The study of the path coloring problem is motivated by the allocation of optical bandwidth to communication requests in all-optical networks that utilize Wavelength Division Multiplexing (WDM). WDM technology establis...
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Process automation concentrates on automating structured processes of an organization in order to achieve excellent service delivery by enabling the employees to pay more attention to semi structured or unstructured p...
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Process automation concentrates on automating structured processes of an organization in order to achieve excellent service delivery by enabling the employees to pay more attention to semi structured or unstructured processes. Achieving service delivery excellence adds value to an organization, increases the customer retention and provides opportunity for strategic growth. The growth of the Sri Lankan healthcare sector is a necessity at this stage due to an increasingly ageing community and a significant increase in non-communicable diseases. Despite many regulations that govern the sector, it continues to be inundated with many problems in relation to delivery of healthcare services. This paper examines service delivery issues in the healthcare institutions in the Western province and suggests mechanisms for automating standard processes in order to achieve strategic growth.
This paper treats the output feedback H 2 control with regional pole placement condition. In general, this problem is a BMI problem which is difficult to be solved theoretically. The purpose of this paper is to propo...
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This paper treats the output feedback H 2 control with regional pole placement condition. In general, this problem is a BMI problem which is difficult to be solved theoretically. The purpose of this paper is to propose an iterative method for obtaining a sub-optimal solution of the H 2 control problem with regional pole placement condition. The key idea of this paper is to employ a full-order observer-based controller. The proposed method produces a sequence of controllers which approaches to the unconstrained globally optimal H 2 controller while it satisfies the D-stability constraint. A numerical example shows the effectiveness of our method
This paper presents conditions for stability of interconnected nonlinear systems consisting of integral input-to-state stable subsystems. Both the necessity and the sufficiency are investigated using a Lyapunov formul...
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ISBN:
(纸本)1424401704;9781424401703
This paper presents conditions for stability of interconnected nonlinear systems consisting of integral input-to-state stable subsystems. Both the necessity and the sufficiency are investigated using a Lyapunov formulation. The ultimate result is a necessary and sufficient condition for integral input-to-state stability (iISS) of the interconnection, which is believed to be the first of its kind. This paper derives two sufficient conditions. One is the iISS-ISS small-gain condition which has been proposed earlier by one of the authors. Its sufficiency is strengthened to cover situations more general than the earlier result. The other condition is a universal representation of the nonlinear small-gain condition which has been a popular tool for dealing with input-to-state stable (ISS) subsystems. This paper proves that, for establishing iISS property of the interconnection, the universal representation can deal with iISS subsystems as much as the iISS-ISS small-gain condition if supply rate functions are smooth everywhere and analytic at zero. Furthermore, two necessary conditions this paper derives demonstrate that the nonlinear small-gain condition in the universal form is also necessary for the iISS property
In previous results, most existing Byzantine agreement (BA) protocols are designed for pure wired or pure wireless networks. In practice, most current networks are combined wired and wireless environments. In this pap...
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In previous results, most existing Byzantine agreement (BA) protocols are designed for pure wired or pure wireless networks. In practice, most current networks are combined wired and wireless environments. In this paper, we extend the BA problem over combined wired/wireless network, consisting of both powerful computing processor and low-power mobile processor. Furthermore, the communication overhead of the BA protocol is inherently large because the BA protocol requires numerous rounds to exchange messages. Secure group communications over a combined wired/wireless network is very important. The protocols proposed in this paper use the hierarchical model concept to reduce the communication overhead and provide secure group communications well suited for combined wired/wireless networks
While the traditional data shipping systems use physical information to organize data, a newer data caching technique maintains both associated answers (data items) of previous queries and their meaning (purpose). Thi...
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While the traditional data shipping systems use physical information to organize data, a newer data caching technique maintains both associated answers (data items) of previous queries and their meaning (purpose). This form of information description is called semantic description, and it makes it possible to reason about and derive knowledge from the given description. In a distributed heterogeneous environment, such as the mobile environment, the semantic data caching paradigm is an important technique for improving the performance of wireless data dissemination systems. Data caching performance depends heavily on the replacement policy being used for the cache management. However, future location ambiguity, limited client resources and frequent client disconnections make cache management a challenge. This paper proposes a future location-aware cache replacement policy to manage a semantic cache. The proposed replacement policy uses the validity of the data fetched from the server and the neighboring locations to decide which of the cache entries is less likely to be needed in the future, and therefore, a good candidate to be evicted when cache space is needed. The replacement policy's preference for cached items to be evicted is modelled as a general function that declines with distance between the cell the candidate for replacement's cached item is bounded to and the query's bound cell. For better efficiency the overall replacement granularity is dynamically achieved along three levels: ring, cell and data item. Simulation study of the proposed approach shows that it outperforms both the least recently used (LRU) and furthest away replacement (FAR) schemes, where only temporal locality is considered. Moreover, the proposed scheme is easier to implement than the industry standard policies
This paper investigates necessary conditions for stability of nonlinear systems made of feedback interconnection of two iISS subsystems. The integral input-to-state stability (iISS) is a dissipative property which inc...
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This paper investigates necessary conditions for stability of nonlinear systems made of feedback interconnection of two iISS subsystems. The integral input-to-state stability (iISS) is a dissipative property which includes the input-to-state stability (ISS) as a special case. It is proved that at least one subsystem needs to be ISS for global asymptotic stability of the feedback loop when two subsystems are not completely specified and only their supply rates are available. In contrast, the situation where ODEs describing subsystems are available does not exclude pairs of subsystems which are only iISS. This paper further investigates necessary conditions for global asymptotic stability, and proves that the nonlinear small-gain condition is necessary in the case of unspecified iISS subsystems described with supply rates. When one of the two subsystems is given as a specific ODE, the nonlinear small-gain condition is no longer necessary, while the linear small-gain condition is necessary in the case of linear systems. For nonlinear systems, the necessity recovers only if the supply rate fits the known subsystem tightly in the shape as well as the magnitude
This paper addresses the problem of face recognition in the presence of facial deformations caused by expressions. An isometric mapping between surfaces is assumed, which allows preservation of geodesic distance betwe...
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This paper addresses the problem of face recognition in the presence of facial deformations caused by expressions. An isometric mapping between surfaces is assumed, which allows preservation of geodesic distance between facial points. Subject to this assumption, we propose a novel technique which integrates 2D and 3D information to establish a new deformation invariant representation of the face. The 3D surface is used to define a polar geodesic coordinate space which is independent of the intrinsic geometry of the face. The corresponding color image is embedded in this space and serves as the recognition data. A preceding stage of hierarchical diffeomorphic grid-based image warping before the recognition process combined with a lip segmentation technique are also employed to increase the overall performance of the algorithm.
Peer-to-peer (P2P) systems are flexible, robust, and self-organizing resource sharing infrastructures which are typically designed in a fully decentralized manner. However, a key problem of such systems are peers over...
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Peer-to-peer (P2P) systems are flexible, robust, and self-organizing resource sharing infrastructures which are typically designed in a fully decentralized manner. However, a key problem of such systems are peers overusing a resource. This paper presents a fully decentralized scheme to achieve fair use in P2P systems, which does not require a priori information about a peer. The approach developed is based on a scarce resource trading scheme (SRTCPU), which utilizes CPU time as a form of payment. SRTCPU provides an incentive to offer CPU time in return of consuming a scarce resource. A distributed DNS has been implemented as an example application that uses SRTCPU.
In this paper the impact of user's hand holding a multiple-input-multiple-output (MIMO) terminal on the system performance is investigated. A 4times4 MIMO system is considered with a personal digital assistant (PD...
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In this paper the impact of user's hand holding a multiple-input-multiple-output (MIMO) terminal on the system performance is investigated. A 4times4 MIMO system is considered with a personal digital assistant (PDA) terminal equipped with a compact array of 4 patch elements. The radiation patterns of the antenna elements are simulated in the presence of the other elements and in the presence of a user's hand. The obtained patterns are used to evaluate the covariance matrix of the receive antenna which is incorporated in a correlation-based MIMO channel model. MIMO channel capacity is calculated to demonstrate the capacity degradation caused by the user's hand.
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