Naturality of the conditional and the recursion ∗

In a class of categories, including E. Manes's assertional ones, the control structures if-then-else and repeat-until are modeled as natural transformations of suitable functors. This context show how the three basic pieces of any structured programming language (concatenation, conditional and recursion) share naturality.     

Simulation and Improvement of the Processing Subsystem of the Manchester Dataflow Computer

The Manchester dataflow computer is a famous dynamic dataflow computer.It is centralized in architecture and simple in organization.Its overhead for communication and scheduling is very small.Its efficiency comes down,when processing elements in the processing subsystem increase.Several articles evaluated its performance and presented improved methods.The authors studied its processing subsystem and carried out the simulation.The simulation results show that the efficiency of the processing subsystem drops dramatically when average instruction execution microcycles become less and the maximum instruction execution rate is nearly attained.Two improved methods are presented to oversome the disadvantage.The improved processing subsystem with a cheap distributor made up of a bus and a two-level fixed priority circuit possesses almost full efficiency no matter whether the average nstruction execution microcycles number is large or small and even if the maximum instruction execution rate is approached.     

Theory and Practice of the Stereo-View on the CRT Screen

Of the various kinds of research on the Virtual Reality and GIS,stereo-view is one of the key technologies.The following two aspects are covered in this paper,(1) Physiological fundamental of the natural binocular stereo-vision,theory of 3D color TV and the stereo-view on the CRT screen are presented,especially the theory of widely adopted Time-Division System is introduced.(2)The preliminary practice for using the stereo-view technology on the screen to the terrain visual simulation is described,and the paper shows how to use 3DS to construct a movable real stereo terrain perspective by taking DTM data as the first hand information for the purpose of terrain visual simulation.     

An easy and efficient combination of the Mixed Finite Element Method and the Method of Lines for the resolution of Richards’ Equation

In this work, the Mixed Hybrid Finite Element (MHFE) method is combined with the Method Of Lines (MOL) for an accurate resolution of the Richard's Equation (RE). The combination of these methods is often complicated since hybridization requires a discrete approximation of the time derivative whereas with the MOL, it should remain continuous. In this paper, we use the new mass lumping technique developed in Younes et al. [Younes, A., Ackerer, P., Lehmann, F., 2006. A new mass lumping scheme for the mixed hybrid finite element method. International Journal for Numerical Methods in Engineering 67, pp. 89–107.] for the MHFE method. With this formulation, the MOL is easily implemented and sophisticated time integration packages can be used without significant amount of work.Numerical simulations are performed on both homogeneous and heterogeneous porous media to show the efficiency and robustness of the developed scheme.     

Presence in personalised e-learning – the impact of cognitive and emotional factors and the moderating role of gender

ABSTRACT

Digital technologies offer tremendous opportunities to develop flexible and personalised e-learning environments which are capable of delivering high-quality services. The success of these e-learning environments is linked to their ability to elicit subjective experiences of presence, through which e-learners feel individually ‘placed’ within a true, humanised education environment. We built an integrated model that situates cognitive processes (the e-learner’s perceived control, focused attention, mental imagery) and emotion at the core of presence formation, and considers the moderating role of gender. We tested the model with a large sample of students at a personalised e-learning environment. The results indicate that cognitive and emotional processes, all unleashed by external stimuli coming from the personalised e-learning environment, activate presence and that gender has a crucial moderating role for emotion-presence predictions.     

Tracking the calibration stability and consistency of the 3.7, 11.0 and 12.0 μm channels of the NOAA-KLM AVHRR with MODIS

The NOAA-KLM satellites (NOAA-15 to 18) are the current polar-orbiting operational environmental satellites (POES) that carry the Advanced Very High Resolution Radiometer (AVHRR). This study examines the calibration stability and consistency of all three infrared channels (3.7, 11.0 and 12.0 μm) of AVHRR onboard NOAA-15 to 18. The short-term stability is examined from variations of the scan-by-scan gain response, while the long-term stability and calibration consistency are examined by tracking the trends of gain response and measured scene brightness temperatures. The relative differences of observed scene brightness temperatures among NOAA-15 to 18 AVHRR are determined using MODIS as a transfer radiometer based on observations from simultaneous nadir overpasses (SNO). Results show that variations of the scan-to-scan gain responses are within 0.10% under normal operational conditions, while long-term gain changes over six years from 2001 to 2006 vary from 2 to 4% depending on channel. Long-term trending results show that total six-year drifts in observed brightness temperature from NOAA-15 to 18 AVHRR are less than 0.5 K for a given scene temperature in the 250 to 270 K range for the 3.7, 11.0 and 12.0 μm channels, respectively. The calibration consistency is examined for a scene temperature range of 220 to 290 K. The temperature biases among NOAA-16 to 18 AVHRR are within ±0.5 K for the 11.0 and 12.0 μm channels. For NOAA-15 AVHRR, biases of –2.0 K at 11.0 μm and –1.5 K at 12.0 μm are found in comparison with others at the low end of the temperature range. For the 3.7 μm channel, relative biases up to a few degrees among NOAA-15 to 18 could be found at low brightness temperatures.     

Nomadicity and the Care of Place—on the Aesthetic and Affective Organization of Space in Freelance Creative Work

While information and communication technology enables freelancers to work “anytime anywhere”, it has become apparent that not all places seem to be equally suitable for their work. Drawing from CSCW literature on the practical accomplishment of mobile work and theoretical literature on creativity, insights from ethnographic studies in New York, Berlin and Wiesbaden are discussed. The paper follows workers in their everyday attempts to seek out and enact work environments, which enable them to be creative and productive. In these processes, mobility features both as a problem and a resource. The search for the right place makes these workers restless, but sometimes restlessness and nomadicity can inspire creativity. Similarly, new mobile, social and collaborative technologies allow a new balancing of solitude and sociality. I call this emerging nexus of practices which entails aesthetic, affective, social and socio-political dimensions the care of place. A conjoint theoretical and empirical analysis aims to draw attention to everyday lived practices of nomadicity and the care of place in a wider discursive and socio-political context to inform CSCW design.     

An examination of the Internet’s development as a disabling environment in the context of the social model of disability and anti-discrimination legislation in the UK and USA

Research indicates that inaccessible website design persists despite the existence of anti-discrimination legislation and the influence of the social model of disability on policy development. In this paper, the concept of universal access is examined in the light of the social model of disability in relation to both the physical and virtual environments. The manner in which disability is often deemed a design afterthought is highlighted. The need for universal access is then placed alongside a discussion of access to the Internet in relation to an ageing population and people with cognitive difficulties. Subsequently, anti-discrimination provisions are analysed in relation to how they support designers’ focus on an accepted normality to which reasonable adjustments need to be made, rather than the acquisition of full universal access.     

Design and Study of the Active Router Structure

Active network is a new framework where network nodes not only forward packets, but also perform customized computation on the packets flowing through them. It provides a programmable interface to the user where users dynamically inject services into the intermediate nodes. This paper brings forward a structure of active router based on 1P network, analyses the extended definition field of IP datagram at~u the format of the active 1P datagram, studies the module structure, the logic flow chart and the arithmetic of active router, thereby realizes the active networks technology in IP network and extends the service in existent network.     

Does the user behavior effect the productivity of hammer drilling? – Analysis of the influences of feed and lateral force

The objective of this study was to investigate the relationship between feed and lateral force with productivity in hammer drilling. Necessary user forces and vibration caused by hammer drilling leads to user fatigue and long-term injuries. Through an increase in productivity, the stress duration and thus injuries caused can be reduced. The user, who influences productivity, applies lateral forces in addition to the feed force during hammer drilling. Their influence and interaction with the feed force on productivity has not yet been investigated. In this study, a total of 1152 boreholes were performed on an automated test bench. Along with the feed and lateral forces, the setup, consisting of hammer drill and drill bit model, was varied in order to investigate interaction effects as well as discuss transferability of the findings. The productivity was evaluated by the rate of penetration (ROP). It was observed that the ROP decreased with increasing lateral forces (p < .001, r = 0.315) and increased with increasing feed force. The detailed courses of these relationships were setup-specific. At low feed forces, the feed and lateral force interacted on the ROP. The investigated relationships indicate an efficient operating range depending on the user forces and setup used, which enables a reduction of the user's stress duration. The findings help engineers develop power tools that provide more efficient and hence less fatiguing work, making them more ergonomic for the user.     

Thermodynamic modeling of the Mg–Bi and Mg–Sb binary systems and short-range-ordering behavior of the liquid solutions

In order to investigate the short range ordering behavior of liquid Mg–Bi and Mg–Sb solutions, thermodynamic modeling of the Mg–Bi and Mg-Sb binary systems has been performed. All available thermodynamic and phase diagram data of the Mg–Bi and Mg–Sb binary systems have been critically evaluated and all reliable data have been simultaneously optimized to obtain one set of model parameters for the Gibbs energies of the liquid and all solid phases as functions of composition and temperature. In particular, the Modified Quasichemical Model, which accounts for short-range-ordering of nearest-neighbor atoms in the liquid, was used for the liquid solutions. A comparative evaluation of both systems was helpful to resolve inconsistencies of the experimental data. The thermodynamic modeling shows the strong ordering behavior in the liquid Mg–Bi and Mg–Sb solutions at Mg₃Bi₂ and Mg₃Sb₂ compositions, respectively, and predicts the metastable liquid miscibility gaps at sub-solidus temperatures. All calculations were performed using the FactSage thermochemical software.     

Creating and modulating rhythms by controlling the physics of the body

The motion behaviors of vertebrates require the correct coordination of the muscles and of the body limbs even for the most stereotyped ones like the rhythmical patterns. It means that the neural circuits have to share some part of the control with the material properties and the body morphology in order to rise any of these motor synergies. To this respect, the chemical downward neuromodulators that supervise the pattern generators in the spinal cord create the conditions to merge (or to disrupt) them by matching the phase of the neural controllers to the body dynamics. In this paper, we replicate this control based on phase synchronization to implement neuromodulators and investigate the interplay between control, morphology and material. We employ this mechanism to control three robotic setups of gradual complexity and actuated by McKibben type air muscles: a single air muscle, an elbow-like system and a leg-like articulation. We show that for specific values, the control parameters modulate the internal dynamics to match those of the body and of the material physics to either the rhythmical and non-rhythmical gait patterns.     

The verification and analysis on the results of the video retrieval system

The retrieval of video information is a key multimedia technology, which has been paid wide-range attention recently. This paper introduces the verification and analysis of video information results in the video retrieval system from three aspects： first, the way of the browse and navigation; second, video summary; third, display and interaction interface.     

Development and Application of the Cauchy–Poisson Method to Layer Elastodynamics and the Timoshenko Equation

We consider a generalization of the Cauchy–Poisson method to an n-dimensional Euclidean space and its application to the construction of hyperbolic approximations. In Euclidean space, constraints on derivatives are introduced. The principle of hyperbolic degeneracy in terms of parameters is formulated and its implementation in the form of necessary and sufficient conditions is given. As the particular case of a four-dimensional space with preserving operators up to the sixth order a generalized hyperbolic equation is obtained for bending vibrations of plates with coefficients dependent only on the Poisson number. As special cases, this equation includes all the well-known Bernoulli–Euler, Kirchhoff, Rayleigh, and Timoshenko equations. As a development of Maxwell’s and Einstein’s research on the propagation of perturbations with finite velocity in a continuous medium, Tymoshenko’s non-trivial construction of the equation for bending vibrations of a beam is noted.     

On the variation and specialisation of workload—A case study of the Gnome ecosystem community

Most empirical studies of open source software repositories focus on the analysis of isolated projects, or restrict themselves to the study of the relationships between technical artifacts. In contrast, we have carried out a case study that focuses on the actual contributors to software ecosystems, being collections of software projects that are maintained by the same community. To this aim, we defined a new series of workload and involvement metrics, as well as a novel approach— $\widetilde{\mathbf{T}}$ -graphs—for reporting the results of comparing multiple distributions. We used these techniques to statistically study how workload and involvement of ecosystem contributors varies across projects and across activity types, and we explored to which extent projects and contributors specialise in particular activity types. Using Gnome as a case study we observed that, next to coding, the activities of localization, development documentation and building are prevalent throughout the ecosystem. We also observed notable differences between frequent and occasional contributors in terms of the activity types they are involved in and the number of projects they contribute to. Occasional contributors and contributors that are involved in many different projects tend to be more involved in the localization activity, while frequent contributors tend to be more involved in the coding activity in a limited number of projects.     

In silico analysis of the binding of agonists and blockers to the β2-adrenergic receptor

Activation of G protein-coupled receptors (GPCRs) is a complex phenomenon. Here, we applied Induced Fit Docking (IFD) in tandem with linear discriminant analysis (LDA) to generate hypotheses on the conformational changes induced to the β(2)-adrenergic receptor by agonist binding, preliminary to the sequence of events that characterize activation of the receptor. This analysis, corroborated by a follow-up molecular dynamics study, suggested that agonists induce subtle movements to the fifth transmembrane domain (TM5) of the receptor. Furthermore, molecular dynamics also highlighted a correlation between movements of TM5 and the second extracellular loop (EL2), suggesting that freedom of motion of EL2 is required for the agonist-induced TM5 displacement. Importantly, we also showed that the IFD/LDA procedure can be used as a computational means to distinguish agonists from blockers on the basis of the differential conformational changes induced to the receptor. In particular, the two most predictive models obtained are based on the RMSD induced to Ser207 and on the counterclockwise rotation induced to TM5.     

The Synthesis and Display of the Natural Eroded Terrain

ＴｈｅＳｙｎｔｈｅｓｉｓａｎｄＤｉｓｐｌａｙｏｆｔｈｅＮａｔｕｒａｌＥｒｏｄｅｄＴｅｒａｉｎＺｏｕＲｏｎｇｊｉｎＪｉａｎｇｓｕＵｎｉｅｒｓｉｔｙｏｆＳｃｅｎｃｅａｎｄＴｅｃｈｎｏｌｏｇｙ，ＪｉａｎｇｓｕＺｈｅｎＪｉａｎｇ，２１２０００Ａｂｓｔｒａｃｔ...     

On the Communication Structures of Hyper-Ring and Hypercube Multicomputers

The well-known torus an its variants,which we call hyper-rings,as well as hypercube architectures are further studied and evaluated as interconnecion networks for multicomputers,Comparisons are made among hyper-rings and between hyper-ring and hypercube networks under different communication patterns.It is concluded that although it is believed that a hypercube is generally superior to hyper-rings in performance,this is not always the case,paricu larly for locally constrained applications,where communications occur mostly among neighboring nodes.