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1.
Abstract

Until recently, hardware was upgraded simply by ordering a larger, faster, more expensive computer. Now, upgrading a system is more complex but potentially more rewarding. The complexity results from the many alternative approaches available, the advent of distributed processing with its networking implications, the proliferation of microcomputers and office systems and the potential need to integrate them, and the options available for obtaining equipment. An understanding of an organization's needs and careful planning can make an equipment upgrade successful.  相似文献   

2.
The User-in-Context Iterative Assessment (UCIA) approach allows decision makers to acquire rich knowledge about their users and the way technology is used in the context of their work. A case study involving the introduction of a handheld medication administration device for nurses on a medical-surgical ward is used to illustrate how a UCIA approach can help provide healthcare IT professionals and hospital administrators with the data that they need to choose and implement IT applications that have the potential to maximize cost savings, while improving the delivery of patient care.  相似文献   

3.
This article reports on an action research project to investigate the barriers to adoption and assimilation of electronic health records (EHRs) in small physician practices. The project draws on theories of technology-use mediation and communities of practice to develop interventions to promote adoption and integration of EHRs into chronic care management processes in these practice settings. The field results suggest that developing community-based knowledge and resources to assist physician organizations one-on-one may be essential for their effective utilization of EHRs.  相似文献   

4.
5.
Andrew R. Teel  Luca Zaccarian   《Automatica》2006,42(12):2219-2222
We discuss the lack of “uniformity” in definitions of uniform global asymptotic stability (UGAS) that have been used in various textbooks, monographs, and papers over the years. Sometimes UGAS is taken to be the combination of uniform local stability (ULS) and uniform global attractivity (UGA). Other times it also encompasses uniform global boundedness (UGB). This paper contains an explicit, smooth scalar example that shows that these definitions do not agree in general, even when the right-hand side is locally Lipschitz in the state uniformly in time (and thus bounded in time). We also discuss various notions of global asymptotic stability with relaxed uniformity (with respect to the initial time) requirements for the behavior of the solutions. In particular, we consider class- estimates and Lyapunov characterizations.  相似文献   

6.
Meaning making by leadership in a crisis is required to reduce uncertainty. We used analytic criteria for meaning making suggested by crisis management literature to investigate public leaders’ quotations in news coverage of a health crisis. The quotations were examined in terms of the five frame functions, which include offering a credible explanation of what happened, offering guidance, instilling hope, showing empathy, and suggesting that leaders are in control. The Middle East respiratory syndrome outbreak in South Korea was examined. As a result, the most salient frame function identified was displaying they are in control of the emergency, followed by offering guidance and explaining what happened. The salience of leaders’ meaning making disappeared in coverage by a liberal newspaper.  相似文献   

7.
Environmental modelling is done more and more by practising ecologists rather than computer scientists or mathematicians. This is because there is a broad spectrum of development tools available that allows graphical coding of complex models of dynamic systems and help to abstract from the mathematical issues of the modelled system and the related numerical problems for estimating solutions. In this contribution, we study how different modelling tools treat a test system, a highly non-linear predator–prey model, and how the numerical solutions vary. We can show that solutions (a) differ if different development tools are chosen but the same numerical procedure is selected; (b) depend on undocumented implementation details; (c) vary even for the same tool but for different versions; and (d) are generated but with no notifications on numerical problems even if these could be identified. We conclude that improved documentation of numeric methods used in the modelling software is essential to make sure that process based models formulated in terms of these modelling packages do not become “black box” models due to uncertainty in integration methods.  相似文献   

8.
Li Yu   《Systems & Control Letters》2004,53(3-4):321-323
The errors are pointed out in the above paper. And then, a new delay-dependent condition is presented for the robust stability of uncertain time-delay systems, which is an improvement on the corresponding results in the above paper.  相似文献   

9.
This paper presents a new class of algorithms based on Youden designs to detect and restore edges present in an image imbedded by mixture or “salt and pepper” noise. The mixture noise consists of a uncorrelated or correlated noisy background plus uncorrelated impulsive noise. The objective is to restore pixels affected by the impulsive part of the mixture noise. The approach is to consider that these pixels have lost their true value and their estimate is obtained via the normal equation that yields the least sum of square error (LSSE). This procedure is known in the literature as “The Missing Value Approach Problem”. The estimates are introduced into the image data and an ANOVA technique based on Youden design is carried out. We introduce Youden designs which are special Symmetric Balanced Incomplete block (SBIB) designs, the pertinent statistical tests and estimates of the factor effects. We derive the estimate of the missing value for the uncorrelated noise environment as well as for the correlated one. The high level of performance of these algorithms can be evaluated visually via the input/output images and objectively via the input/output signal-to-noise ratio (SNR).  相似文献   

10.
The paper investigates the problem of identifying uncertainty models of causal, SISO, LTI, discrete-time, BIBO stable, unknown systems, using frequency domain measurements corrupted by Gaussian noise of known covariance. Additive uncertainty models are looked for, consisting of a nominal model and an additive dynamic perturbation accounting for the modeling error. The nominal model is chosen within a class of affinely parametrized models with transfer function of given (possibly low) order. An estimate of the parameters minimizing the H modeling error is obtained by minimizing an upper bound of the worst-case (with respect to the modeling error) second moment of the estimation error. Then, a bound in the frequency domain guaranteeing to include, with probability α, the frequency response error between the estimated nominal model and the unknown system is derived.  相似文献   

11.
An integrated learning object, a web-based inquiry environment “Young Scientist” for basic school level is introduced by applying the semiosphere conception for explaining learning processes. The study focused on the development of students’ (n = 30) awareness of the affordances of learning objects (LO) during the 3 inquiry tasks, and their ability of dynamically reconstructing meanings in the inquiry subtasks through exploiting these LO affordances in “Young Scientist”. The problem-solving data recorded by the inquiry system and the awareness questionnaire served as the data-collection methods.It was demonstrated that learners obtain complete awareness of the LO affordances in an integrated learning environment only after several problem-solving tasks. It was assumed that the perceived task-related properties and functions of LOs depend on students’ interrelations with LOs in specific learning contexts. Learners’ overall awareness of certain LO affordances, available in the inquiry system “Young Scientist”, developed with three kinds of patterns, describing the hierarchical development of the semiosphere model for learners. The better understanding of the LO affordances, characteristic to the formation of the functioning semiosphere, was significantly related to the advanced knowledge construction during these inquiry subtasks that presumed translation of information from one semiotic system to another. The implications of the research are discussed in the frames of the development of new contextual gateways for learning with virtual objects. It is assumed that effective LO-based learning has to be organized through pedagogically constrained gateways by manifesting certain LO affordances in the context in order to build up the dynamic semiosphere model for learners.  相似文献   

12.
Consider the following safe path planning problem: Given a set of trajectories (paths) of k point robots with maximum unit speed in a bounded region over a (long) time interval [0,T], find another trajectory (if it exists) subject to the same maximum unit speed limit, that avoids (that is, stays at a safe distance of) each of the other k trajectories over the entire time interval. We call this variant the continuous model of the safe path planning problem. The discrete model of this problem is: Given a set of trajectories (paths) of k point robots in a graph over a (long) time interval 0,1,2,…,T, find a trajectory (path) for another robot, that avoids each of the other k at any time instant in the given time interval.We introduce the notions of the avoidance number of a region, and that of a graph, respectively, as the maximum number of trajectories which can be avoided in the region (respectively, graph). We give the first estimates on the avoidance number of the n×n grid Gn, and also devise an efficient algorithm for the corresponding safe path planning problem in arbitrary graphs. We then show that our estimates on the avoidance number of Gn can be extended for the avoidance number of a bounded (fat) region. In the final part of our paper, we consider other related offline questions, such as the maximum number of men problem and the spy problem.  相似文献   

13.
Classic analyses of system implementations view user participation as a key element for successful implementation. However, under some conditions, avoiding user participation offers an alternative route to a successful implementation; this is advisable especially when the user network is weak and aligning user needs with the technological capabilities will take too much resource. To illustrate such situation, we analyse how a successful implementation outcome of an enterprise resource planning (ERP) system emerged in a recently established conglomeration of two previously independent universities. The ERP was used to replace several legacy student administration systems for both political and functional reasons. It was deemed successful by both project consultants and the new university's management while the users were marginalised (‘black boxed’) and left to ‘pick up the pieces’ of an incomplete system using traditional methods such as shadow systems and work‐a‐rounds. Using a process approach and an actor–network theory ‘reading’ of related socio‐technical events, we demonstrate how three networks of actors – management, the project team and the administrative users – collided and influenced the implementation outcome and how the management and project network established the ERP as a reliable ally while at the same time the users – while being enrolled in the network – were betrayed through marginalisation. Our analysis also suggests a useful way to conduct a ‘follow the network’ analysis explaining and accounting for the observed implementation outcome. We illustrate the benefits of using a socio‐technical processual analysis and show how stable actor networks must be constructed during large‐scale information technology change and how different actor groups perceive and influence differently the implementation outcome.  相似文献   

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