In this paper transformation-free proxy cryptosystems (TFP systems) are studied. The TFP system is a modification of the proxy cryptosystem introduced by Mambo and Okamoto [6] in which a ciphertext transformation by t...
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ISBN:
(纸本)1581139551
In this paper transformation-free proxy cryptosystems (TFP systems) are studied. The TFP system is a modification of the proxy cryptosystem introduced by Mambo and Okamoto [6] in which a ciphertext transformation by the original decryptor is necessary. The TFP system allows proxy decryptor to do decryption without any ciphertext transformation, so that it can release the original decryptor more efficiently from a large amount of decrypting operations. An active identity-based and a directory-based TFP systems based on pairings are proposed. Furthermore, two applications of directory-based TFP system in electronic commerce are also investigated. Copyright 2004 ACM.
It is widely believed that memory traces can be stored through synaptic conductance modification of dense excitatory recurrent connections (ERCs) in the hippocampal CA3 region, namely associative memory. ERCs, on the ...
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It is widely believed that memory traces can be stored through synaptic conductance modification of dense excitatory recurrent connections (ERCs) in the hippocampal CA3 region, namely associative memory. ERCs, on the other hand, are crucial to maintain spontaneous rhythmic activity in CA3. Since it is experimentally suggested that synaptic conductances of ERCs are modified through spike-timing-dependent synaptic plasticity (STDP), rhythmic activity might modify ERCs with the presence of STDP because rhythmic activity involves discharges of pyramidal cells. Memory patterns that are stored using ERCs might thus be modified or even destroyed. Rhythmic activity itself might also be modified. In this study, we assumed that the synaptic modification in the hippocampal CA3 was subject to STDP, and examined the coexistence of memory traces and rhythmic activity. The activity of the network was dominated by radially propagating burst activities (radial activities) that initiated at local regions and acted as pacemakers. The frequency of the rhythmic activity converged into one specific frequency with time, depending on the shape of the STDP functions. This indicates that rhythmic activity could be regulated by STDP. By applying theta burst stimulation locally to the network, we found that the stimulation whose frequency was higher than that of the spontaneous rhythmic activity could organize a new radial activity at the stimulus site. Newly organized radial activities were preserved for seconds after the termination of the stimulation. These results imply that CA3 with STDP has an ability to self-regulate rhythmic activity and that memory traces can coexist with the rhythmic activity by means of radial activity.
Creativity has become an important asset in today'sfast changing environment. It is especially important indesign, which demands innovative solutions for *** believe that creativity can and should beencouraged in ...
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Creativity has become an important asset in today'sfast changing environment. It is especially important indesign, which demands innovative solutions for *** believe that creativity can and should beencouraged in work groups. In this paper, we proposea framework for supporting creativity in problemsolving. Through the use of problem, domain and usermodels and information retrieval and agent technology,we hope to support creative cooperative work.
作者：
Vivacqua, Ade Souza, JComputer Science Program
Graduate School Engineering Federal University of Rio de Janeiro Rio de Janeiro Brazil DCC
Institute of Mathematics Federal University of Rio de Janeiro Rio de Janeiro Brazil
Creativity has become an important asset in today's fast changing environment. It is especially important in design, which demands innovative solutions for every project. We believe that creativity can and should ...
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ISBN:
(纸本)0780379411
Creativity has become an important asset in today's fast changing environment. It is especially important in design, which demands innovative solutions for every project. We believe that creativity can and should be encouraged in work groups. In this paper, we propose a framework for supporting creativity in problem solving. Through the use of problem, domain and user models and information retrieval and agent technology, we hope to support creative cooperative work.
The internal structural changes around the crack-tip and the pertinent crack growth behavior in an amorphous metal are studied by a large scale molecular dynamics (MD) simulation. The Finnis-Sinclair potential for α-...
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The internal structural changes around the crack-tip and the pertinent crack growth behavior in an amorphous metal are studied by a large scale molecular dynamics (MD) simulation. The Finnis-Sinclair potential for α-iron is used as an interatomic potential. The model amorphous metal was created by melting-rapid quenching simulation. The crack opens in similar fashion and it has smooth surfaces during the amorphous state. As it deformed, nano-scaled crystalline phase grows around the crack-tip. The distribution of deformation zones and deformation mechanism are significantly altered. The grains are not deformed while they are relatively small. The emission of dislocations from the crack-tip is observed, after the crystal phase covered the crack-tip surfaces. The grain size appeared small in the vicinity of the crack-tip, and becomes gradually large as it separates form the crack-tip.
We have developed a method of catalyst preparation for carbon nanotube (CNT) growth that uses solid-state diffusion to precipitate Co particles in a Cu matrix and control the size and size distribution of catalyst par...
We have developed a method of catalyst preparation for carbon nanotube (CNT) growth that uses solid-state diffusion to precipitate Co particles in a Cu matrix and control the size and size distribution of catalyst particles. Copper is an excellent electrical and thermal conductor, and has a small or negligible solubility for Co. Cu–Co alloys of approximately 5 atm% Co were formed in bulk by splat quenching the liquid alloy and on Si substrates by e-beam evaporation of the alloy, sputtering of the alloy, and sputter deposition of thin films of pure Cu and Co. The Co easily precipitates from dilute solutions of Cu–Co with heat treatment. These alloys and films were used to generate uniform distributions of Co precipitates, and CNTs were successfully grown by plasma enhanced chemical vapor deposition (PE-CVD) and thermal CVD on the materials. These alloys can be patterned by photolithography and sputtering in order to grow CNTs in defined locations. Therefore, the technique is amenable to very large scale silicon integration for field emission applications. The results of this work and data from field emission studies are presented herein.
Experimental evidences suggest involvement of the hippocampus in temporal sequence learning. Taking physiological differences between the hippocampal CA3 and CA1 regions into account, we propose a mechanism of tempora...
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Experimental evidences suggest involvement of the hippocampus in temporal sequence learning. Taking physiological differences between the hippocampal CA3 and CA1 regions into account, we propose a mechanism of temporal sequence encoding. Input signals that mimicked the activity of the rat entorhinal cortex during animal's spatial behavior were applied to a model hippocampal CA3-CA1 network. Following an organization of spatiotemporal patterns of spontaneous activity in the CA3 region, Schaffer collateral synaptic conductances were modified eventually forming a distinct spatial pattern. As a result, a CA1 pyramidal cell assembly was tuned to a specific sequence of input signals.
To help programmers debug visual programs, we propose an animated execution method with supporting functions to be used with the animated execution. The animated execution animates state transitions as the program is ...
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To help programmers debug visual programs, we propose an animated execution method with supporting functions to be used with the animated execution. The animated execution animates state transitions as the program is executed. To make it easy for the programmer to interpret the animation, it is displayed in a manner similar to the visual program. The functions are used to narrow the possible locations of bugs and to test fixed components quickly. We have implemented animated execution and the functions on 3D-PP, our three-dimensional visual programming system.
Anonymity can protect a user's privacy, however it is hard to manage. It is hard to disclose anonymously. In addition, it is also hard to make people trust anonymous information. In this paper, we provide a key ex...
ISBN:
(纸本)1581139551
Anonymity can protect a user's privacy, however it is hard to manage. It is hard to disclose anonymously. In addition, it is also hard to make people trust anonymous information. In this paper, we provide a key exchange scheme for not only anonymous, but also traceable disclosure. To be more precise, one who provides information can anonymously guarantee communication with particular person. Furthermore, his anonymity can be retained even if he discloses communication contents. These features can not realized by using signature scheme, or any other existing methods. Our method enable those features, and it can be useful when a group is dealing with confidential information. Copyright 2004 ACM.
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