UML Deficiencies from the perspective of Automatic Performance Model Generation

A discussion surrounding the use of UML for distributed system design

An 00 visual language definition approach supporting multiple views

The formal approach to visual language definition is to use graph grammars and/or graph transformation techniques. These techniques focus on specifying the syntax and manipulation rules of the concrete representation. This paper presents a constraint and object-oriented approach to defining visual languages that uses UML and OCL as a definition language. Visual language definitions specify a mapping between concrete and abstract models of possible visual sentences, which carl subsequently be used to determine if instances of each model "validly" express each other. This technique supports many:many mappings between concrete and abstract model instances, and supports the implementation of functionality that requires feedback from the abstract domain to the concrete

To assess the value of satellite photographs in resource evaluation on a national scale

The author has identified the following significant results. Small scale ERTS-1 imagery has enabled investigators to study large areas at a time. The imagery appears to confirm a new theory that Archean greenstone belts in NE Botswanna and SW Rhodesia are co-extensive and that these so-called schist relics formerly covered a much wider area than is apparent now. The central parts of the region bounded by the schist relics are believed to have suffered granitization. A remnant of an older drainage system to the southwest of the Okavango Swamps, which seems to have been newly discovered on the imagery, may be an indication of the seismic instability of the region. Even quite small earth movements in the swamps could radically affect the direction of water flow. The imagery has proved successful in showing areas infested by the water weed Salvinia Auriculata in the Chobe and Zambesi rivers. This will be immensely valuable in later surveys on the ground. If the satellite was to have continued working, the imagery would have enabled workers to determine the extent of encroachment of the weed without recourse to field observations

C# 3.0 makes OCL redundant!

Other than its 'platform independence' the major advantages of OCL over traditional Object Oriented programming languages has been the declarative nature of the language, its powerful navigation facility via the iteration operations, and the availability of tuples as a first class concept. The recent offering from Microsoft of the "Orcas" version of Visual Studio with C# 3.0 and the Linq library provides functionality almost identical to that of OCL. This paper examines and evaluates the controversial thesis that, as a result of C# 3.0, OCL is essentially redundant, having been superseded by the incorporation of its advantageous features into a mainstream programming language

Cost-effectiveness of granulocyte colony-stimulating factor prophylaxis for febrile neutropenia in patients with non-Hodgkin's lymphoma in the United Kingdom (UK)

Introduction: We report a cost-effectiveness evaluation of granulocyte colony-stimulating factors (G-CSFs) for prevention of febrile neutropenia (FN) following chemotherapy for non-Hodgkin’s lymphoma (NHL) in the United Kingdom (UK). Methods: A mathematical model was constructed simulating the experience of patients with NHL undergoing chemotherapy. Three strategies were modelled: primary prophylaxis (G-CSFs administered in all cycles); secondary prophylaxis (G-CSFs administered in all cycles following an FN event), and no G-CSF prophylaxis. Three G-CSFs were considered: filgrastim; lenograstim and pegfilgrastim. Costs were taken from UK databases and utility values from published sources with the base case analysis using list prices for G-CSFs and a willingness to pay (WTP) threshold of £20,000 per QALY gained. A systematic review provided data on G-CSF efficacy. Probabilistic sensitivity analyses examined the effects of uncertainty in model parameters. Results: In the base-case analysis the most cost-effective strategy was primary prophylaxis with pegfilgrastim for a patient with baseline FN risk greater than 22%, secondary prophylaxis with pegfilgrastim for baseline FN risk 8-22%, and no G-CSFs for baseline FN risk less than 8%. Using a WTP threshold of £30,000, primary prophylaxis with pegfilgrastim was cost-effective for baseline FN risks greater than 16%. In all analyses, pegfilgrastim dominated filgrastim and lenograstim. Sensitivity analyses demonstrated that higher WTP threshold, younger age, or reduced G-CSF prices result in G-CSF prophylaxis being cost-effective at lower baseline FN risk levels. Conclusions: Pegfilgrastim was the most cost-effective G-CSF. The most cost-effective strategy (primary or secondary prophylaxis) was dependent on underlying FN risk level, patient age, and G-CSF price

Cost-effectiveness of granulocyte colony-stimulating factor prophylaxis for febrile neutropenia in patients with non-Hodgkin's lymphoma in the United Kingdom (UK)

Introduction: We report a cost-effectiveness evaluation of granulocyte colony-stimulating factors (G-CSFs) for prevention of febrile neutropenia (FN) following chemotherapy for non-Hodgkin’s lymphoma (NHL) in the United Kingdom (UK). Methods: A mathematical model was constructed simulating the experience of patients with NHL undergoing chemotherapy. Three strategies were modelled: primary prophylaxis (G-CSFs administered in all cycles); secondary prophylaxis (G-CSFs administered in all cycles following an FN event), and no G-CSF prophylaxis. Three G-CSFs were considered: filgrastim; lenograstim and pegfilgrastim. Costs were taken from UK databases and utility values from published sources with the base case analysis using list prices for G-CSFs and a willingness to pay (WTP) threshold of £20,000 per QALY gained. A systematic review provided data on G-CSF efficacy. Probabilistic sensitivity analyses examined the effects of uncertainty in model parameters. Results: In the base-case analysis the most cost-effective strategy was primary prophylaxis with pegfilgrastim for a patient with baseline FN risk greater than 22%, secondary prophylaxis with pegfilgrastim for baseline FN risk 8-22%, and no G-CSFs for baseline FN risk less than 8%. Using a WTP threshold of £30,000, primary prophylaxis with pegfilgrastim was cost-effective for baseline FN risks greater than 16%. In all analyses, pegfilgrastim dominated filgrastim and lenograstim. Sensitivity analyses demonstrated that higher WTP threshold, younger age, or reduced G-CSF prices result in G-CSF prophylaxis being cost-effective at lower baseline FN risk levels. Conclusions: Pegfilgrastim was the most cost-effective G-CSF. The most cost-effective strategy (primary or secondary prophylaxis) was dependent on underlying FN risk level, patient age, and G-CSF price