Computer Model

Conscious events interact with memory systems in learning, rehearsal and retrieval (Ebbinghaus 1885/1964; Tulving 1985). Here we present hypotheses that arise from the IDA computional model (Franklin, Kelemen and McCauley 1998; Franklin 2001b) of global workspace theory (Baars 1988, 2002). Our primary tool for this exploration is a flexible cognitive cycle employed by the IDA computational model and hypothesized to be a basic element of human cognitive processing. Since cognitive cycles are hypothesized to occur five to ten times a second and include interaction between conscious contents and several of the memory systems, they provide the means for an exceptionally fine-grained analysis of various cognitive tasks. We apply this tool to the small effect size of subliminal learning compared to supraliminal learning, to process dissociation, to implicit learning, to recognition vs. recall, and to the availability heuristic in recall. The IDA model elucidates the role of consciousness in the updating of perceptual memory, transient episodic memory, and procedural memory. In most cases, memory is hypothesized to interact with conscious events for its normal functioning. The methodology of the paper is unusual in that the hypotheses and explanations presented are derived from an empirically based, but broad and qualitative computational model of human cognition.

Command Control, Communication Computer and Intelligence (C4I) systems enables modern military forces to achieve information superiority in the battlefield. C4I are complex System of systems (SOS) where individual systems interact locally to achieve global SOS behaviors. To build software for C4I systems conventional software engineering SwE process and practices have shortcomings and are not capable to support certain aspect of these systems. If C4I systems fail to operate as required due to the fact that SwE process was unable to fulfill its requirements, the consequences may not be tolerated because of the criticality of the mission of these systems in information warfare (IW). This paper highlights the distinguished characteristics and operational requirements of C4I systems which poses challenges to SwE process and practices. This paper also discuss the possible future research areas in order to enhance SwE process so that better software could drive these complex systems as required.

In this paper a new pedestrian mobility model for outdoor scenarios is presented. It captures realistic features like moving-in-groups, conscious traveling and smart traveling. The routing algorithm proposed within the model works under a step by step approach, leading users to their destination while, at the same time, using more attractable streets from a pedestrian point of view. The model concept is perfectly generic and applicable to any pedestrian outdoor scenario, provided that the street database and pedestrian traffic information is available. The mobility model was validated using Lisbon's downtown as a case study. The output shows a high correlation between simulated and real data, thus validating the approach.

Abstract—The current proliferation of mobile devices has resulted in a large diversity of hardware specifications, each designed for different services and applications (e.g. cell phones, smart phones, PDAs). At the same time, e-mail message delivery has become a vital part of everyday communications. This article provides a cost-aware study of an RSA-based e-mail protocol executed upon the widely used Apple iPhone1,2 with ARM1176JZF-S, operating in an High Speed Downlink Packet Access (HSDPA) mobile environment. The proposed study employs formal analysis techniques, such as probabilistic model checking, and proceeds to a quantitative analysis of the e-mail protocol, taking into account computational parameters derived by the devices ’ specifications. The value of this study is to form a computer-aided framework which balances the tradeoff between gaining in security, using high-length RSA keys, and conserving CPU resources, due to hardware limitations of mobile devices. To the best...

As simulator-based training systems become more complex, the amount of effort required to generate, monitor, and maintain training exercises multiplies greatly. This has significantly increased the burden on the instructors, potentially making the training experience less efficient as well as less effective. Research on intelligent tutoring systems (ITS) has largely addressed this issue by replacing the instructor with a computer model of the appropriate pedagogical concepts and the domain expertise. While this approach is highly desirable, the effort required to develop and maintain an ITS can be quite significant. A more modest as well as practical alternative to an ITS is the development of intelligent computer-based tools that can support the instructors in their tasks. The advantage of this approach is that various tools can be developed to address the different aspects of the instructor's duties. Moreover, without the burden of having to repace the instructor, these tools are more easily developed and fielded in existing trainers. One aspect of an instructor's task is to assess the students' performance after each training exercise and select the next exercise based on their previous performances. It would clearly be advantageous if this exercise selection process were to be automated, thus relieving the instructor of a significant burden and allowing him to concentrate on other tasks. Therefore, the focus of this paper is the development of a stand-alone system capable of determining exercise progression and remediation automatically during a training session in a simulator-based trainer, on the basis of the students's past performance. Instructional heuristics were developed to carry out the exercise progression process. A prototype was developed and applied to gunnery training on the Army M1 main battle tank. I. PROBLEM STATEMENT AND OBJECTIVE OF RESEARCH NTELLIGENT tutoring systems (ITS) are generally devel-I oped to take the place of the instructor. Ideally, by having no human instructor, the efficiency of an instructor is increased infinitely. Control of the progression of exercises, evaluation of performance, feedback to student, and student record update are some of the functions that can be automated by an ITS. However, the level of effort required to develop and field a full ITS can be quite high and therefore very costly, especially when applied to previously existing simulator-based trainers. This paper presents the concept of an Intelligent instructor Support System (ZZSS) [l] as an alternative to an ITS for simulator-based training. Rather than replace the isntructor, IISS provides the tools for automating various facets of an Manuscript

The core deficit in attention deficit/hyperactivity disorder (ADHD) continues to present an enigma to scientists, professionals and parents alike. Medication with methylphenidate has to some extent proven successful, but it is still not known exactly what parts of the deficits in ADHD medication influences. It is thus important to further delineate the nature of ADHD and thoroughly investigate the possible subtypes. In this paper we describe some experiments investigating the nature of inhibition, resource allocation, sustained and selective attention, distractibility and task switching among children with ADHD. The conclusions could be used to advocate for different models of ADHD, e.g., a model of deficient response inhibition or a model of non-optimal resource allocation. Below we present our first steps toward a robot model of ADHD. The computational model can reproduce some of the behaviors shown in children with ADHD in experimental situations. The model suggests that a defici...

Globalization of the construction industry has brought unique challenges such as coordination among project participants from different countries. This research attempts to understand cultural differences in international joint-venture (IJV) teams composed of Japanese and American participants, and to develop a prototype computational model-"Cross-Cultural"-Virtual Design Team (CC-VDT)-to seek better organization designs for cross-cultural engineering teams. Based on our case studies, we characterize cultural differences along the dimension of cultural values and cultural practices. Cultural values refer to an individual's preferences in decision making and communication. Cultural practices include the cultural norms for adopting specific coordination mechanisms to control organizations and tasks. CC-VDT incorporates value-practice dimensions based on our observations and a literature survey. The simulated results of the effects of cultural impacts are qualitatively consistent with cultural contingency theory and our observations, validating the reasoning of CC-VDT. These results extend the possibility of using simulation modeling to capture distinguishing cross-cultural phenomena that emerge in global construction projects.

This study presents an initial computational model of shared situation awareness (SA) based upon data collected from a simulated training exercise, designed to mimic real life events in a military personnel recovery center. Situation awareness was measured during the exercise using the Situation Awareness Global Assessment Technique (SAGAT). Our initial model examined how well five factors (social network distance, physical distance, rank similarity, branch similarity, and experience similarity) predicted shared SA. Overall, regression analyses highlighted the significant influence of geographical distribution (physical distance) on the development of shared SA and frequency of communications amongst team members. The discussion centers on the need for developing useful technological tools and techniques for supporting communication and collaboration among distributed teams.

Obtaining accurate system models for verification is a hard and time consuming process, which is seen by industry as a hindrance to adopt otherwise powerful modeldriven development techniques and tools. In this paper we pursue an alternative approach where an accurate high-level model can be automatically constructed from observations of a given black-box embedded system. We adapt algorithms for learning finite probabilistic automata from observed system behaviors. We prove that in the limit of large sample sizes the learned model will be an accurate representation of the data-generating system. In particular, in the large sample limit, the learned model and the original system will define the same probabilities for linear temporal logic (LTL) properties. Thus, we can perform PLTL model-checking on the learned model to infer properties of the system. We perform experiments learning models from system observations at different levels of abstraction. The experimental results show the learned models provide very good approximations for relevant properties of the original system.

A model based on the nite volume method combined with a rst-order approximate Riemann solver is used to solve the two-dimensional shallow w ater wave equation on an unstructured triangular grid. Veri cation of the model is achieved by comparing the model results with analytical solutions as well as documented published results with very good agreement. The model is applied to a case study involving the sudden collapse of a water supply reservoir. These reservoirs are generally located in elevated positions in residential areas and represent a potential risk to life and property. The model is used to predict the progress of the ood ensuing from the instantaneous collapse of a water supply reservoir. The model is conservative, robust, e cient, capable of simulating the wetting and drying processes, resolves shocks, simulates ow around complex geometry and obstacles and includes the in uence of steep bed slopes and friction. 1991 Mathematics Subject Classi cation. 65C20, 65M99.

The model of inclined seam excavation is established acc ording to the deformation characteristics of inclined seam and the principles of FEA. It carried out numerical s imulation method to research rock mass movement, surface subsidence and distribution of stress, which simulated excavat ion with the ANSYS software, at the same time the basi c characteristics of rock movement and the correlative par ameters of surface subsidence are obtained. The ANSYS software can not only compute the deformation mechanism of surface subsidence, but also draw up the distribution contours of stress, the distribution contours of horizontal displace and vertical subsidence. The computing model visuall y displays the deformation and stress distribution of the o verburden rock board, coal strata and lower rock board. The deformation mechanism of surface subsidence provides a refe rence for inclined seam excavation under the building. The underground excavation of mine is the huge and complex system eng...

Most computational models of gender classification use global information (the full face image) giving equal weight to the whole face area irrespective of the importance of the internal features. Here we use a two-way representation of face images that includes both global and featural information. We use dimensionality reduction techniques and a support vector machine classifier and show that this method performs better than either global or feature based representations alone.

Synthetic biology is an emerging field that strives to build increasingly complex biological networks through the integration of molecular biology and engineering. The growth of the field has been supported by progress in the design and construction of synthetic genetic and protein networks. This has led to the possibility of assembling modular components to attain novel biological functions and tools. In addition, these synthetic networks give rise to insights that facilitate the investigation of interactions and phenomena in naturally-occurring networks. Integration of well-characterized biological components into higher order networks requires computational modeling approaches to rationally construct systems that are directed towards a desired outcome. A computational approach would improve the predictability of the underlying mechanisms that would otherwise be difficult to deduce through experimentation alone. The analysis and interpretation of both qualitative and quantitative ...

Simulation of quantum computers using classical computers is a hard problem with high memory and computational requirements. Parallelization can alleviate this problem, allowing the simulation of more qubits at the same time or the same number of qubits to be simulated in less time. A promising approach is to exploit the high performance computing capabilities provided by the latest graphical processing units. In this paper we present a parallel implementation of the QC-lib quantum computer simulator on the GPU using the CUDA programming model. The proposed scheme for partitioning the terms that describe the state of a quantum register takes advantage of the specific characteristics of the CUDA memory spaces and allows for an efficient parallelization of the general singe qubit operator. Experimental results indicate that very good speed-ups can be obtained in contrast with the sequential implementation.

The generalisation of the Internet and the recent technological developments in embedded systems and wireless networks contribute to the realisation of a vision where access to information is possible at any moment and from anywhere. This is particularly attractive with information that is relevant to a specific geographic location. Applications that rely on locationbased services to provide information to mobile users, or that support interaction with real devices in the user neighbourhood, are called location-dependent applications and enhance the relationship between mobile users and a specific geographic location. However, the design of such applications breaks with the existing paradigms and methodologies as the mobile devices and the wireless communication infrastructures have characteristics that are very different from those of desktop computers and wired communication systems. The Around architecture is an open and extensible framework for location-based services that allows network services to be associated with specific geographic locations. By using this architecture applications can select services that are relevant for specific locations. Within the context of the Around project we have developed a prototype system with multiple locationbased services and an application that accesses these services to provide information related to a town transportation system. This paper reports on the design and development of this location-based application. Its design raised several new issues, going from the computational model to the interface paradigm, which are also discussed in this paper. The developed application is composed of several modules: a set of agents which are autonomous units with the knowledge necessary to select and use location-based services in a specific thematic area (e.g. transportation); an HTML output area based on a browser metaphor; and a location-context module responsible for determining the user context. The results show that an application architecture based on a modular approach turns to be very flexible as it becomes very easy to extend its functionality by simply adding or changing the agents that deal with each location-based service.

A central puzzle for theories of choice is that people's preferences between options can be reversed by the presence of decoy options (that are not chosen) or by the presence of other irrelevant options added to the choice set. Three types of reversal effect reported in the decision-making literature, the attraction, compromise, and similarity effects, have been explained by a number of theoretical proposals. Yet a major theoretical challenge is capturing all 3 effects simultaneously. We review the range of mechanisms that have been proposed to account for decoy effects and analyze in detail 2 computational models, decision field theory (Roe, Busemeyer, & Townsend, 2001) and leaky competing accumulators (Usher & McClelland, 2004), that aim to combine several such mechanisms into an integrated account. By simulating the models, we examine differences in the ways the decoy effects are predicted. We argue that the LCA framework, which follows on Tversky's relational evaluation with loss aversion (Tversky & Kahneman, 1991), provides a more robust account, suggesting that common mechanisms are involved in both high-level decision making and perceptual choice, for which LCA was originally developed.

Many animal species live as a group and must therefore move as such. Several authors have suggested that the mechanisms underlying collective movements in primate species appear to rely on complex cognitive skills, given their high level of cognitive abilities. However, recent studies have highlighted the fact that complex patterns do not necessarily imply complex mechanisms. We used a modeling approach to investigate the patterns of collective movement in a semi-freeranging group of brown lemurs. We recorded via digital video cameras the order and joining latencies of the 11 individuals of the group during the departure time of spontaneous group movements. We then assessed whether mimetic mechanisms or the existence of a leader were underlying conditions for the joining process by testing 5 computer models relying respectively on 5 hypotheses: the independence of individuals, an anonymous mimetism, a mimetism according to kinship, a mimetism according to affiliation, and eventually the existence of a leader. We found that departure latencies, associations, and the order of individuals at departure time could all be explained by the mimetism according to affiliation model. Thus, an individual's decision to join the collective movement or not depended on the decision taken by its preferred social partners. These results show the importance of social parameters in primate decision making and that the high cohesion displayed

Balancing computational efficiency with recognition accuracy is one of the major challenges in real-world video-based face recognition. A significant design decision for any such system is whether to process and use all possible faces detected over the video frames, or whether to select only a few 'best' faces. This paper presents a video face recognition system based on probabilistic Multi-Region Histograms to characterise performance trade-offs in: (i) selecting a subset of faces compared to using all faces, and (ii) combining information from all faces via clustering. Three face selection metrics are evaluated for choosing a subset: face detection confidence, random subset, and sequential selection. Experiments on the recently introduced MOBIO dataset indicate that the usage of all faces through clustering always outperformed selecting only a subset of faces. The experiments also show that the face selection metric based on face detection confidence generally provides better recognition performance than random or sequential sampling. Moreover, the optimal number of faces varies drastically across selection metric and subsets of MOBIO. Given the trade-offs between computational effort, recognition accuracy and robustness, it is recommended that face feature clustering would be most advantageous in batch processing (particularly for video-based watchlists), whereas face selection methods should be limited to applications with significant computational restrictions.

Background-The anisotropy of cardiac tissue is a key determinant of 3D electric propagation and the stability of activation wave fronts in the heart. The electric properties of ventricular myocardium are widely assumed to be axially anisotropic, with activation propagating most rapidly in the myofiber direction and at uniform velocity transverse to this. We present new experimental evidence that contradicts this view. Methods and Results-For the first time, high-density intramural electric mapping (325 electrodes at Ϸ4ϫ4ϫ1-mm spacing) from pig left ventricular tissue was used to reconstruct 3D paced activation surfaces projected directly onto 3D tissue structure imaged throughout the same left ventricular volume. These data from 5 hearts demonstrate that ventricular tissue is electrically orthotropic with 3 distinct propagation directions that coincide with local microstructural axes defined by the laminar arrangement of ventricular myocytes. The maximum conduction velocity of 0.67Ϯ0.019 ms Ϫ1 was aligned with the myofiber axis. However, transverse to this, the maximum conduction velocity was 0.30Ϯ0.010 ms Ϫ1 , parallel to the myocyte layers and 0.17Ϯ0.004 ms Ϫ1 normal to them. These orthotropic conduction velocities give rise to preferential activation pathways across the left ventricular free wall that are not captured by structurally detailed computer models, which incorporate axially anisotropic electric properties. Conclusions-Our findings suggest that current views on uniform side-to-side electric coupling in the heart need to be revised. In particular, nonuniform laminar myocardial architecture and associated electric orthotropy should be included in future models of initiation and maintenance of ventricular arrhythmia. (Circ Arrhythmia Electrophysiol. 2009;2:433-440.)

Working memory resources are needed for processing and maintenance of information during cognitive tasks. Many models have been developed to capture the effects of limited working memory resources on performance. However, most of these models do not account for the finding that different individuals show different sensitivities to working memory demands, and none of the models predicts individual subjects' patterns of performance. We propose a computational model that accounts for differences in working memory capacity in terms of a quantity called source activation, which is used to maintain goal-relevant information in an available state. We apply this model to capture the working memory effects of individual subjects at a fine level of detail across two experiments. This, we argue, strengthens the interpretation of source activation as working memory capacity.

This paper aims to present a methodology to link analysis process to the development of land cover change model. We developed a method to partitioning the study area, located at Central-North region of Rondônia, in land units, characterized by history of occupation using a TM/Landsat image series, from 1985 to 2000 and a geographic database to store spatial and non-spatial information. Land Unities, called UOP, express different land cover patterns linked to different deforestation process in time and space. The UOP mapping allowed us to analyze the study area throughout deforestation indicators and to capture the diversity of occupation processes and some factors that affects deforestation distribution. This work allowed us to define some computational modeling requirement to support Rondônia space-time complexity as, multiple resolutions, multiple times events, multiple actors and behaviors.

In daily human interactions spatial reasoning occupies an important place. With this ability we can build relations between objects and people, and we can predict the capabilities and the knowledge of the people around us. An interactive robot is also expected to have these abilities in order to establish an efficient and natural interaction.

In this paper, we propose a novel region-based active contour model for image segmentation. Our model incorporates the global and local information in the energy function, enabling efficient segmentation of images while accounting for intensity inhomogeneity. Another interesting property of the proposed model is its convexity, making it independent of the initial condition and hence ideal for an automatic segmentation. Furthermore, the energy function of the proposed model is minimized in a computationally efficient way by using the Chambolle method. Experimental results on natural and medical images demonstrate the performance of our model over the current state-of-the-art.

Knowledge management (KM) represents a topic of considerable current interest. However, the majority of extant KM research treats knowledge as a static object that can be acquired, stored and retrieved through information technology. Two fundamental problems emerge from this current majority view: (1) many scholars view knowledge as distinct from information, and (2) very little attention is paid to the

An agent-based computational modeling of the lottery market is established in this paper. Gamblers are modeled as autonomous agents with fuzzy logic and genetic algorithms. Three empirical observations from lottery markets are taken into account in the model of agents, namely, the halo effect and lottomnia, conscious selection of betting numbers, and aversion to regrets. The effect of the lottery tax rate (takeout rate) on tax revenue is studied in this framework. Our results show the existence of the Laffer curve. The Laffer curve indicates an optimal lottery tax rate at 40%, which is surprisingly close to the empirical tax rate averaged over the 25 lottery markets, 42%. The sensitivity of this result to the emergence of the interdependent preferences is also examined.

Predatory fishes, such as tunas, billfishes, and sharks, coexist in pelagic regions of the tropical oceans. In situ experiments have revealed horizontal and vertical movement patterns for different pelagic species, but the influence of the biotic environment on movement behaviour has not been studied. In this paper, we propose a simple model in which the movement behaviour of these fishes is driven entirely by the biotic environment, without implementing physiological constraints. We explore this concept via computer simulations based on the Latent Energy Environments model [Menczer, F., Belew, R.K., 1996a. From complex environments to complex behaviors. Adapt. Behav. 4(3/4), 317-63]. In our model, multiple behaviours for artificial fishes evolve in a three-dimensional environment where spatial and temporal distributions of prey are patterned after hydroacoustic data taken during ultrasonic telemetry experiments on tunas in the open ocean in French Polynesia. Interactions among individuals are modeled through their shared prey resources. Movement patterns of the adapted individuals are analyzed to: (i) compare artificial individuals with real fishes (three species of tuna, three species of billfishes, and one species of shark) observed by ultrasonic telemetry; and (ii) examine how the artificial fishes exploit their environment. Most of the individuals evolved vertical patterns virtually identical to those exhibited by fishes in the wild. The agreement between our simple model and the ethological data validates the use of computational models for studies of the characteristics of multiple species inhabiting a common ecosystem.

The 64-residue protein chymotrypsin inhibitor 2 (CI2) is a single module of structure. It folds and unfolds as a single co-operative unit by simple Function and Design two-state kinetics via a single rate determining transition state. This Cambridge Centre for Protein transition state has been characterized at the level of individual residues Engineering, University Chemical Laboratory by analysis of the rates and equilibria of folding of some 100 mutants strategically distributed at 45 sites throughout the protein. Only one Lensfield Road, Cambridge CB2 1EW, U.K.

The introduction to medicine of techniques coming from Computational Modeling among other areas, made the use of imaging data such us Computed Tomography (CT), Magnetic Resonance Imaging (MRI), Single Photon Emission Tomography (SPECT), Positron Emission Tomography (PET) and Ultrasound (US) mandatory in order to apply these techniques to patient specific data. The process of identifying different tissues and organs, called segmentation, is a major concern in this analysis. Our aim in this paper is to present a novel image segmentation method based on the topological asymptotic expansion of a cost functional endowed to quantify the cost associated to a specific segmentation of the image data.

We present an image-based 3D reconstruction pipeline for acquiring geo-referenced semi-dense 3D models. Multiple overlapping images captured from a micro aerial vehicle platform provide a highly redundant source for multiview reconstructions. Publicly available geo-spatial information sources are used to obtain an approximation to a digital surface model (DSM). Models obtained by the semi-dense reconstruction are automatically aligned to the DSM to allow the integration of highly detailed models into the original DSM and to provide geographic context.

Activation of the complement system contributes significantly to the pathogenesis of numerous acute and chronic diseases. Recently, a monoclonal antibody (5Gl. 1) that recognizes the human complement protein C5, has been shown to effectively block C5 cleavage, thereby preventing the generation of the pro-inflammatory complement components C5a and C5b-9. Humanized 5Gl. 1 antibody, Fab and scFv molecules have been produced by grafting the complementarity determining regions of 5Gl. 1 on to human framework regions. Competitive ELISA analysis indicated that no framework changes were required in the humanized variable regions for retention of high affinity binding to C5, even at framework positions predicted by computer modeling to influence CDR canonical structure. The humanized Fab and scFv molecules blocked complement-mediated lysis of chicken erythrocytes and porcine aortic endothelial cells in a dose-dependent fashion, with complete complement inhibition occurring at a three-fold molar excess, relative to the human C5 concentration. In contrast to a previously characterized anti-C5 scFv molecule, the humanized h5Gl. 1 scFv also effectively blocked C5a generation. Finally. an intact humanized h5Gl.l antibody blocked human complement lytic activity at concentrations identical to the original murine monoclonal antibody. These results demonstrate that humanized h5Gl. 1 and its recombinant derivatives retain both the affinity and blocking functions of the murine 5G 1.1 antibody, and suggest that these molecules may serve as potent inhibitors of complement-mediated pathology in human inflammatory diseases. (0 1997 Elsevier Science Ltd. All rights reserved.

We describe a method for the visual interactive simulation of wires contacting with rigid multibodies. The physical model used is a hybrid combining lumped elements and massless quasistatic representations. The latter is based on a kinematic constraint preserving the total length of the wire along a segmented path which can involve multiple bodies simultaneously and dry frictional contact nodes used for roping, lassoing and fastening. These nodes provide stick and slide friction along edges of the contacting geometries. The lumped element resolution is adapted dynamically based on local stability criteria, becoming coarser as the tension increases, and up to the purely kinematic representation. Kinematic segments and contact nodes are added and deleted and propagated based on contact geometries and dry friction configurations. The method gives dramatic increase on both performance and robustness because it quickly decimates superfluous nodes without loosing stability, yet adapts to complex configurations with many contacts and high curvature, keeping a fixed, large integration time step. Numerical results demonstrating the performance and stability of the adaptive multiresolution scheme are presented along with an array of representative simulation examples illustrating the versatility of the frictional contact model.

ErbB tyrosine kinase receptors mediate mitogenic signal cascade by binding a variety of ligands and recruiting the different cassettes of adaptor proteins. In the present study, we examined heregulin (HRG)-induced signal transduction of ErbB4 receptor and found that the phosphatidylinositol 3′-kinase (PI3K)-Akt pathway negatively regulated the extracellular signal-regulated kinase (ERK) cascade by phosphorylating Raf-1 on Ser259. As the time-course kinetics of Akt and ERK activities seemed to be transient and complex, we constructed a mathematical simulation model for HRG-induced ErbB4 receptor signalling to explain the dynamics of the regulation mechanism in this signal transduction cascade. The model reflected well the experimental results observed in HRG-induced ErbB4 cells and in other modes of growth hormone-induced cell signalling that involve Raf-Akt cross-talk. The model suggested that HRG signalling is regulated by protein phosphatase 2A as well as Raf-Akt cross-talk, and p...

This work presents a computational model (XML) of the Brazilian Sign Language (Libras), based on its phonology. The model was used to create a sample of representative signs to aid the recording of a base of videos whose aim is to support the development of tools to support genuine social inclusion of the deaf.

This article investigated the role of the recognition criterion in the verbal overshadowing effect (VOE). In 3 experiments, people witnessed an event, verbally described a perpetrator, and then attempted identification. The authors found in Experiment 1, which included a "not present" response option and both perpetrator-present (PP) and perpetrator-absent (PA) lineups, an increased reluctance to identify a person from both lineup types after verbalization. Experiment 2 incorporated a forced-choice procedure, and the authors found no effect of verbalization on identification performance. Experiment 3 replicated the essential aspects of these results. Consequently, the VOE may reflect a change in recognition criterion rather than a changed processing style or alteration of the underlying memory trace. This conclusion was confirmed by computational modeling of the data.

Many studies have focused in designing a set of good DNA sequences as it is one of the crucial tools in improving the reliability and efficiency of DNA computing. In this paper, an improved model of Ant Colony System is developed in optimizing DNA sequences design. The proposed model suggests that each artificial ant represents a possible solution of the

Although substantial advances have been achieved in last twenty years, in practice we are still far from taking full advantage of the potential of knowledge-based systems (KBS). Very few KBS have survived their evaluation period and only one third of those that were initially reported as successful are still in use. The primary purpose of the paper is to report on three KBS applications that have been developed for research purposes in the field of civil engineering. The main challenge underlying all three projects has been to develop computer support systems that would induce changes and improvements to the way that engineers solve their everyday problems. A great deal of effort has been put into eliciting knowledge and reasoning strategies from engineering experts with the aim of building up a computer model of their expertise in order to assist engineers in their decision-making processes. The paper closes by highlighting the principal achievements and the main issues concerning the future development of KBS for solving real life problems.

The paper describes some of the initial results of the CIGRE Working Group C4.605 "Modeling and aggregation of loads in flexible power networks". One of the tasks of the working group is to provide recommendations on developing equivalent static and dynamic models for clusters of diverse loads/generators, i.e., models of distribution network cells and microgrids and recommendations on procedures for data/response gathering and processing. This paper focuses on critical review of existing literature on aggregated models of wind-based generation, active distribution network cells and microgrids for power system studies.