Multi-model nature of time and temporal relations in the SL semantic language

Temporal relations is one of the most complicated and poorly understood trends in linguistics. For analysis the linguistic superoperators of the SL semantic language were used. Objective and subjective frames of reference were introduced. The multi-model nature of time was studied and the tendency of natural language to the three-dimensional time model was suggested. The relations specified by temporal prepositions were analyzed. The temporal relation proved to be invariant in the space of three-dimensional time, i.e., to its usage in the past, present, and future, and specified by three parameters such as the dynamics, topological zone, and time marker.     

Directional relations and frames of reference

As an intermediate category between metric and topology, directional relations are as much varied as “right of”, “before”, “between”, “in front of”, “back”, “north of”, “east of”, and so on. Directional relations are ambiguous if taken alone without the contextual information described by frames of reference. In this paper, we identify a unifying framework for directional relations and frames of reference, which shows how a directional relation with its associated frame of reference can be mapped to a projective relation of the 5-intersection model. We discuss how this knowledge can be integrated in spatial query languages.     

COMMON-SENSE SPATIAL REASONING FOR INFORMATION CORRELATION IN PERVASIVE COMPUTING

The current technological trend depicts a scenario in which space, and more generally the environment in which the computation takes place, represents a key aspect that must be considered in order to improve systems' context awareness, even if the kind of information processed is not only of spatial nature. This article focuses on the notions of “place” and “conceptual spatial relation” to present a formal model of space supporting common-sense spatial reasoning. The model can be viewed as the semantic specification for a hybrid logic, whose formulas represent spatially qualified information. Interesting classes of common-sense spatial models are identified according to the properties of their characteristic relations and an axiomatization of the associated hybrid language is given; a sound and complete tableau-based calculus for these classes of models is provided.     

Dynamic neural observers and their application for identification and purification of water by ozone

A dynamic neural network is applied to estimate the state of the “phenol-water-ozone” chemical system. A new method based on dynamic neural observers with sliding mode (signum) term is used to estimate the dynamics of decomposition of phenols by ozone and to identify their kinetic parameters without the use of any process model. Decomposition of phenols and their mixtures by ozone in a semi-batch reactor is regarded as a dynamic process with an uncertain model (“black box”). Only the content of gaseous ozone is measured at the reactor output during ozonization. Variations of this variable are used to construct a total characteristic curve of the ozonization process. A dynamic state observer is used to estimate the phenol ozonization constant at different pH values from 2 to 12. Experimental data on decomposition dynamics are in good agreement with their estimates. Our method is helpful in on-line monitoring of water purification process without the use of special chemical sensors.     

A language learning support system using course-centered ontology and its evaluation

This paper presents a course-centered ontology for assisting learning support systems to embody the relations among knowledge points and also among the learning materials for those knowledge points. An “individual-class-individual” ontology design (first an individual-class design, then an innovative design about relations among bottom individuals), was applied to the construction of a course-centered ontology for an existing Japanese grammar course. Furthermore, a customizable language learning support system was built to manipulate the course-centered ontology to provide an interface for the learning objects arrangement which displays the visual representation of knowledge points and their relations. The intention underlying the development of the system is to encourage instructors to orient their teaching materials to specific knowledge points and even directly to relations between knowledge points. With these orientations, the learning support system is able to provide an environment in which learners can readily distinguish between related knowledge points. Finally, based on the result of a preliminary evaluation, a study to explore the impact of learning styles and learning habits on learning performance was conducted to further evaluate our ontology-based learning support system. The results of the study suggest three main points: (a) the experimental students who learned with our system achieved significantly better learning achievement than those who just did self-study with textbooks after studying the same target contents for 60 mins; (b) the learning achievement of experimental group was not related to either their learning style in Sequential/Global dimension or their habit of “learning from comparison”; (c) in terms of the learning perception of experimental group, compared to “Sequential learners”, most “Global learners” had a stronger feeling that the comparison function is useful in improving their learning performance, and the learners who don't habitually “learning from comparison” were more likely to suffer from lack of the attention and feel more pressure than those who do habitually “learning from comparison”.     

Visualization and User-Modeling for Browsing Personal Photo Libraries

We present a user-centric system for visualization and layout for content-based image retrieval. Image features (visual and/or semantic) are used to display retrievals as thumbnails in a 2-D spatial layout or “configuration” which conveys all pair-wise mutual similarities. A graphical optimization technique is used to provide maximally uncluttered and informative layouts. Moreover, a novel subspace feature weighting technique can be used to modify 2-D layouts in a variety of context-dependent ways. An efficient computational technique for subspace weighting and re-estimation leads to a simple user-modeling framework whereby the system can learn to display query results based on layout examples (or relevance feedback) provided by the user. The resulting retrieval, browsing and visualization can adapt to the user's (time-varying) notions of content, context and preferences in style and interactive navigation. Monte Carlo simulations with machine-generated layouts as well as pilot user studies have demonstrated the ability of this framework to model or “mimic” users, by automatically generating layouts according to their preferences.     

Interactive frames constructed in Second Life meetings: a study in educational and professional settings

Based on the analysis of “real” Second Life meetings data, in educational and professional settings, our objective is to understand the actual uses of this kind of Virtual World and more particularly, the interactive frames constructed in SL meetings and their interrelation with uses of communication media. The originality of our analytical framework stems from the combination of two perspectives: a third view perspective based on analyses of observational data and a first view perspective based on users’ reports on their experience in SL. Our results highlight: boundaries between serious and recreational registers; avatar’s expression and attribution of feelings to the person “behind”; spatial positioning as indicators and constructors of roles and engagement; management of communication fluidity and joint focus; narrowing of communication media used for task focus content; emerging mediation role for management of fractured exchanges.     

Estimation of attraction domains in wheeled robot control

Considered is the control design problem for planar motion of a wheeled robot. The mathematical model of the robot accounts for kinematic relationships between the velocity of a given point of chassis referred to as the reference point, orientation of the chassis, and control. Among the kinematic relations is the requirement that each of the four wheels perform a slip-free motion. The rear wheels are assumed to be driving while the front wheels are responsible for the rotation of the chassis. The control objective is to place the reference point in the prespecified trajectory and to stabilize the motion of the reference point along the prespecified trajectory. The trajectory consists of line segments and circular arcs. In the mathematical model under consideration, the current curvature of the trajectory of the reference point is taken as control; it is related to the steering angle of the front wheels by a simple algebraic expression. The control is subject to two-sided constraints due to limitations on the steering angle of the front wheels. For the control law proposed, the attraction domain in the space “distance to the trajectory—orientation” is analyzed. For the initial conditions from this domain, the system is guaranteed to hit a trajectory with given index of exponential stability.     

度量参数与空间关系描述的研究

度量参数作为对9交集拓扑关系模型所识别的关系种类的细化,在判断一种几何结构是否匹配一个空间术语时,相比于单独使用拓扑,它能提供更精确的描述。文中分析了9交集模型在实际应用中的不足以及目前的度量参数不支持带孔面对象的缺点,定义了三对细化的面面拓扑关系,并提出了一组支持带孔面对象的面对象间空间关系度量参数。这些度量参数加强了面对象间空间关系的描述,可广泛应用于空间查询和空间分析中。     

Equivalence relations among interconnection networks

The interconnection network equivalence notions reported in the literature are formalized via conjugation maps over the sets of interconnections of such networks. Various forms of relations including group isomorphisms among interconnection networks are introduced. Equivalence relations express the degrees of freedom in “making one network behave like another.” Examples of these relations for commutative cube-connected networks with individual stage control are also included. In addition, an algorithm is provided to construct equivalence maps among such networks.     

Fractional attitude-reactive control for robust quadrotor position stabilization without resolving underactuation

Quadrotors are Unmanned Aerial Systems (UAS), whose nonlinearities, uncertainties, and unavoidable aerodynamic disturbances stand for a difficult control problem. Additionally, the highly nonlinear coupling between the position and the orientation dynamics exacerbates the underactuation problem when the objective is the position tracking. In this paper, aiming at designing a robust position controller without resolving underactuation, a novel “reactive orientation control” is proposed. The orientation controller is model-free and it is build upon differintegral fractional operators to react to a continuous and bounded additive term that stands for an affine exogenous position controller. Such term indeed becomes an attitude disturbance that is purposely injected to displace the quadrotor towards the desired position of the underactuated coordinates. The closed-loop analysis shows that the norm of the transfer function between the disturbance and the position tracking error is minimized for a stable and robust position regime. Simulations and experimental results are given to discuss the feasibility of the proposed scheme.     

Topological spatial relations for active visual search

If robots are to assume their long anticipated place by humanity’s side and be of help to us in our partially structured environments, we believe that adopting human-like cognitive patterns will be valuable. Such environments are the products of human preferences, activity and thought; they are imbued with semantic meaning. In this paper we investigate qualitative spatial relations with the aim of both perceiving those semantics, and of using semantics to perceive. More specifically, in this paper we introduce general perceptual measures for two common topological spatial relations, “on” and “in”, that allow a robot to evaluate object configurations, possible or actual, in terms of those relations. We also show how these spatial relations can be used as a way of guiding visual object search. We do this by providing a principled approach for indirect search in which the robot can make use of known or assumed spatial relations between objects, significantly increasing the efficiency of search by first looking for an intermediate object that is easier to find. We explain our design, implementation and experimental setup and provide extensive experimental results to back up our thesis.     

Computational Models in Architecture: Understanding Multi-Dimensionality and Mapping

The aim of this paper is to discuss computational thinking and parametric design and thus “what model is” in the realm of mathematics in architecture. Here we investigate how multi-dimensionality and reference systems should be contemplated, along with what mapping is and how it is related with algorithms in computational design. Set theory and functional relations are re-visited and similarity/similitude concepts and the importance of nondimensional parameters relating different reference systems (interpreted as domain and range relations) are pointed out. In this context, computational design approaches based on modern biomimetic studies in architecture which are beyond metaphors or analogies are considered as the prominent cases of the present inquiry.     

Adaptive sliding-mode controller based on the “Super-Twist” state observer for control of the Stewart platform

To provide a highly efficient control of nonlinear systems in the presence of nonmodeled dynamics and external perturbations, a new control law with feedback based on the sliding modes with an observer of the “Super-Twist” kind was proposed. For acceptable use of the continuous observer signal in the controller, presented were adaptive laws for adjustment of the control system parameters. Using the methods of Lyapunov function, system stability (convergence to a zone) was proved. This technique was proposed as an example of control and stabilization of the position of a parallel manipulator (Gough–Stewart platform). The presented mechanism with six degrees of freedom is used to control the secondary mirror of the “Large Millimeter Telescope Alfonso Serrano” situated in the state of Puebla, Mexico.     

Mining language variation using word using and collocation characteristics

Two textual metrics “Frequency Rank” (FR) and “Intimacy” are proposed in this paper to measure the word using and collocation characteristics which are two important aspects of text style. The FR, derived from the local index numbers of terms in a sentences ordered by the global frequency of terms, provides single-term-level information. The Intimacy models relationship between a word and others, i.e. the closeness a term is to other terms in the same sentence. Two textual features “Frequency Rank Ratio (FRR)” and “Overall Intimacy (OI)” for capturing language variation are derived by employing the two proposed textual metrics. Using the derived features, language variation among documents can be visualized in a text space. Three corpora consisting of documents of diverse topics, genres, regions, and dates of writing are designed and collected to evaluate the proposed algorithms. Extensive simulations are conducted to verify the feasibility and performance of our implementation. Both theoretical analyses based on entropy and the simulations demonstrate the feasibility of our method. We also show the proposed algorithm can be used for visualizing the closeness of several western languages. Variation of modern English over time is also recognizable when using our analysis method. Finally, our method is compared to conventional text classification implementations. The comparative results indicate our method outperforms the others.     

Spatial relations between 3D objects: The association between natural language,topology, and metrics

With the proliferation of 3D image data comes the need for advances in automated spatial reasoning. One specific challenge is the need for a practical mapping between spatial reasoning and human cognition, where human cognition is expressed through natural-language terminology. With respect to human understanding, researchers have found that errors about spatial relations typically tend to be metric rather than topological; that is, errors tend to be made with respect to quantitative differences in spatial features. However, topology alone has been found to be insufficient for conveying spatial knowledge in natural-language communication. Based on previous work that has been done to define metrics for two lines and a line and a 2D region in order to facilitate a mapping to natural-language terminology, herein we define metrics appropriate for 3D regions. These metrics extend the notions of previously defined terms such as splitting, closeness, and approximate alongness. The association between this collection of metrics, 3D connectivity relations, and several English-language spatial terms was tested in a human subject study. As spatial queries tend to be in natural language, this study provides preliminary insight into how 3D topological relations and metrics correlate in distinguishing natural-language terms.     

Statistical properties of differences between low and high resolution CMAQ runs with matched initial and boundary conditions

Numerical simulations of air quality models provide unique and different outputs for different choices of grid size. Thus, an important task is to understand the characteristics of model outcomes as a function of grid size in order to assess the quality of the model as to its fitness for meeting a specific design objective. This type of assessment is somewhat different than that of traditional operational performance and diagnostic type model evaluation. There, the objective is towards assessing errors in numerical models of air quality and utilizing concentration measurements from monitors to provide the bases for guidance towards model improvement and for their assessment of ability to predict and retrospectively map air quality. However, observations used as “truth” to assess model performance have themselves properties unique to the data collection protocols, siting and spatial density of deployment. In the data assimilation community, the term “model error” is used for the difference between model output given perfect inputs and the “truth” (Kalnay, 2003). In this paper, we are concerned with one aspect of this “model error”, the discrepancy due to discretization of space by choice of grid size in the model. To understand discrepancy due to discretization, outputs from the Community Multiscale Air Quality model (CMAQ) at two resolutions are studied. The lower resolution run is carried out so that its initial and boundary conditions are as similar as possible to those for the higher resolution run, thus minimizing this source of discrepancies and allowing us to isolate discrepancies due to discretization. Differences are analyzed from a statistical perspective by comparing marginal distributions of two outputs and considering spatial variation of the differences. Results indicate sharp increases in spatial variation of the differences for the first few hours of running the model, followed by small increases thereafter. The spatial variation of the differences depends on the individual spatial structure of the original processes, which we show varies with the time of day. We also show that the spatial variations on sub-regions depend on whether the sub-region is in a rural or an urban area.     

A GENERAL APPROACH TO THE STUDY OF SPATIAL SYSTEMS;I. The Relational Representation of Measurable Attributes

In this, the First part of a two part work, a general model of spatial organization is introduced. Following a brief synopsis of some of Spinoza's and Leibniz's views regarding natural structure, an extension of the Spinozian model is presented in which the attribute spatial extension is portrayed as a relational system that implicitly underlies the differentiation of sensible space into “modifications” (“natural systems”) and the latter's subdifferentiation into “modes” On the basis of this model, all instances of modal differentiation are understood to take place in a manner explained by this relational structure, the existence (but not the specific characteristics) of which is initially assumed. The nature of the structure is then deduced according to a “most-probable-state” kind of logic; next, it is demonstrated via simulation that the resulting aspatial model of internal relations has a corresponding spatial interpretation (and therefore, in theory, that sensible space structures can be supported by the particular rational ordering posed). The matter of how to apply the model to the study of real world systems is taken up last; discussion focuses on related aspects of the treatment of equilibrium and nonequilibrium systems and the recognition and measurement of modal structures.