General Event Research Articles

The Relevance of Non-Generic Events in Scale Space Models

In order to investigate the deep structure of Gaussian scale space images, one needs to understand the behaviour of spatial critical points under the influence of blurring. We show how the mathematical framework of catastrophe theory can be used to describe and model the behaviour of critical point trajectories when various different types of generic events, viz. annihilations and creations of pairs of spatial critical points, (almost) coincide. Although such events are non-generic in mathematical sense, they are not unlikely to be encountered in practice due to numerical limitations. Furthermore, the behaviour of these trajectories leads to the observation that fine-to-coarse tracking of critical points doesn't suffice, since they can form closed loops in scale space. The modelling of the trajectories include these loops. We apply the theory to an artificial image and a simulated MR image and show the occurrence of the described behaviour.

Composite event detection as a generic middleware extension

Event-based communication provides a flexible and robust approach to monitoring and managing large-scale distributed systems. Composite event detection extends the scope and flexibility of these systems by allowing application components to express interest in complex patterns of events. This makes it possible to handle the large numbers of events generated in Internet-wide systems, and in network monitoring and pervasive computing applications. In this article, we introduce a novel generic composite event detection framework that can be added on top of existing middleware architectures, as demonstrated in our implementation over JMS. We argue that the framework is flexible, expressive and easy to implement. Based on finite state automata extended with a rich time model and parameterization support, it provides a decomposable core language for specifying composite events. This allows detection to be distributed automatically throughout the system, guided by distribution policies that control the quality of service. Finally, tests show that using our composite event system over JMS can reduce bandwidth consumption while maintaining low notification delay for composite events.

Supporting Public Availability and Accessibility with Elvin: Experiences and Reflections

We provide a retrospective account of how a generic event notification service called Elvin and a suite of simple client applications: CoffeeBiff, Tickertape and Tickerchat, came to be used within our organisation to support awareness and interaction. After overviewing Elvin and its clients, we outline various experiences from data collated across two studies where Elvin and its clients have been used to augment the workaday world to support interaction, to make digital actions visible, to make physical actions available beyond the location of action, and to support content and socially based information filtering. We suggest there are both functional and technical reasons for why Elvin works for enabling awareness and interaction. Functionally, it provides a way to produce, gather and redistribute information from everyday activities (via Elvin) and to give that information a perceptible form (via the various clients) that can be publicly available and accessible as a resource for awareness. The integration of lightweight chat facilities with these information sources enables awareness to easily flow into interaction, starting to re-connect bodies to actions, and starting to approximate the easy flow of interaction that happens when we are co-located. Technically, the conceptual simplicity of the Elvin notification, the wide availability of its APIs, and the generic functionality of its clients, especially Tickertape, have made the use of the service appealing to developers and users for a wide range of uses.

Tsunami risk assessment in the Marquesas Islands (French Polynesia) through numerical modeling of generic far-field events

Abstract. Earthquakes occurring at the Pacific Rim can trigger tsunamis that propagate across the ocean and can produce significant damages far away from the source. In French Polynesia, the Marquesas Islands are the most exposed to the far-field tsunami hazards, since they are not protected by any outer coral reef and since submarine slopes are less steep than in other islands. Between 1994 and 1996, four tsunamis have reached the bays of the archipelago, among them, the tsunami initiated by the Chilean Mw 8.1 earthquake, produced up to 3 m high waves in Tahauku Bay. Numerical modeling of these recent events has already allowed us to validate our method of resolution of hydrodynamics laws through a finite-difference scheme that simulates the propagation of the tsunamis across the ocean and computes the inundation heights (run-up) in remote bays. We present in this paper the simulations carried out to study potentially threatening areas located at the Pacific Rim, on the seismogenic Aleutian and Tonga subduction zones. We use a constant seismic moment source (that of the Mw 8.1 Chile 1995 earthquake, M0 = 1.2 1021 N.m) located at several potential epicenters, with the fault strike adapted from the regional seismotectonics pattern. Our results show that the sources chosen in the Aleutian trench do not produce large inundations in the Marquesas bays, except for the easternmost source (longitude 194° E). Sources located in the Tonga trench do not produce high amplifications either, except for the northernmost one (latitude 16° S). We also discuss the behaviour of the tsunami waves within the archipelago, and evidence contrasting responses depending on the arrival azimuths. These results show that, for a given initial seismic energy, the tsunami amplification in remote bays is highly dependent on the source location and fault strike.

MEASURING SELF-PERCEIVED RACIAL AND ETHNIC DISCRIMINATION IN SOCIAL SURVEYS

The aim of this article is to encourage a research agenda that attends to methodological considerations regarding measuring self-perceived racial and ethnic discrimination in social surveys. Toward this end, the author compared validity of alternative measures of discrimination. The first measure asks whether something unfair or bad has happened because of race and ethnicity, whereas the second measure asks about generic unfair events independent of attribution to race or ethnicity. In a probability sample of 586 Black respondents living in the Detroit metropolitan area interviewed in 1995, it was found that the prevalence of self-perceived racial and ethnic discrimination depended on question framing. Moreover, different respondents were likely to respond affirmatively to explicit versus generic measures of discrimination; importantly, the mental health consequences of self-perceived racial and ethnic discrimination varied by question framing. The results confirmed that the prevalence, correlates, and psychological impact of self-perceived discrimination should be evaluated on the basis of measurement sensitivity.

Why Do People Attend Events: A Comparative Analysis of Visitor Motivations at Four South Island Events

The comparative analysis of the motivations of visitors at four South Island, New Zealand, events—two food and beverage festivals, an air show, and a country and music festival—highlights the diversity in motives that are to be found from event to event. Event-specific factors are especially important; there is little evidence yet of generic event motivations. In contrast to earlier case studies, the comparative approach employed here gives more weight and greater visibility to events per se as a distinctive phenomenon.

Impersonal passives in icelandic

This paper argues that /celandic impersonal passives have a constructional property that expresses generic events. After having demonstrated their basic characteristics, it is shown that the notion of 'activity' is inadequate for the explanation of why the construction is licensed. The behaviour of the adverbial ser moovitandi is diagnosed to show indefiniteness tied up with the construction.

Propriétés configurationnelles et contraintes aspectuelles: Un ça objet déficient

This paper argues that the feature specification of a Swiss French deficient ça accounts for its syntactic distribution. Contrary to the ordinary accusative clitics le, la, les, this pronominal form lacks number, gender and Case feature, but has a temporal-aspectual locative feature. The arguments that support ça's caselessness are based on the following diagnostic: 1. (i) the impossibility of doubling the deficient ça, 2. (ii) the impossibility of ça being an enclitic and 3. (iii) its interaction with topicalisation and right dislocation which differs from what can be observed with ordinary clitics in this context. Another distinction in the feature make-up of ça vs. ordinary clitics is the ambiguous categorical status of ça as both D and DP. As a result of its feature composition, ça requires geric event quantification. This interpretation is always available with transitive eventive verbs but with unaccusatives and transitive statives, the reading is blocked in the present tense. It is demonstrated that the aspectual non-ambiguity of the Swiss French deficient ça, i.e. the fact that it can only appear in contexts of generic event quantification, is responsible for ungrammatical sequences such as ∗Je ça aime (‘I that like’) in this grammar.

A generic event control framework for modular flexible manufacturing systems

A generic event control framework is presented for a class of modular flexible manufacturing systems (FMSs). A modular FMS is characterized as a set of flexible workstations inter-connected by a material handling system consisting of a transporter and a stocker. Many of the existing FMS implementations in industry fall into this class. Furthermore, the modularity also allows the capability to effectively model a complex FMS by decomposing it into several modular FMSs. In order to achieve reconfigurability of control system for various FMS implementations and control policies, the proposed control framework is defined as a set of distributed resource controllers and a central system supervisor coordinating them. The resource controllers are further classified into workstation, transporter, and stocker controllers. As the controllers exchange a series of events according to pre-defined protocols, they are modelled as event handlers in which control actions are made based on the event occurrences. Specifically, for each controller, an event-based control structure specified in terms of generic logical and performance control functions, is presented. Since the proposed framework is defined by the use of the interacting distributed processes with the well-defined protocols and computationally efficient algorithms, it is expected that the framework is easily implementable for most industrial FMSs. Finally, the performance and reconfigurability is demonstrated by the distributed simulation from which we can also verify the correctness of the proposed algorithms.

Malignant transformation of duct-like cells originating from acini in transforming growth factor α transgenic mice

Background & Aims: In transgenic mice overexpressing transforming growth factor (TGF)-α in the exocrine pancreas, progressive pancreatic fibrosis and a transdifferentiation of acinar cells to duct-like cells occurs. The present study was undertaken to analyze this transdifferentiation process. Methods: Pancreatic specimens were characterized using light microscopy and immunohistochemistry. Expression of the epidermal growth factor receptor (EGFR) and TGF-α was evaluated with slot blot and Western analysis. To identify other generic events, K- ras mutations were screened with an enriched polymerase chain reaction approach and p53 expression was detected with immunohistochemistry. Results: Morphological examination revealed an aggregation of interlobular fibroblasts and a decrease in acinar cell height starting at day 14 after birth. In older animals, these acinar cells change to duct-like cells, which form tubular structures and express ductal markers. Evidence for dysplastic changes was found in 12 of 21 TGF-α transgenic mice older than 1 year. We also observed four malignant pancreatic tumors, which were multicentric and originated from dysplastic tubular complexes. They displayed a mixed cystic-papillary phenotype strongly positive for carbonic anhydrase activity. EGFR expression progressively increased in the transition from acinar to duct-like and transformed cells. Activating K- ras mutations could not be detected; however, tubular complexes and tumors displayed increased immunoreactivity for nuclear p53. Conclusions: These data suggest an involvement of the TGF-α/EGFR pathway in conjunction with other yet unknown events in pancreatic tumor development. Furthermore, these observations are in favor of an acinar-ductal carcinoma sequence. Thus, these transgenic animals will be useful to define genetic alterations associated with a transition from acinar cells to a neoplastic ductal phenotype. GASTROENTEROLOGY 1998;115:1254-1262

Distributed Systems Management Software-in-the-Loop

IT experts expect open distributed processing to become the predominant computing infrastructure in the late nineties. All computer supported work places of large enterprises and organizations will then be networked and will be integrated into cross-regional and cross-sector business and information processes. The size and complexity of such applications, the local autonomy, distribution and heterogeneity of participating subsystems, and their asynchronous interaction, however, require new architectures, strategies, and tools for their technical management. In previous work we placed a production rule interpreter into the monitoring, decision, control action loop to provide flexible, operational semantics of well-understood management policies. In this article we extend this work in two directions. First we map the structure and dynamic behavior of policies into a graph representation. This semantic representation enables a systematic prediction of the effects of policy executions and allows for a better impact analysis in case of policy changes. Then we introduce a declarative event definition mechanism. It supports a causal and temporal correlation of individual events and serves to instantiate and adapt a predefined generic event handler to the specific needs of the actual management application. Such event handlers join in the interaction between monitoring agents and policy interpreter. By event correlation they may reduce the number of events triggering management actions significantly and help to filter secondary events.

Development of a photochemical airshed model for Sydney, New South Wales, Australia

This paper describes the development of an airshed modelling system for the Environment Protection Authority of NSW (EPANSW). The airshed modelling system is one of the key outcomes of the Metropolitan Air Quality Study (MAQS). It will provide the tools necessary to aid in the development of an Air Quality Management Plan for photochemical smog within the Sydney, Lower Hunter, and Illawarra regions. The three dimensional airshed model was run for a 2 day generic Sydney oxidant event using historical data and some preliminary results from other MAQS projects. Predicted maximum smog concentrations obtained from the simulations appear to be comparable with the observations.

‘Narratives of Survival in the Post‐Colonial North’

ABSTRACTScholars have recently paid more attention to narratives of colonial contact in Australia, as elsewhere (cf. Hill 1988). Western elements and characters (such as Captain Cook) have been widely documented in Australian Aboriginal narratives which nevertheless are clearly not close accounts of past events. This has promoted reconsideration of the distinction between ‘myth’ and ‘history‘. If we follow Turner's (1988) suggestion that myth is the formulation of ‘essential’ properties of social experience in terms of ‘generic events‘, while ‘history’ is concerned with the level of ‘particular relations among particular events’, we need not restrict ourselves to seeing myth as charter for a social order distinct from western influence. In the paper I examine two stories of cultural and physical survival from the Katherine area, Northern Territory, and seek to identify in them fundamental themes and enduring narrative precipitates of social experience lived in intense awareness of colonial and post‐colonial relationships between Aborigines and whites.

Tap processes

Developing distributed systems includes activities such as testing, verification, debugging and performance analysis. We identify the set of generic events that are commonly monitored by different development tools, and the characteristics of a generic monitoring tool. We then introduce new language-based constructs to be used for the development of event-based development tools for distributed systems. Those constructs are easy to use, and provide accurate information about the monitored system without causing any perturbation.

An approach to the analysis of common cause failure data for plant-specific application

The analysis of common cause failures of redundant systems, i.e. failure of multiple components due to a shared cause within their mission time, involves the estimation of probabilities of events for which data based on operating experience are hard to obtain and, when available, do not often provide enough information for unambiguous interpretation and use in the analysis. Because of rarity of common cause failure events on a plant- and system-specific basis, plant-specific probabilistic risk assessments have to rely heavily on the industry (genetic) experience to develop a statistically significant data base for estimation of common cause failure probabilities. The overall approach is described in detail in NUREG/CR 4780 (1989). The process of interpreting generic experience event data and translating them for plant-specific applications involves considerable judgement for which only limited explicit guidance was provided in the aforementioned document. The methods and suggestions given in this paper are intended to fill the gap and to provide the analyst with tools that would enable him or her to adopt a self-consistent, systematic and well-documented approach to failure event interpretation and to provide a quantitative assessment for plant-specific studies. Formulae and parameter estimates are developed to address the most commonly encountered cases in common cause failure data analysis, i.e. events involving degraded states of components, and failures separated in time. Several examples are provided to illustrate the application.

EuList threads: A concurrency toolbox

Many current high level languages have been designed with support for concurrency in mind, providing constructs for the programmer to build explicit parallelism into a program. TheEuLisp threads mechanism, in conjunction with locks, and a generic event waiting operation provides a set of primitive tools with which such concurrency abstractions can be constructed. The object system (Telos) provides a powerful approach to building and controlling these abstractions. We provide a synopsis of this ‘concurrency toolbox’, and demonstrate the construction of a number of established abstractions using the facilities ofEuLisp: pcall, futures, stack groups, channels, CSP and Linda.

Collapse of spherically symmetric textures.

We examine the collapse of spherically symmetric texture configurations without resort to a sigma-model approximation, in both Minkowski and Friedmann universes. Relations between topological charge and unwinding time are found, and it is demonstrated that while any texture of topological charge Q>0.5 can in principle unwind, one expects the generic unwinding events to involve a characteristic, background-dependent charge. In Minkowski, radiation-, and matter-dominated universes we find that unwindings typically involve charges of Q\ensuremath{\sim}0.74, 0.82, and 0.89, respectively. We also investigate the attainability of self-similarity (on which the only known analytic solution is based) in the evolution of textures, and demonstrate analytically that exact self-similar solutions in flat space exist only for an integer topological charge.

Safety assessment of spent fuel transportation in extreme environments

A preliminary estimate of the health effects and/or consequences resulting from sabotage of spent fuel truck shipments has been made. This estimate is based upon a measured quantity (078 ± 0.05 g) of respirable radioactive material released from a 1 4 scale event. A linear extrapolation from the 1 4 scale event to the generic full scale event has been made and an aerosolized release fraction (0.0065%) of the total heavy metal inventory of a three-PWR assembly truck cask has been calculated. Although scaling of the source term parameters is tentative at this point in the program, a full scale experiment is planned in 1981 to verify the scaling methodology used in these calculations. A preliminary correlation between spent fuel and surrogate fuel source terms has been shown to be feasible and that radionuclide size partitioning can be determined experimentally. Finally, it has been shown, based on our preliminary experimental source term data, that a maximum of 25 total latent cancer fatalities could occur, assuming a release in downtown New York City. This is 20 times smaller than the latent cancer fatalities predicted in the so called “Urbban Study.”

Metrology Problems in General Engineering: A Comparison with Precision Engineering

Sustainability assessment needs to be embedded into manufacturers’ daily operations for continuous improvement. Existing factories, especially small and medium enterprises (SMEs), often lack infrastructure and capital to enable such regular assessment. An integrated tool has been developed based on a generic discrete event simulation (DES) factory model, which is linked to the company's resource planning system in order to not only assess the sustainability performance of each company's as-is operations, but also optimise their future performance. An Australian company was used as a case study to demonstrate the validity of the tool.

The structure and evolution of flow fields and other vector fields

As the field evolves with time, discrete events occur which alter the patterns of folds and cusps. Thom's (1975) list of elementary catastrophes describes these events when the changes in the field are the result of changes of an underlying scalar generating function. In that case the generic events are lips, beak-to-beak, swallowtail, hyperbolic umbilic and elliptic umbilic. If the vector field evolves with time in a more general way, the only generic events are lips, beak-to-beak and swallowtail. Similarly, in a three-dimensional vector field constrained by being derived from an underlying generating function, the generic singularities are the first five in Thom's list: the fold, cusp, swallowtail, elliptic and hyperbolic umbilic; but when the field is not constrained in this way, only the fold, cusp and swallowtail will occur generically. Two geophysical illustrations are used.