Matching attack patterns to security vulnerabilities in software-intensive system designs Fortifying software applications from attack is often an effort that occurs late in the software development process. Applying patches to fix vulnerable applications in the field is a common approach to securing applications. Abstract representations of attacks such as attack trees and attack nets can be used for identifying potential threats before a system is released. We have constructed attack patterns that can illuminate security vulnerabilities in a software-intensive system design.Matching our attack patterns to vulnerabilities in the design phase may stimulate security efforts to start early and to become integrated with the software process. The intent is that our attack patterns can be used to effectively encode software vulnerabilities in vulnerability databases. A case study of our approach with undergraduate students in a security course indicated that our attack patterns can provide general descriptions of vulnerabilities. The students were able to accurately map the patterns to vulnerabilities in a system design.Security, Design The cost associated with addressing software problems increases as the lifecycle of a project matures. The cost of finding and fixing a bug after a software product has been released can be 100 times more expensive than solving the problem in the requirements or design phase [3] . Thus, patching vulnerable software after release can be a costly way of securing applications. Furthermore, patches are not always applied by owners/users of the vulnerable software; patches can contain yet more vulnerabilities [20] . Another security technique is to rely on devices external to a software system such as intrusion detection systems and firewalls. These protection mechanisms can provide some security, but are only available when software development is complete. The rising concerns of software security suggest that security focuses should be applied throughout the software process to afford more cost effective solutions and provide opportunities for stronger, layered defenses, a best practice technique [10] .. Many intrusions are based on a small number of known attacks, implying that the vulnerabilities are also the same or similar [13] . Furthermore, vulnerabilities can be attacked for years after their discovery [2] . Software engineers can make use of this pattern behavior of vulnerabilities. According to Christopher Alexander [1] , a pattern describes a situation where a problem recurs and provides a solution that can be applied regardless of the environment in which the problem occurs. Alexander makes this claim in the context of architecting buildings, but his idea has also been adopted in the software community.. Gamma et al. [7] make use of patterns for object-oriented design and show how they can be effectively reused in many types of programs. Also, Schumacher and Roedig [18] make use of patterns in the context of security. They define a security pattern as a particular recurring security problem that arises in specific contexts and presents a well-proven generic scheme for its solution [18] . We use attack patterns to describe the components and events of a software system that are involved with the manipulation of common vulnerabilities. These attack patterns can be reused to identify vulnerabilities in software systems. While most patterns provide both a generic problem and a solution, our current research does not provide solutions to the attack patterns.. We propose a methodology for early identification of system vulnerabilities that we call Security Analysis for Existing Threats (SAFE-T) [8] . With SAFE-T, software engineers match attack patterns to system designs to identify potential vulnerabilities. SAFE-T is a means for security to start in the design phase of the software process and provides a taxonomy of attack patterns that can describe common security problems. Security awareness plagues software engineers today [10, 18, 20] and so we attempt to illuminate vulnerabilities with a software engineering approach.. Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage, and that copies bear this notice and the full citation on the first page. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. In this research, we examined 244 previously-reported vulnerabilities from four web-based security vulnerability databases (SecurityFocus, Help Net Security, Secunia, and SecurityTracker) to serve as a source of information for our study. The vulnerability descriptions included the components 1 in the software system that are susceptible to attack and the events that would occur in such an attack. The descriptions were abstracted into regular expressions to provide a general representation of an attack. The events in the regular expressions are symbolized by the component in the system that triggered the event, and we call these expressions attack patterns. The ability of the patterns to describe vulnerabilities was assessed in an experiment with in an undergraduate security course performing SAFE-T. Students were asked to match our attack patterns to a given system design. The students, novices to our approach, accurately detected vulnerabilities in two system design experiments. Our studies were specifically targeted at undergraduate students because a research goal involved the development of a security identification technique that could be used effectively by relatively inexperienced, non-security experts.. In Section 2, we provide related work in abstracting vulnerabilities and vulnerability taxonomies. In Section 3 we discuss our contribution of attack patterns. In Section 4 the validation technique and results are presented and in section 5 we discuss the limitations of our approach. In Section 6 we conclude and summarize our findings. In this section we discuss how vulnerabilities can be abstracted into a general representation. We then discuss taxonomies of vulnerabilities.

O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O B O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O B O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O B O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O B O O O O O O O O O O O O O O O O B O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O B O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Supporting the annotation of chronic obstructive pulmonary disease (COPD) phenotypes with text mining workflows Background: Chronic obstructive pulmonary disease (COPD) is a life-threatening lung disorder whose recent prevalence has led to an increasing burden on public healthcare. Phenotypic information in electronic clinical records is essential in providing suitable personalised treatment to patients with COPD. However, as phenotypes are often "hidden" within free text in clinical records, clinicians could benefit from text mining systems that facilitate their prompt recognition. This paper reports on a semi-automatic methodology for producing a corpus that can ultimately support the development of text mining tools that, in turn, will expedite the process of identifying groups of COPD patients. In this paper, we elucidate our proposed text miningassisted methodology for the gold-standard annotation of COPD phenotypes in a corpus of full-text scientific articles. We demonstrate with the proposed scheme that the annotation task can be kept simple for curators whilst producing expressive and computable annotations. By constructing a semi-automatic annotation workflow in Argo, we seamlessly integrate and take advantage of several automatic NLP tools for the task. Furthermore, we are providing the domain experts with a highly intuitive interface for creating and manipulating annotations. The comparison of annotations automatically generated by the workflow against manually validated ones (i.e., gold standard) reveals an F-score of 45.70% using relaxed matching. New concept recognisers trained on these gold standard annotations demonstrate dramatically better performance (i.e., with a 20-to 30-percentage point margin in terms of F-scores) over the off-the-shelf components used in the Argo workflow.. Manual expert validation of the text mining-generated annotations on the remaining 21 papers in the corpus is still ongoing. In the meantime, we are enhancing our ontology concept linkers, which, once ready, will be applied on the gold standard concepts to enrich our corpus with computable annotations. Our expert collaborators are also working hard on obtaining a subset of clinical records from their hospital, which will then be used to augment our corpus. With the resulting resource, which will be made publicly available upon completion, we aim to support the development and evaluation of text mining systems that can ultimately be applied to evidence-based healthcare and clinical decision support systems. Performance is compared with that of the components utilised in the text mining-assisted workflow. Table 6 Results of evaluation using a fixed split over 381 paragraphs (training set: 75% or 286 paragraphs; held-out set: 25% or 95 paragraphs), using exact matching Various corpora have been constructed to support the development of clinical natural language processing (NLP) methods. Some contain annotations formed on the basis of document-level tags indicating the specific diseases that clinical reports pertain to. In the 2007 Computational Medicine Challenge data set [9] , radiology reports were assigned codes from the ninth revision of the International Classification of DiseasesClinical Modification (ICD-9-CM) terminology [10] . In similar corpora, chest X-ray reports were manually labelled with any of four pneumonia-related concepts [11] whilst any of 80 possible disease names were assigned to documents in another collection of clinical records [12] with the assistance of automatic tools MetaMap Transfer (MMTx) [13] for concept recognition and NegEx [14] for negation detection. Whilst suitable for evaluating information retrieval methods, such document-level annotations cannot sufficiently support the extraction of phenotypic concepts which are described in clinical records in largely variable ways, making it necessary for automated methods to perform analysis by looking at their actual mentions within text.. Several other clinical corpora were thus enriched with text-bound annotations, which serve as indicators of specific locations of phenotypic concept mentions within text. For instance, all mentions of signs or symptoms, medications and procedures relevant to inflammatory bowel disease were marked up in the corpus developed by South et al [15] . Specific mentions of diseases and signs or symptoms were similarly annotated under the ShARe scheme [16, 17] and additionally linked to terms in the SNOMED Clinical Terms vocabulary [18] . Whilst the scheme developed by [19] had similar specifications, it is unique in terms of its employment of an automatic tool to accelerate the annotation process. One difficulty encountered by annotators following such scheme, however, is with manually mapping mentions of phenotypic concepts to vocabulary terms, owing to the high degree of variability in which these concepts are expressed in text. For instance, many signs or symptoms (e.g., gradual progressive breathlessness), cannot be fully mapped to any of the existing terms in vocabularies.. Alleviating this issue are schemes which were designed to enrich corpora with finer-grained text-bound annotations. The Clinical e-Science Framework (CLEF) annotation scheme [20] which defined several clinical concept types and relationships, required the decomposition of phrases into their constituent concepts which were then individually assigned concept type labels and linked using any of their defined relationships. Also based on a fine-grained annotation approach is the work by Mungall et al. [21] on the ontology-driven annotation of inter-species phenotypic information based on the EQ model [22] . Although their work was carried out with the help of the Phenote software [23] for storing, managing and visualising annotations, the entire curation process was done manually, i.e., without the support of any NLP tools. The effort we have undertaken, in contrast, can be considered as a step towards automating such EQ model-based fine-grained annotation of phenotypic information.. In this regard, our work is unique amongst annotation efforts within the clinical NLP community, but shares similarities with some phenotype curation pipelines employed in the domain of biological systematics. Curators of the Phenoscape project [24] manually link EQ-encoded phenotypes of fishes to the Zebrafish Model Organism Database using Phenex [25] which is a tool for managing character-by-taxon matrices, a formal approach used by evolutionary biologists. To accelerate this process, Phenex has been recently enhanced with NLP capabilities [26] upon the integration of a text analytic known as CharaParser [27] . Based on a combination of bootstrapping and syntactic parsing approaches [28] , CharaParser can automatically annotate structured characteristics of organisms (i.e., phenotypes) in text, but currently does not have full support for linking concepts to ontologies [29] . Also facilitating the semi-automatic curation of systematics literature is GoldenGATE [30] , a stand-alone application modelled after the GATE framework [31] , which allows for the combination of various NLP tools into text processing pipelines. It is functionally similar to our Webbased annotation platform Argo [32] in terms of its support for NLP workflow management and manual validation of automatically generated annotations. However, the latter fosters interoperability to a higher degree by conforming to the industry-supported Unstructured Management Information Architecture [33] and allowing workflows to be invoked as Web services [34] .. By producing our proposed fine-grained phenotype annotations which are linked to ontological concepts, we are representing them in a computable form thus making them suitable for computational applications such as inferencing and semantic search. The Phenomizer tool [35] , for instance, has demonstrated the benefits of encoding phenotypic information in a computable format. Leveraging the Human Phenotype Ontology (HPO) [36] whose terms are linked to diseases in the Online Mendelian Inheritance in Man (OMIM) vocabulary [37] , it supports clinicians in making diagnoses by semantically searching for the medical condition that best matches the HPO signs or symptoms given in a query. We envisage that such an application, when integrated with a repository of phenotypes and corresponding clinical recommendations, e.g., Phenotype Portal [38] and the Phenotype KnowledgeBase [39] , can ultimately assist point-of-care clinicians in more confidently providing personalised treatment to patients. Our work on the annotation of COPD phenotypes aims to support the development of similar applications in the future. An umbrella term for a range of lung abnormalities, chronic obstructive pulmonary disease (COPD) pertains to medical conditions in which airflow from the lungs is repeatedly impeded. This life-threatening disease, known to be primarily caused by tobacco smoke, is not completely reversible and is incurable. COPD was ranked by the World Health Organization as the fifth leading cause of death worldwide in 2002, and is predicted to become the third by year 2030. Estimates have also shown that the mortality rate for COPD could escalate by at least 30% within the next decade if preventive measures are not implemented [1] .. The disease and clinical manifestations of COPD are heterogeneous and widely vary from one patient to another. As such, its treatment needs to be highly personalised in order to ensure that the most suitable therapy is provided to a patient. COPD phenotyping allows for well-defined grouping of patients according to their prognostic and therapeutic characteristics, and thus informs the development and provision of personalised therapy [2] .. The primary approach to recording phenotypic information is by means of electronic clinical records [3] . However, as clinicians at the point of care use free text in describing phenotypes, such information can easily become obscured and inaccessible [4] . In order to expedite the process of identifying a given patient's COPD group, the phenotypic information locked away within these records needs to be automatically extracted and distilled for the clinicians' perusal.. Capable of automatically distilling information expressed in natural language within documents, text mining can be applied on clinical records in order to efficiently extract COPD phenotypes of interest. However, the development of sophisticated text mining tools is reliant on the availability of gold standard annotated corpora, which serve as evaluation data as well as provide samples for training machine learning-based approaches.. This paper presents our ongoing efforts on the annotation of COPD phenotypes in a collection of scientific papers. In our previous publication [5] on which this work is built upon, we proposed to form a corpus of clinical records from the Multiparameter Intelligent Monitoring in Intensive Care II (MIMIC II) Clinical Database [6, 7] . However, our UK-based expert collaborators (i.e., stakeholders who will incorporate our text mining technology into their systems in the near future) recently pointed out that there are substantial discrepancies between the hospital system in the US (on which MIMIC II is focussed) and that in the UK. After considering their advice, we decided to utilise scientific articles from various COPD-relevant journals, rather than build a corpus of clinical records which are highly US-specific. As previous work demonstrated techniques which successfully extracted information from unseen data even if the training/development data used was of a different document type [8] , we believe that a gold standard corpus of full scientific articles should still allow for the development of phenotype extraction tools for clinical records. Nevertheless, our collaborators are still currently working on obtaining a subset of clinical records from their own hospital, which will also be annotated to become part of an augmented version of our corpus.. In embarking on this effort, we are building a resource that will support the development of text mining methods for the automatic extraction of COPD phenotypes from free text. We envisage that such methods will ultimately foster the development of applications which will enable point-of-care clinicians to more easily and confidently identify a given COPD patient's group, potentially leading to the provision of the most appropriate personalised treatment. Furthermore, text mining methods can be employed in order to facilitate the linking of COPD phenotypes with genotypic information contained in published scientific literature.. In the remainder of this paper, we firstly provide a review of the state of the art (Related Work). We proceed to describing our methods for corpus development (Methods), including our strategy for document selection followed by our proposed annotation scheme. A discussion of our text mining-assisted annotation workflow is also provided. We then share the results and analysis of our evaluation (Results and Discussion). Lastly, we conclude the paper with a summary of our contributions and an overview of ongoing and future work. We describe in this section our strategies for collecting documents for the corpus and our proposed annotation scheme. We also elaborate on the technology behind our text mining-assisted annotation methodology.

O O O O B I I I O O O O O O O B I I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Randomized nonuniform sampling and reconstruction in fractional Fourier domain The fractional Fourier transform (FRFT) is one of the most useful tools for the nonstationary signal processing. In this paper, the randomized nonuniform sampling and approximate reconstruction of the nonstationary random signals in the fractional Fourier domain (FRFD) are developed. The nonuniform samples are treated as random perturbations from a uniform grid. The samples used for the sinc interpolation reconstruction are placed on another nonuniform grid which is not necessarily equal to the samples originally acquired. When considering the second-order random statistic characters, the nonuniform sampling is equivalent to the uniform sampling of the signal after a pre-filter in the FRFD, where the frequency response is related to the characteristic function (with its argument scaled by csc α) of the perturbations. The effectiveness of the reconstruction is analyzed and the mean square error (MSE) is computed by utilizing the equivalent filter system. Furthermore, the randomized reconstruction of the chirp period stationary random signal is proposed. At last, the minimum MSE on the special cases of the randomized sampling and reconstruction is discussed. The effectiveness of the proposed reconstruction method is verified by the simulation. As the nonstationary signals, especially for the chirp signals, have compact support in the fractional Fourier domain (FRFD), the fractional Fourier transform (FRFT) became a powerful tool in the nonstationary signal processing [1] [2] [3] . The FRFT is a generalized form of the Fourier transform (FT), and its properties have been derived in a number of research papers [4] [5] [6] [7] [8] . The sampling theorem of the nonstationary signals plays an important role in digital signal processing, and arouses researchful interest in the literatures. The expansions of the uniform sampling theorem about the nonstationary signals in the FRFD have been investigated in [9] [10] [11] [12] [13] .. Shannon sampling theorem is the classical uniform sampling theorem. However, sometimes samples cannot be collected uniformly in a variety of applications, such as in the fields of synthetic aperture Radar (SAR), astronomies and geophysics. The issue of approximate reconstruction using nonuniform samples or its transformed version has attracted much attention in the signal processing community [14] [15] [16] [17] [18] [19] [20] [21] . Yao and Thomas [14] stated that when the sampling instants t n did not derived by more than T=4 from a uniform grid with spacing of T, the bandlimited signal in the Fourier domain (FD) could be completely reconstructed by the Lagrange interpolation. The generalized nonuniform sampling theorem similar to [14] was also derived in the FRFD [15] . The complexity of the Lagrange interpolation motivated other much simpler approximate reconstruction methods. Tao et al. [17] derived the periodic nonuniform sampling and reconstruction in the FRFD at first, and other early works on nonuniform sampling and reconstruction in the FRFD were developed in [18] [19] [20] [21] . These sampling theorems verified that if a signal was bandlimited or compact in a FRFD, it could be sampled by using the FRFT instead of the FT with a larger sampling interval. In fact, some signals have random characters. Some related results on random variables and fractional stationarity concepts in the FRFD were derived in [22] [23] [24] [25] [26] . The above generalized sampling theorems are suitable for the class of deterministic signals which have compact support in the FRFD. The reference [27] derived the sampling methods for random signals with known spectral densities in the mean square sense, including uniform and nonuniform sampling. The sampling theorem in the FRFD and its relation to the von Neumann ergodic theorem were also discussed in [28] .. The reconstructions of the signals from nonuniform samples are more difficult to complete than that from uniform samples, and the complexity of the implementation of the nonuniform sampling theorem makes it difficult to be used in practice [15] . Although the periodic nonuniform sampling is a quite fascinating sampling theorem, not all of the nonuniform sampling cases can be modeled by it. In this paper, we propose a randomized nonuniform sampling and approximate sinc interpolation reconstruction method for the chirp stationary signals, which are nonstationary in the usual sense or in the FD [25] . The nonuniform samples are regarded as random perturbations from a uniform sampling grid in the analysis. Therefore, the nonuniform sampling sequence has random characters. On the basis of the second-order statistic theory, the randomized nonuniform sampling is equivalent to the uniform sampling of the signal after a pre-filter. The prefilter is a fractional multiplicative filter, whose frequency response is the characteristic function (with its argument scaled by csc α) of the random sampling perturbations. Thus, the randomized sampling and approximate reconstruction can be considered by an equivalent filter system. The mean square error (MSE) which represents the performance of the reconstruction is analyzed by the equivalent system. Furthermore, the case of the chirp period stationary random signal is developed. Special cases of the sinc interpolation reconstruction are discussed and simulated at last.. The paper is organized as follows: the preliminaries are reviewed in Section 2. In Section 3, for nonstationary signals, nonuniform sampling with random perturbations and approximate reconstruction are proposed. Then the error of the reconstruction is analyzed in detail. Section 4 investigates the randomized sinc interpolation reconstruction of the chirp period stationary signals, which can be implemented by a finite summation. The special cases and simulation results of the reconstruction are discussed in Section 5. Conclusions are drawn in Section 6. For nonstationary signals, which are chirp stationary in the FRFD, a randomized nonuniform sampling and sinc interpolation reconstruction method is proposed in this paper. Where the nonuniform samples are regarded as the random perturbations of the uniform samples. The reconstruction based on the chirp modulated sinc interpolation uses the sampling instants from another random perturbations in average sampling period. The randomized sampling and reconstruction process have been proven to be equivalent to a fractional filter system in the sense of random statistic character. The frequency response of the filter is the characteristic function (with scaled argument) of the perturbations. The error of the approximate reconstruction can be controlled by the random perturbations at some level. The reconstruction of the chirp period stationary random signal is also discussed. Besides, our results can be extended to multichannel sampling theorem for multicomponent chirp stationary signals or to other transform domains.

O B I O O O O O O O B I I O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O B I O O O O O O O O O O B I O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


OntoGene in BioCreative II.5 Abstract-We describe a system for the detection of mentions of protein-protein interactions in the biomedical scientific literature. The original system was developed as a part of the OntoGene project, which focuses on using advanced computational linguistic techniques for text mining applications in the biomedical domain. In this paper, we focus in particular on the participation to the BioCreative II.5 challenge, where the OntoGene system achieved best-ranked results. Additionally, we describe a feature-analysis experiment performed after the challenge, which shows the unexpected result that one single feature alone performs better than the combination of features used in the challenge. A S a way to cope with the constantly increasing generation of results in molecular biology, some organizations maintain various types of databases that aim at collecting the most significant information in a specific area. For example, UniProt/SwissProt [1] collects information on all known proteins. MINT [2] and IntAct [3] are the databases collecting protein interactions. Most of the information in these databases is derived from the primary literature by a process of manual revision known as "literature curation.". Typically, a text mining system is designed to locate relevant information within a given text collection (e.g., the PubMed database of biomedical literature), not only by finding relevant articles (which is the task of information retrieval systems), but also by extracting very specific information of interest to the user, such as, for example, protein-protein interactions (PPI). 1 Text mining systems are based on a variety of different approaches, ranging from simple bag-of-words techniques to more complex natural language approaches, with various degrees of success.. The work presented here is part of a larger effort undertaken in the OntoGene project [6] aimed at improving biomedical text mining through the usage of advanced natural language processing techniques. The results of the entity detection feed directly into the process of identification of protein interactions. Our approach relies upon information delivered by a pipeline of NLP tools, including sentence splitting, tokenization, part of speech tagging, term recognition, noun and verb phrase chunking, and a dependency-based syntactic analysis of input sentences [7] , [8] . The syntactic parser [9] takes into account constituent boundaries defined by previously identified multiword entities. Therefore, the richness of the entity annotation has a direct beneficial impact on the performance of the parser, and thus, leads to better recognition of interactions [10] .. There have recently been numerous results showing the potential of dependency-based language analysis for text mining. Pyysalo et al. [11] describe a manually annotated corpus, which includes a dependency-based analysis of each sentence. Clegg and Shepherd [12] use dependency graphs in order to benchmark four publicly available natural language parsers. Fundel et al. [13] describe a large-scale relation mining application based upon the Stanford Lexicalized Parser.. In this paper, we first describe in Section 2 the overall architecture of our text mining system. We then present in Section 3 the results obtained in the recent BioCreative II.5 competition. Additionally, in Section 4, we briefly sketch how the system could be used in the curation process.

O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O


The new generation of computer literacy A tremendous mismatch is developing between two of the most critical components of any computer literacy course: the textbooks and the students.We are encountering a "new generation" of students (literally as well as figuratively!) who are much better acquainted with computer usage than their earlier counterparts. Yet many textbooks with increasing emphasis in those same computer tools continue to appear. There are signs of a coming change in that a few authors and publishers apparently are becoming aware of the need for innovations in texts for non-scientists.These textbooks open the door for a new orientation to principles in the teaching of computer literacy. Two of the most common terms used to describe events and circumstances in computer science are "new generation" and "crisis.". Possibly in a new field nothing is seen as neutral or dispassioned; instead we proclaim the doom and urgency for change of "crisis" or the salvation of "new generation.". This latter is applied primarily to developments in technology (hardware and certain aspects of software); and the former most often alerts us to problems in the management of the technologies and in recruitment at all levels.. While, for reasons to be explained, our choice to describe a recent development in curriculum and pedagogy as heralding a "new Permission to copy without fee all or part of this material is granted provided that the copies are not made or distributed for direct commercial advantage. the ACM copyright notice and the title of the publication and its date appear, and notice is given that copying is by permission of the Association for Computing Machinery. To copy otherwise, or to republish, requires a fee and/ or specific permission. 0 1989 ACM 0-89791-298-5/89/ooO2/0177 $1.50 generation," the title could as well have been "The Crisis in Computer Literacy.". This aspect of our curriculum is a mess! Present students are increasingly sophisticated regarding computer technology.. Obviously media, the general cultural attention to computers, and growing-up in the information age have contributed to a familiarity with at least some aspects of computing.. And, of course, high schools (even grade schools) are increasing their offerings in computer-related courses. Almost eighty percent of the states officially encourage schools to provide students with some exposure to computers [S] . Indeed, Gilbert and Green report that in 1985 over sixty percent of incoming freshmen had at least a half-year of computer instruction [6] .. These trends in pre-college schooling are accelerating.. Recent legislation in California, for example, mandates, as of July 1988, that to receive full credentials all teachers must take a fifth year of the program that includes computer education.. The bill justifies this requirement on the basis that 'I... public school pupils need quality instruction and support in the areas of computer education . . . for entry into an increasingly technological society" [3] . As an additional measure of this acceleration, An Electronic Learning survey conducted in September 1986 found that over fifty percent of the nation's largest education schools required a course in computer literacy for graduation.. A similar survey five years earlier showed only five percent [4] ! And of course many of the other schools strongly recommend such a course.

O O B O B I O O O O O O O O O O O O O O B I O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O B O B I O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O


Reliability and heterogeneity of railway services Reliability is one of the key factors in transportation, both for passengers and for cargo. This paper examines reliability in public railway systems. Reliability of railway services is a complex matter, since there are many causes for disruptions and at least as many causes for delays to spread around in space and time. One way to increase the reliability is to reduce the propagation of delays due to the interdependencies between trains. In this paper we attempt to decrease these interdependencies by reducing the running time differences per track section, i.e. by creating more homogeneous timetables. Because of the complexity of railway systems, we use network wide simulation for the analysis of the alternative timetables. We report on both theoretical and practical cases. Besides a comparison of different timetables, also general timetabling principles are deduced. 5001-6182 BusinessReliability is one of the key factors in transportation, both for passengers and for cargo. This paper examines reliability in public railway systems. Reliability of railway services is a complex matter, since there are many causes for disruptions and at least as many causes for delays to spread around in space and time.One way to increase the reliability is to reduce the propagation of delays due to the interdependencies between trains. In this paper we attempt to decrease these interdependencies by reducing the running time differences per track section, i.e. by creating more homogeneous timetables.Because of the complexity of railway systems, we use network wide simulation for the analysis of the alternative timetables. We report on both theoretical and practical cases. Besides a comparison of different timetables, also general timetabling principles are deduced. Railway infrastructure capacity is limited and has therefore to be used carefully. Due to the increased utilization of the railway infrastructure in the Netherlands over the past years, the railway system has become quite vulnerable to disruptions. This resulted in a lower punctuality and in many customer complaints.. In the Netherlands, the railway system is characterized by many interconnected relations. Passenger transfers, rolling stock circulations and crew schedules all play their role in the relations between trains. However, the shared use of the same infrastructure by different railway services, with different origins and destinations, different speeds, and different halting patterns, is probably the main reason for the propagation of delays throughout the network. This makes such a national railway system much more vulnerable to disruptions than metro systems.. Reliability is, together with door-to-door travel time, one of the predominant performance measures in railway traffic. The predictability of the arrival times is a big factor in deciding to use rail or road transport, both for passengers and for cargo.. In this paper we investigate the effect of the heterogeneity of the timetable on the reliability of the railway system. This is a subject on which a lot of practical intuition exists, but hardly any scientific literature can be found. Railway traffic is considered to be heterogeneous when trains have large running time differences on the same track sections. When running times per track section are more or less equal for all trains, then the timetable is called homogeneous. The research goal of this paper implies that we are mainly interested in relatively small initial (primary) disturbances, because no reasonable timetable is robust enough to handle large disturbances or disruptions without severe on-line adjustments of the railway traffic.. Many characteristics and details of a railway timetable have their influence on the reliability. Therefore, to understand the relations properly, one first needs to know how a timetable is constructed. Starting from the market demand, line planning is the first phase in railway planning, where train connections are determined: starting and ending stations of lines are chosen, including the routes, and the stations at which has to be stopped for alighting and boarding. The chosen lines determine the service differentiation -intercity trains, local trains, cargo, etc.-and consequently a large part of the heterogeneity of the timetable. The line planning step is followed by the timetabling step, where departure and arrival times are chosen. There are often several iterations between these two steps, because a preferred line plan does not imply a feasible timetable. Feedback loops may have to be executed. tions nor the impact on e crew schedules. Again, feedback loops may be necessary. liability and and more homogeneous timetables both for a theoretical cas used for the evaluation of t e range of disturbance istributions and disturbance levels is used for this evaluation.. When the timetable is finished, the rolling stock circulation is planned. This step also includes shunting and scheduling repositioning trips. Both for the regular trains and for the shunting work, train drivers have to be scheduled. For passenger trains, also conductors are needed. Although the steps presented in the flow-diagram above depend on each other in the presented order, coordination between these steps is not easy. This means that not all the forward consequences of a certain planning step are taken into account immediately. For example, in the timetabling phase, one cannot always foresee the resulting impact on the rolling stock circula th. The line plan and the timetable determine the heterogeneity of the railway system to a large extent. Since we investigate the influence of the heterogeneity on the re the punctuality, we focus on the line planning and the timetabling steps. In this paper we develop timetables which mainly differ from each other in heterogeneity. While keeping the numbers of stops per hour equal for all stations, we develop more heterogeneous e and for a practical case.. To quantify the differences between these timetables, two new heterogeneity measures are proposed. These new measures follow the ideas described by Carey (Carey, 1999) , but they also take into account several other characteristics of the timetable. These two new heterogeneity measures are not only he timetables, but also for the prediction of the reliability. In this paper, detailed simulation of the railway systems is used for the comparison of the heterogeneous and the homogeneous timetables. A wid d. Because cargo trains cover less than ten percent of the Dutch railway traffic, we concentrate on passenger trains in this paper. Furthermore, we assume, as is common in several European countries, that the timetables are cyclic. This means that assenger services are repeated every cycle time, typically every hour.. nes. Notice that many of Europe's main lines are, at least, double track lines indeed. e f homogenization is further discussed in section 6. Conclusions follow in section 7.. . Punctuality and Reliability which both bsorb primary delays fast and cause as few secondary delays as possible.. -as well as for international omparisons-a five minute margin is more common. cal e ercentage of realized passenger transfers and the average delays of the passengers. p When researching heterogeneity, double track sections are more relevant than single track sections or sections with four parallel tracks. Indeed, the timetable for singletrack lines is mostly dictated by the distances between passing points. In the case of four parallel tracks, trains with different speeds are usually already separated, and each track has its own speed: one track for slow traffic, and one for fast traffic. The interesting part is where all trains for one direction run on one track: double track li This paper starts with an introduction on railway reliability, including a literature overview. This is followed in section 3 by a discussion on heterogeneity and its influence on reliability. Also the new heterogeneity measures are introduced here. Sections 4 and 5 present a theoretical and a practical case, respectively. The principl o In this paper the Sum of Shortest Headway Reciprocals (SSHR) and Sum of Arrival Headway Reciprocals (SAHR) were described. These measures are used for evaluating the heterogeneity of the timetable and for the prediction of the reliability. The SSHR can be applied to a whole section and has the desirable property that it decreases both when trains are spread better over the hour and when railway traffic is more homogeneous. The SAHR also has the property of decreasing when the trains are spread better over the hour. It lacks a direct link to the heterogeneity, but takes it into account implicitly.. The presented cases show a large reliability increase for homogenized services, which supports the hypothesis that we stated in section 3: the heterogeneity resulting from the line plan and the timetable has a negative influence on the punctuality and the reliability of a railway system.. In other words, when the SSHR and SAHR show large decreases, then there are usually also large decreases in delay propagation. Therefore, a relatively simple rule of thumb for timetable design is to minimize the SSHR and the SAHR. This may improve the reliability of the offered services.. Although homogenization may lead to a sizable increase in punctuality of the offered railway services, homogenization may also effect other features of the railway product, both for passengers and for operators and infrastructure managers. When homogenizing train services, these other consequences should also be considered. This is a subject for further research. The relationship between the consequences for the different operators and the infrastructure managers also stresses the importance of cooperation between these parties. The measures: SSHR and SAHR The measures SSHR and SAHR are both able to predict reliability changes. The SSHR is applicable to track sections between stations, whereas the SAHR can be used for a station, or for all arrivals from a certain track at that station.. Although a large decrease in the SSHR or in the SAHR leads to a large decrease in delays in most cases, it is hard to predict the exact size of the delay reduction. Using a weighted average of the two measures may be advantageous, because it takes heterogeneity into account, and it weighs the arrival headways more heavily than the departure delays. In this paper we study the effect of homogenization on the reliability and the punctuality of a railway system. For obtaining more homogeneous timetables, we have chosen the option of shifting stops from the short distance services to the long distance services until the numbers of stops of the trains per track section are as much equal as possible. This leads to more equal running times per track section.. The cyclic timetables were developed with the automatic timetabling tool DONS (Hooghiemstra, 1994) . Any real-life or artificial railway network can be defined with this tool. On this infrastructure, train lines can be defined, including their intermediate stops, their rolling stock types, transfer connections and other characteristics. DONS will then provide a feasible timetable, or, if this is not possible, tell which constraints following from the input make a timetable infeasible.. For the comparison of the timetables, simulation of railway traffic has been used. The simulations reported on in this paper are performed with SIMONE. This simulation model is in use both by ProRail, the Dutch railway infrastructure manager, and by Netherlands Railways, the predominant Dutch operator of passenger trains. It is used both for timetable comparisons and for scientific research. A more detailed description of SIMONE is given by Bouwman (2000, 2001) .

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Natural and virtual environments for the training of emergency medicine personnel Abstract EMERGENZA (emergency in Italian) is a 'serious' game, developed in the context of the RIMSI project and designed to improve the training of emergency medicine operators. To achieve this goal, it adopts natural interaction paradigms in immersive environments. Virtual reality systems have been used recently in combination with natural interface systems for enhancing patients' rehabilitation procedures though are proving especially effective in the development of clinical decision support and medical training systems. The use of immersive simulations in medical training is extremely useful to confront emergency operators with scenarios that range from usual (e.g. unconscious person on the ground) to extreme (car accident with several injured people) without exposing the simulation participants in any harm. It is critical to exploit 3D virtual worlds in order to provide as much contextual information as possible to the operators. In fact, each emergency procedure needs to be adapted depending on the environmental threats and the presence of multiple injured people in need of assistance or bystanders. EMERGENZA allows to simulate a first-aid scenario with a configurable virtual environment using interactive 3D graphics. Users can interact through a natural interface for navigation and interaction with the virtual environment. In order to evaluate the prototype, several heuristics have been chosen and tested to measure the overall system usability. Results show that the adoption of natural interaction in immersive virtual environments receives good feedback from users. In the field of emergency, medicine simulation is extremely useful to teach emergency medical technicians (EMTs) and medics to operate in harmful or critical situations. Medical simulations have been enacted for centuries, even if in primitive forms [1] . Practice is a key component for the maintenance and learning of skills in medicine [2] , and in this regard, medical simulation encompasses different solutions. According to the pioneer David Gaba [3] , there are five categories of medical simulation: verbal simulations, standardized patients, part-task trainers, electronic patients and computer patients. A verbal simulation is a role playing game. Standardized patients are actors employed to train junior doctors in communication and physical examination skills as well as patient history taking. Task trainers usually depict body parts, and the most complex versions are also used as surgical trainers. Electronic patients are probably the most realistic devices for simulations. They are full-size heavy mannequins 1 with human-like behaviour (eye blinking, breathe and pulse) and are usually computer controlled in order to induce disease symptoms. Electronic patients and task trainers are the most expensive devices, however, with respect to standardized patients and verbal simulations ease the repeatability of the simulation scenarios. Computer patients can be used to reduce the cost of simulations, and they are software-based interactive characters that have the same purpose of standardized patients but can also in part replace electronic patients. The interesting feature of computer-based medical simulation is the possibility to replicate very complex scenarios at a very low cost. As an example, imagine the scenario of a bus crash on a highway. Such a scenario requires the intervention of multiple medical operators with the need of a high skill in managing and prioritizing patient assistance procedures. The enactment of such a scenario requires a vast amount of free ground, several electronic patients and actors together with trainees. Electronic mannequins are quite expensive since their cost ranges from 20 to 80k $. Only a few medical schools and the military can afford such expenses. Therefore, simulations involving the use of an electronic mannequin are usually enacted in emergency room environment or in simple nonhospital environment, and they use a single electronic patient.. A computer-based simulation can also improve the trainee environmental awareness without any risk for the simulation participants, and medical operators can be confronted with situations involving many risks both for the patient and for themselves. These situations and the actual actions to be performed can be simulated realistically not only at no cost but also without any risk for the trainees. An example is a basic life support (BLS) scenario in an apartment of a burning building where simulation participants need to take care of their team safety before assisting the patient, requesting, if needed, firemen support. This paper is organized as follows. First, in Sect. 2, the major related works regarding systems and ''serious games'' for training and rehabilitation are presented. Section 3 describes the use cases and the main scenario. Section 4 is dedicated to system architecture, navigation metaphor, user interaction with implementation details. Section 5 shows prototype assessment, heuristics used for user tests, the evaluation process and discussion of the results. Lastly, some conclusions are drawn, and future works are discussed. The EMERGENZA prototype is part of the so-called serious games technologies for the improvement of skills and knowledge in medicine. Serious games provide an interactive environment where students and teachers are represented by avatars. Currently, most of the simulated training sessions in medicine occur in real environments such as laboratories, though more realistic digital simulations that facilitate learning in a safe environment can be implemented through emerging technologies such as tracking and VR environments.. EMERGENZA features a 3D virtual environment, highresolution graphics and natural interaction interfaces to improve the effectiveness of the training of medical personnel in emergency situations. It provides an immersive and intelligent digital environment which can respond to natural gestures and actions of more team members in a simulated situation of emergency. The system has been developed to improve the learning methods currently in use and to solve some common issues.. Simulation in medicine has really improved in both fidelity and validity, though there are still several issues that justify skepticism in its adoption in the training process. Nonetheless, several schools of medicine all around the world are integrating simulations in doctor training and even offer certifications for simulation centres [36] . The main reason of delay in the adoption is related to the cost of personnel, equipment and programs that can be mitigated with the creation of large structures that promote the collaboration between different hospital units.. In this context, the proposed prototype is extremely valuable. In fact, it can reduce the cost of simulation replacing expensive structures and devices with virtual worlds. Moreover, a system is proposed that enables the simulation of dangerous and extreme scenarios enriching the training of junior doctors. Furthermore, compared to simulations with mannequins, the system allows:. 1. to have an intelligent system that responds automatically to user actions, 2. to receive continuous audiovisual feedbacks, 3. to simulate an immersive environment such as that with the use of mannequins, but at a lower cost, enhancing learnability and memorability of procedures, 4. to be corrected on the fly and have system feedback in real time (the debriefing phase assumes instead a period of time between the wrong action and the correction).. The use of the session configuration tool enables trainers to define complex and varied situations to keep their trainees always focused on the environment, patient condition and bystanders. The whole standard procedure can thus be learned as a complex interaction of medics, bystanders and patients in the environment. Interactive sessions with EMERGENZA can also be recorded and used as training materials. In this way, a large database can be build quickly to evaluate errors and the most common difficulties of trainees. These data, in addition to increasing the effectiveness of training, can be useful to assess how well these simulation environments work and how they can be improved. Regarding future work, an interactive prototype is currently under development for the proper execution of the Surgical Safety Checklist (Fig. 12) procedure that must precede every surgical operation as proposed by the World Health Organization [37] .. Practicing few individual critical steps defined by the checklist that medical operators have to carry out 'before induction of anaesthesia', 'before skin incision' and 'before H6b I was concentrated on the assigned tasks rather than on the mechanisms used to perform those tasks or activities 3.1 patient leaves operating room' can minimize the most common and avoidable risks that endanger the outcome of a surgical operation. Each expected action in the checklist will be translated into a series of gestures and activities that the virtual system will be able to recognize and register. In particular, a multi-user scenario with three actors (surgeon, anaesthesia professional and nurse) and, for each step of the procedure, the actions that each actor has to perform have been identified. This scenario too has been designed as a 'serious game': there will be a maximum time for operators in order to complete the procedure, and for each item of the checklist, actors will have to raise their arm to decide who should carry out the specific action.. Compared to the BLSD scenario, in which the user has to explore the virtual space, this second scenario is more static. The focus is on the training and the improvement of communication skills between the actors and the respect of roles and tasks. Users are expected to interact via voice (using the Microsoft Kinect TM SDK speech recognition engine) and gestures. This second scenario will allow the trainers to observe the dynamics of dialogue between the trainees (sessions will be registered for the debriefing phase) and the trainees to familiarize naturally with the procedure. The literature in the field of medical training systems reveals, in recent years, an orientation towards the design of high configurable prototypes [3] [4] [5] [6] . These systems are difficult to implement and maintain due to the fact that medical procedures are becoming everyday more complicated. On the other hand, very specialized systems [8, 9] have been designed that are not adaptable and flexible enough to be deployed in different scenarios. Furthermore, for the most part, the majority of interfaces of these systems are not fully immersive and intuitive. Even if they exploit different tools for interaction such as haptic sensors, cameras and markers, they could benefit a lot from natural interaction techniques.. The Cybermed framework [4] is a system for medical training via computer network. It has advanced features for configuring some aspects of the simulation such as the number of users, the gestures to manipulate the objects, the type of devices (mouse or haptic systems), the choice of the actors for remote mentoring and distance learning (tutor or participants), though it does not really allow an exhaustive characterization of the situation or the definition of complex medical procedures. SOFA [5] , ViMet [6] and GiPSi [7] frameworks instead are open-source projects which feature an high level of modularity and rely on the capability of a multi-model representation of simulation models (deformable models, collision models, instruments) exposing appropriate APIs.. Although they easily allow to simulate a scenario, say a laparoscopy, they neither provide a real natural and immersive interface nor they go beyond enabling the system to respond to punctual stimuli (e.g. in the laparoscopy use case, deformation of the liver and collision with the ribs). Spring [8] is a more specific mouse-based desktop framework for real-time surgical simulations, which provides a basic configurability of patient-specific anatomy. Laerdal MicroSim [9] is a non-immersive simulation system that presents to trainees pre-hospital, in-hospital and military scenarios. As can be seen in Fig. 1 , in the pre-hospital scenario, the user can interact with the patient through a simple 2D interface and has a static view of the scene. Recent studies [10, 11] instead have proved the benefits of game dynamics to boost the adoption of simple computerbased virtual patients by groups of students for training sessions in the medical field.. Regarding more immersive solutions, Honey et al. have created a virtual environment in second life for haemorrhage management [12] ; Cowan et al. [13] have developed a system for the inter-professional education (IPE) for critical care providers where an immersive 3D situation is accessed across the network in a 'multi-player online' environment, allowing trainees to participate, as avatars, from remote locations. Sliney et al. [15] propose a system, named JDoc, which uses realistic situations to train junior doctors in dealing with the frenzy of a first-aid hospital. Immersivity and realism are one of the key points for users engagement in the development of training systems. This is confirmed by Buttussi et al. [14] who obtained encouraging results evaluating a 3D serious game as a support tool for medicine students.. Natural interaction is definitely the other key factor that can be a plus in medical training systems. Several so-called natural interfaces featuring natural interaction systems have been used in medical rehabilitation, although sparsely, leveraging different technologies (e.g. Nintendo Wii, PlayStation EyeToy), as part of physical therapy. Haptic sensors are commonly used in rehabilitation to ease the interaction with the systems [16, 17] . Markers and accelerometers/gyroscopes provided by the Nintendo Wii have been used to get information about scene orientation and objects positioning in order to improve systems responsiveness [18] . These solutions, despite being easy to implement, have the disadvantage to be not really natural, forcing users to wear or to hold different devices with their hands in order to interact with the system [19] .. As regards Kinect-enabled systems, they are commonly used in rehabilitation. Lange et al. [20] , for example, have developed a Kinect-based game 'JewelMine' that consists of a set of balance training exercises to stimulate the players to reach out of their base of support. This kind of software takes advantage of the situation realism and the naturalness allowed by the Kinect sensor in gestures tracking. This is relevant especially to encourage physical exercise but is not very common in medical operators training systems. LISSA [21] is a Kinect-based system developed to train specific skills in cardiopulmonary resuscitation (CPR). This system is one of the first medical training softwares exploiting motion tracking but, compared to EMERGENZA, LISSA is more skill-oriented rather than procedure-oriented.. A comparison of solutions adopted by previous works and by EMERGENZA is available in Table 1 .. Taking into account all these issues, EMERGENZA, a system that developed in the RIMSI project for the simulation and training of medical and para-medical personnel in emergency medicine, is proposed. The prototype aims at reproducing pre-hospital scenarios with critical environmental situations in a reconfigurable way. It was decided to portrait this kind of scenarios since they are the most expensive and difficult to reproduce in simulation facilities. The system is composed by a scenario editor for the instructors and a simulator. Users are able to navigate a virtual realistic environment as both first and third person character controllers. To improve the immersivity of the system, a gesture-driven interface based on the Kinect TM has been developed.

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Evolutionary Optimization of Service Times in Interactive Voice Response Systems Abstract-A call center is a system used by companies to provide a number of services to customers, which may vary from providing simple information to gathering and dealing with complaints or more complex transactions. The design of this kind of system is an important task, since the trend is that companies and institutions choose call centers as the primary option for customer relationship management. This paper presents an evolutionary algorithm based on Dandelion encoding to obtain near-optimal service trees which represent the structure of the desired call center. We introduce several modifications to the original Dandelion encoding in order to adapt it to the specific problem of service tree design. Two search space size reduction procedures improve the performance of the algorithm. Systematic experiments have been tackled in order to show the performance of our approach: first, we tackle different synthetic instances, where we discuss and analyze several aspects of the proposed evolutionary algorithm, and second, we tackle a real application, the design of the call center of an Italian telecommunications company. In all the experiments carried out we compare our approach with a lower bound for the problem based on information theory, and also with the results of a Huffman algorithm we have used for reference. This paper has proposed an evolutionary algorithm for designing interactive voice response systems within call center systems in an optimal way. The problem is equivalent to the design of an oriented tree with the minimum average service time. The proposed evolutionary algorithm uses an encoding based on the Dandelion code, recently proposed as a good technique for tree encoding in heuristic algorithms. Several modifications of the Dandelion encoding have been applied in order to adapt it to the specific problem tackled and to improve the performance of the algorithm. Specifically, two search space size reduction procedures have been presented which improves the quality of the solutions found by the evolutionary algorithm. Systematic experiments have been carried out in order to test the performance of our approach, including a real case of the design of a call center for an Italian mobile telecommunications company. The results obtained showed that our approach is able to obtain very good services trees improving the results of a Huffman approach and very close to a lower bound (entropic bound) for the problem. As future work, we can consider the recursive use of the algorithm for the case of grouping services in such a way that tree substructures can be considered for the nodes which must be grouped. Also, the joint optimization of the IVR part and human part of the call centers can be accomplished with certain modifications in the algorithm.

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The emotion paradox in the aging brain This paper reviews age differences in emotion processing and how they may relate to age-related changes in the brain. Compared with younger adults, older adults react less to negative situations, ignore irrelevant negative stimuli better, and remember relatively more positive than negative information. Older adults' ability to insulate their thoughts and emotional reactions from negative situations is likely due to a number of factors, such as being less influenced by interoceptive cues, selecting different emotion regulation strategies, having less age-related decline in prefrontal regions associated with emotional control than in other prefrontal regions, and engaging in emotion regulation strategies as a default mode in their everyday lives. Healthy older adults' avoidance of processing negative stimuli may contribute to their well-maintained emotional well-being. However, when cardiovascular disease leads to additional prefrontal white matter damage, older adults have fewer cognitive control mechanisms available to regulate their emotions, making them more vulnerable to depression. In general, although age-related changes in the brain help shape emotional experience, shifts in preferred strategies and goal priorities are also important influences. Emotions prepare the body for action, guide decisions, and highlight what should be attended to and remembered. However, it can be difficult to turn off or ignore emotions. When negative emotions last for a long time and are maintained even when no longer appropriate, disorders such as chronic depression or anxiety ensue. As emotions are central to everyday function and well-being, it is important to understand how aging affects the experience and regulation of emotion. Recent research reveals intriguing findings about emotion and aging and raises questions about which aspects of these age-related changes in emotional processing can be accounted for by age-related changes in the brain, and which are more influenced by other factors, such as changes in other body systems, increased experience, or shifts in goals. In this paper, I review various types of age differences in emotion experience and regulation, and discuss relevant changes in the brain. Knowing about the declines expected in cognitive function and physical health for older adults might lead one to predict significant declines in well-being and emotion regulation. But a paradox of aging is that the frequency of negative affect and incidence of depression actually decrease. What might explain this surprising pattern? This review highlights the fact that age-related changes in emotion cannot be explained simply by which brain regions decline most structurally with age, although such brain changes may help shape emotion regulation strategies. In addition, other obvious explanations, such as the ideas that older adults are more skilled at regulating emotions or experience negative stimuli less intensely, also are insufficient to explain the full pattern of age-related changes. Instead, it is important to consider age-related shifts in preferred strategies and priorities and how these interact with the strengths and vulnerabilities of the aging brain to better understand how emotional experience changes with age.. Compared with younger adults, older adults pay attention to different types of emotional stimuli and prefer to regulate their emotions in different ways. In their attention and memory, older adults often show a positivity effect, in which they favor positive relative to negative stimuli more than younger adults do. Despite age impairments in ignoring neutral distractions, older adults are even better than younger adults at ignoring distracting negative stimuli. Furthermore, with age preferred emotion regulation strategies shift to favor suppression over rumination or reappraisal. When viewing emotional stimuli, older adults often show an increase in prefrontal activity (relative to viewing neutral stimuli) that is greater than that shown by younger adults.. How do these findings relate to the fact that that ventromedial prefrontal brain regions, supporting the types of emotion processing strategies older adults excel at and prefer, decline less structurally than dorsal and lateral prefrontal brain regions (Fig. 1) ? Ventromedial PFC has been linked to many aspects of emotion regulation, and older adults have been shown to engage it more when deeply processing positive stimuli than younger adults. However, not all of the age changes in emotion processing can be explained by a greater reliance on ventromedial PFC among older adults. In younger adults, lateral left inferior frontal gyrus is associated with ignoring negative distraction, which is something that older adults excel at despite significant agerelated declines in cortical thickness in this region. Older adults often show greater increases in dorsal PFC activity when viewing negative stimuli (relative to neutral stimuli) compared with younger adults (Fig. 5A) , again despite the fact that there are agerelated declines in this region. Thus, older adults appear to recruit a variety of prefrontal regions when confronted with negative stimuli-including prefrontal subregions that show significant age-related structural decline as well as those that do not.. This pattern of findings can be explained by the idea that, in addition to age-related changes in brain circuitry underlying emotional processing, there are age-related changes in emotional goals that lead older adults to focus more on regulating emotions. Older adults therefore are more likely to recruit prefrontal resources to regulate emotions than younger adults are. Some emotion regulation strategies, such as reappraisal, may be more difficult for older than younger adults to successfully implement. But unless specifically asked to use such strategies, older adults may be able to downregulate negative affect more effectively than younger adults by focusing more of their resources on this goal and by using strategies that work well for them, such as selectively attending to or ignoring stimuli.. In conclusion, the brain shows many changes with age, and in cognition, these changes mostly result in declines in function. This is not the case for emotional processing. Understanding how some emotional functions can be well-maintained despite declines in brain function should not only advance theories about emotion, but should also help clinicians design interventions to support effective emotional processes throughout life.

O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Adaptive Passivity-Based Control of PEM Fuel Cell/Battery Hybrid Power Source for Stand-Alone Applications 1 Abstract-In this paper, a DC hybrid power source composed of PEM fuel cell as main source, Li-ion battery storage as transient power source and their power electronic interfacing is modelled based on Euler-Lagrange framework. Subsequently, adaptive passivity-based controllers are synthesized using the energy shaping and damping injection technique. Local asymptotic stability is insured as well. In addition, the power management system is designed in order to manage power flow between components.Evaluation of the proposed system and simulation of the hybrid system are accomplished using MATLAB/Simulink. Afterwards, linear PI controllers are provided for the purpose of comparison with proposed controllers responses. The results show that the outputs of hybrid system based on adaptive passivity-based controllers have a good tracking response, low overshoot, short settling time and zero steady-state error. The comparison of results demonstrates the robustness of the proposed controllers for reference DC voltage and resistive load changes. Distributed Generation (DG) has the advantages of low investment, low pollution, high efficiency, and high reliability. Fuel cells (FCs) are mostly being used due to some merits compared to the other types of DG sources [1] . However, one main disadvantage of fuel cell is its slow dynamics [2] . Hence, hybrid power sources are introduced to make the best use of its advantages and elimination of the aforementioned disadvantage [3] [4] [5] . Batteries are a secondary source which can supply power under transient conditions [6] .. Fuel cells act as converters which convert the chemical energy into electrical energy [7] . Proton Exchange Membrance (PEM) fuel cell is a prime candidate for hybrid systems, because it has higher power density and lower operating temperature than the other types of FC systems [8] .. Power electronic converters have a significant role in the hybrid systems [9] . These are interface between the DG sources and the other parts of hybrid system [7, 10] . Recently, some of researchers have concerned on control of hybrid power sources [11] [12] [13] . The methods of controller design classifies into two categories: linear and nonlinear. The linear methods performed relying on locally linearized models. Hence, their performance will not remain the same under any changes on equilibrium points. The PI controller is a main linear controller which is being used in DG applications [14] [15] [16] [17] . The dynamic equations of the power electronic converters have a nonlinear nature due to the multiplications of the state variables by the control inputs [18] . Therefore, the nonlinear methods such as robust [19] [27, 28] .. Lee has used EL-PBC for control of three phase AC/DC voltage source converter [29] . Also, a single phase PWM current source inverter control with applying IDA-PBC has been implemented by Komurcugil [30] . The control of DG hybrid systems based on the IDA-PBC is achieved [31] . In the most of hybrid systems, the value of the resistive load is constant but unknown. Therefore, adaptive type of controllers has been used to handle this type of uncertainty. Sira-Ramirez et al., has developed adaptive input-output linearization controller [32] , and adaptive passivity based controller [33] for DC/DC converters.. The study in this paper is concentrated on the lagrangian modeling of the fuel cell/battery DC hybrid power source, which the fuel cell is a main power source and battery storage is used as a transient power source. The control signals are achieved by Adaptive PBC (APBC). Power flow between hybrid system components is managed in the power management unit.. The paper is organized as follows. Section II introduces the hybrid DC power source and explains the suitable model of each component which is applied on hybrid system. Section III presents Euler-Lagrange model of DC hybrid power source. Adaptive Passivity-Based Controllers design is achieved in section IV Linear PI controllers are provided in section V for comparison with proposed system. Section VI describes power management system. Section VII validates the proposed model by simulation results and section VIII concludes the paper.

B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O