People with disabilities face major problems in their daily lives in communicating with other people. Sign languages (SLs) are the basic means of communication between hearing-impaired people and also form their natur...
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People with disabilities face major problems in their daily lives in communicating with other people. Sign languages (SLs) are the basic means of communication between hearing-impaired people and also form their natural way of speaking. Systems that could act as interpreters between deaf people and people that do not speak SL, would facilitate the formers' life. Such systems would have to cope with bidirectional translation of sign language sentences and spoken language sentences. Various research works have been presented recently, concerning mostly SL recognition, rather than spoken language interpretation. The system we present, aims at Greek sign language (GSL) recognition, too, through the use of hidden Markov models (HMMs). The recognition rates we achieved for GSL sentences, formed out of a 33-sign vocabulary, exceed 86% and are quite promising.
Hierarchical Automata has been widely used in modeling dynamic aspects of reactive software, such as in UML Statecharts. At the same time, model checking is an automatic technique to ensure the correctness of software...
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This paper presents a scalable architecture for supporting large-scale interactive Internet games. In order to support a large number of participants and to divide the workload, the virtual world is divided into parti...
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In this paper, we present three parallel approximate string matching methods on a parallel architecture with heterogeneous workstations to gain supercomputer power at low cost. The first method is the static master-wo...
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Running a large-scale distributed simulation may need a large amount of computing resources at geographically different locations. These resources may be from different organizations. The simulation may run for a long...
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Running a large-scale distributed simulation may need a large amount of computing resources at geographically different locations. These resources may be from different organizations. The simulation may run for a long period of time and the availability and amount of computing resources available may change during the course of simulation execution. Therefore, coordinating and managing resources for distributed simulation to complete the simulation efficiently and effectively is a critical issue. This paper describes a load management system for HLA-based distributed simulation. The system is constructed on top of a grid computing environment supported by Globus. The overall structure of the system is presented in the paper and how the system saves and restores a federate is also discussed in detail.
This paper presents a scalable architecture for supporting large-scale interactive Internet games. In order to support a large number of participants and to divide the workload, the virtual world is divided into parti...
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ISBN:
(纸本)9780769516080
This paper presents a scalable architecture for supporting large-scale interactive Internet games. In order to support a large number of participants and to divide the workload, the virtual world is divided into partitions. Each partition is then assigned to a server. A client (i.e., a player or a participant) will join a server according to the position of the avatar it controls. Compared to a centralized architecture, this distributed client-server architecture is more scalable. In addition, compared to a fully distributed, peer-to-peer architecture, it also provides a means for detecting cheating in distributed games. Since interactions and accounting information must be forwarded directly to one of the servers for qualification and verification, cheating amongst distributed players of the game will be minimized. To support secured communication for interactions and accounting information as well as to speedup periodic update messages (e.g., position updates), a hybrid communication scheme using both TCP and IP multicast is used between clients and the associated server. The communication among servers is enabled by the Run-Time Infrastructure (RTI) services. The High Level Architecture (HLA) Data Distribution Management (DDM) is employed to limit the amount of communication between the servers. In addition, the Ownership Management (OM) is also employed to implement the need for transferring the avatars between servers. In this paper, the design detail of the architecture will be presented. An experimental interactive Internet game realized using the architecture will be also described in the paper.
Automatic generation of test data for a given path in a program is an elementary problem in software testing, the difficulty of which lies in how to solve the nonlinear constraint. Gupta et al. (1998) proposed a metho...
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ISBN:
(纸本)0769514081
Automatic generation of test data for a given path in a program is an elementary problem in software testing, the difficulty of which lies in how to solve the nonlinear constraint. Gupta et al. (1998) proposed a method, which is referred to as the iterative relaxation method, to address the above problem by linearizing the predicate functions. This paper improves the iterative relaxation method by omitting the constructions of predicate slice and input dependency set, and proves the equivalence of systems of constraints generated by both methods. Since it is not necessary for our method to analyze the dependencies between statements on the path in the course of deriving a system of constraints, our method still works when some statements are only object or executable codes rather than source codes on the path. Therefore, our method can also be used for generating test data for black-box testing and regression testing. We have developed a prototype of a path-wise test data generator whose fundamental algorithm is presented in this paper. The initial experiments with this prototype have shown that our method is practical.
Unified Modeling Language (UML) has been widely used in software development. Verifying if an UML model meets the required properties has become a key issue. Model checking is an important technology of automatic form...
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ISBN:
(纸本)0769514081
Unified Modeling Language (UML) has been widely used in software development. Verifying if an UML model meets the required properties has become a key issue. Model checking is an important technology of automatic formal verification to ensure the correctness of design specifications. An approach of model checking UML statecharts is given in this paper At first, the brief syntax and semantics of UML statecharts are described. Then, the way of how UML statecharts is structurally expressed by extended hierarchical automaton and the labeled transition system are defined. The correctness of operational semantics of UML statecharts can be ensured through finding the maximal non-conflict transition set. For the system with infinite runs, the operational semantics can be mapped to a Buchi automaton and linear temporal logic properties of the system can be verified based on the automata theory of model checking. The paper also presents the method of verifying complex system consist of multiple objects modeled by statecharts and collaboration diagram.
In this paper we propose a high-performance flexible text searching implementation on a heterogeneous cluster of workstations using MPI message passing library. We test this parallel implementation and present experim...
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