FORMAL ANALYSIS OF WEB SERVICE COMPOSITION

Ph.DDOCTOR OF PHILOSOPH

Verification of functional and non-functional requirements of web service composition

Abstract. Web services have emerged as an important technology nowadays. There are two kinds of requirements that are crucial to web service composition, which are functional and non-functional requirements. Functional requirements focus on functionality of the composed service, e.g., given a booking service, an example of functional requirements is that a flight ticket with price higher than $2000 will never be purchased. Non-functional requirements are concerned with the quality of service (QoS), e.g., an example of the booking service’s non-functional requirements is that the service will respond to the user within 5 sec-onds. Non-functional requirements are important to web service composition, and are often an important clause in service-level agreements (SLAs). Even though the functional requirements are satisfied, a slow or unreliable service may still not be adopted. In our paper, we propose an automated approach to verify combined functional and non-functional requirements directly based on the semantics of web service composition. Our approach has been implemented and evaluated on the real-world case studies, which demonstrate the effectiveness of our method.

Automated runtime recovery for QoS-based service composition

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Efficient detoxication of hydroxylamine and nitrite through heterotrophic nitrification and aerobic denitrification by Acinetobacter johnsonii EN-J1

The co-existence of hydroxylamine (NH2OH) and nitrite (NO2–-N) can aggravate the difficulty of wastewater treatment. The roles of hydroxylamine (NH2OH) and nitrite (NO2–-N) in accelerating the elimination of multiple nitrogen sources by a novel isolated strain of Acinetobacter johnsonii EN-J1 were investigated in this study. The results demonstrated that strain EN-J1 could eliminate 100.00% of NH2OH (22.73 mg/L) and 90.09% of NO2–-N (55.32 mg/L), with maximum consumption rates of 1.22 and 6.75 mg/L/h, respectively. Prominently, the toxic substances NH2OH and NO2–-N could both facilitate nitrogen removal rates. Compared with the control treatment, the elimination rates of nitrate (NO3–-N) and NO2–-N were enhanced by 3.44 and 2.36 mg/L/h after supplementation with 10.00 mg/L NH2OH, and those of ammonium (NH4+-N) and NO3–-N were improved by 0.65 and 1.00 mg/L/h after the addition of 50.00 mg/L NO2–-N. Furthermore, the nitrogen balance results indicated that over 55.00% of the initial total nitrogen was transformed into gaseous nitrogen by heterotrophic nitrification and aerobic denitrification (HN-AD). Ammonia monooxygenase (AMO), hydroxylamine oxidoreductase (HAO), nitrate reductase (NR), and nitrite reductase (NIR), which are essential for HN-AD, were detected at levels of 0.54, 0.15, 0.14, and 0.01 U/mg protein, respectively. All findings confirmed that strain EN-J1 could efficiently execute HN-AD, detoxify NH2OH and NO2–-N, and ultimately promote nitrogen removal rates

Optimizing selection of competing features via feedback-directed evolutionary algorithms

Software that support various groups of customers usually require complicated configurations to attain different functionalities. To model the configuration options, feature model is proposed to capture the commonalities and competing variabilities of the product variants in software family or Software Product Line (SPL). A key challenge for deriving a new product is to find a set of features that do not have inconsistencies or conflicts, yet optimize multiple objectives (e.g., minimizing cost and maximizing number of features), which are often competing with each other. Existing works have attempted to make use of evolutionary algorithms (EAs) to address this problem. In this work, we incorporated a novel feedback-directed mechanism into existing EAs. Our empirical results have shown that our method has improved noticeably over all unguided version of EAs on the optimal feature selection. In particular, for case studies in SPLOT and LVAT repositories, the feedback-directed Indicator-Based EA (IBEA) has increased the number of correct solutions found by 72.33% and 75%, compared to unguided IBEA. In addition, by leveraging a pre-computed solution, we have found 34 sound solutions for Linux X86, which contains 6888 features, in less than 40 seconds.No Full Tex

The economic burden of cervical cancer from diagnosis to one year after final discharge in Henan Province, China: A retrospective case series study.

BACKGROUND: In China, the disease burden of cervical cancer remains substantial. Human papillomavirus (HPV) vaccines are expensive and not yet centrally funded. To inform immunization policy, understanding the economic burden of the disease is necessary. This study adopted a societal perspective and investigated costs and quality of life changes associated with cervical cancer from diagnosis to one year after final discharge in Henan province, China. METHODS: Inpatient records of cervical cancer patients admitted to the largest cancer hospital in Henan province between Jan. 2017 and Dec. 2018 were extracted. A telephone interview with four modules was conducted in Jun.-Jul. 2019 with a 40% random draw of patients to obtain direct non-medical costs and indirect costs associated with inpatients, costs associated with outpatient visits, and changes in quality of life status using the EQ-5D-5L instrument. Direct medical expenditures were converted to opportunity costs of care using cost-to-charge ratios obtained from hospital financial reports. For each clinical stage (IA-IV), total costs per case from diagnosis to one year after final discharge were extrapolated based on inpatient records, responses to the telephone interview, and recommendation on outpatient follow-ups by Chinese cervical cancer treatment guidelines. Loss in quality-adjusted life years was obtained using the 'under the curve' method and regression predictions. RESULTS: A total of 3,506 inpatient records from 1,323 patients were obtained. Among 541 randomly selected patients, 309 completed at least one module of the telephone interview. The average total costs per case associated with cervical cancer from diagnosis to one year after final discharge ranged from $8,066-$22,888 (in 2018 US Dollar) and the quality-adjusted life years loss varied from 0.05-0.26 for IA-IV patients. CONCLUSIONS: The economic burden associated with cervical cancer is substantial in Henan province. Our study provided important baseline information for cost-effectiveness analysis of HPV immunization program in China

The Impact of Intracerebral Hemorrhage on the Progression of White Matter Hyperintensity

Objective: The exact relationship between white matter hyperintensity (WMH) and intracerebral hemorrhage (ICH) after ICH remains unclear. In this retrospective study, we investigated whether patients with ICH had more severe WMH progression.Patients and Methods: A total of 2,951 patients aged ≥40 years with ICH who received brain computed tomography (CT) imaging within 12 h of ICH symptom onset were screened. Ninety patients with two fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) assessments, including 36 patients with Lobar ICH, 40 with basal ganglia region ICH and 14 with ICH at other sites, were included in the final study. We selected 90 age- and gender-matched healthy individuals with two MRI scans as the control group. The WMH volumes at baseline and follow-up were assessed using the FLAIR image by MRICRON and ITK-SNAP software, while the hematoma volumes were calculated based on the CT images using ITK-SNAP software.Results: The annual progression rate of WMH was significantly higher in the ICH group compared with the control group (p < 0.05). Furthermore, WMH progression was associated with the ICH volume. The largest ICH volume (>30 mL) was associated with the highest annual progression rate of WMH (p < 0.05). In contrast, no trend toward an association between ICH location and the annual progression rate of WMH was observed (p > 0.05).Conclusions: Our results showed that ICH patients had more severe WMH progression and that larger ICH volume was related to greater progression of WMH after ICH. These results could provide important prognostic information about patients with ICH

Service adaptation with probabilistic partial models

Web service composition makes use of existing Web services to build complex business processes. Non-functional requirements are crucial for the Web service composition. In order to satisfy non-functional requirements when composing a Web service, one needs to rely on the estimated quality of the component services. However, estimation is seldom accurate especially in the dynamic environment. Hence, we propose a framework, ADFlow, to monitor and adapt the workflow of the Web service composition when necessary to maximize its ability to satisfy the non-functional requirements automatically. To reduce the monitoring overhead, ADFlow relies on asynchronous monitoring. ADFlow has been implemented and the evaluation has shown the effectiveness and efficiency of our approach. Given a composite service, ADFlow achieves 25 %–32 % of average improvement in the conformance of non-functional requirements, and only incurs 1 %–3 % of overhead with respect to the execution time.No Full Tex