A hybrid system approach for supporting digital libraries

A digital library (DL) consists of a database which contains library information and a user interface which provides a visual window for users to search relevant information stored in the database. Thus, an abstract structure of a digital library can be defined as a combination of a special purpose database and a user-friendly interface. This paper addresses one of the fundamental aspects of such a combination. This is the formal data structure for linking an object oriented database with hypermedia to support digital libraries. It is important to establish a formal structure for a digital library in order to efficiently maintain different types of library information. This article discusses how to build an object oriented hybrid system to support digital libraries. In particular, we focus on the discussion of a general purpose data model for digital libraries and the design of the corresponding hypermedia interface. The significant features of this research are, first, a formalized data model to define a digital library system structure; second, a practical approach to manage the global schema of a library system; and finally, a design strategy to integrate hypermedia with databases to support a wide range of application areas. Received: 15 December 1997 / Revised: June 1999     

Knowledge management in biomedical libraries: A semantic web approach

In recent years, technological advances in high-throughput techniques and efficient data gathering methods, coupled with a world-wide effort in computational biology, have resulted in an enormous amount of life science data available in repositories devoted to biomedical literature. These repositories lack the ability to attain an effective and accurate search. Using semantic technologies as the key for interoperation enables searching and processing of biomedical literature in a more efficient way. However, emerging semantic applications take for granted specific knowledge that biomedical researchers may not have. This paper presents design principles for easy-to-use biomedical semantic applications by means of ontology-based annotations and faceted search. The proposed approach is backed with a usable prototype that shows the breakthroughs of adding these principles to a biomedical digital library where identifying and searching information are critical aspects for non-semantic Web experts.     

Digital libraries in knowledge management: an e-learning case study

Knowledge and libraries – this conceptual symbiosis is as old as the idea of libraries itself: libraries collect artifacts of explicated knowledge and make them available for building up new knowledge in all areas of everyday life. Learning and qualification management support are further essential links in the knowledge supply chain, which starts at the expert knowledge of an author and ends at the targeted enhancement of another persons individual knowledge. Digital libraries and e-learning systems are thus important enabling technologies for the knowledge supply chain in the digital age.The e-Qualification project presented in this paper combines digital library, e-learning, and authoring support into an adaptable qualification management framework that provides integrated support and mediation for the various stakeholders involved in the qualification management process.     

Predictive energy management for hybrid vehicle

Hybrid vehicle control strategies are algorithms devoted to the energy management. At each sampling time they choose the powertrain operating point in order to minimize a criterion, usually the fuel consumption. In simulation, an optimization algorithm can be derived from the minimum principle. For real time control, a Model Predictive Control scheme can be used but it requires the prediction of the future driving conditions. Their time ordered prediction is very difficult. Moreover, if the optimal costate is constant, only the prediction of their distribution is sufficient and allows deriving a real time control strategy. Experimental results are provided to illustrate the benefits of this approach.     

Predictive energy management of hybrid long-haul trucks

This paper presents a novel predictive control scheme for energy management in hybrid trucks that drive autonomously on the highway. The proposed scheme uses information from GPS together with information about the speed limits along the planned route to schedule the charging and discharging of the battery, the vehicle speed, the gear, and when to turn off the engine and drive electrically. The proposed control scheme divides the predictive control problem into three layers that operate with different update frequencies and prediction horizons. The top layer plans the kinetic and electric energy in a convex optimization problem. In order to avoid a mixed-integer problem, the gear and the switching decision between hybrid and pure electric mode are optimized in a lower layer in a dynamic program whereas the lowest control layer only reacts on the current state and available references. The benefits of the proposed predictive control scheme are shown by simulations between Frankfurt and Koblenz. The simulations show that the predictive control scheme is able to significantly reduce the mechanical braking, resulting in fuel reductions of 4% when allowing an over and under speed of 5 km/h.     

Microgrid management using hybrid inverter fuzzy-based control

Neural Computing and Applications - Microgrid systems are becoming a very promising solution to meet the power demand growth especially in remote areas where diesel generators (DG) are commonly...     

Business-driven short-term management of a hybrid IT infrastructure

We consider the problem of managing a hybrid computing infrastructure whose processing elements are comprised of in-house dedicated machines, virtual machines acquired on-demand from a cloud computing provider through short-term reservation contracts, and virtual machines made available by the remote peers of a best-effort peer-to-peer (P2P) grid. Each of these resources has different cost basis and associated quality of service guarantees. The applications that run in this hybrid infrastructure are characterized by a utility function: the utility gained with the completion of an application depends on the time taken to execute it. We take a business-driven approach to manage this infrastructure, aiming at maximizing the profit yielded, that is, the utility produced as a result of the applications that are run minus the cost of the computing resources that are used to run them. We propose a heuristic to be used by a contract planner agent that establishes the contracts with the cloud computing provider to balance the cost of running an application and the utility that is obtained with its execution, with the goal of producing a high overall profit. Our analytical results show that the simple heuristic proposed achieves very high relative efficiency in the use of the hybrid infrastructure. We also demonstrate that the ability to estimate the grid behaviour is an important condition for making contracts that allow such relative efficiency values to be achieved. On the other hand, our simulation results with realistic error predictions show only a modest improvement in the profit achieved by the simple heuristic proposed, when compared to a heuristic that does not consider the grid when planning contracts, but uses it, and another that is completely oblivious to the existence of the grid. This calls for the development of more accurate predictors for the availability of P2P grids, and more elaborated heuristics that can better deal with the several sources of non-determinism present in this hybrid infrastructure.     

The Canadian Initiative on digital libraries

The Canadian Initiative on Digital Libraries (CIDL)/Initiative canadienne sur les bibliothèques numériques (ICBN) <http://www.nlc-bnc.ca/cidl> is a bilingual networked organisation created in 1997 under the umbrella of Library & Archives Canada (formerly National Library of Canada). The CIDL mission is to promote, coordinate and facilitate the development of Canadian digital collections and services in order to optimise national interoperability and long-term access to Canadian digital library resources.     

Dynamic buffer management using optimal control of hybrid systems

This paper studies a dynamic buffer management problem with one buffer inserted between two interacting components. The component to be controlled is assumed to have multiple power modes corresponding to different data processing rates. The overall system is modeled as a hybrid system and the buffer management problem is formulated as an optimal control problem. Different from many previous studies, the objective function of the proposed problem depends on the switching cost and the size of the continuous state space, making its solution much more challenging. By exploiting some particular features of the problem, the best mode sequence and the optimal switching instants are characterized analytically using a variational approach. Simulation results based on real data shows that the proposed method can significantly reduce the energy consumption compared with another heuristic scheme in several typical situations.     

A hybrid proposal for cross-sectoral analysis of knowledge management

At present time, although many theoretical formulations have been successfully proposed, there is a lack of ICT-based tools to support practical deployment of knowledge management (KM) in real settings. To bridge this gap, a hybrid artificial intelligence system is proposed in present study, aimed at gaining deeper knowledge about KM practices in four different economic sectors. By means of soft computing, companies are diagnosed according to their status regarding KM and subsequent explanations about crucial KM practices and perspectives are generated. Interesting conclusions are then derived from these explanations, allowing KM managers to optimise their decisions and obtain better results. Experimental results of real-life data from Spanish companies associated with different economic sectors validate the proposed combination of techniques.     

Proxy-based hybrid cache management in Mobile IP systems

In this paper, we propose and analyze a proxy-based hybrid cache management scheme for client-server applications in Mobile IP (MIP) networks. We leverage a per-user proxy as a gateway between the server and the mobile host (MH) such that any communication between the MH and server must pass through the proxy. The proxy has dual responsibilities in our design. It keeps track of the current location of the MH by acting as a regional Gateway Foreign Agent (GFA) as in the MIP Regional Registration protocol for mobility management. The proxy is also responsible for cache consistency management and query processing on behalf of the MH. To reduce the network traffic, a threshold-based hybrid cache consistency management policy is applied. That is, when a data object is updated at the server, the server sends an invalidation report to the MH through the proxy to invalidate the cached data object, provided that the size of the data object exceeds the given threshold. Otherwise, the server sends a fresh copy of the data object through the proxy to the MH. We identify the best “threshold” value that would minimize the overall network traffic incurred due to mobility management, cache consistency management, and query processing, when given a set of parameter values characterizing the operational and workload conditions of the MIP network.     

The unseen and unacceptable face of digital libraries

The social and organisational aspects of digital libraries (DLs) are often overlooked, but this paper reviews how they can affect users awareness and acceptance of DLs. An analysis of research conducted within two contrasting domains (clinical and academic) is presented which highlights issues of user interactions, work practices and organisational social structures. The combined study comprises an analysis of 98 in-depth interviews and focus groups with lecturers, librarians and hospital clinicians. The importance of current and past roles of the library, and how users interacted with it, are revealed. Web-based DLs, while alleviating most library resource and interaction problems, require a change in librarians and DL designers roles and interaction patterns if they are to be implemented acceptably and effectively. Without this role change, users will at best be unaware of these digital resources and at worst feel threatened by them. The findings of this paper highlight the importance of DL design and implementation of the social context and supporting user communication (i.e., collaboration and consultation) in information searching and usage activities.     

The effects of case libraries on problem solving

Abstract The purpose of the study was to investigate the effects of providing access to a case library of related stories while undergraduates solved ill-structured problems. While solving complex food product development problems, the experimental group accessed experts' stories of similar, previously solved problems; the comparable group accessed fact sheets (expository representation of stories' content); and the control group accessed text selected at random from a textbook dealing with issues unrelated to the stories. On multiple-choice questions assessing processes related to problem solving (prediction, inferences, explanations, etc.), experimental students out-performed the comparable and control groups. Performance on short-answer questions also assessing problem-related skills was not significantly different, in part because of test fatigue. Analysis of interviews identified a number of factors that students used in deciding how to apply their study strategies, including causal factors, grounding phenomenon, grounding in context, and outcomes.     

Neuro-fuzzy ART-based document management system: application to mail distribution and digital libraries

A new document management system is proposed in this paper. Its kernel is based on a new set of neuro-fuzzy systems of the ART family: FasArt and RFasArt. The first one, FasArt, is used to support a simple Optical Character Recognition (OCR) that inherits fine properties of ART architectures, such as fast and incremental learning, stability and modularity. On the other hand, RFasArt is a new recurrent version of FasArt which efficiently exploits contextual information in the task of logical labeling. The proposed system is extensively tested in two real-world applications, i.e. E-mail of printed business letter and digital library of scientific papers. Experimental results show logical labeling and OCR rates over 90%. The proposed system is better compared to a previous system proposed by the group, where instead of using contextual information in an integrated way, a postprocessing Viterbi-based model was employed.     

A workflow management system to feed digital libraries: proposal and case study

Building a digital library of antique documents involves not only technical implementation issues, but also aspects related to the digitization of large collections of documents. Antique documents are usually delicate and need to be handled with care. Also, a poor state of preservation and the use of unrecognizable font types make automatic text recognition more difficult, hence requiring a further human revision to perform text corrections. This makes the participation of experts in the digitization process mandatory and, therefore, costly. In this paper, we present a framework for managing the workflow of the digitization of large collections of antique documents. We describe the digitization process, and a tool supporting all of its phases and tasks. We also present a case study in which we describe how the workflow management system was applied to the digitization of more than 10,000 documents from journals of the 19th century. In addition, we describe the resulting digital library, focusing on the most important technological issues.     

Supervision and hybrid control accommodation for water asset management

The paper presents a supervision and hybrid control accommodation strategy applied to the online water asset management of a canal. This strategy is organized in a conceptual framework based on two principal operating modules. The discharge supervision module carries out the monitoring of discrepancies between the expected and measured values and makes the resource state diagnosis. The hybrid control accommodation module allows the setpoint calculation to be given according to the detected discrepancies, the resource state and the time delays. The design method of a water asset management of a canal network is presented and the strategy performance is evaluated in presence of the usual disturbances of a canal showing its effectiveness.     

Hardware-in-the-loop validation of a power management strategy for hybrid powertrains

Previously, a hybrid powertrain management strategy was developed that controls the power sources based on frequency content, mitigating aggressive engine transients. This article presents a hardware-in-the-loop validation of this strategy, with a real engine and battery integrated into a diesel hybrid electric vehicle simulation, thereby allowing for a realistic evaluation of fuel economy, soot emissions, and battery life. Considering an aggressive drive cycle and a state-of-charge regulation strategy as a benchmark, the frequency-based strategy yields 5.9% increase in fuel economy, 62.7% decrease in soot emissions, and 23% reduction in effective Amp-hours processed, which should yield an increase in battery life.     

Improved supply chain management based on hybrid demand forecasts

Demand forecasts play a crucial role for supply chain management. The future demand for a certain product is the basis for the respective replenishment systems. Several forecasting techniques have been developed, each one with its particular advantages and disadvantages compared to other approaches. This motivates the development of hybrid systems combining different techniques and their respective strengths. In this paper, we present a hybrid intelligent system combining Autoregressive Integrated Moving Average (ARIMA) models and neural networks for demand forecasting. We show improvements in forecasting accuracy and propose a replenishment system for a Chilean supermarket, which leads simultaneously to fewer sales failures and lower inventory levels than the previous solution.     

Least costly energy management for series hybrid electric vehicles

Energy management of plug-in hybrid electric vehicles (HEVs) has different challenges from non-plug-in HEVs, due to bigger batteries and grid recharging. Instead of tackling it to pursue energetic efficiency, an approach minimizing the driving cost incurred by the user – the combined costs of fuel, grid energy and battery degradation – is here proposed. A real-time approximation of the resulting optimal policy is then provided, as well as some analytic insight into its dependence on the system parameters. The advantages of the proposed formulation and the effectiveness of the real-time strategy are shown by means of a thorough simulation campaign.