49 research outputs found
Market coupling and the organization of counter-trading: separating energy and transmission again?
No full textThe horizontal integration of the energy market and the organization of transmission services remain two open issues in the restructured European electricity sector. The coupling of the French, Belgian and Dutch electricity markets (the trilateral market) in November 2006 was a real success that the inclusion of Germany to the trilateral market should soon prolong. But the extension of market coupling whether in Central Western Europe or in other European regions encounters several difficulties and the future remains far from clear. The highly meshed grid of continental Europe complicates things and it is now sometimes recognized that the penetration of wind will further exacerbate these difficulties. The nodal system could go a long way towards solving these problems, but its implementation is not yet foreseen in the EU. This paper analyzes versions of market coupling that differ by the organization of counter- trading. While underplayed in current discussions, counter-trading will become a key element of market coupling as its geographic coverage expands and wind penetration develops. We consider a stylized six node example found in the literature and simulate market coupling for different assumptions of zonal decomposition and coordination of TSOs. We show that these assumptions matter: market coupling can be quite vulnerable to the particular situation on hand; counter-trading can work well or completely fail depending on the case and it is not clear beforehand what will prevail. Our analysis relies on standard economic notions such as social welfare, Nash and Generalized Nash equilibrium. But the use of these notions is probably novel. We also simplify matters by assuming away strategic behaviour. The nodal organization is the reference first best scenario: different zonal decompositions and degrees of coordinations are then studied with respect to this first best solution.D52, D58, Q40
Urinary Function Following Radical Hysterectomy (based on various types, Piver classification) in Urinary Function in Relation to and Following Treatment of Gynaecological Malignancies
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Field and Numerical Studies of Tracer Gas Transport and Surface Gas Transfer in Laterally Uniform, Partially Stratified Estuaries
No full textU.S. Environmental Protection Agency Project R811809-01-0Center for Water and the Environmen
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Texas Department of Water Resources Report LP-106: Final Report
No full textCenter for Water and the Environmen
Detecting non-secure memory deallocation with CBMC
No full text2021 Fall.Includes bibliographical references.Scrubbing sensitive data before releasing memory is a widely recommended but often ignored programming practice for developing secure software. Consequently, sensitive data such as cryptographic keys, passwords, and personal data, can remain in memory indefinitely, thereby increasing the risk of exposure to hackers who can retrieve the data using memory dumps or exploit vulnerabilities such as Heartbleed and Etherleak. We propose an approach for detecting a specific memory safety bug called Improper Clearing of Heap Memory Before Release, referred to as Common Weakness Enumeration 244. The CWE-244 bug in a program allows the leakage of confidential information when a variable is not wiped before heap memory is freed. Our approach uses the CBMC model checker to detect this weakness and is based on instrumenting the program using (1) global variable declarations that track and monitor the state of the program variables relevant for CWE-244, and (2) assertions that help CBMC to detect unscrubbed memory. We develop a tool, SecMD-Checker, implementing our instrumentation based algorithm, and we provide experimental validation on the Juliet Test Suite that the tool is able to detect all the CWE-244 instances present in the test suite. The proposed approach has the potential to work with other model checkers and can be extended for detecting other weaknesses that require variable tracking and monitoring, such as CWE-226, CWE-319, and CWE-1239
Can Computed Tomography Predict Resectability of Ovarian Carcinoma at Primary Laparotomy?
No full textOBJECTIVE: To assess the ability of computed tomography in predicting whether suspected ovarian cancer could be fully excised at primary laparotomy. DESIGN: Retrospective analysis of patient notes and pre-operative computed tomography scans. Setting A UK NHS cancer centre. POPULATION: Seventy-seven women who underwent laparotomy for an ovarian tumour and who had had a pre-operative computed tomography scan. METHODS: Women who had a computed tomography scan before laparotomy for an ovarian tumour were identified. Analysis was undertaken to determine the accuracy of computed tomography in predicting malignancy, stage and residual disease. The computed tomography parameters significantly associated with residual disease were determined by a chi2 analysis. These parameters, in addition to age and CA125, were used to generate a predictive model. This model was further refined by stepwise logistic regression and a clinical scoring index was generated. MAIN OUTCOME MEASURES: To identify those computed tomography parameters significantly associated with residual disease and to use these with CA125 and age to generate a useful clinical scoring index to predict residual disease in suspected ovarian cancer. RESULTS: Seventy-seven women underwent a laparotomy for an ovarian tumour and had a pre-operative computed tomography scan. Fifty-one of these women had malignant disease and twenty-five of these women had residual disease remaining. The sensitivity of computed tomography in predicting malignancy was 90% with a specificity of 85% and the overall accuracy of computed tomography for predicting stage of disease was 73% (37/51). The overall sensitivity of computed tomography in predicting residual disease was 88%, the specificity was 92% and the positive predictive value was 85%. The parameters on computed tomography that were significantly (P <0.05) associated with residual disease were ascites, omental cake, mesenteric disease, paracolic gutter deposits, diaphragmatic deposits and pleural effusion. The predictive model generated was more accurate than computed tomography alone (sensitivity 88%, specificity 98%, positive predictive value 95%). Using stepwise logistic regression enabled the predictive model to be simplified to include mesenteric disease, omental cake, age and CA125 without any change in sensitivity or specificity and this model was used to generate a scoring index. CONCLUSION: This study shows that prediction of resectability by computed tomography is excellent and is further improved by the generation of a predictive model, which can be used to generate a simple scoring index. This scoring system now needs to be tested prospectively to ensure that its performance remains as good in an independent sample population
Improving outcomes in gynaecological cancer: the impact of centralisation on patient flows and service provision
No full textResponses to a postal questionnaire and cancer registry data were utilised to evaluate the impact of the recent NHS Executive guidelines for the management of gynaecological malignancies on patient flows and service provision in the West Midlands. They were also used to assess the service provision in the west midlands in relation to these guidelines. Eighty-nine per cent (16/18) trusts returned completed questionnaires. Seventy-two per cent (46/64) of recommendations were achieved by all four centres; 18% (10/57) by all 12 units. The cancer registration data revealed 404 cases that would need to be transferred to the cancer centres per annum in order to implement the guidelines. A more detailed analysis for the northern area of the region estimated that a further 120 cases per annum would need to be managed at the main centre. This study has shown that implementation of the guidelines will require significant shifts in patient flows. This will increase workloads for the cancer centre and have an impact on service provision and resource allocation
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Development of an online collaborative working environment for design and manufacturing
No full textoai:irep.ntu.ac.uk:1This research is to develop a novel collaborative working environment (CWE) for manufacturing and design using advanced Web/Internet technologies such as Web Service, Grid Service and other related software tools/packages. To achieve the above, the following research modules are developed by the author: A service oriented framework for computer aid design, which acts as an online collaboration system, has been developed with the utilisation of the latest technology, Web Service. The concept of Service-Oriented Architecture has been implemented in the framework. Users from anywhere in the world can join the design process from their PCs, no matter what operation system they are using. The service-oriented system has the capability of going through firewalls and can afford multi-users due to the characteristics of Web service. Also the loose-coupling structure makes the system very easy to be updated. Another module for the CWE is to solve the software sharing problem when the platform is used among several geographically dispersed users or organisations. A software package bank system has been developed, which utilised the ideology of service oriented approach and successfully solved traditional problems in this field. Based on the outcomes mentioned above, the research finally developed a more powerful infrastructure using Grid service, which is a further development of Grid computing and Web service. The Grid service is considered to be the most important future solvent for Internet
Reenergising professional creativity from a CHAT perspective: Seeing knowledge and history in practice
No full textThis is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2011 Regents of the University of California.This article offers a critical examination of aspects of a practice- and theory-developing intervention in the teacher education setting in England designed as a variation of Developmental Work Research. A positive case is argued for the distinctiveness of such cultural-historical activity theory [CHAT-] informed interventions and some points of contrast are drawn with the British tradition of educational action research. In describing the practice-developing intervention, the twin focus on seeing knowledge and history in human activity systems is advanced as two dimensions of CHAT's distinctive approach, with the goal of stimulating and studying the emergence of professional creativity. Creativity under this interpretation is defined as the perception and analysis of opportunities for learning within the social situation of development and the production of new conceptual tools and approaches to the social organisation of work. Professional creativity is advanced as a much needed capacity among teachers in industrial workplaces influenced by the techniques of New Public Management. Common ground between CHAT and action research approaches is seen in their optimistic and modernist commitments to progress, and CHAT-framed interventions, like action research approaches, are presented as part of an evolving intellectual project
