The Object Management Group (OMG) have defined mechanisms to support the persistence of CORBA objects with both the now deprecated Persistent Object Service (POS) and the new Persistent State Service (PSS). In this paper we describe both specifications and show that they are deficient in a number of areas. We introduce an alternative CORBA persistence mechanism that makes use of a novel persist...

Modeling and simulation will provide crucial capabilities for complex systems engineering, but existing languages, frameworks, and tools fall short of both fundamental and practical needs. This paper describes work-in-progress to fill these needs, based on a foundation of logic-based description and a system of concepts to describe complex dynamic systems. The modeling framework can include map...

The recent OMG work on Queries, Views and Transformations (QVT) has led to five proposals that contain suggestions for notations for model-to-model transformations. This work is a valuable foundation, but the success of the MDA initiative and of QVT in particular will depend on the availability of a concrete syntax for model-to-model transformations that is able to express non-trivial transform...

Distributed callbacks differ from CORBA’s conventional synchronous invocation model because they decouple the request for a service from the response(s). Callbacks are often useful when consumers of events don’t need to wait synchronously for suppliers to generate the events. In addition, they can be used to deliver responses to long-running operations, rather than making clients block waiting ...

In July 2001, the Space Domain Task Force of the Object Management Group (OMG) issued a Request for Proposal (RFP) on Telemetric and Command Data Specification. This RFP solicited proposals that define telemetry and commanding data specifications in support of all phases of the satellite, payload, and ground segment lifecycle: system design, development, test, validation, and mission operations...

MASIF is a standard for mobile agent systems which has been adopted as an OMG technology. It is an early attempt to standardize an area of industry that, even though popular in the recent past, still has not caught on. In its short history MASIF has raised interest in industry and academia. There are already a number of projects pursuing MASIF reference implementation. MASIF addresses the inter...

One fifth of all cases of A virus hepatitis (AVH) have symptoms of gastroenteritis at the onset. This study investigated the mediated intestinal absorption of D-xylose (D-xyl) and 3-o-methyl-D-glucose (3-omG) and the non-mediated permeation of lactulose (Lacl, mol wt 342) and L-rhamnose (L-rh, mol wt 164) during acute and remission phases of AVH. Ten patients with AVH were given an oral load co...

This is the final column in our series covering the OMG CORBA Messaging specification [1]. Our previous columns in this series covered the communications models supplied by Messaging [2], explained how to program asynchronous method invocations (AMI) in C++ [3], and described timeindependent invocation (TII) and interoperable routing [4]. We finish this series by highlighting the quality of ser...

One hundred and eighty day-old Cobb broiler chickens were used to evaluate the effects of feeding diets containing neem leaf meal (NLM), garlic (GM) their combination (NLM + GM) on haematological serum indices finishing broiler. The birds divided into twelve treatment groups fifteen chicks with three replicate five each. contained NLM, GM NLM at four levels inclusion; Omg/kg, 500mg/kg, 1000mg/k...