Influences of Form and Function on the Acceptability of Projective Prepositions in Swedish

Abstract

Projective prepositions express the relation between two objects by referring to a direction in space and have traditionally been regarded as expressing purely geometric relations. Recent studies have shown that the appropriateness of English and Spanish projectives also depends on functional relations between objects. This study investigates if the acceptability of the Swedish projectives över, under, ovanför and nedanför are influenced by functional factors as well, and whether över and under are differentially influenced by function than ovanför and nedanför, as has been shown for their English cognates. It also investigates how the shape and parts of the related objects influence their functional interaction, and thereby the acceptability of the prepositions. This is done with respect to the predictions of the AVS-model, a model of the perceptual processes underlying the apprehension of projectives, which takes both the geometric and the functional relation between objects into account. It was found that acceptability judgments about the prepositions are influenced by function as their corresponding English and Spanish prepositions. The acceptability of över was more sensitive to function than ovanför, whereas under and nedanför were not differentially influenced by function, as has been shown for Spanish. It was further found that the shape and parts of both of the related objects influence acceptability regions associated with the prepositions in predictable ways, as functional interactions between objects largely depend on their parts. The results finally show that the AVS-model needs to be further developed in order to account for the form and function of the located object.     

On Embedding a Qualitative Representation in a Two-Dimensional Plane

Abstract

This paper discusses embedding in a two-dimensional plane a symbolic representation for spatial data using the simple objects, points (P), lines (L), circuits (C), and areas (A). We have proposed PLCA as a new framework for a qualitative spatial reasoning. In a PLCA expression, the entire figure is represented in a form in which all the objects are related. We investigate the conditions for two-dimensional realizability of a PLCA expression, and derive the relation that the numbers of objects in a PLCA expression should have. In this process, we use the well-known Euler's formula. We also give an algorithm for drawing the figure of the PLCA expression that satisfies this condition in a two-dimensional plane and prove its correctness. The algorithm generates a quantitative expression from qualitative expression.     

Approximate qualitative spatial reasoning

Qualitative relations between spatial regions play an importantrole in the representation and manipulation of spatial knowledge.The RCC5 and RCC8 systems of relations,used in the Region-Connection Calculus, are of fundamentalimportance. These two systems deal with ideal regions havingprecisely determined location. However,in many practical examples of spatial reasoning,regions are represented by finite approximations rather than known precisely.Approximations may be given by describing how a regionrelates to cells forming a partition of the space underconsideration. Although the RCC5 and RCC8 systems have beengeneralized to ``egg-yolk' regions, in order to modelcertain types of vagueness, their extension to regionsapproximated in this way has not been discussed before.This paper presents two methods, the syntactic and the semantic, by which the RCC5 and RCC8 systemsmay be defined for approximate regions. The syntactic uses algebraicoperations on approximate regions which generalize operations on preciseregions. The semantic method makes use of the set of preciseregions which could be the intended interpretation of anapproximate region. Relationships between these two methods arediscussed in detail.alternative to navigation training with a map.     

The Space within Fisherman's Folly: Playing with a Puzzle in Mereotopology

Abstract

In this paper we propose a spatial ontology for reasoning about holes, rigid objects and a string, taking a classical puzzle as a motivating example. In this ontology the domain is composed of spatial regions whereby a theory about holes is defined over a mereotopological basis. Within this theory we define a data structure, named chain, that facilitates a clear and efficient representation of the puzzle states and its solution.     

天基空间目标监视的短弧段定轨技术

利用两个短弧段的天基测角资料实现对空间目标的轨道确定是天基空间目标监视系统需解决的重要问题之一。提出利用二体轨道的角动量和能量守恒方程计算空间目标初轨的新方法,该方法将短弧段的主要测量信息表示为弧段属性,由两个短弧段的弧段属性建立守恒方程,采用变量替换法求解守恒方程获得多个初轨,通过方差分析从中选择合适的初轨。针对轨道改进中的迭代发散和收敛于局部极小点的问题,提出了选取多个迭代初值进行轨道改进的采样方法。仿真结果表明,初轨确定算法是可行的,轨道改进能成功解算最小二乘轨道。     

Mereological inheritance

In recent investigations of Spatial Reasoning, SpatialKnowledge Representation, and Geographic Information Systems, asignificant effort has been spent by many scholars of the areaabout the problem of representing properties of spatial objects bymeans of logical theories.An analogous effort has been the problem of analyzingthe qualitative relations which can be established between twospace regions. These investigations have led to a generalframework of the field known by the term ``mereo-topology'.Though both the above mentioned approaches have proved to besuccessful in the investigation of formal and practically relevantaspects of spatial objects, no attempt has been carried out in the direction of integrating the approaches and looking at the relationshipbetween a general logical theory of space and mereo-topology from an analytical point of view, in particular for exploiting thecombinatorial behaviour of such an integrated model.This paper intends to fill the gap and analyze the behaviour ofspatial formulae of a logical theory of space as objects which canbe classified based on the behaviour they exhibit with respect tothe parts and supertparts of the regions where they are true. Wename these categories of behaviourinheritance modalities.     

Mining Spatial Associations with Limited Sensory Information

Abstract

Human navigation in an unknown environment requires an understanding of the spatial relationships of the terrain. For example, a soldier who is on a reconnaissance mission in a new city needs to “know” the spatial layout of the surroundings with high confidence. Oftentimes, this understanding must be acquired within a very short amount of time and with limited sensory inputs. The soldier would benefit from a digital avatar that draws inferences about the spatial layout of the city based on an initial set of observations and guides the soldier either in further exploring the environment or in making decisions based on these inferences. In this paper, we present and evaluate an inductive approach to learning spatial associations using sensory data that is available from the simulation environment of a computer game, Unreal Tournament. We study two kinds of spatial relationships between nodes on a level of a game map: nodes that are placed near each other to satisfy some spatial requirement and nodes that are placed near each other to satisfy the design preferences of a level architect. We show that we can infer both kinds of relationships using an association rule mining algorithm. Furthermore, we show how to use an ontology to distinguish between these relationships in order to discover different types of spatial arrangements on a specific map. We discuss how the inferred associations can be used to control an avatar that makes recommendations for navigating unexplored areas on a map. We conclude with some thoughts on the applicability of our methods to scenarios in the real world, beyond the simulation environment of a game, and on how the learned associations can be represented and queried by a simple question-answer type system.     

A space based radar on a micro-satellite for in-situ detection of small orbital debris

The increase in the number of satellites in the Near Earth Orbit is exponential. The consequent increase in pollution of the orbital environment is of growing concern to the international community. There are currently only two observation systems available for measurement of orbital debris. Ground based radar and telescopes can detect objects larger than about 7 cm. Passive space based systems provide an accurate statistical estimation of flux for debris smaller than about 0.1 mm in size. Consequently, there is no way of obtaining information about debris in the millimeter-size range. Considering that the relative speed between objects in space is commonly in the km/s range, millimeter sized debris carry enough energy to be deadly to astronauts or to totally destroy the functioning of any satellite. Then National space agencies have recommended launching orbital spacecraft carrying debris detection experiments for gaining a better understanding of small debris.CNES (the French Space Agency) is developing a new family of micro-satellites, that will make possible to put into orbit a totally new system of radar that could measure in-situ flux of debris. We present results of this system analysis, which would cumulate the advantages of both ground-based radar and in orbit passive experiments.The proposed method for detection is quite original and allows the radar to act like a band-pass filter with respect to the debris diameter. The optimum frequency is shown to be in the Ka-band. Two points are critical in the definition of the radar: the average power available and the false alarm probability in the detection criterion. Therefore, we present a special receiver chain in order to optimize the signal-to-noise ratio. The estimate of the radial velocity through Doppler frequency measurement may be used to discriminate orbital debris from meteoroids. This system could be built today using an existing Continuous Wave amplifier. Several hundreds of objects per year could be detected yielding an accurate statistical estimation.The orbital debris radar would be a major contribution to our knowledge of millimeter sized debris. This experiment would contribute to making the current models more accurate at all inclinations. The micro-satellite concept would make the orbital debris radar mission cheap enough for considering a constellation of such satellites.     

Alexandre Ananoff (1910–1992): 30 years to promote astronautics before Sputnik

2012 marks the 20th anniversary of Alexandre Ananoff's death. Born in 1910 in Tbilisi, Georgia, the Russian–French space expert and enthusiast Alexandre Ananoff is known for being the organiser of the first International Astronautical Congress at La Sorbonne University, Paris, in September–October 1950, as well as being the author of the famous book L’Astronautique (1950) and for advising fellow author Hergé for his book adventures of Tintin on the Moon. The purpose of our paper is to present his complete works promoting space, from his first public presentations after discovering the works of Tsiolkovsky in the late 20s to his analysis of the first Sputnik launch in the popular French magazine Paris Match in 1957.A. Ananoff was a real ambassador for astronautics and a pioneer in space education for the general public—probably the first one in France. He built a unique collection of books and novels about space travel (donated before his death to the French Air and Space Museum of Paris-Le Bourget), wrote dozens of articles, gave numerous lectures and corresponded with most of the space pioneers around the world. However, he was criticised for being an autodidact and was very disappointed by the lack of consideration accorded him within his own country. During the 60s, he progressively stopped his space activities to turn his attention to becoming a specialist of 18th century French painters. He published his Memoirs of an Astronaut in 1978 and gave his last lecture at IAC in September 1979. He died in Paris on 25 December 1992, aged 82. His last wish was that his ashes could be sent on the Moon, an end accomplishment for all his efforts.     

Topologically Characterized Movement Patterns: A Cognitive Assessment

Abstract

In this paper, we discuss the role of topology as a predictor for the conceptualization of dynamically changing spatial configurations (referred to as movement patterns). We define meaningful units of movement patterns as paths through a topologically defined conceptual neighborhood graph. Topology plays a central role in formal approaches to human cognition and in predicting cognitive similarity ratings—although primarily for static spatial configurations. Formal specifications of the role of topology for characterizing movement patterns do exist, yet there is paucity of behavioral validation. To bridge this gap, we conducted an experiment based on the grouping paradigm to assess factors that underlie conceptualizations of movement patterns. The experiment was designed such that paths through the conceptual neighborhood graph were distinguished by topologically differentiated ending relations. We believe topology can make an important contribution in explaining movement conceptualizations. One recently formulated topology-based contribution is the endpoint hypothesis, asserting that a cognitive focus is placed on event ending relations. We discuss the results of our experiment in relation to previous experiments targeted toward a framework for modeling the cognitive conceptualization of dynamically changing spatial relations.     

The knowledge of knots: an interdisciplinary literature review

ABSTRACT

Knots can be found and used in a variety of situations in the 3D world, such as in vines, in the DNA, polymer chains, electrical wires, in mountaineering, seamanship and when ropes or other flexible objects are involved for exerting forces and holding objects in place. Research on knots as topological entities has contributed with a number of findings, not only of interest to pure mathematics, but also to statistical mechanics, quantum physics, genetics, and chemistry. Yet, the cognitive (or algorithmic) aspects involved in the act of tying a knot are a largely uncharted territory. This paper presents a review of the literature related to the investigation of knots from the topological, physical, cognitive and computational (including robotics) standpoints, aiming at bridging the gap between pure mathematical work on knot theory and macroscopic physical knots, with an eye to applications and modeling.     

Relation algebras over containers and surfaces: An ontological study of a room space

Recent research in geographic information systems hasbeen concerned with the construction of algebras tomake inferences about spatial relations by embeddingspatial relations within a space in which decisionsabout compositions are derived geometrically. Wepursue an alternative approach by studying spatialrelations and their inferences in a concrete spatialscenario, a room space that contains such manipulableobjects as a box, a ball, a table, a sheet of paper,and a pen. We derive from the observed spatialproperties an algebra related to the fundamentalspatial concepts of containers and surfaces and showthat this container-surface algebra holds allproperties of Tarski's relation algebra, except forthe associativity. The crispness of the compositionscan be refined by considering the relative size of theobjects) and their roles (i.e., whether it isexplicitly known that the objects are containers orsurfaces).     

Probability of Collision Error Analysis

The decision for the International Space Station (ISS) to maneuver to avoid a potential collision with another space object will be based on the probability of collision, P _C. The calculation of P _C requires the covariance of both objects at conjunction. It is well known that the covariance computed by US Space Command is optimistic (too small), especially at altitudes where atmospheric drag is the dominant perturbation, because its computation assumes there are no dynamic model errors. In this paper the effect of errors in the covariance on P _C and the sensitivity of P _C to the encounter geometry are investigated.     

Managing Temporal Constraints with Preferences

Abstract

Preferences in temporal problems are common but significant in many real world applications. In this paper, we extend our temporal reasoning framework, managing numeric and symbolic information, in order to handle preferences. Unlike the existing models managing single temporal preferences, ours supports four types of preferences, namely: numeric and symbolic temporal preferences, composite preferences and conditional preferences. This offers more expressive power in representing a wide variety of temporal constraint problems. The preferences are considered here as a set of soft constraints using a c-semiring structure with combination and projection operators. Solving temporal constraint problems with preferences consists in finding a solution satisfying all the temporal constraints while optimizing the preference values. This is handled by a variant of the branch and bound algorithm, we propose in this paper, and where constraint propagation is used to improve the time efficiency. Experimental tests, we conducted on randomly generated temporal constraint problems with preferences, favor a variant of MAC as the constraint propagation strategy that should be used within the branch and bound algorithm.     

The emerging China–EU space partnership: A geotechnological balancer

Through a techno-nationalist lens, this paper will assess the growing China–European Union (EU) space partnership, and its implications for international space cooperation and competition. Techno-nationalism (jishu minzuzhuyi), the idea that technological strength is an effective determinant of national power in a harshly competitive world,³ informs both Chinese and US perceptions of China's space development. Using this lens elevates all space activities—manned, unmanned, military and scientific—to the strategic level. It is our contention that because of the increasing China–EU space partnership, the USA must re-evaluate its approach to China—away from the containment approach, which has thus far predominated, toward an approach which would offer the USA the opportunity to influence and, thereby, decrease the importance of the emerging partnership.     

Meeting the needs of the new millennium: passenger space travel and world economic growth

Without doubt, humans’ most urgent need at the start of the new millennium is the continuation of economic growth, which is the only means by which the great majority of the world population can lift themselves out of the poverty in which they live. A sine qua non for continuing economic growth is for the rich countries to continue to develop new industries—as they did throughout the 20th century, thereby creating high-productivity employment for hundreds of millions of people around the world. Arguably the most significant of these thus far is the development of passenger air travel from zero in 1900 to 1.5 billion passengers per year by 2000. It is becoming clear that passenger space travel could grow to reach a similar economic scale—and that no other space activity has comparable potential. The paper describes the potential contribution to world economic growth of passenger space travel; the failure of government space agencies either to aid its development or to make a contribution to economic growth commensurate to their cost; and the value for economic policy of prioritising the realisation of passenger space travel. The faster passenger space travel services grow, the more the space industry will contribute to “Meeting the Needs of the New Millennium”.