CREOLE: a Universal Language for Creating, Requesting, Updating and Deleting Resources

In the context of Service-Oriented Computing, applications can be developed following the REST (Representation State Transfer) architectural style. This style corresponds to a resource-oriented model, where resources are manipulated via CRUD (Create, Request, Update, Delete) interfaces. The diversity of CRUD languages due to the absence of a standard leads to composition problems related to adaptation, integration and coordination of services. To overcome these problems, we propose a pivot architecture built around a universal language to manipulate resources, called CREOLE, a CRUD Language for Resource Edition. In this architecture, scripts written in existing CRUD languages, like SQL, are compiled into Creole and then executed over different CRUD interfaces. After stating the requirements for a universal language for manipulating resources, we formally describe the language and informally motivate its definition with respect to the requirements. We then concretely show how the architecture solves adaptation, integration and coordination problems in the case of photo management in Flickr and Picasa, two well-known service-oriented applications. Finally, we propose a roadmap for future work.Comment: In Proceedings FOCLASA 2010, arXiv:1007.499

CRUD-DOM: a model for bridging the gap between the object-oriented and the relational paradigms : an enhanced performance assessment based on a case study

The development of database applications comprises three different tiers: application tier, database tier and finally the middle tier also known as the data access layer. The development of each tier per-se entails many challenges. Very often the most difficult challenges to be addressed derive from non-functional requirements, as productivity, usability, performance, reliability, high-availability and transparency. This paper is focused on defining and presenting a model for the data access layer aimed to integrate object-oriented application tiers and relational database tiers. The model addresses situations on which users need to explicitly write down complex static CRUD expressions and simultaneously get advantages regarding some non-functional requirements. The model, known as CRUD Data Object Model (CRUD-DOM), tackles the following non-functional requirements: performance, usability and productivity. The main contributions of this paper are threefold: 1) to present an extended model of CRUD-DOM; 2) to carry out an extended performance assessment based on a case study; 3) to present a tool, called CRUD Manager (CRUD-M), which provides automatic code generation with complementary support for software test and maintenance. The main outcome from this paper is the evidences that the pair CRUD-DOM and CRUD-M effectively addresses productivity, performance and usability requirements in the aforementioned context

Extending RBAC model to control sequences of CRUD expressions

In database applications, access control is aimed at requests are mainly formalized by Create, Read, Update and Delete (CRUD)expressions. The supervision process can be formalized at a high level, such as based on the RBAC model, but in the end the relevant aspect is the data being accessed through each CRUD expression. In critical database applications access control can be enforced not on a CRUD by CRUD basis but enforced at the level of sequences of CRUD expressions (workflow). This situation can occur whenever established security policies are based on strict procedures that define step by step the actions (sequences of CRUD expressions) to be followed. Current RBAC models do not support this type of security policies. To overcome this security gap, we leverage previous researches to propose an extension to the RBAC model to control for each role which sequences of CRUD expressions are authorized. We demonstrate empirical evidence of the effectiveness of our proposal from a use case based on Java and JDBC. Our use case is based on typed security layers built from a software architectural model and also from metadata based on the proposed RBAC model extension

Heat and mass transfer analysis for crud coated PWR fuel

In water-cooled nuclear reactors, various species are present in the coolant, either in ionic solution, or entrained as very fine particles. Most arise from corrosion of primary circuit surfaces, or from chemicals, such as boric acid, lithium hydroxide, zinc and hydrogen, deliberately added to the coolant. These materials deposit on the surfaces of fuel pins, typically in the upper regions of the core, forming what is generally termed “crud”. This thesis reports a study of the thermal-hydraulic consequences of this deposit. These crud deposits are generally found to contain a large population of through-thickness chimneys, and it is believed that this gives rise to a wick-boiling mechanism of heat transfer. A coupled two-dimensional model of the processes of heat conduction, advection and species diffusion in the crud has been developed. An iterative scheme has been employed to solve the set of coupled equations of each process. The wick boiling process has been found to be an efficient heat transfer mode, taking away about 80% of the heat generated. It has also been found that consideration of heat transfer in the clad can increase the predicted solute concentration in the crud. The effects of some important parameters, such as chimney density, chimney radius, porosity of the crud, crud thickness, clad heat flux and boron concentration in the coolant have been investigated. The fuel thermal performance has been characterized in terms of an effective crud thermal conductivity, and the non-linear dependence this has on parameters such as crud thickness and chimney density had been determined. Lastly, it is observed that plausible pore sizes of the crud, coupled with higher temperatures in the crud, may be such that a film of vapour is generated at the base of the crud. Initial estimates are presented of the cladding temperatures and solute concentration that may be generated as a consequence of this vapour layer

Recommendations for minimizing green crud

The Array A-2 Green Crud problem, the investigation, and resulting recommendations were presented in ATM 1059 of 23 September 1971. With the occurrence of Green Crud in the Array E system in January, 1972 a second investigation of the means to prevent and/or remedy Green Crud was initiated. This ATM describes the results of this latter investigation.prepared by J. Matthis, D. K. Breseke

CRUD resistant fuel cladding materials

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, 2013."June 2013." Cataloged from PDF version of thesis.Includes bibliographical references (pages 27-29).CRUD is a term commonly used to describe deposited corrosion products that form on the surface of fuel cladding rods during the operation of Pressurized Water Reactors (PWR). CRUD has deleterious effects on reactor operation and currently, there is no effective way to mitigate its formation. The Electric Power Research Institute (EPRI) CRUD Resistant Fuel Cladding project has the objective to study the effect of different surface modifications of Zircaloy cladding on the formation of CRUD, and ultimately minimize its effects. This modification will alter the surface chemistry and therefore the CRUD formation rate. The objective of this study was to construct a pool boiling facility at atmospheric pressure and sub-cooled boiling conditions, and test a series of samples in simulated PWR water with a high concentration of nanoparticulate CRUD precursors. After testing, ZrC was the only material out of six that did not develop dark, circular spots, which are hypothesized to be the beginnings of CRUD boiling chimneys. Further testing will be needed to confirm that it is indeed more CRUD resistant, even under realistic PWR conditions in a parallel testing facility.by Ekaterina Paramonova.S.B

CRUD-DOM: a model for bridging the gap between the object-oriented and the relational paradigms

Best Paper AwardObject-oriented programming is the most successful programming paradigm. Relational database management systems are the most successful data storage components. Despite their individual successes and their desirable tight binding, they rely on different points of view about data entailing difficulties on their integration. Some solutions have been proposed to overcome these difficulties, such as Embedded SQL, object/relational mappings (O/RM), language extensions and even Call Level Interfaces (CLI), as JDBC and ADO.NET. In this paper we present a new model aimed at integrating object-oriented languages and relational databases, named CRUD Data Object Model (CRUD-DOM). CRUDDOM relies on CLI (JDBC) and aims not only at exploring CLI advantages as preserving its performance and SQL expressiveness but also on providing a typestate approach for the implementation of the ResultSet interface. The model design aims to facilitate the development of automatic code generation tools. We also present such a tool, called CRUD Manager (CRUD-M), which provides automatic code generation with a complementary support for software maintenance. This paper shows that CRUD-DOM is an effective model to address the aforementioned objectives.(undefined