1145137
Agent-assisted collaborative concept map
Merlin is a collaborative concept map that enables students to discuss their ideas. The agent in Merlin aims to monitor the students' content of discussion in order to provide context-sensitive help. Keywords in the students' discussion in a chat box are compared to the knowledge domain and appropriate support material is adapted to the student model. Instructional media is generated using design patterns.
13477825
A HYBRID GENETIC ALGORITHM FOR OPTICAL ORTHOGONAL CODE CONSTRUCTION
Optical orthogonal codes (OOCs) are used to uniquely identify stations within an optical code division multiple access (CDMA) local area network (LAN). Previous efforts in constructing OOCs have focused on the use of deterministic techniques, which relied heavily on the use of Galois fields. These techniques severely restrict the availability of the resulting OOCs. This paper considers an evolutionary approach by proposing a hybrid genetic algorithm (hGA) as a flexible technique to construct OOCs. This hGA uses the simulated annealing (SA) method to generate its initial population. The effectiveness of the proposed hGA for OOC construction is demonstrated in two stages. First, we show that the SA-generated initial population is better than the randomly generated initial population in terms of fitness. Due to this, the hGA is able to converge on average two times faster compared to the use of the GA-only scheme. Second, we compare the code availability and performance of the hGA-constructed OOCs (hGA OOCs) against that of three other OOCs. Through these comparisons, we show why the proposed hGA is a more flexible technique for constructing OOCs with higher availability and better performance.
30879352
An Ant Colony Optimization Approach to the Degree-Constrained Minimum Spanning Tree Problem
This paper presents the application of an Ant Colony Optimization (ACO) algorithm approach for communications networks design problem. We explore the use of ACO’s for solving a network optimization problem, the degree-constrained minimum spanning tree problem (d-MST), which is a NP-Hard problem. The effectiveness of the proposed algorithm is demonstrated through two kinds of data set: structured hard (SHRD) complete graphs and misleading (M-graph) complete graphs. Empirical results show that ACO performs competitively with other approaches based on evolutionary algorithm (EA) on certain instance set problem.
8958554
Nested mappings: schema mapping reloaded
Many problems in information integration rely on specifications, called schema mappings, that model the relationships between schemas. Schema mappings for both relational and nested data are well-known. In this work, we present a new formalism for schema mapping that extends these existing formalisms in two significant ways. First, our nested mappings allow for nesting and correlation of mappings. This results in a natural programming paradigm that often yields more accurate specifications. In particular, we show that nested mappings can naturally preserve correlations among data that existing mapping formalisms cannot. We also show that using nested mappings for purposes of exchanging data from a source to a target will result in less redundancy in the target data. The second extension to the mapping formalism is the ability to express, in a declarative way, grouping and data merging semantics. This semantics can be easily changed and customized to the integration task at hand. We present a new algorithm for the automatic generation of nested mappings from schema matchings (that is, simple element-to-element correspondences between schemas). We have implemented this algorithm, along with algorithms for the generation of transformation queries (e.g., XQuery) based on the nested mapping specification. We show that the generation algorithms scale well to large, highly nested schemas. We also show that using nested mappings in data exchange can drastically reduce the execution cost of producing a target instance, particularly over large data sources, and can also dramatically improve the quality of the generated data.
8865105
Edge and node searching problems on trees
In this paper, we show that there is a natural correspondence between a tree's edge-search strategy and its node-search strategy. By doing so, we simplify the previous linear time algorithm for determining the edge-search number of a tree, and improve the running time of a previous algorithm for constructing an edge-search strategy (or plan) for a tree containing n vertices from O(n log n) to O(n) time.
826292
Hamiltonian-laceability of star graphs
Suppose G is a bipartite graph with two partite sets of equal size. G is said to be strongly hamiltonian-laceable if there is a hamiltonian path between every two vertices that belong to different partite sets, and there is a path of (maximal) length N-2 between every two vertices that belong to the same partite set, where N is the order of G. The star graph is known to be bipartite. In this paper, we show that the n-dimensional star graph, where n/spl ges/4 is strongly hamiltonian-laceable.
34381900
Using spatial warning signals to capture a driver's visual attention
This study was designed to assess the potential benefits of using spatial auditory or vibrotactile warning signals in the domain of driving performance, using a simulated driving task. Across six experiments, participants had to monitor a rapidly presented stream of distractor letters for occasional target digits (simulating an attention-demanding visual task, such as driving). Whenever participants heard an auditory cue (E1-E4) or felt a vibration (E5-E6), they had to check the front and the rearview mirror for the rapid approach of a car from in front or behind and respond accordingly (either by accelerating or braking). The efficacy of various auditory and vibrotactile warning signals in directing a participant's visual attention to the correct environmental position was compared (see Table 1). The results demonstrate the potential utility of semantically-meaningful or spatial auditory, and/or vibrotactile warning signals in interface design for directing a driver's, or other interface-operator's, visual attention to time-critical events or information.
40677597
CHANT (CHinese ANcient Texts): a comprehensive database of all ancient Chinese texts up to 600 AD
The CHinese ANcient Texts (CHANT) database is a long-term project which began in 1988 to build up a comprehensive database of all ancient Chinese texts up to the sixth century AD. The project is near completion and the entire database, which includes both traditional and excavated materials, will be released on the CHANT Web site (www.chant.org) in mid-2002. With more than a decade of experience in establishing an electronic Chinese literary database, we have gained much insight useful to the development of similar databases in the future. We made use of the best available versions of all texts, noting variant readings in footnotes. The biggest problem we encountered is the inclusion of rare and obsolete Chinese characters. For excavated materials, we also have to incorporate a considerable number of inscriptions in the original oracle bones and bronze forms. Since we started building the database, information technology has advanced so rapidly that we had to upgrade the technical devices already in use in the database. Unification of different sub-databases is also a daunting task. To maintain our competitive edge over free online Chinese databases, we need to continue developing new databases employing the existing ones.