Object-oriented View Research Articles

A closer look at process-based simulation with stackless coroutines

Validating discrete-event computer simulations for a particular problem domain often involves the help of a domain expert. This means that a certain structural closeness between the simulator’s inner workings and the modeled system is needed in order to allow the expert to follow the implementation in analogy. Process-based simulation imposes an object-oriented view onto a modeled system which allows for a high degree of structural closeness in most cases. In comparison, event-based simulation requires a procedural definition with a relatively low degree of structural closeness for many cases, but outperforms the process-based approach both in terms of performance and portability. Recent advances in compiler technology have introduced a portable way of rewriting thread-based code into event-based code, effectively providing the means to implement portable green-threads in compiled system languages.

Object, Reduction, and Emergence: An Object-Oriented View

Abstract Object-Oriented Ontology (OOO) is a contemporary form of realism concerned with the investigation of “objects” broadly construed. It may be characterised in terms of a metaphysical pluralism to the extent that it recognises infinitely many different kinds of emergent entities, and this fact in turn leads to a number of questions concerning the nature of objects and emergence in OOO: what is the precise meaning of an emergent entity in OOO? How has emergence been denied throughout the history of Western thought? Is there a specific object-oriented account of emergence? What is the causal mechanism which provides the conditions of possibility for the generation of emergent entities? In this article, I aim to answer all these questions by constructing the first extensive account of real emergence in the context of Object-Oriented Ontology, and I also seek to tie this analysis to the notion of “vicarious” or indirect causation.

Object-Based Comparison of Data-Driven and Physics-Driven Satellite Estimates of Extreme Rainfall.

The Global Precipitation Measurement (GPM) constellation of spaceborne sensors provides a variety of direct and indirect measurements of precipitation processes. Such observations can be employed to derive spatially and temporally consistent gridded precipitation estimates either via data-driven retrieval algorithms or by assimilation into physically based numerical weather models. We compare the data-driven Integrated Multisatellite Retrievals for GPM (IMERG) and the assimilation-enabled NASA-Unified Weather Research and Forecasting (NU-WRF) model against Stage IV reference precipitation for four major extreme rainfall events in the southeastern United States using an object-based analysis framework that decomposes gridded precipitation fields into storm objects. As an alternative to conventional "grid-by-grid analysis," the object-based approach provides a promising way to diagnose spatial properties of storms, trace them through space and time, and connect their accuracy to storm types and input data sources. The evolution of two tropical cyclones are generally captured by IMERG and NU-WRF, while the less organized spatial patterns of two mesoscale convective systems pose challenges for both. NU-WRF rain rates are generally more accurate, while IMERG better captures storm location and shape. Both show higher skill in detecting large, intense storms compared to smaller, weaker storms. IMERG's accuracy depends on the input microwave and infrared data sources; NU-WRF does not appear to exhibit this dependence. Findings highlight that an object-oriented view can provide deeper insights into satellite precipitation performance and that the satellite precipitation community should further explore the potential for "hybrid" data-driven and physics-driven estimates in order to make optimal usage of satellite observations.

Capturing the world with verbs: Preschool science education beyond nouns and objects

This article seeks to contribute new perspectives to the ontology and epistemology of preschool science education by exploring the idea of using everyday verbs, rather than nouns, to discern possibilities for science learning in preschool. Herein, the author merges empirical examples from preschools with findings from research on children’s noun and verb learning and posthumanist perspectives on matter and concepts. What comes out of the exploration is a radical way of viewing and knowing the world. The verbs trigger a shift from an object-oriented view of the world to seeing action and non-tangible processes and phenomena in one’s surroundings. Further, the verbs highlight the potential science learning that emerges in action and in child–matter relations, opening up to preschool science pedagogies that go beyond subjective/objective and concrete/abstract binaries.

Towards an Indexical Paradoxico-Metaphysics

Abstract This paper sketches a metaphysical view according to which the furniture of the universe is made of indexicals. The view draws from work in the philosophy of language and thought concerning demonstratives, proper names and other deictic operations (by Perry, Kaplan, Kripke among others). It also draws on Levinas‘ conception of the Other as beyond any substantive description. Indexicalism, as I call it, is compared with object-oriented views such as Harman‘s and Garcia‘s. Indexicalism lapses into paradox concerning totality and proves to be self-destructive. It is defended, however, as a paradoxico-metaphysics.

The Economic World Obverse: Freedom Through Markets After Arts Education

What role does arts education play in artistic activity and income? In light of the rise of university arts education and its effects, especially the changing role of teaching in artistic careers, this article questions key assumptions of both winner-take-all and economic-world-reversed analyses of artistic careers. While almost all studies of remuneration in the creative arts find that income is highly skewed, these dominant perspectives take an object-oriented view of artistic life that neglects the vast majority of activities that underpin and compose contemporary arts practices. Looking at arts practices more holistically and using the changing status of art teaching as an exemplar of the expanded field of artistic practice, we document the challenges that the rise of arts education present to traditional analyses of artistic careers, income, and success.

A Taxonomy of Uninterpretable Interactions from Interaction Design Perspective

Objective: The aim of this study is to configure a taxonomy of uninterpretable Interactions. Background: Following the spread of the Internet, smart devices have increasingly covered our lives. Human beings are now living in an era of tremendous information explosion. We live with numerous interactive targets nowadays, and there are many ways to interact with these targets. Being an interaction designer in this era, we need to clearly understand the existing methods of the interaction. While Bill Moggridge posed interaction design as a new discipline in 1984，it still has not formed a structured framework. Method: This study categorizes uninterpretable interactions through case studies, and configures the taxonomy of uninterpretable interactions based on Object-Oriented View of interaction. To explore the use value and impact of the taxonomy of uninterpretable interactions, this study conducted an experiment and analyzed related results. Results: The framework gives a positive impact on the design process, and interaction designers can clarify and broaden the scope of their ideas. Conclusion: A study on the Taxonomy of Uninterpretable Interactions was the part that did not gain a lot of attention in the existing interaction process. The study made the part more clear. And the study also helps interaction designers expand their roles in the development process of products or services. Application: The taxonomy framework of uninterpretable interactions might help interaction designers design uninterpretable interactions more clearly, and it can also be applied to design interpretable interactions.

Integrated ICT System to Increase Physical Activity in Schools: Agent-Oriented Modeling Approach

During the past two decades the use of information and communication technologies (ICT) has fundamentally changed the routines and practices of nearly all aspects of life, sometimes, creating undesired side-effects such as decreased physical activity, obesity, overweight and sedentary behaviour for school-age children. In this case teachers and parents often regard ICT systems (“computers”) as a growing danger for adolescents’ health.The authors aim to discover how integration of advanced and appropriate ICT systems can help to increase physical activity in schools. Thus authors complement to one-sided general public opinion and propose specific positive outcomes of integration of effective ICT systems for increased physical activity, improved teaching and learning environment, higher overall quality and accessibility of education and learning motivation. In this research authors take an agent-oriented modelling approach, as opposed to the more commonly used object-oriented view. “Agents” are defined as the humans and man-made components of a system. The specific agent-oriented model is presented at three levels of abstraction corresponding to a motivation layer, a design layer, and an implementation layer. The research paper also examines the outcomes and evidence of practical implementation of the proposed agent-oriented model during an experiment conducted in the Northeast Latgale region in Latvia from 2012 until 2014.

A Comparative Analysis of Structured and Object-Oriented Programming Methods

The concepts of structured and object-oriented programming methods are not relatively new but these approaches are still very much useful and relevant in today’s programming paradigm. In this paper, we distinguish the features of structured programs from that of object oriented programs. Structured programming is a method of organizing and coding programs that can provide easy understanding and modification, whereas objectoriented programming (OOP) consists of a set of objects, which can vary dynamically, and which can execute by acting and reacting to each other, in much the same way that a real-world process proceeds (the interaction of realworld objects). An object-oriented approach makes programs more intuitive to design, faster to develop, more amenable to modifications, and easier to understand. With the traditional, procedural-oriented/structured programming, a program describes a series of steps to be performed (an algorithm). In the object-oriented view of programming, instead of programs consisting of sets of data loosely coupled to many different procedures, objectoriented programs consist of software modules called objects that encapsulate both data and processing while hiding their inner complexities from programmers and hence from other objects

An Object-Oriented View on Problem Representation as a Search-Efficiency Facet: Minds vs. Machines

From an object-oriented perspective, this paper investigates the interdisciplinary aspects of problem representation as well the differences between representation of problems in the mind and that in the machine. By defining an object as a combination of a symbol-structure and its associated operations, it shows how the representation of problems can become related to control, which conducts the search in finding a solution. Different types of representation of problems in the machine are classified into four categories, and in a similar way four distinct models are distinguished for the representation of problems in the mind. The concept of layered hierarchies, as the main theme of the object-oriented paradigm, is used to examine the implications of problem representation in the mind for improving the representation of problems in the machine.

Seaside: A Flexible Environment for Building Dynamic Web Applications

Page-centric Web development structures an application into individual scripts, each responsible for processing a user request and generating a response. Although software developers have long considered go-to statements harmful, they are still present in today's mainstream frameworks, and they hamper the reuse of pages in different parts of the application. In this article, after briefly discussing the key challenges of modern Web application development, we present Seaside, a highly dynamic framework for developing Web applications in Smalltalk. The Seaside framework provides a uniform, pure object-oriented view for Web applications. Exploiting Smalltalk's reflective features, Seaside reintroduces procedure call abstraction in a client-server context. Furthermore, there's no need to recompile and restart Seaside application servers after each modification. Web developers debug and update applications on the fly, thus reducing development time considerably.

Integration of DFDs into a UML-based Model-driven Engineering Approach

The main aim of this article is to discuss how the functional and the object-oriented views can be inter-played to represent the various modeling perspectives of embedded systems. We discuss whether the object-oriented modeling paradigm, the predominant one to develop software at the present time, is also adequate for modeling embedded software and how it can be used with the functional paradigm. More specifically, we present how the main modeling tool of the traditional structured methods, data flow diagrams, can be integrated in an object-oriented development strategy based on the unified modeling language. The rationale behind the approach is that both views are important for modeling purposes in embedded systems environments, and thus a combined and integrated model is not only useful, but also fundamental for developing complex systems. The approach was integrated in a model-driven engineering process, where tool support for the models used was provided. In addition, model transformations have been specified and implemented to automate the process. We exemplify the approach with an IPv6 router case study.

TODS: cluster object storage platform designed for scalable services

In this paper we present the design and implementation of Tsinghua Object Data Store (TODS), a cluster object storage system to support the building of scalable Internet services. TODS provides a unified, transparent and object-oriented view of the storage devices of the whole cluster, which greatly simplifies cluster service development. In the meantime, it is designed to be scalable and efficient. Services built on it can simply inherit these properties in a lot of cases. TODS supports ACID transactions, which facilitates the building of complex transactional services. TODS abstracts away from service logic most complexities of data management, which have often become major obstacles in developing high quality Internet services. The design principles, architecture and implementation of TODS are discussed. In our performance experiments, the system scales smoothly to a 36-node server cluster and achieves 11,160 in-memory reads per second and 396 transactions per second. We also demonstrate that the programming interface is significantly easier to use than that of RDBMS with a head-to-head comparative experiment.

Incremental maintenance of object-oriented data warehouses

Incremental maintenance of data warehouses has attracted a lot of research attention for the past few years. Nevertheless, most of the previous work is confined to the relational setting. Recently, object-oriented data warehouses have been regarded as a better means to integrate data from modern heterogeneous data sources. However, existing approaches to incremental maintenance of data warehouses do not directly apply to object-oriented data warehouses. In this paper, therefore, we propose an approach to incremental maintenance of object-oriented data warehouses. We focus on two primary issues specifically. First, we identify six categories of potential updates to an object-oriented view and propose an algorithm to find potential updates from the definition of the view. Second, we propose an incremental view maintenance algorithm for maintaining object-oriented data warehouses. We have implemented a prototype system for incremental maintenance of object-oriented data warehouses. Performance evaluation has been conducted, which indicates that our approach is correct and efficient.

Concurrent Data Materialization for Object-Relational Database with Semantic Metadata

For a company with many databases in different data models, it is necessary to consolidate them into one data model interchangeable and present data in one data model concurrently to users. The benefit is to let user stick to his/her own data model to access database in another data model. This paper presents a semantic metadata to preserve database constraints for data materialization to support user's view of database on an ad hoc base. The semantic metadata can store the captured semantics of a relational or an object-oriented database into classes and stored procedures triggered by events. The stored constraints and data can be materialized into a target database upon user request. The user is allowed to perform the data materialization many times alternatively. The process can provide a relational as well as an object oriented view to the users simultaneously. This concurrent data materialization function can be applied to data warehouse to consolidate heterogeneous database into a fact table in a data model of user's choice. Furthermore, a user can obtain either a relational view or an object-oriented view of the same dataset of an object-relational database interchangeably.

A model for collaborative technologies in manufacturing

Groupware or collaborative systems allow a team to interact in a shared workspace despite geographical separation or diverse schedules. Current collaborative integrated manufacturing systems tend to focus on the design stage of the development process. However, design is only one stage of standard frameworks for problem-solving-based development, which typically include a more comprehensive set of stages from problem formulation, planning and design to testing and deployment. Problem solving methodologies and tools, originally developed for single-user environments, can be extended to multi-user collaborative problem solving models and systems. This paper considers the characteristics of existing collaborative systems in manufacturing and then proposes a methodology-based, object-oriented view of the structure of such systems, which also addresses such factors as the effect of distributed cognition and social protocols. We then show that existing research on both individual and collaborative problem solving models pertinent to groupware systems theory, as well as work on the effect of factors such as group cognition, group psychology, sociology and team dynamics, support this approach to the design of collaborative manufacturing environments.

A distributed persistent object store for scalable service

This paper presents a distributed persistent object store designed to simplify scalable service in cluster environment. This distributed object store, called TODS (Tsinghua Object Data Store), presents a single-imaged, transparent persistent and object-oriented view of the storage devices of the whole cluster. TODS is designed to be incremental scalable and efficient, and also has the properties of the high concurrency, high throughput and availability which are necessary for scalable service. TODS supports distributed ACID transactions within the cluster, which qualifies its use in the building of complex transactional services. And the user interface of TODS is fitter for building service than that of file system, and significantly easier to use than that of RDBMS. TODS is a reusable platform for scalable service in cluster by forming many general data management functions into one independent layer. This paper gives the motivation, principle and architecture of TODS. Some technique details are also discussed. In our performance experiments, the system scales smoothly to a 36-node server cluster and achieves 11,160 In-memory reads/sec and 396 transactions/sec.

Extending the ODMG standard with views

Views are an important functionality provided by the relational database systems. However, commercial object-oriented database systems do not support a view mechanism because defining the semantics of views in the context of an object-oriented model is more difficult than in the relational model. Indeed, views are not included in the ODMG standard. In this paper, we present a proposal aimed at including views in the ODMG, by extending the object model and the object definition language (ODL). We consider object-oriented views as having the same functionality as relational views. Views are included in the object model in such a way that (i) views make a new kind of data type definition, just as are classes, interfaces and literals, (ii) an IS-VIEW relationship is introduced in order to specify the derivation of a view from its base class, and (iii) a view instance preserves the identity of its base instance. A view can import attributes, relationships and operations from its base class, and it can also add new operations, derived attributes and derived relationships. The extent of the view is defined by an object query language (OQL) predicate. We also describe a C++ binding showing the practicability of the proposed model.

GOBASE: the organelle genome database.

GOBASE (http://megasun.bch.umontreal.ca/gobase/) is a network-accessible biological database, which is unique in bringing together diverse biological data on organelles with taxonomically broad coverage, and in furnishing data that have been exhaustively verified and completed by experts. So far, we have focused on mitochondrial data: GOBASE contains all published nucleotide and protein sequences encoded by mitochondrial genomes, selected RNA secondary structures of mitochondria-encoded molecules, genetic maps of completely sequenced genomes, taxonomic information for all species whose sequences are present in the database and organismal descriptions of key protistan eukaryotes. All of these data have been integrated and organized in a formal database structure to allow sophisticated biological queries using terms that are inherent in biological concepts. Most importantly, data have been validated, completed, corrected and standardized, a prerequisite of meaningful analysis. In addition, where critical data are lacking, such as genetic maps and RNA secondary structures, they are generated by the GOBASE team and collaborators, and added to the database. The database is implemented in a relational database management system, but features an object-oriented view of the biological data through a Web/Genera-generated World Wide Web interface. Finally, we have developed software for database curation (i.e. data updates, validation and correction), which will be described in some detail in this paper.

Lightweight Object-Oriented Shared Variables for Cluster Computing in Java

This paper describes a lightweight yet powerful approach for writing distributed applications in Java using shared variables. Our approach, called ShareHolder, is inspired by the flexible and intuitive model of information access common to the World Wide Web. The distributed applications targeted by our approach all share a weak consistency model, similar to a user's model of accessing e-mail, bulletin boards, chat rooms, etc. on the Internet. The ShareHolder infrastructure has several advantages. Its highly object-oriented view of shared variables simplifies their initialization and configuration. A shared variable's distribution mechanism is specified through an associated configuration object, and the programmer does not need to write any extra code to implement the sharing mechanism. These configuration objects can be initialized at run-time, allowing tremendous flexibility in dynamic control of distribution of shared variables. Finally, the programmer can easily evolve a serial application into a distributed application for cluster computing by incrementally declaring certain classes as shared.