Smart Proxies Research Articles

Smart Proxy Modeling of a Fractured Reservoir Model for Production Optimization: Implementation of Metaheuristic Algorithm and Probabilistic Application

Numerical reservoir simulation has been recognized as one of the most frequently used aids in reservoir management. Despite having high calculability performance, it presents an acute shortcoming, namely the long computational time induced by the complexities of reservoir models. This situation applies aptly in the modeling of fractured reservoirs because these reservoirs are strongly heterogeneous. Therefore, the domains of artificial intelligence and machine learning (ML) were used to alleviate this computational challenge by creating a new class of reservoir modeling, namely smart proxy modeling (SPM). SPM is a ML approach that requires a spatio-temporal database extracted from the numerical simulation to be built. In this study, we demonstrate the procedures of SPM based on a synthetic fractured reservoir model, which is a representation of dual-porosity dual-permeability model. The applied ML technique for SPM is artificial neural network. We then present the application of the smart proxies in production optimization to illustrate its practicality. Apart from applying the backpropagation algorithms, we implemented particle swarm optimization (PSO), which is one of the metaheuristic algorithms, to build the SPM. We also propose an additional procedure in SPM by integrating the probabilistic application to examine the overall performance of the smart proxies. In this work, we inferred that the PSO had a higher chance to improve the reliability of smart proxies with excellent training results and predictive performance compared with the considered backpropagation approaches.

Applications of smart proxies for subsurface modeling

Abstract Using artificial intelligence (AI) and machine learning (ML) techniques, we developed and validated the smart proxy models for history matching of reservoir simulation, sensitivity analysis, and uncertainty assessment by artificial neural network (ANN). The smart proxy models were applied on two cases, the first case study investigated the application of a proxy model for calibrating a reservoir simulation model based on historical data and predicting well production while the second case study investigated the application of an ANN-based proxy model for fast-track modeling of CO2 enhanced oil recovery, aiming at the prediction of the reservoir pressure and phase saturation distribution at injection stage and post-injection stage. The prediction effects for both cases are promising. While a single run of basic numerical simulation model takes hours to days, the smart proxy model runs in a matter of seconds, saving 98.9% of calculating time. The results of these case studies demonstrate the advantage of the proposed workflow for addressing the high run-time, computational time and computational cost of numerical simulation models. In addition, these proxy models predict the outputs of reservoir simulation models with high accuracy.

Smart Proxies for Accessing Replicated Web Services

SmartWS is a system that relies on smart proxies to encapsulate a variety of Web service-selection policies, including a new policy that combines the advantages of some of the most representative policies already described in the literature. Smart proxies generated by SmartWS can also encapsulate adapters to bridge potential incompatibilities between Web services interfaces and the interfaces expected by clients. Early performance results obtained from experiments carried out on a prototype SmartWS implementation support preliminary guidelines for choosing different server-selection policies.

Smart Proxies for Accessing Replicated Web Services

SmartWS is a system that relies on smart proxies to encapsulate a variety of Web service-selection policies, including a new policy that combines the advantages of some of the most representative policies already described in the literature. Smart proxies generated by SmartWS can also encapsulate adapters to bridge potential incompatibilities between Web services interfaces and the interfaces expected by clients. Early performance results obtained from experiments carried out on a prototype SmartWS implementation support preliminary guidelines for choosing different server-selection policies.

Smart proxies for Jini services

Jini has been advertised as a self-healing infrastructure where both services and consumers of these services come and go. However, it does not explicitly address the issue of how to recover when a consumer communicates with a service, which suddenly fails. This paper presents how smart proxies can be implemented in a Jini environment, allowing a client to transparently reconnect to another instance of a service in case of a failure. An important feature of the Java language: dynamic proxy is used to allow this transparent reconnection scheme.

Evaluating meta-programming mechanisms for ORB middleware

Distributed object computing middleware, such as CORBA, COM+, and Java RMI, shields developers from many tedious and error-prone aspects of programming distributed applications. It is hard to evolve distributed applications after they are deployed, however, without adequate middleware support for meta-programming mechanisms, such as smart proxies, interceptors, and pluggable protocols. These mechanisms can help improve the adaptability of distributed applications by allowing their behavior to be modified without changing their existing software designs and implementations significantly. This article examines and compares common meta-programming mechanisms supported by DOC middleware. These mechanisms allow applications to adapt more readily to changes in requirements and runtime environments throughout their lifecycles. Some of these meta-programming mechanisms are relatively new, whereas others have existed for decades. This article provides a systematic evaluation of these mechanisms to help researchers and developers determine which are best suited to their application needs.

Structuring QoS-supporting services with smart proxies

Structuring QoS-supporting services with smart proxies

Guest Editor's introduction: Selected papers from the 4th USENIX Conference on Object-Oriented Technologies and Systems

Hewlett-Packard Laboratories, 1501 Page Mill Road, Palo Alto, CA 94304, USA Introduction The USENIX Conference on Object-Oriented Technologies and Systems (COOTS) is held annually in the late spring. The conference evolved from a set of C++ workshops that were held under the auspices of USENIX, the first of which met in 1989. Given the growing diverse interest in object-oriented technologies, the C++ focus of the workshop eventually became too narrow, with the result that the scope was widened in 1995 to include object-oriented technologies and systems. COOTS is intended to showcase advanced RD the architecture and implementation of distributed object systems (e.g. CORBA, DCOM, RMI); object-oriented programming and specification languages; object-oriented design and analysis. The 4th meeting of COOTS was held 27 - 30 April 1998 at the El Dorado Hotel, Santa Fe, New Mexico, USA. Several tutorials were given. The technical program proper consisted of a single track of six sessions, with three paper presentations per session. A keynote address and a provocative panel session rounded out the technical program. The program committee reviewed 56 papers, selecting the best 18 for presentation in the technical sessions. While we solicit papers across the spectrum of applications of object-oriented technologies, this year there was a predominance of distributed, object-oriented papers. The accepted papers reflected this asymmetry, with 15 papers on distributed objects and 3 papers on object-oriented languages. The papers in this special issue are the six best distributed object papers (in the opinion of the program committee). They represent the diversity of research in this particular area, and should give the reader a good idea of the types of papers presented at COOTS as well as the calibre of the work so presented. The papers The paper by Jain, Widoff and Schmidt explores the suitability of Java for writing performance-sensitive distributed applications. Despite the popularity of Java, there are many concerns about its efficiency; in particular, networking and computation performance are key concerns when considering the use of Java to develop performance-sensitive distributed applications. This paper makes three contributions to the study of Java for these applications: it describes an architecture using Java and the Web to develop MedJava, which is a distributed electronic medical imaging system with stringent networking and computation requirements; it presents benchmarks of MedJava image processing and compares the results to the performance of xv, which is an equivalent image processing application written in C; it presents performance benchmarks using Java as a transport interface to exchange large medical images over high-speed ATM networks. The paper by Little and Shrivastava covers the integration of several important topics: transactions, distributed systems, Java, the Internet and security. The usefulness of this paper lies in the synthesis of an effective solution applying work in different areas of computing to the Java environment. Securing applications constructed from distributed objects is important if these applications are to be used in mission-critical situations. Delegation is one aspect of distributed system security that is necessary for such applications. The paper by Nagaratnam and Lea describes a secure delegation model for Java-based, distributed object environments. The paper by Frolund and Koistinen addresses the topical issue of providing a common way for describing Quality-of-Service (QoS) features in distributed, object-oriented systems. They present a general QoS language, QML, that can be used to capture QoS properties as part of a design. They also show how to extend UML to support QML concepts. The paper by Szymaszek, Uszok and Zielinski discusses the important issue of efficient implementation and usage of fine-grained objects in CORBA-based applications. Fine-grained objects can have serious ramifications on overall application performance and scalability, and the paper suggests that such objects should not be treated as first-class CORBA objects, proposing instead the use of collections and smart proxies for efficient implementation. The paper by Milojicic, LaForge and Chauhan describes a mobile objects and agents infrastructure. Their particular research has focused on communication support across agent migration and extensive resource control. The paper also discusses issues regarding interoperation between agent systems. Acknowledgments The editor wishes to thank all of the authors, reviewers and publishers. Without their excellent work, and the contribution of their valuable time, this special issue would not have been possible.

Reflective object-oriented distributed system for heterogeneous multimedia environments

In this paper, object-oriented techniques and concepts (e.g. object migration, inheritance, delegation) and reflection are applied to the design of a distributed system called the Reflective Object-oriented Distributed System (RODS). RODS hides object distribution and underlying platform heterogeneity to simplify the development of distributed multimedia applications. RODS has two major components: The Flexible Multimedia Object Adaptor (FMOA) and the Reflective Object Request Broker (RORB). The FMOA is an application framework of classes to facilitate the construction of distributed multimedia applications. The RORB is a CORBA Object Request Broker that integrates additional features such as smart proxies, delegation, migration, and sharing. By utilizing a reflective model, RORB allows the application programmer and the system to dynamically modify distributed object management policies.