Model driven architecture(MDA) is an evolutionary step in software development.Model transformation forms a key part of MDA.The transformation from computation independent model(CIM) to platform independent model(PIM)...Model driven architecture(MDA) is an evolutionary step in software development.Model transformation forms a key part of MDA.The transformation from computation independent model(CIM) to platform independent model(PIM) is the first step of the transformation.This paper proposes an approach for this transformation with pattern.In this approach, we take advantage of"reuse"from various standpoints.Feature model is used to describe the requirement of the application.This can help us bring"reuse"into effect at requirement level.Moreover we use pattern to transform CIM to PIM.This can help us bring"reuse"into effect at development level.Meanwhile, pattern was divided into four hierarchies.Different hierarchies of pattern are used to help us utilize reuse at different phase of development.From another standpoint, feature model describes the problem of a domain while pattern describe the problem across domains.This can help us reuse the element in and across domains.Finally, the detailed process of the transformation is given.展开更多
The developments in the field of Information and Communication Technology (ICT) in the country has rapidly happen after year 2009 .Government has developed many programs and initiations to develop ICT in the country...The developments in the field of Information and Communication Technology (ICT) in the country has rapidly happen after year 2009 .Government has developed many programs and initiations to develop ICT in the country after three decades of war was ended up. As a result disabled community can make many opportunities to use the ICT and at the same time create a gap, which is commonly referred to as Disability Digital Divide. The purpose of this study was to examine empirically the current status of adoption of ICT and in turn the digital divide resulting from which in the disability community in Sri Lanka and the factors affecting this behavior. A questionnaire and Interviewed based survey (n = 107) was carried out to collect the data from the disabled people who used ICT in the Colombo, Gampaha, and Kaluthara district. An empirical model was developed to show the relationship between the level of adoption of 10 basic, intermediate, and advanced ICT facilities and a number of factors to reflect the WWW, Smart phones, and Computer usage aspects of disabled community. Based on the Innovatiotr---Diffusion Theory, the status of Digital Divide of a disabled community was specified by means of an Index. The results show that this community did not become innovators or early-adopters of ICT by adopting WWW or computer related technologies but was mostly confined to the smart phone related facilities. The results from this study highlight that the income of a disabled person, awareness about the information and technology, interest of new technology usage, social and cultural background of a person, use of English language in day-to-day life give a significant impact on the adoption oflCT by the disabled community.展开更多
To reduce channel noise,fading,and inter-user interference effectively in the chaotic communication systems with multi-user,a blind channel equalization algorithm based on dual unscented Kalman filter algorithm is pro...To reduce channel noise,fading,and inter-user interference effectively in the chaotic communication systems with multi-user,a blind channel equalization algorithm based on dual unscented Kalman filter algorithm is proposed.Assuming that the coefficients of a multi-input multi-output (MIMO) channel can be described by an autoregressive model,two separate state-space representations are used for the signals and coefficients.Then two unscented Kalman filters are used to estimate chaotic signals and channel coefficients simultaneously.The simulation results indicate that the algorithm can effectively track the coefficients of the multi-path fading channel in chaotic MIMO communication systems at a fast convergence speed.展开更多
This paper explores the potentials of traditional forms of communication in rural development communication. Experimenting a local development communication model that can be used at the grass-root level communication...This paper explores the potentials of traditional forms of communication in rural development communication. Experimenting a local development communication model that can be used at the grass-root level communication at the community development programs in Sri Lanka is the research objective. This study is a participatory research. Live participatory observation, impact analysis using a questionnaire and direct interview tools were used to analyze the impact of the creative model. This research study was experimented at Rasnayakapura divisional secretariat, Sri Lanka from 2004 to 2005. Results suggest that the traditional forms of communication can be utilized as a useful instrument in the rural community programs more than the dominant use of mass media and conventional use of small group communication. Forms of traditional communication are rich in communication because of their closeness to rural life, credibility, Utilization of familiar signs & symbols, Participation of the same community, collective presentation, Utilization of past experiences, plot and the stories from their own life and psychological understanding (attraction, attention, rationality). Communicating a message through entertainment was the practice of this model. Finally impact analysis confirmed the success of the model.展开更多
An aggregated channel model is achieved by fitting the Weibull distribution, which includes the effects of atmospheric attenuation, M distributed atmospheric turbulence and nonzero boresight pointing errors. With this...An aggregated channel model is achieved by fitting the Weibull distribution, which includes the effects of atmospheric attenuation, M distributed atmospheric turbulence and nonzero boresight pointing errors. With this approximate channel model, the bit error rate (BER) and the ergodic capacity of free-space optical (FSO) communication systems utilizing sub- cartier binary phase-shift keying (BPSK) modulation are analyzed, respectively. A closed-form expression of BER is de- rived by using the generalized Gauss-Lagueree quadrature rule, and the bounds of ergodic capacity are discussed. Monte Carlo simulation is provided to confirm the validity of the BER expressions and the bounds of ergodic capacity.展开更多
This paper considers the distributed Kalman filtering fusion with passive packet loss or initiative intermittent communications from local estimators to fusion center while the process noise does exist. When the local...This paper considers the distributed Kalman filtering fusion with passive packet loss or initiative intermittent communications from local estimators to fusion center while the process noise does exist. When the local estimates are not lost too much, the authors propose an optimal distributed fusion algorithm which is equivalent to the corresponding centralized Kalman filtering fusion with complete communications even if the process noise does exist. When this condition is not satisfied, based on the above global optimality result and sensor data compression, the authors propose a suboptimal distributed fusion algorithm. Numerical examples show that this suboptimal algorithm still works well and significantly better than the standard distributed Kalman filtering fusion subject to packet loss even if the process noise power is quite large.展开更多
A tunable thermo-optic intensity-modulated switch is investigated theoretically and numerically. It is based on the infiltration of temperature-sensitive mixture liquids into index-guiding photonic crystal fibers (P...A tunable thermo-optic intensity-modulated switch is investigated theoretically and numerically. It is based on the infiltration of temperature-sensitive mixture liquids into index-guiding photonic crystal fibers (PCFs). The switching function attributes to the thermo-optic effect of the effective refractive index of the cladding. The simulation illustrates that the switch presents a tunable transition point according to the concentration of the mixture liquids, and the on-off switching functionality can be realized within a narrow temperature range of 2 ℃. The switches have wide application for innovative all-in-fiber optical communication and logic devices.展开更多
基金supported by the National Natural Science Foundation of China (Grant No.601730301)the National BasicResearch Program of China (973 Program) (Grant No.2002CB312001)
文摘Model driven architecture(MDA) is an evolutionary step in software development.Model transformation forms a key part of MDA.The transformation from computation independent model(CIM) to platform independent model(PIM) is the first step of the transformation.This paper proposes an approach for this transformation with pattern.In this approach, we take advantage of"reuse"from various standpoints.Feature model is used to describe the requirement of the application.This can help us bring"reuse"into effect at requirement level.Moreover we use pattern to transform CIM to PIM.This can help us bring"reuse"into effect at development level.Meanwhile, pattern was divided into four hierarchies.Different hierarchies of pattern are used to help us utilize reuse at different phase of development.From another standpoint, feature model describes the problem of a domain while pattern describe the problem across domains.This can help us reuse the element in and across domains.Finally, the detailed process of the transformation is given.
文摘The developments in the field of Information and Communication Technology (ICT) in the country has rapidly happen after year 2009 .Government has developed many programs and initiations to develop ICT in the country after three decades of war was ended up. As a result disabled community can make many opportunities to use the ICT and at the same time create a gap, which is commonly referred to as Disability Digital Divide. The purpose of this study was to examine empirically the current status of adoption of ICT and in turn the digital divide resulting from which in the disability community in Sri Lanka and the factors affecting this behavior. A questionnaire and Interviewed based survey (n = 107) was carried out to collect the data from the disabled people who used ICT in the Colombo, Gampaha, and Kaluthara district. An empirical model was developed to show the relationship between the level of adoption of 10 basic, intermediate, and advanced ICT facilities and a number of factors to reflect the WWW, Smart phones, and Computer usage aspects of disabled community. Based on the Innovatiotr---Diffusion Theory, the status of Digital Divide of a disabled community was specified by means of an Index. The results show that this community did not become innovators or early-adopters of ICT by adopting WWW or computer related technologies but was mostly confined to the smart phone related facilities. The results from this study highlight that the income of a disabled person, awareness about the information and technology, interest of new technology usage, social and cultural background of a person, use of English language in day-to-day life give a significant impact on the adoption oflCT by the disabled community.
基金Supported by National Natural Science Foundation of China (No. 60872123)Joint Fund of National Natural Science Foundation of China and Guangdong Provincial Natural Science Foundation (No. U0835001)Fundamental Research Funds for Central Universities (No. 2011ZM0033)
文摘To reduce channel noise,fading,and inter-user interference effectively in the chaotic communication systems with multi-user,a blind channel equalization algorithm based on dual unscented Kalman filter algorithm is proposed.Assuming that the coefficients of a multi-input multi-output (MIMO) channel can be described by an autoregressive model,two separate state-space representations are used for the signals and coefficients.Then two unscented Kalman filters are used to estimate chaotic signals and channel coefficients simultaneously.The simulation results indicate that the algorithm can effectively track the coefficients of the multi-path fading channel in chaotic MIMO communication systems at a fast convergence speed.
文摘This paper explores the potentials of traditional forms of communication in rural development communication. Experimenting a local development communication model that can be used at the grass-root level communication at the community development programs in Sri Lanka is the research objective. This study is a participatory research. Live participatory observation, impact analysis using a questionnaire and direct interview tools were used to analyze the impact of the creative model. This research study was experimented at Rasnayakapura divisional secretariat, Sri Lanka from 2004 to 2005. Results suggest that the traditional forms of communication can be utilized as a useful instrument in the rural community programs more than the dominant use of mass media and conventional use of small group communication. Forms of traditional communication are rich in communication because of their closeness to rural life, credibility, Utilization of familiar signs & symbols, Participation of the same community, collective presentation, Utilization of past experiences, plot and the stories from their own life and psychological understanding (attraction, attention, rationality). Communicating a message through entertainment was the practice of this model. Finally impact analysis confirmed the success of the model.
文摘An aggregated channel model is achieved by fitting the Weibull distribution, which includes the effects of atmospheric attenuation, M distributed atmospheric turbulence and nonzero boresight pointing errors. With this approximate channel model, the bit error rate (BER) and the ergodic capacity of free-space optical (FSO) communication systems utilizing sub- cartier binary phase-shift keying (BPSK) modulation are analyzed, respectively. A closed-form expression of BER is de- rived by using the generalized Gauss-Lagueree quadrature rule, and the bounds of ergodic capacity are discussed. Monte Carlo simulation is provided to confirm the validity of the BER expressions and the bounds of ergodic capacity.
基金supported by the National Natural Science Foundation of China under Grant Nos.60934009, 60901037 and 61004138
文摘This paper considers the distributed Kalman filtering fusion with passive packet loss or initiative intermittent communications from local estimators to fusion center while the process noise does exist. When the local estimates are not lost too much, the authors propose an optimal distributed fusion algorithm which is equivalent to the corresponding centralized Kalman filtering fusion with complete communications even if the process noise does exist. When this condition is not satisfied, based on the above global optimality result and sensor data compression, the authors propose a suboptimal distributed fusion algorithm. Numerical examples show that this suboptimal algorithm still works well and significantly better than the standard distributed Kalman filtering fusion subject to packet loss even if the process noise power is quite large.
基金supported by the National Key Basic Research and Development Program of China(No.2010CB327801)
文摘A tunable thermo-optic intensity-modulated switch is investigated theoretically and numerically. It is based on the infiltration of temperature-sensitive mixture liquids into index-guiding photonic crystal fibers (PCFs). The switching function attributes to the thermo-optic effect of the effective refractive index of the cladding. The simulation illustrates that the switch presents a tunable transition point according to the concentration of the mixture liquids, and the on-off switching functionality can be realized within a narrow temperature range of 2 ℃. The switches have wide application for innovative all-in-fiber optical communication and logic devices.