Dependable computing

Computer systems are characterised by four fundamental properties functionality, performance, cost and dependability [1], Dependability is the quality of the delivered service such that reliance can justifiably be placed on this service [2], Dependability is therefore related to the extent that we can trust the system to be able to support our needs and is generally considered to be a highly desirable characteristic of a HIT service. Dependability encompasses a number of attributes [3]  

Security is sometimes quoted as a further attribute whilst other texts consider it to be a composite of confidentiality, integrity and availability. Note that the terms availability and reliability are often confused and examination of their definitions highlights an important difference. Availabihty is how consistently we are able to gain access to the functionality we require when we need it. Reliability on the other hand is about preserving operation of the system once we have access to it. So, not being able to log on because the application server had been shut down would impact availability. The system terminating execution of a report prematurely would affect reliability. 

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Moving responsibility for the force computation away from the patches required a move away from pure message-driven execution to dependency-driven execution in which patches control the data (atomic coordinates) needed for compute objects to execute. A compute object, upon creation, registers this dependency with those patches from which it needs data. The patch then triggers force calculation by notifying its dependent compute objects when the next timestep s data is available. Once a compute object has received notification from all of the patches it depends on, it is placed in a prioritized queue for eventual execution. 

With time-dependent computer simulation and visualization we can give the novices to QM a direct mind s eye view of many elementary processes. The simulations can include interactive modes where the students can apply forces and radiation to control and manipulate atoms and molecules. They can be posed challenges like trapping atoms in laser beams. These simulations are the inside story of real experiments that have been done, but without the complexity of macroscopic devices. The simulations should preferably be based on rigorous solutions of the time dependent Schrddinger equation, but they could also use proven approximate methods to broaden the range of phenomena to be made accessible to the students. Stationary states and the dynamical transitions between them can be presented as special cases of the full dynamics. All these experiences will create a sense of familiarity with the QM realm. The experiences will nurture accurate intuition that can then be made systematic by the formal axioms and concepts of QM. 

This relation enables evaluating the fragility parameter Ks as well as the structural relaxation times r over the whole temperamre range To < T < Ta-Because T] depends on polymer microstructure and molar mass, Ap likewise exhibits the same dependence. Computations of Ks within the entropy theory have not been possible before. 

Avizienis and He 1999] A. Avizienis and Y. He. Microprocessor Entomology A Taxonomy of Design Faults in COTS Microprocessors, in Proc. Dependable Computing for Critical Applications (DCCA 99), pp. 3-23, San Jose, CA, 1999. 

Dacier, M., F. Pouget, and H. Debar. Honeypots, A Practical Mean to Validate Malicious Fault Assumptions, in Proceedings of the 10th Pacific Ream Dependable Computing Conference (PRDC 04), Feb. 2004. 

An analysis of computer simulations of water at different pressures by Hummer et al. (110) suggested that hydrophobic contact pairs become increasingly destabilized with increasing pressure. The proposed scenario could explain the pressure denaturation of proteins as a swelling in terms of water molecules that enter the hydrophobic core by creating water-separated hydrophobic contacts. Additional support for the validity of Hummer s IT-model analysis has been achieved by pressure-dependent computer simulation studies of isolated pairs of hydrophobic particles, as well as rather concentrated solutions of hydrophobic particles (111, 112). Recently, the pressure-induced swelling of a polymer composed of apolar particles at low temperatures can be observed (113). 

Figure 2 shows /Z versus dependence computed from Eq. /7/... 

Laprie J. Dependable computing and fault tolerance concepts and terminology. Laboratory for analysis and architecture of systems. National Center for Scientific Research 1985. http // www.macedo.ufbabr/conceptsANDTermonology.pdf. 

Section 6.1 introduced the concept of dependable computing and the notion that availability and reliability are two of its key characteristics. A HIT system which is relied on clinically for the delivery of care can quickly result in a hazardous scenario when it becomes unavailable to users. This is particularly the case for systems that deliver data which is consumed quickly by its users and influences clinical decisions in a short timeframe. One study reported that for each minute of system downtime it took approximately 4.5 min for staff to complete the equivalent work had the system been operational [1]. 

MCFEARIN, L NAIR, V. Control-flow checking using assertions. In CONFERENCE ON DEPENDABLE COMPUTING FOR CRITICAL APPLICATIONS, Urbana-Champaign, USA Proceedings... Washington, USA IEEE Computer Society, 1995, pp. 103-112. 

Note that although computational method used here is of low level it nevertheless responds to present desiderate having an non (orbitalic) basis dependent computational output and discussion, whereas further (Hartree-Fock) ab initio, (Moller-Plesset) perturbation methods and basis set dependency considerations, as HF, MP2, and DFT, respectively, for instance, can be further considered for comparative analysis. 

Alvisi, L., D. Malkhi, L. Pierce, and M. K. Reiter. 1999. Fault detection for Byzantine quorum systems. Pp. 357-372 in Proceedings of the 7 IFIP Working Conference on Dependable Computing for Critical Applications, San Jose, Calif., January 6-8, 1999. Los Alamitos, Calif IEEE Computer Society. 

Siewerdt E., Sistemas Criticos em Sistemas de Ttans-porte, Atech Tecnologias Criticas, LADC-Latin American Dependable Computer, Escola Politecnica de Sao Paulo, Sao Paulo, 2003. 

Koutras V. R, Platis A. N., 2006, Resource availability optimization for priority classes in a website, 12th IEEE International Symposium on Pacific Rim Dependable Computing(PRDC 06), Jeske, Giardo, Dai (eds) 2006 IEEE Computer Society Press, LosAlamitos, California, pp. 305-312. 

Rodriguez, M. Salles, E Fabre, J.-C. Arlat, X 1999. MAFALDA Microfemel Assessment by Fault Injection and Design Aid, in Proc. 3rd European Dependable Computing Conf. (EDCC-3), (Hlavicka, E. M. X Pataricza, A. Ed.), (Prague, Czech Republic), LNCS 143-60. 

Gacek, C., De Lemos, R. Architectural Description of Dependable Software Systems. In Besnard, D., Gacek, C., Jones, C. (eds.) Proceedings of Structure for Dependability Computer-Based Systems from an Interdisciplinary Perspective, pp. 127-142. Springer, Heidelberg (2006)... 

Walter, M., Trinitis, C., Karl, W. OpenSESAME An Intuitive Dependability Modeling Environment Supporting Inter-Component Dependencies. In Proceedings of the Pacific Rim International Symposium on Dependable Computing, Seoul, Korea, December 2001, pp. 76-83 (2001)... 

Sousa, R, Bessani, A., Correia, M., Neves, N., Verissimo, R Resilient Intrusion Tolerance through Proactive and Reactive Recovery. In Procs. of the 13th IEEE Pacific Rim Dependable Computing Conference, pp. 373-380 (2007)... 

Toth, T., Voros, A., Majzik, I. K-induction based verification of real-time safety critical systems. In Zamojski, W., Mazurkiewicz, J., Sugier, J., Walkowiak, T., Kacprzyk, J. (eds.) New Results in Dependability Comput. Syst. AISC, vol. 224, pp. 469-478. Springer, Heidelberg (2013)... 

Vieira, M., et al. Benchmarking the Robustness of Web Services. In 13th Pacific Rim International Symposium on Dependable Computing, PRDC 2007, pp. 322-329 (2007) RTCA DO-178C/EUROCAE ED-12C - Software Considerations in Airborne Systems and Equipment Certification (2011)... 

Mendes, N., Neto, A., Duraes, J., Vieira, M., Madeira, H. Assessing and comparing security of web servers. In 14th IEEE Pacific Rim International Symposium on Dependable Computing, PRDC 2008, pp. 313-322 (2008)... 

Laprie, J.C. Dependable computing Concepts, limits, challenges. In Proceedings of the Twenty-Fifth International Conference on Fault-Tolerant Computing, FTCS 1995, pp. 42-54. IEEE Computer Society, Washington, DC (1995)... 

Ficco, M., Coppolino, L., Romano, L. A weight-based symptom correlation approach to sql injection attacks. In Fourth Latin-American Symposium on Dependable Computing, LADC 2009, pp. 9-16 (September 2009)... 

Walkowiak, T. Michalska, K. 2011. Functional based reliability analysis of Web based information systems. Dependable computer systems / Wojciech Zamojski [et al.] (eds.). Berlin Heidelberg Springer, 257-269. 

Vache, G. Towards Information System Security Metrics. In Proceedings of Seventh European Dependable Computing Conference, Kaunas, Lithuania, pp. 41-44 (2008)... 

Perez, J., Azkarate-askasua, M., Perez, A. Codesign and Simulated Fault Injection of Safety-Critical Embedded Systems Using SystemC. In European Dependable Computing Conference, p. 9 (2010)... 

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