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Fedyukovich G.,USI Inc | Gurfinkel A.,SEI | Sharygina N.,USI Inc
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2015

The paper presents SimAbs, the first fully automated SMT-based approach to synthesize an abstraction of one program (called target) that simulates another program (called source). SimAbs iteratively traverses the search space of existential abstractions of the target and choses the strongest abstraction among them that simulates the source. Deciding whether a given relation is a simulation relation is reduced to solving validity of ∀∃-formulas iteratively. We present a novel algorithm for dealing with such formulas using an incremental SMT solver. In addition to deciding validity, our algorithm extracts witnessing Skolem relations which further drive simulation synthesis in SimAbs. Our evaluation confirms that SimAbs is able to efficiently discover both, simulations and abstractions, for C programs from the Software Verification Competition. © Springer-Verlag Berlin Heidelberg 2015. Source


Veatch R.W.,SEI
Society of Petroleum Engineers - SPE Hydraulic Fracturing Technology Conference 2013 | Year: 2013

"Propping Outside the Pay" is a hydraulic fracturing procedure used or applied on or to a vertical well. For applicable wells, it has the potential to enhance/increase fracture flow capacity and the resulting: (a) producing flow rate (b) total recoverable reserves and (c) monetary returns. It introduces an added aspect to optimizing treatment, i.e., proppant pile height above the pay. Hence "Propping Outside the Pay" is a double optimization approach, i.e., fracture penetration (Xf) and piled proppant height above the pay (H/p). The process creates more flow capacity from the pay to the wellbore through hydraulically created fractures that extend significantly outside the pay. It employs either one or both of the following: (a) injecting quantities of fracture propping material (proppant) that are greater than that normally used, and/or (b) creating more flow connections (e.g. perforations or open hole) from the wellbore to the propped fracture than are normally made. Additional proppant piled above the pay, and in the fracture below the pay (where proppant can settle) increases the fracture total cross sectional area and flow capacity. If the entire propped fracture is connected to the wellbore, the added fracture flow capacity enhances production rates over and above that predicted by the commonly used methods that are normalized on pay. At issue is economic viability, i.e., the additional proppant and perforating additional costs versus the monetary returns. Perforating costs are usually not significant as compared to first order proppant costs. Also, the applicable candidate wells require in-situ stress profiles such that the fracture will vertically propagate sufficiently above and/or below the pay to provide the opportunity to create additional fracture flow capacity. Experience indicates that a significant number of candidate wells exist. Computational studies showed that net present value returns from using the process can be significantly increased. The degree of increase depends upon the relative vertical fracture height to pay ratio, rock mechanics and reservoir parameters, hydrocarbon prices, fracturing costs, well spacing, etc. Examples comparing "Typical" cases to "Propping Outside the Pay" cases are shown. Copyright 2013, Society of Petroleum Engineers. Source


Shoemaker D.,University of Detroit Mercy | Mead N.R.,SEI
CrossTalk | Year: 2013

This paper proposes a set of Supply Chain Risk Management (SCRM) activities and practices for Information and Communication Technologies (ICT). This set can be used as a starting point to create a body of knowledge in SCRM to ensure the integrity of ICT products. Source


Mead N.R.,SEI | Shoemaker D.,University of Detroit Mercy
CrossTalk | Year: 2010

Education in software assurance (SwA) is an essential element in the effort to produce secure code. This article describes two efforts that support national cybersecurity education goals: development of SwA learning artifacts that can be integrated into conventional learning environments and establishment of a reference curriculum for a master's degree program, known as the MSwA. Source


Lapham M.A.,SEI
CrossTalk | Year: 2014

Today's systems are increasingly reliant on software which must be sustained into the future. To sustain these systems organizations must define sustainment, meet criteria to enter sustainment, and overcome some classic sustainment challenges. This article discusses these tasks along with historical parallel development and sustainment and potential future trends in software sustainment. Source

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