Through the mapping from UMQL （ unified multimedia query language） conditional expressions to UMQA （unified multimedia query algebra） query operations, a translation algorithm from a UMQL query to a UMQA query pla...Through the mapping from UMQL （ unified multimedia query language） conditional expressions to UMQA （unified multimedia query algebra） query operations, a translation algorithm from a UMQL query to a UMQA query plan is put forward, which can generate an equivalent UMQA internal query plan for any UMQL query. Then, to improve the execution costs of UMQA query plans effectively, equivalent UMQA translation formulae and general optimization strategies are studied, and an optimization algorithm for UMQA internal query plans is presented. This algorithm uses equivalent UMQA translation formulae to optimize query plans, and makes the optimized query plans accord with the optimization strategies as much as possible. Finally, the logic implementation methods of UMQA plans, i.e., logic implementation methods of UMQA operators, are discussed to obtain useful target data from a muifirnedia database. All of these algorithms are implemented in a UMQL prototype system. Application results show that these query processing techniques are feasible and applicable.展开更多
Recent advances in wireless mobile computing, digital library, and distributed multimedia technologies are stimulating the development of mobile multimedia digital library systems （ M2DLS） that allow mobile clients ...Recent advances in wireless mobile computing, digital library, and distributed multimedia technologies are stimulating the development of mobile multimedia digital library systems （ M2DLS） that allow mobile clients to access multimedia material anywhere and anytime over a cellular radio network. This paper addresses the problem of providing synchronized multimedia retrieval in these sys- tems. An efficient inter-media synchronization scheme called wireless prioritized feedback （WPF） for mobile multimedia on-demand retrieval in digital library systems over CDMA cellular radio networks in the absence of synchronized clocks is presented. In the WPF scheme, base stations use preferential lightweight message called feedback units transmitted by mobile mediaphones to detect and correct asynchronies. The algorithm is described with pseudo code, and experiments are described to demonstrate the efficiency of WPF.展开更多
In the Engine CAD application system engineering database management system (ECAD-EDBMS) is the kernel. ECAD-EDBMS can manage and process the multimedia such as graphics, data, text, sound, image and video. It provide...In the Engine CAD application system engineering database management system (ECAD-EDBMS) is the kernel. ECAD-EDBMS can manage and process the multimedia such as graphics, data, text, sound, image and video. It provides the integrated environment and more functions for many subsystems of ECAD and engine designers. So it improves the design efficiency.展开更多
This thesis aims at providing an overview of the recent developments and reforms in the college English education. With the employment of multi-media teaching facilities, intercultural competence, i.e., the flexible a...This thesis aims at providing an overview of the recent developments and reforms in the college English education. With the employment of multi-media teaching facilities, intercultural competence, i.e., the flexible adoption of the systems of value outlook and behavior mode of the target language, has indisputably been integrated into the second language learning and teaching curriculum. This thesis compares and analyzes the nature and composition of cultural cognition.展开更多
Based on the constructivism, using the College English（new edition） CD-ROMs for classroom teaching as main media, this paper explores the feasibility of the classroom teaching mode of appropriate combination of trad...Based on the constructivism, using the College English（new edition） CD-ROMs for classroom teaching as main media, this paper explores the feasibility of the classroom teaching mode of appropriate combination of traditional methods with the multimedia overhead projector. The new teaching mode proves to be successful in that it has greatly improved the students＇ ability to use English in an all-round way and has obvious advantages over the only traditional method.展开更多
With the development of social economy,the multimedia and network teaching is more and more important in college English teaching,especially in vocational college.It can not only help students to give full play to the...With the development of social economy,the multimedia and network teaching is more and more important in college English teaching,especially in vocational college.It can not only help students to give full play to their collective consciousness and make our English course be full of vitality,but also make the amount of information in class redoubled.For the multimedia and network teaching,there're some problems in English teaching.So the multimedia and network teaching has both necessities and problems.展开更多
For the current foreign language teaching, using multimedia technology has become a necessity in information age. The modernization of computer has paved a new way of deepening teaching reform and improving teaching e...For the current foreign language teaching, using multimedia technology has become a necessity in information age. The modernization of computer has paved a new way of deepening teaching reform and improving teaching efficiency and quality. With the computer technology applied in education, language teachers have witnessed dramatic changes in the ways that languages are taught. Multimedia technology applied in English teaching has been considered to be a more effective medium, which represents an inevitable trend of applied linguistics.展开更多
Advanced English is a key course for English majors in advanced stage.This paper first proposes the problems in tradi tional advanced English teaching.Then it explains the theoretical basis and finally the paper state...Advanced English is a key course for English majors in advanced stage.This paper first proposes the problems in tradi tional advanced English teaching.Then it explains the theoretical basis and finally the paper states advantages of multimedia teach ing in Advanced English.展开更多
First, the date palm kernel is used to produce granular activated carbon （GAC） by a physiochemical activation process. The process involves six steps： washing, drying, crushing, sieving, carbonization, and activati...First, the date palm kernel is used to produce granular activated carbon （GAC） by a physiochemical activation process. The process involves six steps： washing, drying, crushing, sieving, carbonization, and activation. Secondly, the ability of the produced GAC to remove pollutants is examined through batch experiments of residual chlorine adsorption whereas the equilibrium isotherm experimental data are tested for the Langmuir and Freundlich isotherms equations. Thirdly, the experimental and theoretical study of dynamic adsorption process and the effect of major operating parameters on dynamic adsorption are investigated. The results show that the Langmuir isotherm gives the best fitting to experimental data, which indicates that the residual chlorine adsorption can be characterized by mono layer adsorption behavior. The produced GAC has a great potential as an adsorbent for residual chlorine in water systems and it can compete favorably with the conventional adsorbents. The Thomas extended model with combined mass transfer resistances is used for verifying the experimental results and the results show that the proposed model coincides well with the experimental data of the dynamic adsorption process.展开更多
According to large coverage of satellites, there are various channel states in a satellite broadcasting network. In order to introduce an efficient rateless transmission method to satellite multimedia broadcasting/mul...According to large coverage of satellites, there are various channel states in a satellite broadcasting network. In order to introduce an efficient rateless transmission method to satellite multimedia broadcasting/multicast services with finite-length packets, a cross-layer packet transmission method is proposed with Luby transform （LT） codes for efficiency in the network layer and low density parity check （LDPC） codes for reliability in the physical layer jointly. The codewords generated from an LT encoder are divided into finite-length packets, which are encoded by an LDPC encoder subsequently. Based on noise and fading effects of satellite channels, the LT packets received from an LDPC decoder either have no error or are marked as erased, which can be mod- eled as a binary erasure channels （BECs）. By theoretical analysis on LT parameters and LDPC parameters, the relationships between LDPC code rates in the physical layer and LT codes word lengths in the network layer are investigated. With tradeoffs between the LT codes word lengths and the LDPC code rates, optimized cross-layer solutions are achieved with a binary search algorithm. Verified by simulations, the proposed solution for cross-layer parameters design can provide the best transmission mode according to satellite states, so as to improve throughput performance for satellite multimedia transmission.展开更多
A geographical information system (GIS) is used to capture, store, retrieve, analyzed and display the spatial (locationally defined) data. In contrast to traditional GIS, multimedia GIS is not only able to collect, an...A geographical information system (GIS) is used to capture, store, retrieve, analyzed and display the spatial (locationally defined) data. In contrast to traditional GIS, multimedia GIS is not only able to collect, analyze and store the data in traditional formats i.e. text, images (pictures) and graphs but also audio (sound), animations and video (moving pictures) as well. In this paper the advantages of multimedia GIS over traditional GIS are explained. Multimedia GIS is fully capable of providing services to both technical and non technical users and users of multimedia GIS can retain more knowledge than users of traditional GIS. It can be applied to various fields such as tourism, environment, education etc. Some implementation issues such as data updating, information retrieval and data compression etc. are also addressed. Finally, future development of MMGIS (using new multimedia technologies such as Virtual Reality and Virtual Reality Modeling Language) is discussed.展开更多
Providing highly efficient underwater transmission of mass multimedia data is challenging due to the particularities of the underwater environment. Although there are many schemes proposed to optimize the underwater a...Providing highly efficient underwater transmission of mass multimedia data is challenging due to the particularities of the underwater environment. Although there are many schemes proposed to optimize the underwater acoustic network communication protocols, from physical layer, data link layer, network layer to transport layer, the existing routing protocols for underwater wireless sensor network(UWSN) still cannot well deal with the problems in transmitting multimedia data because of the difficulties involved in high energy consumption, low transmission reliability or high transmission delay. It prevents us from applying underwater multimedia data to real-time monitoring of marine environment in practical application, especially in emergency search, rescue operation and military field. Therefore, the inefficient transmission of marine multimedia data has become a serious problem that needs to be solved urgently. In this paper, A Layered Load Balance Routing Protocol(L2-LBMT) is proposed for underwater multimedia data transmission. In L2-LBMT, we use layered and load-balance Ad Hoc Network to transmit data, and adopt segmented data reliable transfer(SDRT) protocol to improve the data transport reliability. And a 3-node variant of tornado(3-VT) code is also combined with the Ad Hoc Network to transmit little emergency data more quickly. The simulation results show that the proposed protocol can balance energy consumption of each node, effectively prolong the network lifetime and reduce transmission delay of marine multimedia data.展开更多
Fog computing is introduced to relieve the problems triggered by the long distance between the cloud and terminal devices. In this paper, considering the mobility of terminal devices represented as mobile multimedia u...Fog computing is introduced to relieve the problems triggered by the long distance between the cloud and terminal devices. In this paper, considering the mobility of terminal devices represented as mobile multimedia users(MMUs) and the continuity of requests delivered by them, we propose an online resource allocation scheme with respect to deciding the state of servers in fog nodes distributed at different zones on the premise of satisfying the quality of experience(QoE) based on a Stackelberg game. Specifically, a multi-round of a predictably\unpredictably dynamic scheme is derived from a single-round of a static scheme. The optimal allocation schemes are discussed in detail, and related experiments are designed. For simulations, comparing with non-strategy schemes, the performance of the dynamic scheme is better at minimizing the cost used to maintain fog nodes for providing services.展开更多
Nowadays,healthcare applications necessitate maximum volume of medical data to be fed to help the physicians,academicians,pathologists,doctors and other healthcare professionals.Advancements in the domain of Wireless ...Nowadays,healthcare applications necessitate maximum volume of medical data to be fed to help the physicians,academicians,pathologists,doctors and other healthcare professionals.Advancements in the domain of Wireless Sensor Networks(WSN)andMultimediaWireless Sensor Networks(MWSN)are tremendous.M-WMSN is an advanced form of conventional Wireless Sensor Networks(WSN)to networks that use multimedia devices.When compared with traditional WSN,the quantity of data transmission in M-WMSN is significantly high due to the presence of multimedia content.Hence,clustering techniques are deployed to achieve low amount of energy utilization.The current research work aims at introducing a new Density Based Clustering(DBC)technique to achieve energy efficiency inWMSN.The DBC technique is mainly employed for data collection in healthcare environment which primarily depends on three input parameters namely remaining energy level,distance,and node centrality.In addition,two static data collector points called Super Cluster Head(SCH)are placed,which collects the data from normal CHs and forwards it to the Base Station(BS)directly.SCH supports multi-hop data transmission that assists in effectively balancing the available energy.Adetailed simulation analysiswas conducted to showcase the superior performance of DBC technique and the results were examined under diverse aspects.The simulation outcomes concluded that the proposed DBC technique improved the network lifetime to a maximum of 16,500 rounds,which is significantly higher compared to existing methods.展开更多
Emission intensity and climate change control the transport flux and fate of persistent organic pollutants(POPs)inmultiple environmental compartments.This study applied amultimedia model(BETR model)to explore alternat...Emission intensity and climate change control the transport flux and fate of persistent organic pollutants(POPs)inmultiple environmental compartments.This study applied amultimedia model(BETR model)to explore alternations in the spatio-temporal trends of concentrations and transport flux of benzopyrene(BaP),phenanthrene(Phe),perfluorooctane sulfonates(PFOS)and polychlorinated biphenyls(PCBs)in the Chaohu watershed,located in the lower reaches of the Yangtze River,China in response to changes in source emissions and climate.The potential historic and future risks of these pollutants also were assessed.The results suggest that current trends in concentrations and transport were similar to that of their emissions between 2005 and 2018.During the next 100 years,temporal trends and spatial patterns were not predicted to change significantly,which is consistent with climate change.Based on sensitivity and correlation analyses,climate change had significant effects on multi-media concentrations and transport fluxes of BaP,Phe,PFOS and PCBs,and rainfall intensity was the predominant controlling factor.Risk quotients(RQs)of BaP and Phe-in soil increased from 0.42 to 0.95 and 0.06 to 0.35,respectively,from 2005 to 2090,indicating potential risks.The RQs of the other examined contaminants exhibited little potential risk in soil,water,or sediment.Based on spatial patterns,it was inferred that the ecosystem around Lake Chaohu is the most at risk.The study provides insights needed for local pollution control of POPs in the Chaohu watershed.In addition,the developed approach can be applied to other watersheds world-wide.展开更多
Urban areas are generally regarded as major sources of some semivolatile organic compounds and other persistent organic pollutants（POPs） to the surrounding regions. Huge differences in contaminant emissions between ...Urban areas are generally regarded as major sources of some semivolatile organic compounds and other persistent organic pollutants（POPs） to the surrounding regions. Huge differences in contaminant emissions between urban and rural areas directly affect their fate in environmental media. Little is known about POPs behavior between urban and rural areas at a regional scale. A spatially resolved Berkeley-Trent-Urban-Rural Fate Model（BETR-UR） was designed by coupling land cover information to simulate the transport of POPs between urban and rural areas, and the Bohai Rim was used as a case study to estimate Polycyclic Aromatic Hydrocarbon（PAH） fate. The processes of contaminant fate including emission, inter-compartmental transfer, advection and degradation in urban and rural areas were simulated in the model. Simulated PAH concentrations in environmental media of urban and rural areas were very close to measured values. The model accuracy was highly improved, with the average absolute relative error for PAH concentrations reduced from 37% to 3% compared with unimproved model results. PAH concentrations in urban soil and air were considerably higher than those in rural areas. Sensitivity analysis showed temperature was the most influential parameter for Phen rather than for Bap, whose fate was more influenced by emission rate, compartment dimension, transport velocity and chemical persistence. Uncertainty analysis indicated modeled results in urban media had higher uncertainty than those in rural areas due to larger variations of emissions in urban areas. The differences in urban and rural areas provided us with valuable guidance on policy setting for urban–rural POP control.展开更多
In multimedia conference, the capability of audio processing is basic and requires more for real-time criteria. In this article, we categorize and analyze the schemes, and provide several multipoint speech audio mixin...In multimedia conference, the capability of audio processing is basic and requires more for real-time criteria. In this article, we categorize and analyze the schemes, and provide several multipoint speech audio mixing schemes using weighted algorithm, which meet the demand of practical needs for real-time multipoint speech mixing, for which the ASW and AEW schemes are especially recommended. Applying the adaptive algorithms, the high-performance schemes we provide do not use the saturation operation widely used in multimedia processing. Therefore, no additional noise will be added to the output. The above adaptive algorithms have relatively low computational complexity and good hearing perceptibility. The schemes are designed for parallel processing, and can be easily implemented with hardware, such as DSPs, and widely applied in multimedia conference systems.展开更多
A novel method is proposed to analyze the capacity of future Code Division Multiple Access （CDMA） systems carrying multimedia services. The power level allocation is firstly investigated to meet each call＇s Bit Err...A novel method is proposed to analyze the capacity of future Code Division Multiple Access （CDMA） systems carrying multimedia services. The power level allocation is firstly investigated to meet each call＇s Bit Error Rate （BER） requirement, then the system capacity is defined from the conditions lbr the existence of the physical meaning of these power levels. Simulation results have shown that the capacity analyzing methods can be well used in the performance evaluation of the system accommodating heterogeneous services and the spectral efficiency of this scheme is higher than the existing ones.展开更多
基金The National High Technology Research and Development Program of China(863 Program) (No.2006AA01Z430)
文摘Through the mapping from UMQL （ unified multimedia query language） conditional expressions to UMQA （unified multimedia query algebra） query operations, a translation algorithm from a UMQL query to a UMQA query plan is put forward, which can generate an equivalent UMQA internal query plan for any UMQL query. Then, to improve the execution costs of UMQA query plans effectively, equivalent UMQA translation formulae and general optimization strategies are studied, and an optimization algorithm for UMQA internal query plans is presented. This algorithm uses equivalent UMQA translation formulae to optimize query plans, and makes the optimized query plans accord with the optimization strategies as much as possible. Finally, the logic implementation methods of UMQA plans, i.e., logic implementation methods of UMQA operators, are discussed to obtain useful target data from a muifirnedia database. All of these algorithms are implemented in a UMQL prototype system. Application results show that these query processing techniques are feasible and applicable.
基金Project supported by National Natural Science Foundation of China (Grant No .60221120146) , National Basic Research Pro-gram of China ( Grant No . 973 -G1999032704) , and National Grand Fundamental Post Doctor Research of China (Grant No .2003034146)
文摘Recent advances in wireless mobile computing, digital library, and distributed multimedia technologies are stimulating the development of mobile multimedia digital library systems （ M2DLS） that allow mobile clients to access multimedia material anywhere and anytime over a cellular radio network. This paper addresses the problem of providing synchronized multimedia retrieval in these sys- tems. An efficient inter-media synchronization scheme called wireless prioritized feedback （WPF） for mobile multimedia on-demand retrieval in digital library systems over CDMA cellular radio networks in the absence of synchronized clocks is presented. In the WPF scheme, base stations use preferential lightweight message called feedback units transmitted by mobile mediaphones to detect and correct asynchronies. The algorithm is described with pseudo code, and experiments are described to demonstrate the efficiency of WPF.
文摘In the Engine CAD application system engineering database management system (ECAD-EDBMS) is the kernel. ECAD-EDBMS can manage and process the multimedia such as graphics, data, text, sound, image and video. It provides the integrated environment and more functions for many subsystems of ECAD and engine designers. So it improves the design efficiency.
文摘This thesis aims at providing an overview of the recent developments and reforms in the college English education. With the employment of multi-media teaching facilities, intercultural competence, i.e., the flexible adoption of the systems of value outlook and behavior mode of the target language, has indisputably been integrated into the second language learning and teaching curriculum. This thesis compares and analyzes the nature and composition of cultural cognition.
文摘Based on the constructivism, using the College English（new edition） CD-ROMs for classroom teaching as main media, this paper explores the feasibility of the classroom teaching mode of appropriate combination of traditional methods with the multimedia overhead projector. The new teaching mode proves to be successful in that it has greatly improved the students＇ ability to use English in an all-round way and has obvious advantages over the only traditional method.
文摘With the development of social economy,the multimedia and network teaching is more and more important in college English teaching,especially in vocational college.It can not only help students to give full play to their collective consciousness and make our English course be full of vitality,but also make the amount of information in class redoubled.For the multimedia and network teaching,there're some problems in English teaching.So the multimedia and network teaching has both necessities and problems.
文摘For the current foreign language teaching, using multimedia technology has become a necessity in information age. The modernization of computer has paved a new way of deepening teaching reform and improving teaching efficiency and quality. With the computer technology applied in education, language teachers have witnessed dramatic changes in the ways that languages are taught. Multimedia technology applied in English teaching has been considered to be a more effective medium, which represents an inevitable trend of applied linguistics.
文摘Advanced English is a key course for English majors in advanced stage.This paper first proposes the problems in tradi tional advanced English teaching.Then it explains the theoretical basis and finally the paper states advantages of multimedia teach ing in Advanced English.
基金The National Natural Science Foundation of China(No. 51078074)
文摘First, the date palm kernel is used to produce granular activated carbon （GAC） by a physiochemical activation process. The process involves six steps： washing, drying, crushing, sieving, carbonization, and activation. Secondly, the ability of the produced GAC to remove pollutants is examined through batch experiments of residual chlorine adsorption whereas the equilibrium isotherm experimental data are tested for the Langmuir and Freundlich isotherms equations. Thirdly, the experimental and theoretical study of dynamic adsorption process and the effect of major operating parameters on dynamic adsorption are investigated. The results show that the Langmuir isotherm gives the best fitting to experimental data, which indicates that the residual chlorine adsorption can be characterized by mono layer adsorption behavior. The produced GAC has a great potential as an adsorbent for residual chlorine in water systems and it can compete favorably with the conventional adsorbents. The Thomas extended model with combined mass transfer resistances is used for verifying the experimental results and the results show that the proposed model coincides well with the experimental data of the dynamic adsorption process.
基金supported by the National Natural Science Foundation of China (No.61101125)
文摘According to large coverage of satellites, there are various channel states in a satellite broadcasting network. In order to introduce an efficient rateless transmission method to satellite multimedia broadcasting/multicast services with finite-length packets, a cross-layer packet transmission method is proposed with Luby transform （LT） codes for efficiency in the network layer and low density parity check （LDPC） codes for reliability in the physical layer jointly. The codewords generated from an LT encoder are divided into finite-length packets, which are encoded by an LDPC encoder subsequently. Based on noise and fading effects of satellite channels, the LT packets received from an LDPC decoder either have no error or are marked as erased, which can be mod- eled as a binary erasure channels （BECs）. By theoretical analysis on LT parameters and LDPC parameters, the relationships between LDPC code rates in the physical layer and LT codes word lengths in the network layer are investigated. With tradeoffs between the LT codes word lengths and the LDPC code rates, optimized cross-layer solutions are achieved with a binary search algorithm. Verified by simulations, the proposed solution for cross-layer parameters design can provide the best transmission mode according to satellite states, so as to improve throughput performance for satellite multimedia transmission.
文摘A geographical information system (GIS) is used to capture, store, retrieve, analyzed and display the spatial (locationally defined) data. In contrast to traditional GIS, multimedia GIS is not only able to collect, analyze and store the data in traditional formats i.e. text, images (pictures) and graphs but also audio (sound), animations and video (moving pictures) as well. In this paper the advantages of multimedia GIS over traditional GIS are explained. Multimedia GIS is fully capable of providing services to both technical and non technical users and users of multimedia GIS can retain more knowledge than users of traditional GIS. It can be applied to various fields such as tourism, environment, education etc. Some implementation issues such as data updating, information retrieval and data compression etc. are also addressed. Finally, future development of MMGIS (using new multimedia technologies such as Virtual Reality and Virtual Reality Modeling Language) is discussed.
基金supported by the National Natural Science Foundation of China (No.61401413)the Digital Home Industry Cluster Oriented Technology Service Innovation Pilot Project in 2015
文摘Providing highly efficient underwater transmission of mass multimedia data is challenging due to the particularities of the underwater environment. Although there are many schemes proposed to optimize the underwater acoustic network communication protocols, from physical layer, data link layer, network layer to transport layer, the existing routing protocols for underwater wireless sensor network(UWSN) still cannot well deal with the problems in transmitting multimedia data because of the difficulties involved in high energy consumption, low transmission reliability or high transmission delay. It prevents us from applying underwater multimedia data to real-time monitoring of marine environment in practical application, especially in emergency search, rescue operation and military field. Therefore, the inefficient transmission of marine multimedia data has become a serious problem that needs to be solved urgently. In this paper, A Layered Load Balance Routing Protocol(L2-LBMT) is proposed for underwater multimedia data transmission. In L2-LBMT, we use layered and load-balance Ad Hoc Network to transmit data, and adopt segmented data reliable transfer(SDRT) protocol to improve the data transport reliability. And a 3-node variant of tornado(3-VT) code is also combined with the Ad Hoc Network to transmit little emergency data more quickly. The simulation results show that the proposed protocol can balance energy consumption of each node, effectively prolong the network lifetime and reduce transmission delay of marine multimedia data.
基金supported by the National Natural Science Foundation of China under grant No. 61501080, 61572095, 61871064, and 61877007
文摘Fog computing is introduced to relieve the problems triggered by the long distance between the cloud and terminal devices. In this paper, considering the mobility of terminal devices represented as mobile multimedia users(MMUs) and the continuity of requests delivered by them, we propose an online resource allocation scheme with respect to deciding the state of servers in fog nodes distributed at different zones on the premise of satisfying the quality of experience(QoE) based on a Stackelberg game. Specifically, a multi-round of a predictably\unpredictably dynamic scheme is derived from a single-round of a static scheme. The optimal allocation schemes are discussed in detail, and related experiments are designed. For simulations, comparing with non-strategy schemes, the performance of the dynamic scheme is better at minimizing the cost used to maintain fog nodes for providing services.
文摘Nowadays,healthcare applications necessitate maximum volume of medical data to be fed to help the physicians,academicians,pathologists,doctors and other healthcare professionals.Advancements in the domain of Wireless Sensor Networks(WSN)andMultimediaWireless Sensor Networks(MWSN)are tremendous.M-WMSN is an advanced form of conventional Wireless Sensor Networks(WSN)to networks that use multimedia devices.When compared with traditional WSN,the quantity of data transmission in M-WMSN is significantly high due to the presence of multimedia content.Hence,clustering techniques are deployed to achieve low amount of energy utilization.The current research work aims at introducing a new Density Based Clustering(DBC)technique to achieve energy efficiency inWMSN.The DBC technique is mainly employed for data collection in healthcare environment which primarily depends on three input parameters namely remaining energy level,distance,and node centrality.In addition,two static data collector points called Super Cluster Head(SCH)are placed,which collects the data from normal CHs and forwards it to the Base Station(BS)directly.SCH supports multi-hop data transmission that assists in effectively balancing the available energy.Adetailed simulation analysiswas conducted to showcase the superior performance of DBC technique and the results were examined under diverse aspects.The simulation outcomes concluded that the proposed DBC technique improved the network lifetime to a maximum of 16,500 rounds,which is significantly higher compared to existing methods.
基金supported by the National Key Research and Development Program of China(No.2017YFA0605003)the National Natural Science Foundation of China(Nos.51922010,41521003).
文摘Emission intensity and climate change control the transport flux and fate of persistent organic pollutants(POPs)inmultiple environmental compartments.This study applied amultimedia model(BETR model)to explore alternations in the spatio-temporal trends of concentrations and transport flux of benzopyrene(BaP),phenanthrene(Phe),perfluorooctane sulfonates(PFOS)and polychlorinated biphenyls(PCBs)in the Chaohu watershed,located in the lower reaches of the Yangtze River,China in response to changes in source emissions and climate.The potential historic and future risks of these pollutants also were assessed.The results suggest that current trends in concentrations and transport were similar to that of their emissions between 2005 and 2018.During the next 100 years,temporal trends and spatial patterns were not predicted to change significantly,which is consistent with climate change.Based on sensitivity and correlation analyses,climate change had significant effects on multi-media concentrations and transport fluxes of BaP,Phe,PFOS and PCBs,and rainfall intensity was the predominant controlling factor.Risk quotients(RQs)of BaP and Phe-in soil increased from 0.42 to 0.95 and 0.06 to 0.35,respectively,from 2005 to 2090,indicating potential risks.The RQs of the other examined contaminants exhibited little potential risk in soil,water,or sediment.Based on spatial patterns,it was inferred that the ecosystem around Lake Chaohu is the most at risk.The study provides insights needed for local pollution control of POPs in the Chaohu watershed.In addition,the developed approach can be applied to other watersheds world-wide.
基金supported by the International Scientific Cooperation Program (No. 2012DFA91150)the Chinese Academy of Sciences (No. KZZD-EW-TZ-12)the National Natural Science Foundation of China under Grants (Nos. 414201040045, 41501539)
文摘Urban areas are generally regarded as major sources of some semivolatile organic compounds and other persistent organic pollutants（POPs） to the surrounding regions. Huge differences in contaminant emissions between urban and rural areas directly affect their fate in environmental media. Little is known about POPs behavior between urban and rural areas at a regional scale. A spatially resolved Berkeley-Trent-Urban-Rural Fate Model（BETR-UR） was designed by coupling land cover information to simulate the transport of POPs between urban and rural areas, and the Bohai Rim was used as a case study to estimate Polycyclic Aromatic Hydrocarbon（PAH） fate. The processes of contaminant fate including emission, inter-compartmental transfer, advection and degradation in urban and rural areas were simulated in the model. Simulated PAH concentrations in environmental media of urban and rural areas were very close to measured values. The model accuracy was highly improved, with the average absolute relative error for PAH concentrations reduced from 37% to 3% compared with unimproved model results. PAH concentrations in urban soil and air were considerably higher than those in rural areas. Sensitivity analysis showed temperature was the most influential parameter for Phen rather than for Bap, whose fate was more influenced by emission rate, compartment dimension, transport velocity and chemical persistence. Uncertainty analysis indicated modeled results in urban media had higher uncertainty than those in rural areas due to larger variations of emissions in urban areas. The differences in urban and rural areas provided us with valuable guidance on policy setting for urban–rural POP control.
文摘In multimedia conference, the capability of audio processing is basic and requires more for real-time criteria. In this article, we categorize and analyze the schemes, and provide several multipoint speech audio mixing schemes using weighted algorithm, which meet the demand of practical needs for real-time multipoint speech mixing, for which the ASW and AEW schemes are especially recommended. Applying the adaptive algorithms, the high-performance schemes we provide do not use the saturation operation widely used in multimedia processing. Therefore, no additional noise will be added to the output. The above adaptive algorithms have relatively low computational complexity and good hearing perceptibility. The schemes are designed for parallel processing, and can be easily implemented with hardware, such as DSPs, and widely applied in multimedia conference systems.
基金Supported by the open research fund of the National Mobile Communications Key Lab of the Southeast Uni-versity and by the Hong Kong Research Council.
文摘A novel method is proposed to analyze the capacity of future Code Division Multiple Access （CDMA） systems carrying multimedia services. The power level allocation is firstly investigated to meet each call＇s Bit Error Rate （BER） requirement, then the system capacity is defined from the conditions lbr the existence of the physical meaning of these power levels. Simulation results have shown that the capacity analyzing methods can be well used in the performance evaluation of the system accommodating heterogeneous services and the spectral efficiency of this scheme is higher than the existing ones.
