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.     

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.     

What Do the Sun and the Sky Tell Us About the Camera?

As the main observed illuminant outdoors, the sky is a rich source of information about the scene. However, it is yet to be fully explored in computer vision because its appearance in an image depends on the sun position, weather conditions, photometric and geometric parameters of the camera, and the location of capture. In this paper, we analyze two sources of information available within the visible portion of the sky region: the sun position, and the sky appearance. By fitting a model of the predicted sun position to an image sequence, we show how to extract camera parameters such as the focal length, and the zenith and azimuth angles. Similarly, we show how we can extract the same parameters by fitting a physically-based sky model to the sky appearance. In short, the sun and the sky serve as geometric calibration targets, which can be used to annotate a large database of image sequences. We test our methods on a high-quality image sequence with known camera parameters, and obtain errors of less that 1% for the focal length, 1° for azimuth angle and 3° for zenith angle. We also use our methods to calibrate 22 real, low-quality webcam sequences scattered throughout the continental US, and show deviations below 4% for focal length, and 3° for the zenith and azimuth angles. Finally, we demonstrate that by combining the information available within the sun position and the sky appearance, we can also estimate the camera geolocation, as well as its geometric parameters. Our method achieves a mean localization error of 110 km on real, low-quality Internet webcams. The estimated viewing and illumination geometry of the scene can be useful for a variety of vision and graphics tasks such as relighting, appearance analysis and scene recovery.     

A Note on the Difference between the Camera Resection and the PnP Problem

The camera resection and the PnP problem are both of great importance in computer vision field.However,these two fundamentally different problems are often mistaken one another in the literature.In this short note,the essential differences of these two problems are clarified,and such a clarification seems helpful for those who are working on the problems.     

‘Mind the Gap’: diagnosing the relationship between the IT organisation and the rest of the business

The senior management of many organisations are continually disappointed with the benefits and value which they perceive they are getting from their investments in IT. This frustration with IT, and in particular with the IT function, has seen many organisations choose to rid themselves of the ‘problem’ altogether by outsourcing IT activities to a third party. The fact that there is a separate organisational unit responsible for IT activities has led to the emergence of gap between this so called IT organisation and the rest of the business. Culture is often used to explain the gap as if this somehow justifies an organisations inability to effectively leverage IT. However, the premise underlying this article is that culture is an excuse for rather than a cause of ineffective application of IT for business benefits and value. The clear message from this article is that achieving high performance from IT is not just about the IT function's ability to build, maintain and deliver systems, but is an organisational wide activity requiring a strong business/IT partnership. A framework grounded in the research literature, which identifies the elements to manage in creating high performance from IT, is developed and operationalised. The findings of an exploratory survey are presented and research and practitioner implications developed.     

Root-locus method for the Tsypkin and Jury and Lee criteria†

A method is developed for application of the Tsypkin criterion and the Jury and Lee stability criteria for certain classes of non-linear sampled data systems

The method, which uses root-locus techniques, is based on the root-locus interpretation of the Popov criterion for continuous data non-linear systems. This method was developed by Ramapriyan et al. (1966).     

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.     

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.     

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.     

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.     

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.     

Shaping the drivers’ interaction: how the new vehicle systems match the technological requirements and the human needs

Although it is not always possible to derive from statistics the causes of an accident, data clearly show that they are mostly due to a lack of driver’s perception, with high direct and indirect social costs for society (Hutchinson in Road accidents statistics, Rumsby Scientific Publishing, 1987; Kawai in Convergence 1994, Conference Proceedings, 1994; Boussuge in Bilan et perspectives, Revue Gen. des Routes et des Aerodromes, N. 726, 1995). Therefore, a strong integration among all the actors involved (i.e., the drivers, the vehicle or technical system in general and the driving environment) is quite necessary. From the beginning of 1980s, there has been a shift in system concept design, moving from a technological approach towards a human-centred design approach (Norman and Draper 1986; Rouse 1991). Firstly this approach was applied to the human–computer interaction domain, and has also been extended towards complex and automated technological systems (Sheridan in Telerobotics, automation, and human supervisory control, MIT Press, 1992; Scerbo in Human performance in automated systems: theory and applications, Lawrence Erlbaum Associates, 1996) in several domains as, among the others, automotive (Michon in Generic intelligent driver support, Taylor & Francis, 1994) and industrial plants (Cacciabue in Giuseppe mantovani ergonomia, II Mulino, 2000). According to these perspectives, the role of user’s needs in the design process of a certain system becomes crucial; nevertheless, the technological requirements, i.e., the so-called “machine needs” should maintain a role of which the designer should be totally aware. Otherwise, the risk is to fail the design process making a system incoherent and ineffective. Thus, this paper aims at presenting such types of needs, the mutual interaction between machine and users, as well as the interaction of both with the surrounding environment. The work is based on several experiences conducted in the automotive domain.

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.     

The Determining Method about the Conflict between the Null Constraints and the Set of Functional Dependencies

In this paper the conflict between the null constraints and the set of functional dependencies is defined.Some rules for determining the conflicts and a method for processing the conflicts are obtained.     

“… or is the question of being at once the most basic and the most concrete?” On the ambitions and responsibilities of contemporary American philosophy

At its centennial in 2001, the American Philosophical Association bravely proclaimed: “Philosophy Matters.” But does it? It won’t unless it reaches the concreteness of everyday life. To do so was Martin Heidegger’s ambition, and one can read Saul Kripke’s books as an attempt to get mainstream American philosophy beyond its abstractions. At length, Kripke’s efforts, on one reading, failed while Heidegger’s remained incomplete. A theory of commodification can get us closer to the things that matter to us in everyday life.     

Wag the Dog? Online Conferencing and Teaching

Web-accessible conferencing softwareand ``conversational ethics' drawn from Habermas andRawls have successfully brought together on-lineparticipants separated by geography and viewpoint, andoccasionally resulted in consensus regarding otherwisedivisive issues such as abortion. The author describessuccesses, limitations, and costs of incorporatingthese technologies and discourse ethics in a religiousstudies class. Results are striking, but thepedagogical benefits involve technical risks and highlabor and time costs. This experience, coupled withrecent research, suggests that electronic pedagogies,like other teaching strategies, work for some, but notall students: this argues that we take up electronicteaching as one approach among many.     

On the Relationship Between TMS and Logic Programs

The relationship between TMS and general logic programs is an important issue in non-monotonic logic programming.In this paper,we prove that,after we translate the TMS theory into a general logic program,the TMS‘s well-founded assignment (or extension) is equivalent to the corresponding general logic program‘s stable model.It means that TMS can be completely integrated into a non-monotonic logic programming environment.