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We introduce a partial proximal point algorithm for solving nuclear norm regularized matrix least squares problems with equality and inequality constraints. The inner subproblems, reformulated as a system of semismooth equations, ...
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We introduce a partial proximal point algorithm for solving nuclear norm regularized matrix least squares problems with equality and inequality constraints. The inner subproblems, reformulated as a system of semismooth equations, are solved by an inexact smoothing Newton method, which is proved to be quadratically convergent under a constraint non-degeneracy condition, together with the strong semismoothness property of the singular value thresholding operator. Numerical experiments on a variety of problems including those arising from low-rank approximations of transition matrices show that our algorithm is efficient and robust.
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Information services on the Internet are being used as an important tool to facilitate discovery of the information that is of user interests. Many approaches have been proposed to discover the information on the Internet, while t...
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Information services on the Internet are being used as an important tool to facilitate discovery of the information that is of user interests. Many approaches have been proposed to discover the information on the Internet, while the search engines are the most common ones. However, most of the current approaches of information discovery can discover the keyword-matching information only but cannot recommend the most recent and relative information to users automatically. Sometimes users can give only a fuzzy keyword instead of an accurate one. Thus, some desired information would be ignored by the search engines. Moreover, the current search engines cannot discover the latent but logically relevant information or services for users. This paper measures the semantic-similarity and link-similarity between keywords. Based on that, it introduces the concept of similarity of web pages, and presents a method for information recommendation. The experimental evaluation and comparisons with the existing studies are finally performed.
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In previous work of multiple sensing agent systems (MSASs), they mainly adjust the sensing ranges of agents by centralized heuristics; and the whole adjustment process is controlled in centralized manner. However, such method may ...
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In previous work of multiple sensing agent systems (MSASs), they mainly adjust the sensing ranges of agents by centralized heuristics; and the whole adjustment process is controlled in centralized manner. However, such method may not fit for the characteristics of MSASs where the agents are distributed and decide their activities autonomously. To solve such problem, this paper introduces the social force model for adjusting the sensing ranges of multiple sensing agents, which can make the agents adjust their sensing ranges autonomously according to their social forces to other agents and the sensing objects. Based on the social force model, the coverage and optimization models are presented for both point-type and area-type objects. The presented model can produce appropriate social forces among the sensing agents and objects in MSASs; thereby the system observability and lifetime can be improved.
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As the momentum behind Chip Multi-Processors (CMPs) continues to grow, Last Level Cache (LLC) management becomes a crucial issue to CMPs because off-chip accesses often involve a big latency. Private cache design is distinguished ...
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As the momentum behind Chip Multi-Processors (CMPs) continues to grow, Last Level Cache (LLC) management becomes a crucial issue to CMPs because off-chip accesses often involve a big latency. Private cache design is distinguished by smaller local access latency, good performance isolation and easy scalability, thus is becoming an attractive design alternative for LLC of CMPs. This paper proposes Balanced Private Non-Uniform Cache Architecture (BP-NUCA), a new LLC architecture that starts from private cache design for smaller local access latency and good performance isolation, then introduces a low cost mechanism to dynamically migrate private blocks among peer private caches of LLC to improve the overall space utilization. BP-NUCA achieves this by measuring the cache access pressure level that each cache set experiences at runtime and then using the information to guide block migration among different private caches of LLC. A heavily accessed set, namely a set with high access pressure level, is allowed to migrate its evicted blocks to peer private caches, replacing blocks of sets which are with the same index and have low access pressure level. By migrating blocks from heavily accessed cache sets to less accessed cache sets, BP-NUCA effectively balances space utilization of LLC among different cores. Experimental results using a full system CMP simulator show that BP-NUCA improves the overall throughput by as much as 20.3 %, 12.4 %, 14.5 % and 18.0 % (on average 7.7 %, 4.4 %, 4.0 % and 6.1 %) over private cache, shared cache, shared cache management scheme UCP and private cache organization CC respectively on a 4-core CMP for SPEC CPU2006 benchmarks.
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Service discovery constructs a bridge between the service providers and the service consumers, and is a key point in pervasive computing environments. In group-based service discovery protocols, selective forwarding service reques...
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Service discovery constructs a bridge between the service providers and the service consumers, and is a key point in pervasive computing environments. In group-based service discovery protocols, selective forwarding service requests only based on the service group maybe lead to unnecessary forwarding, which produces large packet redundancy. This paper proposes an efficient service discovery protocol: SIGIFSDP (Service Id Guided Intelligent Forwarding Service Discovery Protocol). In SIGIFSDP, based on GSD, SIGIF (Service Id Guided Intelligent Forwarding) is introduced to select the exact forwarding nodes based on the service id. Theoretical analysis and simulation results using GloMosim verify that SIGIFSDP can save the response time, reduce the service request packets, and improve the efficiency of service discovery.
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Visual odometry estimates a robot's ego-motion with cameras installed on itself. With the advantages brought by camera being a sensor, visual odometry has been widely adopted in robotics and navigation fields. Drift (or error accu...
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Visual odometry estimates a robot's ego-motion with cameras installed on itself. With the advantages brought by camera being a sensor, visual odometry has been widely adopted in robotics and navigation fields. Drift (or error accumulation) from relative motion concatenation is an intrinsic problem of visual odometry in long-range navigation, as visual odometry is a sensor based on relative measurements. General error analysis using ``mean'' and ``covariance'' of positional error in each axis is not fully capable to describe the behavior of drift. Moreover, no theoretic drift analysis is available for performance evaluation and algorithms comparison. Drift distribution is established in the paper, as a function of the covariance matrix from positional error propagation model. To validate the drift model, experiment with a specific setting is conducted.
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The genus Avena L. (Poaceae: Aveneae)) with approximately 30 species forming a distinct polyploid series ranging from diploid through tetraploid to hexaploid with a basic chromosome number of seven (Rajhathy and Thomas 1974; Baum ...
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The genus Avena L. (Poaceae: Aveneae)) with approximately 30 species forming a distinct polyploid series ranging from diploid through tetraploid to hexaploid with a basic chromosome number of seven (Rajhathy and Thomas 1974; Baum 1977; Thomas 1992; Leggett and Thomas 1995; Katsiotis et al. 2000). All Avena species, with the exception of A. macrostachya, are self-pollinated annuals, whereas A. macrostachya is a cross-pollinating, quadrivalent-forming, autotetraploid perennial (Malzew 1930; Baum 1968, 1974; Baum and Rajhathy 1976; Rodionova et al. 1994; Katsiotis et al. 1997). Genome differentiation was initially based on cytological studies of interspecific hybrids and descriptions of species karyotypes (Rajhathy and Thomas 1974; Thomas 1992; Rodionova et al. 1994; Leggett and Markhand 1995). Diploid species have either the A or C genome, tetraploids have either the AB or AC genome and the hexaploids have the ACD genome designation.Although there is considerable morphological, biochemical, geographical, cytotaxonomic and molecular evidence available, much is still unknown about the evolution of the genus. Despite numerous observations made by morphological and cytological studies (Rajhathy et al. 1966; Rajhathy and Thomas 1974; Baum 1977; Linares et al. 1992; Thomas 1992; Leggett and Thomas 1995), the application of different molecular techniques has provided further information on Avena genome relationships, such as in situ hybridization (Chen and Armstrong 1994; Jellen et al. 1994a; Katsiotis et al. 1996; Linares et al. 1998; Irigoyen et al. 2001), the use of molecular markers (Sanchez de la Hoz and Fominaya 1989; Alicchio et al. 1995; O'Donoughue et al. 1995; Ronald et al. 1997; Kianian et al. 1999; Nocelli et al. 1999; Li et al. 2000a, 2000b, 2009; Loskutov and Perchuk 2000; Drossou et al. 2004; Fu and Williams 2008) and the comparison of nucleotide sequences (Cheng et al. 2003; Rodionov et al. 2005; Irigoyen et al. 2006; Nikoloudakis and Katsiotis 2008; Nikoloudakis et al. 2008; Peng et al. 2008). At the diploid level, hybridization among the A and C genome species rarely produces interspecific hybrids, indicating major genomic differences among these species (Fominaya et al. 1988a; Linares et al. 1992; Jellen et al. 1993; Drossou et al. 2004). Although some studies have dealt with phylogenetic relationships among species of different ploidy (Fominaya et al. 1988b; Fabijanski et al. 1990; Gupta et al. 1992; Alicchio et al. 1995; Drossou et al. 2004; Irigoyen et al. 2006; Nikoloudakis et al. 2008), the putative diploid donors of Avena polyploids remain uncertain, especially for the B genome origin in the AB tetraploids and the D genome donor of the ACD hexaploids. There is now good evidence of the close relationships among the A and D genomes (Chen and Armstrong 1994; Jellen et al. 1994a, Leggett and Markhand 1995; Linares et al. 1996, 1998; Loskutov 2008), and the A and B genomes (Leggett and Markhand 1995; Katsiotis et al. 1997). Molecular probes differentiated the D genome (Linares et al. 1998; Peng et al. 2008) and the B genome (Irigoyen et al. 2001; Peng et al. 2008) from the A genome. Using various molecular techniques, A. strigosa (Chen and Armstrong 1994; Jellen et al. 1994a; Leggett and Markhand 1995; Linares et al. 1996), A. canariensis (Li et al. 2000b; Loskutov 2008), A. weistii (Li et al. 2000b; Fu and Williams 2008) and A. longiglumis (Rodionov et al. 2005; Nikoloudakis et al. 2008) had been suggested as the A genome donor of the tetraploid and hexaploid. All of the diploid C genome species have been proposed as the putative donors of the C genome in the hexaploids (Rajhathy and Thomas 1974; Chen and Armstrong 1994; Jellen et al. 1994b; Cheng et al. 2003; Nikoloudakis and Katsiotis 2008).Molecular phylogenetic studies have successfully revealed the origins and evolutionary history of polyploids in plants, clarified the nature of different polyploids and identified their parental lineages and the hybridization
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This paper presents recent advances by an international team which is developing the thermochemical copper-chlorine (Cu-Cl) cycle for hydrogen production. Development of the Cu-Cl cycle has been pursued by several countries within...
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This paper presents recent advances by an international team which is developing the thermochemical copper-chlorine (Cu-Cl) cycle for hydrogen production. Development of the Cu-Cl cycle has been pursued by several countries within the framework of the Generation IV International Forum (GIF) for hydrogen production with the next generation of nuclear reactors. Due to its lower temperature requirements in comparison with other thermochemical cycles, the Cu-Cl cycle is particularly well matched with Canada's Generation IV reactor, SCWR (Super-Critical Water Reactor), as well as other heat sources such as solar energy or industrial waste heat. In this paper, recent developments of the Cu -Cl cycle are presented, specifically involving unit operation experiments, corrosion resistant materials and system integration.
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With future network equipment the security service becomes a critical and serious problem. Especially in the network, users do not want to expose their message to others or to be forged by others. They make extensive use of crypto...
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With future network equipment the security service becomes a critical and serious problem. Especially in the network, users do not want to expose their message to others or to be forged by others. They make extensive use of cryptography and integrity algorithms to achieve security. The sender can achieve the high quality of security service (high security level), only if the receivers and routers along path to receivers can support or satisfy the quality of security service requested by the sender. Therefore, this paper proposes a protocol to provide the needed mechanism for quality of security service, to dynamically negotiate the quality of security service among the senders and receivers of multicasts in the network. It provides different quality of security service resolutions to different receiver nodes with different security service needs and includes six different negotiation styles.
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The multiagent workflow systems can be formalized from an organizational structure viewpoint, which includes three parts: the interaction structure among agents, the temporal flow of activities, and the critical resource sharing r...
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The multiagent workflow systems can be formalized from an organizational structure viewpoint, which includes three parts: the interaction structure among agents, the temporal flow of activities, and the critical resource sharing relations among activities. While agents execute activities, they should decide their strategies to satisfy the constraints brought by the organizational structure of multiagent workflow system. To avoid collisions in the multiagent workflow system, this paper presents a method to determine social laws in the system to restrict the strategies of agents and activities; the determined social laws can satisfy the characteristics of organization structures so as to minimize the conflicts among agents and activities. Moreover, we also deal with the social law adjustment mechanism for the alternations of interaction relations, temporal flows, and critical resource sharing relations. It is proved that our model can produce useful social laws for organizational structure of multiagent workflow systems, i.e., the conflicts brought by the constraints of organization structure can be minimized.
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