Requirements-Driven Adaptation of Choreographed Interactions

Electronic services are emerging as the de-facto enabler of interaction interoperability across organization boundaries. Cross-organizational interactions are often “choreographed”, i.e. specified by a messaging protocol from a global point of view independent of the local view of each interacting organization. Local requirements motivating an interaction as well as the global contextual requirements governing the interaction inevitably evolve over time, requiring adaptation of the corresponding interaction protocol. Adaptation of an interaction protocol must ensure the satisfaction of both sets of interaction requirements while maintaining consistency between the global view and the local views of an interaction specification. Such adaptation is not possible with the current state-of-the-art representations of choreographed interactions, as they capture only operational messaging specifications detached from both local organizational requirements as well as global contextual requirements. This thesis presents three novel contributions that tackle adaptation of choreographed interaction protocols: an automated technique for deriving an interaction protocol from requirements, a formalization of consistency between local and global views, and a framework for guiding the adaptation of a choreographed interaction. A choreographed interaction is specified using models of organizational requirements motivating the interaction. We employ the formal semantics embedded in requirements models to automatically derive an interaction protocol. We propose a framework for relating the global and local views of interaction specification and maintaining consistency between them. We develop a metamodel for interaction specification, from which we enumerate adaptation operations. We build a catalogue that provides guidance on performing each operation and propagating changes between the global and local views. These contributions are evaluated using examples from the literature as well as a real-world case study

Patterns for service-oriented information exchange requirements

Service-Oriented Computing (SOC) is an emerging computing paradigm that supports loosely-coupled inter-enterprise interactions. SOC interactions are predominantly specified in a procedural manner that defines message sequences intermixing implementation with business requirements. In this paper we present a set of patterns concerning requirements of information exchange between participants engaging in service-oriented interactions. The patterns aim at explicating and elaborating the business requirements driving the interaction and separating them from implementation concerns

Customizing choreography: Deriving conversations from organizational dependencies

Evolving business needs call for customizable choreographed interactions. However, choreography descriptions do not capture the problem-domain knowledge required to perform the customization effectively. Hence, we propose performing the customization to models of organizational requirements motivating the interaction. To facilitate the derivation of the resulting choreography description, we propose an alignment between conversations and organizational dependencies. We employ the domain knowledge and formal semantics of requirements models to find customization alternatives and reason about them. Using the alignment, we derive constraints on conversations systematically from customized requirements models

SPECTROPHOTOMETRIC DETERMINATION OF OXYBUTININE HYDROCHLORIDE BY ION-PAIR EXTRACTIONIN IN PHARMACEUTICAL PREPARATIONS

Objective: Simple, sensitive, precise, reproducible and validated visible spectrophotometric methods have been developed for the determination of an antimuscarinic drug, namely oxybutynin hydrochloride (OXB) in pure form and in pharmaceutical preparations.Methods: Two spectrophotometric methods are based on the formation of yellow colored ion-pair complexes between the studied drug, and two sulphonphthalein acid dyes, bromocresol purple (BCP) and bromophenol blue (BPB) with absorption maxima at 410 and 416 nm, respectively.Results: The stoichiometric ratio of the formed ion-pair complexes was found to be 1:1 (drug: reagent) for both methods as deduced by Job's method of continuous variation. Several parameters such as pH, buffer type, and reagent volume, sequence of addition and effect of extracting solvent were optimized to achieve high sensitivity, stability, low blank reading and reproducible results. Under the optimum reaction conditions, linear relationships with good correlation coefficients (0.9996-0.9999) were found between the absorbance's and the concentrations of oxybutynin over the concentration ranges of 1.0–8.0 μg ml-1 and 1.0–12 μg ml-1 with LOD of 0.21 and 0.19 μg ml-1, using BCP and BPB methods, respectively. Various analytical parameters have been evaluated and the results have been validated by statistical data.Conclusion: The proposed methods were validated in accordance with ICH guidelines and successfully applied to the analysis of pharmaceutical formulation. Statistical comparison of the results obtained by applying the proposed methods with those of the reference method revealed good agreement and proved that there was no significant difference in the accuracy and precision between the results.Â

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

Requirements-Driven Design of Service-Oriented Interactions: An Evaluation

This report presents and evaluation of our proposed requirements-driven adaptation process for inter-enterprise service-oriented interactions [1] [2]. We evaluate our adaptation process using two case studies. The first case study we tackle builds on the medical example introduced in [2]. Using a constructed case study allows us to demonstrate our contributions in isolation from noise associated with a real world case study. The medical case study is small enough to be comprehended with little effort and yet it allows for illustrative applications of the adaptation process. The second case study brings together a well-studied example from the literature and real world requirements for vehicle accident insurance and repair scenario. This case study has dual benefit. On the one hand, applying our approach to a widely studied example allows us to compare the approach to other approaches that have been applied to the example and benefit from prior analysis. On the other hand, the real-world scenario allows us to evaluate how our approach performs in a real-world setting

Identification of the hydrodynamic model of an underwater robotic vehicle heaving and pitching near the sea surface using its measured response

An accurate estimation of the hydrodynamic parameters for Underwater Robotic Vehicles (URV) is a top priority for the designing of the control strategies for such vehicles. The identification of these parameters constitutes a main difficulty in the development of a URV. Several methods have been developed to estimate such parameters. These methods include: strip theory, slender body theory, semi-empirical approaches, and parametric identification. Most of these methods have many assumptions and drawbacks that restrict their applicability. -- I am mainly concerned with the parametric identification. One of the advantages of parametric identification is that if it can be done in real time then one can have a tool for updating the dynamic model as the vehicle moves through the water. Responses obtained using this model will be realistic and increase the chances of having better control of the vehicle. -- In this dissertation, I develop a new robust technique for the identification of the damping, restoring, and coupling parameters in the equations describing the coupled heave and pitch motions for an URV sailing near the water surface in random waves. The developed technique is called RDLRNNT, which is a combination of the random decrement technique, multi-linear regression algorithm, and a neural networks technique. RDLRNNT requires only the measured coupled heave rand pitch responses for the URV in random waves and does not require a prior knowledge of the wave excitation. The developed technique would be particularly useful in identifying the parameters for both moderately and lightly damped motions under the action of unknown wave excitations affected by a realistic sea. -- Numerically generated data for the coupled heave and pitch motion of an URV are used initially to test the accuracy of the technique for both different levels of damping and a wide range of damped natural frequencies in heave and pitch motions. Moreover, several case studies are further investigated to test the dependency of the developed technique on the wave excitation forms. Two different excitations are investigated: a wide-band and a narrow-band form. -- Experimental data are also used to validate the identification technique for different functions of wave excitations and different towing speeds. Three main experimental variables are further investigated: the significant wave height (Hs), the wave modal frequency (Ω), and the towing speed (U)

From organizational requirements to service choreography

Choreography is emerging as a standard for specifying multi-participant interactions. However, conventional choreography descriptions provide only a partial view of the interaction. They do not capture critical business-domain knowledge including: goals motivating participants to interact, organizational dependencies that enable the interaction, and physical activities that are part of the interaction contract. In the absence of this knowledge, it is hard to argue if a choreography description satisfies the business goals of participants. This deficiency is critical when the need arises to adapt the choreography to changes in business requirements. In this paper, we argue for representing choreography at the level of requirements motivating the interaction. To bridge the two worlds of choreographed messaging and requirements, we propose an automated technique for deriving choreography descriptions. Utilizing the precise semantics offered by requirements models we infer constraints on the choreographed messaging, from which we generate a choreography description that satisfies the requirements