostly deployed for random network topologies,and not for regular topologies that are often found in data centers.The aim of this paper is to improve scalability and reduce the time required for the shortest-path calculation in data center networks by parallelization on general-purpose hardware.We propose a novel algorithm that parallelizes edge relaxations as a faster and more scalable solution for popular data center topologies.展开更多
A new scheme combining a scalable transcoder with space time block codes (STBC) for an orthogonal frequency division multiplexing (OFDM) system is proposed for robust video transmission in dispersive fading channe...A new scheme combining a scalable transcoder with space time block codes (STBC) for an orthogonal frequency division multiplexing (OFDM) system is proposed for robust video transmission in dispersive fading channels. The target application for such a scalable transcoder is to provide successful access to the pre-encoded high quality video MPEG-2 from mobile wireless terminals. In the scalable transcoder, besides outputting the MPEG-4 fine granular scalability (FGS) bitstream, both the size of video frames and the bit rate are reduced. And an array processing algorithm of layer interference suppression is used at the receiver which makes the system structure provide different levels of protection to different layers. Furthermore, by considering the important level of scalable bitstream, the different bitstreams can be given different level protection by the system structure and channel coding. With the proposed system, the concurrent large diversity gain characteristic of STBC and alleviation of the frequency-selective fading effect of OFDM can be achieved. The simulation results show that the proposed schemes integrating scalable transcoding can provide a basic quality of video transmission and outperform the conventional single layer transcoding transmitted under the random and bursty error channel conditions.展开更多
Topology aggregation is necessary for scalable QoS routing mechanisms. Thekey issue is how to gain good performance while summarizing the topological information. In thispaper, we propose a new method to describe the ...Topology aggregation is necessary for scalable QoS routing mechanisms. Thekey issue is how to gain good performance while summarizing the topological information. In thispaper, we propose a new method to describe the logical link, which is simple and effective innetwork with additive and constrained concave parameters. We extend the method to network associatedwith multi-parameters. Furthermore, we propose a modified star aggregation algorithm. Simulationsare used to evaluate the performance. The results show that our algorithm is relatively good.展开更多
This paper presents a novel full-chip scalable routing framework that simultaneously considers the routing congestion and the circuit performance. In order to bridge the gap, the presented framework calls the detailed...This paper presents a novel full-chip scalable routing framework that simultaneously considers the routing congestion and the circuit performance. In order to bridge the gap, the presented framework calls the detailed router immediately after a global route is extracted. With the interleaving mode of global routing immediately followed by detailed routing, accurate routing resource and congestion information can be obtained, which provides valuable guidance for the following global routing process. The framework features the fast pattern and framed shortest path global router,a maze-based congestion-driven detailed router, and better interaction between the two routers. In the framework, timing critical nets can be assigned higher priority for performance concern, and different net ordering techniques can be adopted for different routing objectives. The framework is tested on a set of commonly used benchmark circuits and compared with a previous multilevel routing framework. Experimental results show that the presented framework obtains significantly better routing solutions than the previous one considering circuit performance, routing completion rate, and runtime.展开更多
The scalable extension of H.264/AVC, known as scalable video coding or SVC, is currently the main focus of the Joint Video Team’s work. In its present working draft, the higher level syntax of SVC follows the design ...The scalable extension of H.264/AVC, known as scalable video coding or SVC, is currently the main focus of the Joint Video Team’s work. In its present working draft, the higher level syntax of SVC follows the design principles of H.264/AVC. Self-contained network abstraction layer units (NAL units) form natural entities for packetization. The SVC specification is by no means finalized yet, but nevertheless the work towards an optimized RTP payload format has already started. RFC 3984, the RTP payload specification for H.264/AVC has been taken as a starting point, but it became quickly clear that the scalable features of SVC require adaptation in at least the areas of capability/operation point signaling and documentation of the extended NAL unit header. This paper first gives an overview of the history of scalable video coding, and then reviews the video coding layer (VCL) and NAL of the latest SVC draft specification. Finally, it discusses different aspects of the draft SVC RTP payload format, in- cluding the design criteria, use cases, signaling and payload structure.展开更多
The synthesis of fluorescent nanomaterials has received considerable attention due to the great potential of these materials for a wide range of applications, from chemical sensing through bioimaging to optoelectron- ...The synthesis of fluorescent nanomaterials has received considerable attention due to the great potential of these materials for a wide range of applications, from chemical sensing through bioimaging to optoelectron- ics. Herein, we report a facile and scalable approach to prepare fluorescent carbon dots (FCDs) via a one-pot reaction of citric acid with ethylenediamine at 150 ℃ under ambient air pressure. The resultant FCDs pos- sess an optical bandgap of 3.4 eV and exhibit strong excitation-wavelength-independent blue emission (λEm = 450 nm) under either one- or two-photon excitation. Owing to their low cytotoxicity and long fluorescence lifetime, these FCDs were successfully used as internalized fluorescent probes in human cancer cell lines (HeLa cells) for two-photon excited imaging of cells by fluorescence lifetime imaging microscopy with a high-contrast resolution. They were also homogenously mixed with commercial inks and used to draw fluo- rescent patterns on normal papers and on many other substrates (e.g., certain flexible plastic films, textiles, and clothes). Thus, these nanomaterials are promising for use in solid-state fluorescent sensing, security labeling, and wearable optoelectronics.展开更多
Superlattice photonic crystals (SPhCs) possess considerablepotentials as building blocks for constructing high-performancedevices because of their great flexibilities in opticalmanipulation. From the prospective of pr...Superlattice photonic crystals (SPhCs) possess considerablepotentials as building blocks for constructing high-performancedevices because of their great flexibilities in opticalmanipulation. From the prospective of practical applications,scalable fabrication of SPhCs with large-area uniformity and precisegeometrical controllability has been considered as one prerequisitebut still remains a challenge.展开更多
In this work, a new method to deal with the unconnected pixels in motion compensated temporal filtering (MCTF) is presented, which is designed to improve the performance of 3D lifted wavelet coding. Furthermore, multi...In this work, a new method to deal with the unconnected pixels in motion compensated temporal filtering (MCTF) is presented, which is designed to improve the performance of 3D lifted wavelet coding. Furthermore, multiple description scalable coding (MDSC) is investigated, and novel MDSC schemes based on 3D wavelet coding are proposed, using the lifting imple- mentation of temporal filtering. The proposed MDSC schemes can avoid the mismatch problem in multiple description video coding, and have high scalability and robustness of video transmission. Experimental results showed that the proposed schemes are feasible and adequately effective.展开更多
Humans can sense, weigh and grasp different objects, deduce their physical properties at the same time, and exert appropriate forces – a challenging task for modern robots. Studying the mechanics of human grasping ob...Humans can sense, weigh and grasp different objects, deduce their physical properties at the same time, and exert appropriate forces – a challenging task for modern robots. Studying the mechanics of human grasping objects will play a supplementary role in visual-based robot object processing. These tools require large-scale tactile data sets with high spatial resolution. However, there is no large human-grasped tactile data set covering the whole hand, because dense coverage of the human hand with tactile sensors is challenging. Hence, the capability of observing and learning from successful daily humanobject interactions is the long-term goal of aiding the development of robots and prosthetics.展开更多
Perovskite solar cells have reached a power-conversion efficiency(PCE) of 25.6%,showing great potential with reliable moisture and heat stability.Most results are achieved on small-area devices,using conventional thin...Perovskite solar cells have reached a power-conversion efficiency(PCE) of 25.6%,showing great potential with reliable moisture and heat stability.Most results are achieved on small-area devices,using conventional thin-film processing technologies like spin-coating method.However,such approaches may not be upscaled for large-area substrates.Thus,strategies and materials need to be developed for manufacturing processing routes to realize future commercial photovoltaic fabrications.Notable results have been achieved on large-area perovskite solar cells.In this review,similarities and differences of large-area perovskite fabrication mechanisms between the various pathways are investigated,especially on the parameters affecting the nucleation and crystal growth kinetics.Moreover,the methods for large-area transporting layers and electrodes are discussed,and some key issues from cells to modules.Challenges and opportunities are proposed to pave the way of high-efficiency perovskite solar modules.展开更多
The recent steady improvements in the performance of the nascent hybrid perovskite photovoltaic(PV)devices have led to power conversion efficiencies that rival the best-performing established PV technologies.However,t...The recent steady improvements in the performance of the nascent hybrid perovskite photovoltaic(PV)devices have led to power conversion efficiencies that rival the best-performing established PV technologies.However,to scale these laboratory demonstrations to PV module-scale production will require development of scalable deposition methods for perovskite thin films.Every record result for perovskite PVs so far was achieved via spin coating,a technique that is popular in research laboratories for thin-film coating over relatively small device areas,but not considered to be a method that could be used to scale up the manufacturing of perovskite PVs.Significantly larger thin-film areas are needed for future commercial PV products.Hence,some researchers have focused their efforts on perovskite deposition techniques that can be considered as scalable for mass production and have achieved notable results even on large areas.Here,we present an overview of the solution-based and vapor-based deposition processes;we explain their influence on the molecular crystal growth behavior of perovskite thin films and discuss the morphology as well as other material quality characteristics.By presenting a comprehensive comparison of the deposition techniques and the corresponding performance parameters for different device sizes,we intent to guide the growing research community through the methods that might enable mass production of perovskite solar products.展开更多
Mobile Ad-hoc Networks (MANETs) operate without infrastructure where nodes can move randomly. Therefore, routing in MANETs is a challenging task. In this paper we evaluate the performance of three important MANET rout...Mobile Ad-hoc Networks (MANETs) operate without infrastructure where nodes can move randomly. Therefore, routing in MANETs is a challenging task. In this paper we evaluate the performance of three important MANET routing protocols: Ad hoc On-Demand Distance Vector (AODV), Dynamic Source Routing (DSR) and Optimized Link State Routing (OLSR) when employed to forward scalable video contents. AODV and DSR are reactive protocols in that routing paths are established once needed. On the other hand, OLSR is a proactive routing protocol where routing information is exchanged and maintained continuously. The goal of the performance evaluation in this study is to assess the performance of AODV, DSR and OLSR in communicating scalable video contents. In the simulation part of this paper, a real video sequence is communicated where the characteristics and quality of the video decoded at receiver nodes are evaluated. NS2 along with extensions and other evaluation frameworks have been used to assess the performance of the MANET routing protocols when used for scalable video communication. The framework allows starting from a raw video that is encoded, packetized, transmitted through a network topology and collected at receiver to be decoded, played, and evaluated. Delay and timing constraints are taken into consideration when decoding the received video packets.展开更多
We describe a system for multipoint videoconferencing that offers extremely low end-to-end delay, low cost and complexity, and high scalability, alongside standard features associated with high-end solutions such as r...We describe a system for multipoint videoconferencing that offers extremely low end-to-end delay, low cost and complexity, and high scalability, alongside standard features associated with high-end solutions such as rate matching and per- sonal video layout. The system accommodates heterogeneous receivers and networks based on the Internet Protocol and relies on scalable video coding to provide a coded representation of a source video signal at multiple temporal and spatial resolutions as well as quality levels. These are represented by distinct bitstream components which are created at each end-user encoder. Depending on the specific conferencing environment, some or all of these components are transmitted to a Scalable Video Conferencing Server (SVCS). The SVCS redirects these components to one or more recipients depending on, e.g., the available network con- ditions and user preferences. The scalable aspect of the video coding technique allows the system to adapt to different network conditions, and also accommodates different end-user requirements (e.g., a user may elect to view another user at a high or low spatial resolution). Performance results concerning flexibility, video quality and delay of the system are presented using the Joint Scalable Video Model (JSVM) of the forthcoming SVC (H.264 Annex G) standard, demonstrating that scalable coding outper- forms existing state-of-the-art systems and offers the right platform for building next-generation multipoint videoconferencing systems.展开更多
Perovskite-based solar cell technology has advanced significantly and the power conversion efficiencies are nowadays on par with commercialized photovoltaic technologies. To realize the potential of perovskite solar c...Perovskite-based solar cell technology has advanced significantly and the power conversion efficiencies are nowadays on par with commercialized photovoltaic technologies. To realize the potential of perovskite solar cells, the focus is now shifting to scalable fabrication technologies that will enable low-cost solution processing of perovskite solar cells over large areas and with high yields. This review article discusses the fundamental concerns that arise when transitioning from laboratory to large area solution coating, available scalable coating technologies, and their applicability to the fabrication of high-performance perovskite solar cells. We find that a significant amount of work has been done to test scalable coating technologies, but also that often the methods that led to highest-performing cells in the laboratory (e.g. antisolvent processing) show limited compatibility with scalable coating methods. To achieve a high-yield and low-cost process, development must emphasize a high degree of control provided by sequential conversion of perovskite films and engineering of additives that fine-tune coating properties of perovskite precursor inks.展开更多
Scalable video coding(SVC)has been widely used in video-on-demand(VOD)service,to efficiently satisfy users’different video quality requirements and dynamically adjust video stream to timevariant wireless channels.Und...Scalable video coding(SVC)has been widely used in video-on-demand(VOD)service,to efficiently satisfy users’different video quality requirements and dynamically adjust video stream to timevariant wireless channels.Under the 5G network structure,we consider a cooperative caching scheme inside each cluster with SVC to economically utilize the limited caching storage.A novel multi-agent deep reinforcement learning(MADRL)framework is proposed to jointly optimize the video access delay and users’satisfaction,where an aggregation node is introduced helping individual agents to achieve global observations and overall system rewards.Moreover,to cope with the large action space caused by the large number of videos and users,a dimension decomposition method is embedded into the neural network in each agent,which greatly reduce the computational complexity and memory cost of the reinforcement learning.Experimental results show that:1)the proposed value-decomposed dimensional network(VDDN)algorithm achieves an obvious performance gain versus the traditional MADRL;2)the proposed VDDN algorithm can handle an extremely large action space and quickly converge with a low computational complexity.展开更多
基金the National Key R&D Program of China(2022YFA1203304)the Natural Science Foundation of Jiangsu Province(BK20220288)+1 种基金Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences(Start-up grant E1552102)the China Postdoctoral Science Foundation(No.2023M732553).
文摘The poor interfacial stability not only deteriorates fibre lithium-ion batteries(FLBs)performance but also impacts their scalable applications.To efficiently address these challenges,Prof.Huisheng Peng team proposed a generalized channel structures strategy with optimized in situ polymerization technology in their recent study.The resultant FLBs can be woven into different-sized powering textiles,providing a high energy density output of 128 Wh kg^(-1) and simultaneously demonstrating good durability even under harsh conditions.Such a promising strategy expands the horizon in developing FLB with particular polymer gel electrolytes,and significantly ever-deepening understanding of the scaled wearable energy textile system toward a sustainable future.
文摘The number of students demanding computer science(CS)education is rapidly rising,and while faculty sizes are also growing,the traditional pipeline consisting of a CS major,a CS master’s,and then a move to industry or a Ph.D.program is simply not scalable.To address this problem,the Department of Computing at the University of Illinois has introduced a multidisciplinary approach to computing,which is a scalable and collaborative approach to capitalize on the tremendous demand for computer science education.The key component of the approach is the blended major,also referred to as“CS+X”,where CS denotes computer science and X denotes a non-computing field.These CS+X blended degrees enable win-win partnerships among multiple subject areas,distributing the educational responsibilities while growing the entire university.To meet the demand from non-CS majors,another pathway that is offered is a graduate certificate program in addition to the traditional minor program.To accommodate the large number of students,scalable teaching tools,such as automatic graders,have also been developed.
基金financially supported by the National Key Research and Development Project funding from the Ministry of Science and Technology of China(2021YFB3800104)the National Natural Science Foundation of China(51822203,52002140,U20A20252,51861145404,62105293,62205187)+4 种基金the Young Elite Scientists Sponsorship Program by CAST,the Self-determined and Innovative Research Funds of HUST(2020KFYXJJS008)the Natural Science Foundation of Hubei Province(ZRJQ2022000408)the Shenzhen Science and Technology Innovation Committee(JCYJ20180507182257563)Fundamental Research Program of Shanxi Province(202103021223032)the Innovation Project of Optics Valley Laboratory of China(OVL2021BG008)。
文摘Over the last decade,remarkable progress has been made in metal halide perovskite solar cells(PSCs),which have been a focus of emerging photovoltaic techniques and show great potential for commercialization.However,the upscaling of small-area PSCs to large-area solar modules to meet the demands of practical applications remains a significant challenge.The scalable production of high-quality perovskite films by a simple,reproducible process is crucial for resolving this issue.Furthermore,the crystallization behavior in the solution-processed fabrication of perovskite films can be strongly influenced by the physicochemical properties of the precursor inks,which are significantly affected by the employed solvents and their interactions with the solutes.Thus,a comprehensive understanding of solvent engineering for fabricating perovskite films over large areas is urgently required.In this paper,we first analyze the role of solvents in the solution-processed fabrication of large-area perovskite films based on the classical crystal nucleation and growth mechanism.Recent efforts in solvent engineering to improve the quality of perovskite films for solar modules are discussed.Finally,the basic principles and future challenges of solvent system design for scalable fabrication of high-quality perovskite films for efficient solar modules are proposed.
文摘Ubiquitous data monitoring and processing with minimal latency is one of the crucial challenges in real-time and scalable applications.Internet of Things(IoT),fog computing,edge computing,cloud computing,and the edge of things are the spine of all real-time and scalable applications.Conspicuously,this study proposed a novel framework for a real-time and scalable application that changes dynamically with time.In this study,IoT deployment is recommended for data acquisition.The Pre-Processing of data with local edge and fog nodes is implemented in this study.The thresholdoriented data classification method is deployed to improve the intrusion detection mechanism’s performance.The employment of machine learningempowered intelligent algorithms in a distributed manner is implemented to enhance the overall response rate of the layered framework.The placement of respondent nodes near the framework’s IoT layer minimizes the network’s latency.For economic evaluation of the proposed framework with minimal efforts,EdgeCloudSim and FogNetSim++simulation environments are deployed in this study.The experimental results confirm the robustness of the proposed system by its improvised threshold-oriented data classification and intrusion detection approach,improved response rate,and prediction mechanism.Moreover,the proposed layered framework provides a robust solution for real-time and scalable applications that changes dynamically with time.
基金supported in part by the National Natural Science Founda⁃tion of China under Grant No.62293485the Fundamental Research Funds for the Central Universities under Grant No.2022RC18.
文摘The emerging new services in the sixth generation(6G)communication system impose increasingly stringent requirements and challenges on video transmission.Semantic communications are envisioned as a promising solution to these challenges.This paper provides a highly-efficient solution to video transmission by proposing a scalable semantic transmission algorithm,named scalable semantic transmission framework for video(SST-V),which jointly considers the semantic importance and channel conditions.Specifically,a semantic importance evaluation module is designed to extract more informative semantic features according to the estimated importance level,facilitating high-efficiency semantic coding.By further considering the channel condition,a cascaded learning based scalable joint semanticchannel coding algorithm is proposed,which autonomously adapts the semantic coding and channel coding strategies to the specific signalto-noise ratio(SNR).Simulation results show that SST-V achieves better video reconstruction performance,while significantly reducing the transmission overhead.
基金This work was supported by the Serbian Ministry of Science and Education(project TR-32022)by companies Telekom Srbija and Informatika.
文摘Data center networks may comprise tens or hundreds of thousands of nodes,and,naturally,suffer from frequent software and hardware failures as well as link congestions.Packets are routed along the shortest paths with sufficient resources to facilitate efficient network utilization and minimize delays.In such dynamic networks,links frequently fail or get congested,making the recalculation of the shortest paths a computationally intensive problem.Various routing protocols were proposed to overcome this problem by focusing on network utilization rather than speed.Surprisingly,the design of fast shortest-path algorithms for data centers was largely neglected,though they are universal components of routing protocols.Moreover,parallelization techniques were mostly deployed for random network topologies,and not for regular topologies that are often found in data centers.The aim of this paper is to improve scalability and reduce the time required for the shortest-path calculation in data center networks by parallelization on general-purpose hardware.We propose a novel algorithm that parallelizes edge relaxations as a faster and more scalable solution for popular data center topologies.
文摘A new scheme combining a scalable transcoder with space time block codes (STBC) for an orthogonal frequency division multiplexing (OFDM) system is proposed for robust video transmission in dispersive fading channels. The target application for such a scalable transcoder is to provide successful access to the pre-encoded high quality video MPEG-2 from mobile wireless terminals. In the scalable transcoder, besides outputting the MPEG-4 fine granular scalability (FGS) bitstream, both the size of video frames and the bit rate are reduced. And an array processing algorithm of layer interference suppression is used at the receiver which makes the system structure provide different levels of protection to different layers. Furthermore, by considering the important level of scalable bitstream, the different bitstreams can be given different level protection by the system structure and channel coding. With the proposed system, the concurrent large diversity gain characteristic of STBC and alleviation of the frequency-selective fading effect of OFDM can be achieved. The simulation results show that the proposed schemes integrating scalable transcoding can provide a basic quality of video transmission and outperform the conventional single layer transcoding transmitted under the random and bursty error channel conditions.
文摘Topology aggregation is necessary for scalable QoS routing mechanisms. Thekey issue is how to gain good performance while summarizing the topological information. In thispaper, we propose a new method to describe the logical link, which is simple and effective innetwork with additive and constrained concave parameters. We extend the method to network associatedwith multi-parameters. Furthermore, we propose a modified star aggregation algorithm. Simulationsare used to evaluate the performance. The results show that our algorithm is relatively good.
文摘This paper presents a novel full-chip scalable routing framework that simultaneously considers the routing congestion and the circuit performance. In order to bridge the gap, the presented framework calls the detailed router immediately after a global route is extracted. With the interleaving mode of global routing immediately followed by detailed routing, accurate routing resource and congestion information can be obtained, which provides valuable guidance for the following global routing process. The framework features the fast pattern and framed shortest path global router,a maze-based congestion-driven detailed router, and better interaction between the two routers. In the framework, timing critical nets can be assigned higher priority for performance concern, and different net ordering techniques can be adopted for different routing objectives. The framework is tested on a set of commonly used benchmark circuits and compared with a previous multilevel routing framework. Experimental results show that the presented framework obtains significantly better routing solutions than the previous one considering circuit performance, routing completion rate, and runtime.
文摘The scalable extension of H.264/AVC, known as scalable video coding or SVC, is currently the main focus of the Joint Video Team’s work. In its present working draft, the higher level syntax of SVC follows the design principles of H.264/AVC. Self-contained network abstraction layer units (NAL units) form natural entities for packetization. The SVC specification is by no means finalized yet, but nevertheless the work towards an optimized RTP payload format has already started. RFC 3984, the RTP payload specification for H.264/AVC has been taken as a starting point, but it became quickly clear that the scalable features of SVC require adaptation in at least the areas of capability/operation point signaling and documentation of the extended NAL unit header. This paper first gives an overview of the history of scalable video coding, and then reviews the video coding layer (VCL) and NAL of the latest SVC draft specification. Finally, it discusses different aspects of the draft SVC RTP payload format, in- cluding the design criteria, use cases, signaling and payload structure.
文摘The synthesis of fluorescent nanomaterials has received considerable attention due to the great potential of these materials for a wide range of applications, from chemical sensing through bioimaging to optoelectron- ics. Herein, we report a facile and scalable approach to prepare fluorescent carbon dots (FCDs) via a one-pot reaction of citric acid with ethylenediamine at 150 ℃ under ambient air pressure. The resultant FCDs pos- sess an optical bandgap of 3.4 eV and exhibit strong excitation-wavelength-independent blue emission (λEm = 450 nm) under either one- or two-photon excitation. Owing to their low cytotoxicity and long fluorescence lifetime, these FCDs were successfully used as internalized fluorescent probes in human cancer cell lines (HeLa cells) for two-photon excited imaging of cells by fluorescence lifetime imaging microscopy with a high-contrast resolution. They were also homogenously mixed with commercial inks and used to draw fluo- rescent patterns on normal papers and on many other substrates (e.g., certain flexible plastic films, textiles, and clothes). Thus, these nanomaterials are promising for use in solid-state fluorescent sensing, security labeling, and wearable optoelectronics.
文摘Superlattice photonic crystals (SPhCs) possess considerablepotentials as building blocks for constructing high-performancedevices because of their great flexibilities in opticalmanipulation. From the prospective of practical applications,scalable fabrication of SPhCs with large-area uniformity and precisegeometrical controllability has been considered as one prerequisitebut still remains a challenge.
基金Project supported by the National Natural Science Foundation ofChina (No. 60472100), the Natural Science Foundation of ZhejiangProvince (Nos. RC01057, Y105577, 601017), the Ningbo Scienceand Technology Project (Nos. 2003A61001, 2004A610001,2004A630002), and the Zhejiang Science and Technology Project(No. 2004C31105), China
文摘In this work, a new method to deal with the unconnected pixels in motion compensated temporal filtering (MCTF) is presented, which is designed to improve the performance of 3D lifted wavelet coding. Furthermore, multiple description scalable coding (MDSC) is investigated, and novel MDSC schemes based on 3D wavelet coding are proposed, using the lifting imple- mentation of temporal filtering. The proposed MDSC schemes can avoid the mismatch problem in multiple description video coding, and have high scalability and robustness of video transmission. Experimental results showed that the proposed schemes are feasible and adequately effective.
文摘Humans can sense, weigh and grasp different objects, deduce their physical properties at the same time, and exert appropriate forces – a challenging task for modern robots. Studying the mechanics of human grasping objects will play a supplementary role in visual-based robot object processing. These tools require large-scale tactile data sets with high spatial resolution. However, there is no large human-grasped tactile data set covering the whole hand, because dense coverage of the human hand with tactile sensors is challenging. Hence, the capability of observing and learning from successful daily humanobject interactions is the long-term goal of aiding the development of robots and prosthetics.
基金supported by the National Key Research and Development Program of China(Nos.2019YFA0707003 and 2019YFE0114100)the National Natural Science Foundation of China(NSFC 51872007)Beijing Municipal Natural Science Foundation(No.7202094).
文摘Perovskite solar cells have reached a power-conversion efficiency(PCE) of 25.6%,showing great potential with reliable moisture and heat stability.Most results are achieved on small-area devices,using conventional thin-film processing technologies like spin-coating method.However,such approaches may not be upscaled for large-area substrates.Thus,strategies and materials need to be developed for manufacturing processing routes to realize future commercial photovoltaic fabrications.Notable results have been achieved on large-area perovskite solar cells.In this review,similarities and differences of large-area perovskite fabrication mechanisms between the various pathways are investigated,especially on the parameters affecting the nucleation and crystal growth kinetics.Moreover,the methods for large-area transporting layers and electrodes are discussed,and some key issues from cells to modules.Challenges and opportunities are proposed to pave the way of high-efficiency perovskite solar modules.
基金funded by the MIT-Tata Grid Edge Solar research program
文摘The recent steady improvements in the performance of the nascent hybrid perovskite photovoltaic(PV)devices have led to power conversion efficiencies that rival the best-performing established PV technologies.However,to scale these laboratory demonstrations to PV module-scale production will require development of scalable deposition methods for perovskite thin films.Every record result for perovskite PVs so far was achieved via spin coating,a technique that is popular in research laboratories for thin-film coating over relatively small device areas,but not considered to be a method that could be used to scale up the manufacturing of perovskite PVs.Significantly larger thin-film areas are needed for future commercial PV products.Hence,some researchers have focused their efforts on perovskite deposition techniques that can be considered as scalable for mass production and have achieved notable results even on large areas.Here,we present an overview of the solution-based and vapor-based deposition processes;we explain their influence on the molecular crystal growth behavior of perovskite thin films and discuss the morphology as well as other material quality characteristics.By presenting a comprehensive comparison of the deposition techniques and the corresponding performance parameters for different device sizes,we intent to guide the growing research community through the methods that might enable mass production of perovskite solar products.
文摘Mobile Ad-hoc Networks (MANETs) operate without infrastructure where nodes can move randomly. Therefore, routing in MANETs is a challenging task. In this paper we evaluate the performance of three important MANET routing protocols: Ad hoc On-Demand Distance Vector (AODV), Dynamic Source Routing (DSR) and Optimized Link State Routing (OLSR) when employed to forward scalable video contents. AODV and DSR are reactive protocols in that routing paths are established once needed. On the other hand, OLSR is a proactive routing protocol where routing information is exchanged and maintained continuously. The goal of the performance evaluation in this study is to assess the performance of AODV, DSR and OLSR in communicating scalable video contents. In the simulation part of this paper, a real video sequence is communicated where the characteristics and quality of the video decoded at receiver nodes are evaluated. NS2 along with extensions and other evaluation frameworks have been used to assess the performance of the MANET routing protocols when used for scalable video communication. The framework allows starting from a raw video that is encoded, packetized, transmitted through a network topology and collected at receiver to be decoded, played, and evaluated. Delay and timing constraints are taken into consideration when decoding the received video packets.
文摘We describe a system for multipoint videoconferencing that offers extremely low end-to-end delay, low cost and complexity, and high scalability, alongside standard features associated with high-end solutions such as rate matching and per- sonal video layout. The system accommodates heterogeneous receivers and networks based on the Internet Protocol and relies on scalable video coding to provide a coded representation of a source video signal at multiple temporal and spatial resolutions as well as quality levels. These are represented by distinct bitstream components which are created at each end-user encoder. Depending on the specific conferencing environment, some or all of these components are transmitted to a Scalable Video Conferencing Server (SVCS). The SVCS redirects these components to one or more recipients depending on, e.g., the available network con- ditions and user preferences. The scalable aspect of the video coding technique allows the system to adapt to different network conditions, and also accommodates different end-user requirements (e.g., a user may elect to view another user at a high or low spatial resolution). Performance results concerning flexibility, video quality and delay of the system are presented using the Joint Scalable Video Model (JSVM) of the forthcoming SVC (H.264 Annex G) standard, demonstrating that scalable coding outper- forms existing state-of-the-art systems and offers the right platform for building next-generation multipoint videoconferencing systems.
基金supported by funding from the Energy Materials and Surface Sciences Unit of the Okinawa Institute of Science and Technology Graduate Universitythe OIST R&D Cluster Research Program+1 种基金the OIST Proof of Concept(POC)ProgramJSPS KAKENHI Grant Number 15K17925
文摘Perovskite-based solar cell technology has advanced significantly and the power conversion efficiencies are nowadays on par with commercialized photovoltaic technologies. To realize the potential of perovskite solar cells, the focus is now shifting to scalable fabrication technologies that will enable low-cost solution processing of perovskite solar cells over large areas and with high yields. This review article discusses the fundamental concerns that arise when transitioning from laboratory to large area solution coating, available scalable coating technologies, and their applicability to the fabrication of high-performance perovskite solar cells. We find that a significant amount of work has been done to test scalable coating technologies, but also that often the methods that led to highest-performing cells in the laboratory (e.g. antisolvent processing) show limited compatibility with scalable coating methods. To achieve a high-yield and low-cost process, development must emphasize a high degree of control provided by sequential conversion of perovskite films and engineering of additives that fine-tune coating properties of perovskite precursor inks.
基金supported by the National Natural Science Foundation of China under Grant No.61801119。
文摘Scalable video coding(SVC)has been widely used in video-on-demand(VOD)service,to efficiently satisfy users’different video quality requirements and dynamically adjust video stream to timevariant wireless channels.Under the 5G network structure,we consider a cooperative caching scheme inside each cluster with SVC to economically utilize the limited caching storage.A novel multi-agent deep reinforcement learning(MADRL)framework is proposed to jointly optimize the video access delay and users’satisfaction,where an aggregation node is introduced helping individual agents to achieve global observations and overall system rewards.Moreover,to cope with the large action space caused by the large number of videos and users,a dimension decomposition method is embedded into the neural network in each agent,which greatly reduce the computational complexity and memory cost of the reinforcement learning.Experimental results show that:1)the proposed value-decomposed dimensional network(VDDN)algorithm achieves an obvious performance gain versus the traditional MADRL;2)the proposed VDDN algorithm can handle an extremely large action space and quickly converge with a low computational complexity.