An object-based classification approach for mapping "migrant housing" in the mega-urban area of the Pearl River Delta (China)

Urban areas develop on formal and informal levels. Informal development is often highly dynamic, leading to a lag of spatial information about urban structure types. In this work, an object-based remote sensing approach will be presented to map the migrant housing urban structure type in the Pearl River Delta, China. SPOT5 data were utilized for the classification (auxiliary data, particularly up-to-date cadastral data, were not available). A hierarchically structured classification process was used to create (spectral) independence from single satellite scenes and to arrive at a transferrable classification process. Using the presented classification approach, an overall classification accuracy of migrant housing of 68.0% is attained

Macroscopic Car Condensation in a Parking Garage

An asymmetric exclusion process type process, where cars move forward along a closed road that starts and terminates at a parking garage, displays dynamic phase transitions into two types of condensate phases where the garage becomes macroscopically occupied. The total car density $\rho_o$ and the exit probability $\alpha$ are the two control parameters. At the transition, the number of parked cars $N_p$ diverges in both cases, with the length of the road $N_s$, as $N_p\sim N_s^{y_p}$ with $y_p=1/2$. Towards the transition, the number of parked cars vanishes as $N_p\sim \epsilon^\beta$ with $\beta=1$, $\epsilon=|\alpha -\alpha^*|$ or $\epsilon=|\rho^*_o -\rho_o|$ being the distance from the transition. The transition into the normal phase represents also the onset of transmission of information through the garage. This gives rise to unusual parked car autocorrelations and car density profiles near the garage, which depend strongly on the group velocity of the fluctuations along the road.Comment: 12 pages including 15 figures; published version in PR

Long Term Contracting in a Changing World

I study the properties of optimal long-term contracts in an environment in which the agent’s type evolves stochastically over time. The model stylizes a buyer-seller relationship but the results apply quite naturally to many contractual situations including regulation and optimal income-taxation. I …first show, through a simple discrete example, that distortions need not vanish over time and need not be monotonic in the shock to the buyer’s valuation. These results are in contrast to those obtained in the literature that assumes a Markov process with a binary state space e.g. Battaglini, 2005. I then show that the study of the dynamics of the optimal mechanism can be significantly simplified by assuming the shocks are independent over time. When the sets of possible types in any two adjacent periods satisfy a certain overlapping condition (which is always satisfied with a continuum of types) and some additional regularity conditions hold, then the optimal mechanism is the same irrespective of whether the shocks are the buyer’s private information or are observed also by the seller. These conditions are satisfied, for example, in the case of an AR(1) process, a Brownian motion, but also when shocks have a multiplicative effect as it is often the case in financial applications. Furthermore, the distortions in the optimal quantities are independent of the distributions of the shocks and, when the buyer’s payoff is additively separable, they are also independent of whether the shocks are transitory or permanent. Finally, I show that assuming the shocks are independent not only does it greatly simplify the analysis, it is actually without loss of generality.asymmetric information, stochastic process, dynamic mechanism design, long-term contracting

Variadic genericity through linguistic reflection : a performance evaluation

This work is partially supported by the EPSRC through Grant GR/L32699 “Compliant System Architecture” and by ESPRIT through Working Group EP22552 “PASTEL”.The use of variadic genericity within schema definitions increases the variety of databases that may be captured by a single specification. For example, a class of databases of engineering part objects, in which each database instance varies in the types of the parts and the number of part types, should lend itself to a single definition. However, precise specification of such a schema is beyond the capability of polymorphic type systems and schema definition languages. It is possible to capture such generality by introducing a level of interpretation, in which the variation in types and in the number of fields is encoded in a general data structure. Queries that interpret the encoded information can be written against this general data structure. An alternative approach to supporting such variadic genericity is to generate a precise database containing tailored data structures and queries for each different instance of the virtual schema.1 This involves source code generation and dynamic compilation, a process known as linguistic reflection. The motivation is that once generated, the specific queries may execute more efficiently than their generic counter-parts, since the generic code is “compiled away”. This paper compares the two approaches and gives performance measurements for an example using the persistent languages Napier88 and PJama.Postprin

Morphology-Induced Collective Behaviors: Dynamic Pattern Formation in Water-Floating Elements

Complex systems involving many interacting elements often organize into patterns. Two types of pattern formation can be distinguished, static and dynamic. Static pattern formation means that the resulting structure constitutes a thermodynamic equilibrium whose pattern formation can be understood in terms of the minimization of free energy, while dynamic pattern formation indicates that the system is permanently dissipating energy and not in equilibrium. In this paper, we report experimental results showing that the morphology of elements plays a significant role in dynamic pattern formation. We prepared three different shapes of elements (circles, squares, and triangles) floating in a water-filled container, in which each of the shapes has two types: active elements that were capable of self-agitation with vibration motors, and passive elements that were mere floating tiles. The system was purely decentralized: that is, elements interacted locally, and subsequently elicited global patterns in a process called self-organized segregation. We showed that, according to the morphology of the selected elements, a different type of segregation occurs. Also, we quantitatively characterized both the local interaction regime and the resulting global behavior for each type of segregation by means of information theoretic quantities, and showed the difference for each case in detail, while offering speculation on the mechanism causing this phenomenon

Joint Event Extraction via Structural Semantic Matching

Event Extraction (EE) is one of the essential tasks in information extraction, which aims to detect event mentions from text and find the corresponding argument roles. The EE task can be abstracted as a process of matching the semantic definitions and argument structures of event types with the target text. This paper encodes the semantic features of event types and makes structural matching with target text. Specifically, Semantic Type Embedding (STE) and Dynamic Structure Encoder (DSE) modules are proposed. Also, the Joint Structural Semantic Matching (JSSM) model is built to jointly perform event detection and argument extraction tasks through a bidirectional attention layer. The experimental results on the ACE2005 dataset indicate that our model achieves a significant performance improvemen

The Impact of Dynamic Furniture on Classroom Performance: A Pilot Study

The purpose of this study was to understand how dynamic classroom furniture may impact classroom performance such as attention, work neatness, and work completion in a second grade general education classroom of 19 students. All students in the classroom were included in this study to understand the implications of environmental modifications on the learning process in general education settings. A descriptive method provided information about the interaction of dynamic furniture on identified learning components. Three different dynamic furniture options were provided: Zuma chairs®, Disc‘O’Sits® (inflated seat cushions), and standing desks with the Original FootFidget®. The class was randomly divided into four groups of up to five students. The groups were rotated through the furniture, allowing one week per group with each type of furniture. The Sensory Processing Measure (Parham & Ecker, 2007) was used to screen the sensory processing of students and a daily self-report rubric provided data on attention behaviors and perception of the dynamic furniture options. Data were graphed and visually analyzed for differences in responses to types of furniture. Responses on the rubrics indicate that the different types of furniture impacted different components of learning in a variety of ways. The data from this study indicates that no one type of furniture provides the same effect for all elementary students, but rather that personal characteristics may dictate the best match for focus, work completion, and neatness

Management of conflict for preliminary engineering design tasks

Much of preliminary engineering design is a constraint-driven non-monotonic exploration process. Initial decisions are made when information is incomplete and many goals are contradictory. Such conditions are present regardless of whether one or several designers contribute to designs. This paper presents an approach for supporting decisions in situations of incomplete and conflicting knowledge. In particular, we use assumptions and conflict management to achieve efficient search in contexts where little reliable information exists. A knowledge representation, containing a semantic differentiation between two types of assumptions, is used within a computational model based on the dynamic constraint satisfaction paradigm. Conflict management strategies consist of three generic mechanisms adapted to the type of constraints involved. These strategies may be refined through consideration of variable importance, context, and design inerti

Using genetic algorithms to optimize the parameters of the adaptive model of collective behavior of the predator attack

Collective behaviour research focuses on behaviour properties of large groups of similar entities. The most studied collective behaviour species are ocks of birds and schools of �sh. There exist many di�erent computational models of collective behaviour, which researchers used to investigate various properties of collective behaviour like: transfer of information across the group, bene�ts of grouping (defence against predator, foraging),group decision{making process and group behaviour types. In this thesis we focused on various group behaviour types, transitions between them and their bene�ts when the prey group is exposed to predator attacks. In our study we implemented the collective behaviour computational model originally presented by Couzin et al. [doi:10.1006/jtbi.2002.3065], who discovered four di�erent be-haviour types by adjusting the radius of the orientation zone: swarming, rotating around an empty core, dynamic parallel movement and highly parallel movement. Swarming is typical for insects, rotating around an empty core (torus) is in special cases exhibited by sh schools and dynamic/highly parallel movement is primary associated with bird ocks and �sh schools. With known behaviour types and using various attack tactics we tried to verify which behaviour type is the most e�cient defence against predator attacks, and whether transitions between these behaviour types contribute to a more e�cient defence