A reference model for team-enabled workflow management systems

Today's workflow systems assume that each work item is executed by a single worker. From the viewpoint of the system, a worker with the proper qualifications selects a work item, executes the associated work, and reports the result. There is usually no support for teams, i.e., groups of people collaborating by jointly executing work items (e.g., the program committee of a conference, the management team of a company, a working group, and the board of directors). In this paper, we propose the addition of a team concept to today's workflow management systems. Clearly, this involves a marriage of workflow and groupware technology. To shed light on the introduction of teams, we extend the traditional organizational meta model with teams and propose a team-enabled workflow reference model. For this reference model and to express constraints with respect to the distribution of work to teams, we use object constraint language (OCL).     

A hyperstability criterion for model reference adaptive control systems

This paper considers the stability problem of the model reference adaptive control systems by means of the properties of hyperstable systems. A theorem concerning the hyperstability of model reference adaptive control systems is presented. This theorem directly gives a structure of the adaption mechanism. The results presented here include all the results obtained by Butchart, Shackcloth, Parks, Winsor, Roy, and Dressler. The hyperstability approach presented in this paper also allows for other solutions to the adaption mechanism and represents a general method for studying this type of adaptive systems. The results are directly applicable to the design of model reference adaptive control systems and they were verified for some particular cases by analogical simulation.     

A condition for decentralization in model reference adaptive systems

It is shown that when the interconnection pattern within a system conforms to certain prescribed symmetry requirements, decentralized adaptive algorithms for identification and control can be developed within a decomposition-decentralization framework. This is useful in the presence of constraints on the available information structure of the system.     

A model reference adaptive control scheme for pure-feedbacknonlinear systems

A model reference adaptive control (MRAC) scheme is presented for nonlinear systems in a pure-feedback canonical form with unknown parameters. The present of parameter uncertainty in the system causes imperfect linearization, i.e. it introduces nonlinear additive terms in the transformed coordinates. Under some mild technical assumptions, global convergence of the output error is established for all initial estimates of the parameter vector lying in an open neighborhood of the true parameters in the parameter space     

A holistic roadmap for survivable infrastructure systems

The role of a holistic risk assessment and management process in information technology (IT), information assurance (IA), and survivable dependable systems is the subject of this paper. To address the multiple dimensions and perspectives of the risks of terrorism to cyber and interconnected physical infrastructures, hierarchical holographic modeling is introduced and is related to the risk assessment and management process. The definition of information assurance as the trust that information presented by the system is accurate and is properly represented necessitates that trust, knowledge management, organizational behavior, and other nontechnology-based considerations be addressed in the protection of IA against terrorist attacks.     

A bilevel mixed-integer program for critical infrastructure protection planning

Vulnerability to sudden service disruptions due to deliberate sabotage and terrorist attacks is one of the major threats of today. In this paper, we present a bilevel formulation of the r-interdiction median problem with fortification (RIMF). RIMF identifies the most cost-effective way of allocating protective resources among the facilities of an existing but vulnerable system so that the impact of the most disruptive attack to r unprotected facilities is minimized. The model is based upon the classical p-median location model and assumes that the efficiency of the system is measured in terms of accessibility or service provision costs. In the bilevel formulation, the top level problem involves the decisions about which facilities to fortify in order to minimize the worst-case efficiency reduction due to the loss of unprotected facilities. Worst-case scenario losses are modeled in the lower-level interdiction problem. We solve the bilevel problem through an implicit enumeration (IE) algorithm, which relies on the efficient solution of the lower-level interdiction problem. Extensive computational results are reported, including comparisons with earlier results obtained by a single-level approach to the problem.     

A model reference adaptive technique of identification for discrete systems

A rapidly convergent algorithm based on a model reference adaptive technique for the identification of the unknown parameters of a noise free discrete dynamical system is presented. This algorithm is based on a geometric interpretation of the Kudva-Narendra scheme. The algorithm does not require any a priori information about the system. An example is included to demonstrate the strength of the algorithm.     

A general knowledge mediation infrastructure for multi-agent systems

Intelligent decision making needs to be equipped with broader knowledge in order to enhance the decision quality. Knowledge for decision making can be categorized as domain specific and general. Applying domain knowledge in intelligent systems is not new, but applying general knowledge to support business decision making is a possible way to obtain an edge over competitors. For this reason, the paper focuses primarily on designing a general knowledge mediation infrastructure (GKMI) which supports the use of general knowledge from multiple heterogeneous sources, and provides an unified access point for typical multi-agent systems (MAS) to access that knowledge. The finite state automaton (FSA) is used to model and analyze the commonsense inference ability of GKMI. By carrying out two use cases of GKMI for MAS development and operation the effectiveness of this infrastructure is examined.     

U-biofeedback: a multimedia-based reference model for ubiquitous biofeedback systems

Biofeedback is a well-accepted approach in preventative and alternative healthcare. It is known to promote wellbeing and help prevent and treat a wide variety of disorders related to the human physiology and psychology. With the exceptional growth of wearable sensor technologies, the potential for devising biofeedback systems that blend into everyday living is immense. Therefore, we present our vision for U-Biofeedback, a reference model for systems designed to continuously monitor our physiology and convey to us important messages regarding our status. Also, we present a case study for an application that implements our reference model. The application is designed to monitor the stress of individuals working in an office setting and provide an assistive response whenever stress reaches elevated levels. By devising an algorithm for stress detection that makes use of Heart Rate Variability (HRV) measures, we were able to identify negative stress situations with an accuracy of 89.63 % and a false positive detection rate of 5.55 % during our evaluation.     

A complex event routing infrastructure for distributed systems

With the growing number of mega services and cloud computing platforms, industrial organizations are utilizing distributed data centers at increasing rates. Rather than the request/reply model, these centers use an event-based communication model. Traditionally, the event-based middleware and the Complex Event Processing (CEP) engine are viewed as two distinct components within a distributed system’s architecture. This division adds additional system complexity and reduces the ability for consuming applications to fully utilize the CEP toolset. This article will address these issues by proposing a novel event-based middleware solution. We introduce Complex Event Routing Infrastructure (CERI), a single event-based infrastructure that serves as an event bus and provides first class integration of CEP. An unstructured peer-to-peer network is exploited to allow for efficient event transmission. To reduce network flooding, superpeers and overlay network partitioning are introduced. Additionally, CERI provides each client node the capability of local complex query evaluation. As a result, applications can offload internal logic to the query evaluation engine in an efficient manner. Finally, as more client nodes and event types are added to the system, the CERI can scale up. Because of these favorable scaling properties, CERI serves as a foundational step in bringing event-based middleware and CEP closer together into a single unified infrastructure component.     

A generalization of the hyperstability conditions for model reference adaptive systems

A generalization of the hyperstability criterion given in the literature is discussed. The new hyperstability conditions were obtained by utilizing the properties of the positive definite kernels. The results presented here are directly applicable for the synthesis of hyperstable adaptation algorithms for various applications.     

Extended Lyapunov adaptation law for model reference systems

An extension of the adaptation methods presented previously by Ten Cate are presented. Proof of asymptotic stability of the error is effected using Lyapunov theory. This method completes the triplet of a group of previously published adaptation rules for a variation suggested by Shahein et al. using a plant-model parameter misalignment function.     

A hardwired NoC infrastructure for embedded systems on FPGAs

A hardwired network-on-chip based on a modified Fat Tree (MFT) topology is proposed as a communication infrastructure for future FPGAs. With extremely simple routing, such an infra structure would greatly enhance the ongoing trend of embedded systems implementation using multi-cores on FPGAs. An efficient H-tree based floor plan that naturally follows the MFT construction methodology was developed. Several instances of the proposed NoC were implemented with various inter-routers links progression schemes combined with very simple router architecture and efficient client network interface (CNI). The performance of all these implementations was evaluated using a cycle-accurate simulator for various combinations of NoC sizes and traffic models. Also a new data transfer circuit for transferring data between clients and NoC operating at different (unrelated) clock frequencies has been developed. Allowing data transfer at one data per cycle, the operation of this circuit has been verified using gate-level simulations for several ratios of NoC/client clock frequencies.     

A decentralized model reference adaptive variable structure controller for large-scale time-varying delay systems

In this note, the problem of decentralized model reference adaptive variable structure control for a class of perturbed large-scale systems with varying time-delay interconnections is investigated. Based on the Lyapunov stability theorem, an adaptive variable structure control strategy for solving the robust tracking problem without the knowledge of upper bound of perturbations is developed. The use of adaptive technique is to adapt the unknown upper bound of perturbations so that the objective of globally asymptotical stability is achieved. Once the system enters the sliding manifold, the dynamics of controlled systems are insensitive to matching perturbations. Finally, an example is given to demonstrate the feasibility of the proposed control scheme.     

A model reference adaptive control system for discrete multivariable systems with time delays

This paper presents a new method for designing a model reference adaptive control system for multivariable plants with time delays in the input and output variables. An adaptive algorithm guarantees the asymptotic stability of the error between the plant output and the reference sequence using no anticipative value of the plant output and unknown plant parameter. The validity of the theoretical result is illustrated by a numerical example.     

Protecting the critical information infrastructure

The same advantage that technologically advanced businesses have over their competitors-their advanced information technology infrastructure-has become a major new vulnerability. As businesses adopt increasingly sophisticated information infrastructures, the complexity of protecting those infrastructures becomes enormous. And the problem isn't helped by the misunderstandings between business and government over what protecting the infrastructure means. So what should you do about hackers? There are three types of problems to be solved: technological, legal, and financial. An overall solution requires effective solutions in each of these three areas     

An adaptation algorithm for parallel model reference adaptive bilinear systems

An adaptation algorithm is presented for parallel model reference adaptive bilinear systems. The output error converges asymptotically to zero and the parameter estimates are bounded for stable reference models. The convergence criterion depends only upon the input sequence and a priori estimates of the maximum parameter values. A passivity condition, which is generally difficult to verify, is not required.     

The reference model for smooth growth of software systems revisited

Terms-Software evolution,The difference equation determining evolutionary growth of (some) software systems is generalized to a differential one. A hypothetical geometric model is derived and its possible uses are illustrated.     

Database e-portfolio systems: A critical appraisal

This article surveys trends in the e-portfolio boom, relating the development of database portfolio systems to portfolio pedagogy. As the market for enterprise-level database systems has grown, portfolio has spread to become a term used to describe systems from assessment initiatives to institutional portals to academic records management tools. After examining materials and demonstration sites, I found that despite sometimes hyperbolic marketing, database portfolio systems have a troubling and mixed relationship to portfolio pedagogy.The article first discusses central concepts—not of portfolios per se, but of portfolio pedagogy. The article then surveys the development of the boom in enterprise database systems and chronicles prominent trends in those systems. Finally, the article makes critical recommendations for realigning database portfolio systems with portfolio pedagogy, and calls for greater involvement of computers and writing scholars in the development of database portfolios.     

Diagnosis mechanism for accurate monitoring in critical infrastructure protection

Wide-area situational awareness for critical infrastructure protection has become a topic of interest in recent years. As part of this interest, we propose in this paper a smart mechanism to: control real states of the observed infrastructure from anywhere and at any time, respond to emergency situations and assess the degree of accuracy of the entire control system. Particularly, the mechanism is based on a hierarchical configuration of sensors for control, the ISA100.11a standard for prioritization and alarm management, and the F-Measure technique to study the level of accuracy of a sensor inside a neighborhood.