The aim of this work is to study the interaction of spoken words and images that are used within programs targeted to popularize knowledge among teenagers. We will look into the program Bit@bit developed by Television...The aim of this work is to study the interaction of spoken words and images that are used within programs targeted to popularize knowledge among teenagers. We will look into the program Bit@bit developed by Television de Catalunya, which is intended to disseminate computer concepts, tools and procedures. In this kind of program, one can find spoken language (on/off screen voices, interviews, etc.), other oral material (sounds, music, songs), written language (descriptions, title sequences, inserts and Uniform Resource Locator, or electronic addresses), and other visual material (film cut images, advertising, other TV programs, cartoons, films, both location or studio images, depicting reality, or computer screens, or logotypes). The profusion of multimodal elements used in this program helps to keep the young audience's attention. The use of references to their world or knowledge, as a target group, is based on interplay among different semiotic strategies. At the same time, the entire program's multi-segmentation into short video clips, combined with a fast paced sound track helps its audience to understand the specialized explanations presented. Of all the multimodal wealth that the program presents, we will concentrate only on the relationship between the words and the images (leaving other secondary semiotics to one side), the main strategy for achieving the objective of transmitting knowledge and winning adolescent audiences.展开更多
From the basic properties of skein systems, we build a generalized tangle algebra (GTA). The elements of GTA are four basic tangles. There are three operations, which are connection, splicing and scalar multiplication...From the basic properties of skein systems, we build a generalized tangle algebra (GTA). The elements of GTA are four basic tangles. There are three operations, which are connection, splicing and scalar multiplication. From GTA we derive two generalized recursion formulae (GRF) and prove the existence of a generalized skein relation which satisfies GRF. The obtained generalized skein relation epitomizes all generalizations from the Jones polynomial and thus forms a unified model. Two important topological parameters, twisting measure and loop values, appear explicitly in the expressions of the unified model, and this fact greatly simplifies the operations.展开更多
This paper proposes relaxed sufficient conditions for the consensus of multi-agent systems by the averaging protocols with time-varying system topology. Bidirectional information exchange between neighboring agents is...This paper proposes relaxed sufficient conditions for the consensus of multi-agent systems by the averaging protocols with time-varying system topology. Bidirectional information exchange between neighboring agents is considered and both the discrete-time and continuous-time consensus protocols are studied. It is shown that the consensus is reached if there exists an unbounded time sequence such that two agents who own the maximum and minimum states at each time instant in the sequence will be jointly connected at some future time. Further, this result is applied to the original nonlinear Vicsek model, and a sufficient condition for the heading consensus of the group with restricted initial conditions is obtained.展开更多
In this paper, the output consensus problem of general heterogeneous nonlinear multi-agent systems subject to different disturbances is considered. A kind of Takagi-Sukeno fuzzy modeling method is used to describe the...In this paper, the output consensus problem of general heterogeneous nonlinear multi-agent systems subject to different disturbances is considered. A kind of Takagi-Sukeno fuzzy modeling method is used to describe the nonlinear agents' dynamics. Based on the model, a distributed fuzzy observer and controller are designed based on parallel distributed compensation scheme and internal reference models such that the heterogeneous nonlinear multi-agent systems can achieve output consensus. Then a necessary and sufficient condition is presented for the output consensus problem. And it is shown that the consensus trajectory of the global fuzzy model is determined by the network topology and the initial states of the internal reference models. Finally, some simulations are given to illustrate and verify the effectiveness of the proposed scheme.展开更多
文摘The aim of this work is to study the interaction of spoken words and images that are used within programs targeted to popularize knowledge among teenagers. We will look into the program Bit@bit developed by Television de Catalunya, which is intended to disseminate computer concepts, tools and procedures. In this kind of program, one can find spoken language (on/off screen voices, interviews, etc.), other oral material (sounds, music, songs), written language (descriptions, title sequences, inserts and Uniform Resource Locator, or electronic addresses), and other visual material (film cut images, advertising, other TV programs, cartoons, films, both location or studio images, depicting reality, or computer screens, or logotypes). The profusion of multimodal elements used in this program helps to keep the young audience's attention. The use of references to their world or knowledge, as a target group, is based on interplay among different semiotic strategies. At the same time, the entire program's multi-segmentation into short video clips, combined with a fast paced sound track helps its audience to understand the specialized explanations presented. Of all the multimodal wealth that the program presents, we will concentrate only on the relationship between the words and the images (leaving other secondary semiotics to one side), the main strategy for achieving the objective of transmitting knowledge and winning adolescent audiences.
文摘From the basic properties of skein systems, we build a generalized tangle algebra (GTA). The elements of GTA are four basic tangles. There are three operations, which are connection, splicing and scalar multiplication. From GTA we derive two generalized recursion formulae (GRF) and prove the existence of a generalized skein relation which satisfies GRF. The obtained generalized skein relation epitomizes all generalizations from the Jones polynomial and thus forms a unified model. Two important topological parameters, twisting measure and loop values, appear explicitly in the expressions of the unified model, and this fact greatly simplifies the operations.
基金the National Science Foundation under Grant Nos.ECS-0093176 and DMS-0504462the National Natural Science Foundation of China under Grant 60628302
文摘This paper proposes relaxed sufficient conditions for the consensus of multi-agent systems by the averaging protocols with time-varying system topology. Bidirectional information exchange between neighboring agents is considered and both the discrete-time and continuous-time consensus protocols are studied. It is shown that the consensus is reached if there exists an unbounded time sequence such that two agents who own the maximum and minimum states at each time instant in the sequence will be jointly connected at some future time. Further, this result is applied to the original nonlinear Vicsek model, and a sufficient condition for the heading consensus of the group with restricted initial conditions is obtained.
基金supported in part by the National Natural Science Foundation of China under Grant Nos.61375105 and 61403334Chinese Postdoctoral Science Fundation under Grant No.2015M581318
文摘In this paper, the output consensus problem of general heterogeneous nonlinear multi-agent systems subject to different disturbances is considered. A kind of Takagi-Sukeno fuzzy modeling method is used to describe the nonlinear agents' dynamics. Based on the model, a distributed fuzzy observer and controller are designed based on parallel distributed compensation scheme and internal reference models such that the heterogeneous nonlinear multi-agent systems can achieve output consensus. Then a necessary and sufficient condition is presented for the output consensus problem. And it is shown that the consensus trajectory of the global fuzzy model is determined by the network topology and the initial states of the internal reference models. Finally, some simulations are given to illustrate and verify the effectiveness of the proposed scheme.