A Framework for Automated Generation of Specialized Function Variants

Efficient large-scale scientific computing requires efficient code, yet optimizing code to render it efficient simultaneously renders the code less readable, less maintainable, less portable, and requires detailed knowledge of low-level computer architecture, which the developers of scientific applications may lack. The necessary knowledge is subject to change over time as new architectures, such as GPGPU architectures like CUDA, which require very different optimizations than CPU-targeted code, become more prominent. The development of scientific cloud computing means that developers may not even know what machine their code will be running on when they are developing it. This work takes steps towards automating the generation of code variants which are automatically optimized for both execution environment and input dataset. We demonstrate that augmenting an autotuning framework with a performance database which captures metadata about environment and input and performing decision tree learning over that data can help more fully automate the process of enhancing software performance

Balanced cross sections, seismic stratigraphy, and structural interpretation of the intracontinental Palmyride fold belt, Syria

Copyright 1991, Thomas Chaimov. See also: http://atlas.geo.cornell.edu/dissertations/Chaimov_1991.htmThe Palmyride fold belt in central Syria is the result of Late Mesozoic and Cenozoic inversion of a Late Paleozoic and Mesozoic intraplate trough located within the northern Arabian platform. Detailed analysis of available seismic reflection profiles from the Palmyrides reveals the Late Mesozoic to present transpressive structures of the Palmyrides and clarifies the timing and magnitude of such deformation within the belt. Uplift of the Mesozoic Palmyride trough began in the Late Cretaceous, rejuvenated in the Middle Eocene, and culminated in the period from the Miocene to present. Each of the three episodes of deformation was temporally associated with a distant (~300 km) Arabian plate margin tectonic event as follows: (1) Late Cretaceous collision between the northern and eastern margin of the Arabian plate and a microplate or island arc; (2) Middle Eocene incipient faulting of the Red Sea/Dead Sea fault system; and (3) Miocene to present shortening of the Arabian-Eurasian plate collision zone along the Bitlis/Zagros suture in Turkey and Iran. Despite this repeated tectonism, only 20-25 km of shortening accumulated in the southwestern, most strongly deformed sector of the belt, diminishing to only a few kilometers 400 km along strike to the northeast. And although Triassic evaporites form local detachment surfaces, there has been no large-scale lateral transport of Mesozoic and Cenozoic rocks over Paleozoic rocks in the Palmyrides of Syria. Rather, deep structures in Paleozoic rocks appear to be in general concord with structures in overlying Mesozoic and Cenozoic rocks

Fit of screw - retained fixed partial denture in partial edentulism

Introduction. There are many ways to treat partially edentulous patients. In the last few decades, dental implants have become a valuable option for prosthodontic rehabilitation. The use of endosseous dental implants to replace natural teeth lost to periodontal disease, trauma, or complication of dental caries has become a predictable form of prosthetic treatment. A lot of research studies have demonstrated that implant prostheses represent a predictable and successful restorative solution for these cases. Passive fit of an implant framework is one of the mechanical parameters expected to influence the longevity of an implant prosthesis. Aim of study. To review the published literature for investigating the accuracy of fit of screw-retained fixed partial denture fabricated using different methods of manufacturing. Methods and materials. A comprehensive electronic search was performed through PubMed (MEDLINE). The following keywords were combined: “fixed prosthesis”, “implant,” “framework,” “fit,” “accuracy,” “fitting surface,” “bridge,” and “screw - retained. Results. A total of 30 articles were considered for review. After article selection, the relevant information from each article was extracted. From the selected studies, several implant framework fabrication methods were identified: conventional casting of metal alloys; sectioning and reconnection through soldering (the sectioned framework is indexed and reconnected with fused solder), CAD/ CAM, which involves fabricating the implant framework by means of computer numeric controlled milling; spark erosion, used to refine the fitting surface of the framework and framework bonding to a prefabricated abutment cylinder, where the framework body is constructed with space to accommodate a prefabricated cylinder and resin bonding is used to attach the framework body to the cylinders Conclusion. No method of manufacturing is ideal for fabrication of screw-retained fixed implant frameworks in all aspects. Casting of metal alloys generally does not provide an acceptable implant framework fit unless additional treatment is performed. The benefit of soldering is unclear and perhaps replaced by laser welding. Spark erosion, CAD/CAM, and framework bonding to prefabricated cylinders have great potential to overcome significant inaccuracies produced by the fabrication procedure and provide implant frameworks with excellent fit. CAD/CAM provides better results

Sustainability of Concrete in the Pacific Northwest

Reducing the CO2 emitted by the production of cement can greatly reduce the carbon emissions attributable to the built industry. By specifying concrete mixes with lower global warming potentials (GWPs), structural engineers can reduce the carbon emissions of concrete used in the built industry. This thesis uses a cradle-to-gate life cycle assessment (LCA) to explore the impact that SCMs have on the GWP of concrete in Seattle. The objectives of this project are to: (1) demonstrate that the use of supplementary cementitious material in concrete mixes reduces the GWP of concrete, (2) compare the GWP of the NRMCA Pacific Northwest regional benchmark mix designs with commonly used mix designs in Seattle, (3) quantify how different supplementary cementitious materials can have an impact on concrete’s GWP, and (4) investigate barriers that prevent structural engineers in Seattle from specifying sustainable concrete. The results of this study are consistent with existing research in demonstrating that the use of SCMs in concrete mixes reduces the GWP of concrete. Slag is the most used SCM in the Pacific Northwest. All continuously approved mix designs in Seattle that utilize slag have lower GWPs than NRMCA regional benchmarks, so if a continuously approved concrete mix design in Seattle with slag, is specified, the building will meet one stipulation for a LEED credit. With the use of SCMs, commonly utilized concrete mixes can be considered a sustainable building material. For specified concrete that is not a continuously-approved mix, structural engineers in Seattle still specify an SCM, thereby making the concrete more sustainable. The thesis provides a framework that could be used by other major cities to evaluate how sustainable their concrete is and highlight which SCMs are being utilized the most.Key Words: concrete, cement, global warming potential, supplementary cementitious material, continuously-approved mix design, sustainabilit

Mesozoic and Cenozoic deformation inferred from seismic stratigraphy in the southwestern intracontinental Palmyride fold-thrust belt, Syria

This paper was published in the Geological Society of America Bulletin. The Geological Society of America retains the copyright to this paper. Geological Society of America, P.O. Box 9140 , Boulder, CO 80301-9140 USA See also: http://www.geosociety.org/; http://atlas.geo.cornell.edu/syria/chaimov_gsa_bull_1992.htmlThe Palmyride fold belt in central Syria is an intracontinental northeast-trending, 400 by 100 km transpressive belt embedded in the northern Arabian platform. During the Late Paleozoic and most of the Mesozoic the region of the present-day mountains was a rift-like trough that collected over 5 km of sediments, for a total Phanerozoic thickness of over 10 km. The southwestern sector of the fold belt is bounded in the north by the Jhar fault and in the south by the south-vergent frontal thrust faults of the Palmyrides, with the broad Al-Daww depression in between. Structural features that characterize the southern and southwestern region of the Palmyrides include a short wavelength, typically 5-10 km, fold style controlled by a regional low-angle decollement within Triassic beds, and small inverted Jurassic and Early Cretaceous normal faults. Small intermontane basins (about 10 X 30 km) whose strata can be used to document the history of Palmyride deformation flank growth fault-bend folds and are mainly a product of Cenozoic shortening in the belt. These structures are elucidated by about 2000 km of newly available seismic reflection data in the Palmyrides. Synthetic seismic traces generated solely from forward modeling of outcrop information constrain seismic stratigraphic picks in two small basins about 100 km northeast of Damascus. There, minor Late Cretaceous uplift caused local onlap, marking the first inversion phase of the Palmyride trough. Tectonic quiescence throughout the Paleogene, interrupted only in the Middle Eocene by minor tectonism, resulted in monotonous deposition of about 2500 m of mostly limestone. Marked onlap and probable downlap of Lower Miocene strata onto an Oligocene angular unconformity indicate accelerated tectonism by Late Oligocene to Early Miocene time. This marks the beginning of the major phase of inversion and uplift of the Palmyrides. Recent seismicity indicates that transpression continues today. Despite its relative remoteness from convergent plate boundaries (the nearest, the Bitlis suture in southern Turkey, is about 300 km distant), the Late Cretaceous, Middle Eocene, and Neogene phases of deformation in the intraplate setting of the Palmyrides have a direct temporal relationship with major regional tectonism that occurred along the surrounding Arabian plate boundaries. The Palmyride trough was inverted in Late Cretaceous time and, subsequently, developed into a transpressive zone throughout Neogene and Quaternary times. Thus, the initiation of inversion in the Palmyrides, an integral part of the Syrian Arc, which extends from central Syria southward to central Sinai, apparently predates development of the Red Sea/Dead Sea plate boundary. In contrast, the intense Neogene through Quaternary deformational episode is clearly related to development of the Red Sea/Dead Sea fault system and to convergence along the northern boundary of the Arabian plate in southern Turkey

Upper crustal velocity structure and basement morphology beneath the intracontinental Palmyride fold-thrust belt and north Arabian platform in Syria

An edited version of this paper was published in Geophysical Journal International by Blackwell Publishing. Copyright 1993, Blackwell Publishing. See also: http://www.blackwellpublishing.com/journal.asp?ref=0956-540X&site=1; http://atlas.geo.cornell.edu/syria/seber_gji_1993.htmThe intracontinental Palmyride fold-thrust belt, which is the site of an inverted Mesozoic rift, is sandwiched between two crustal blocks, the Aleppo plateau in the north and the Rutbah uplift in the south. The 400 x 100 km belt merges with the Dead Sea fault system in the southwest and gradually ends near the Euphrates depression in the northeast. Very dense (i.e., 100 m geophone spacing), reversed and multifold seismic refraction profiling was carried out to map approximately the upper 15 km of the crust in the early 1970s. These refraction data are utilized to model sedimentary rock thickness, seismic velocity, and basement morphology. Extensive data coverage also enables identification of the major faults of the region. A 2-D ray tracing technique is used in the modeling. Interpretation of these data indicates that five distinct velocity layers characterize the upper crust of the northern Arabian platform in Syria. The P-wave velocities within these layers are (in km s-1): 2.0-2.8, 4.0-4.4, 5.2-5.3 , 5.5-5.7, corresponding to sedimentary rocks from Quaternary to late Precambrian in age, and 5.9-6.0, corresponding to metamorphic basement. A comparison of the velocity models with the available drill hole information and seismic reflection profiles shows strong velocity variations in a given geologic formation, depending on the depth and location of the formation. The depth to metamorphic basement beneath the Palmyride fold belt clearly shows a deep trough, filled with Phanerozoic sedimentary rocks. These rocks decrease in thickness from about 11 km in the southwest to about 9 km in the central segment of the belt. The basement depth is about 6 km in the Aleppo plateau and not less than 8 km in the Rutbah uplift. Deeper basement in the Rutbah uplift is probably the result of a Precambrian rifting episode, clearly identified to the south in Jordan and Saudi Arabia. Cenozoic crustal shortening of about 20-25% across the southwestern segment of the Palmyride belt has not been sufficient to substantially reduce the size of the basement trough beneath this mountain belt. Finally, northeast decreasing basement depth in the Palmyrides supports the idea that the Palmyride Mesozoic rifting was developed as an aulacogen of the rifted Levantine margin along the eastern Mediterranean

Seismic fabric and 3-D upper crustal structure of the southwestern intracontinental Palmyride fold belt, Syria

Copyright 1993, AAPG. Reprinted by permission of the AAPG whose permission is required for further use. See also: http://aapgbull.geoscienceworld.org/; http://atlas.geo.cornell.edu/syria/chaimov_aapg_bull_1993.htmlThe Palmyride fold belt, a 400 X 100 km transpressive belt in central Syria that is the northeastern arm of the Syrian Arc, which includes the Negev fold belt in the Sinai, is the result of Late Mesozoic and Cenozoic inversion of a Late Paleozoic and Mesozoic, NE-trending, linear intracontinental basin located within the northern Arabian platform. The southwestern Palmyrides, near the Dead Sea transform fault system and the Anti-Lebanon mountains, are characterized by short wavelength (5-10 km) en echelon folds separated by small intermontane basins that developed mainly in Neogene to Recent times. A new three-dimensional data cube, 60 X 70 km, generated on a Landmark Graphics (TM) workstation and based on approximately 700 km of two-dimensional seismic reflection profiles, elucidates the structure of the upper 10 km of the crust in the southwestern Palmyrides. Visualization of the subsurface structure, which is represented by a prominent Upper Cretaceous reflection surface in the data cube, is augmented by the topography and Bouguer gravity of the same region. Preexisting discontinuities, probable normal fault relicts of the Mesozoic Palmyride rift, likely controlled the development of individual Neogene thrusts. The new subsurface image shows important structural features not identified in outcrop. Short, WNW-trending transcurrent, or transfer, faults link the short, en echelon NE-trending thrust faults and blind thrusts of the Palmyrides. A pervasive regional decollement is not observed, even though Triassic evaporites host local detachments. There has been no wholesale transport of shallower strata on a regional decollement that decouples Mesozoic and Cenozoic rocks from underlying Paleozoic rocks. Unlike topographic relief, which only roughly resembles subsurface structures, the Bouguer gravity signature of the southwestern Palmyrides closely mimics underlying shallow geologic structures both on a large (~50 km wavelength) and a small (~5-10 km) scale. Relatively uncommon reflections from deformed Paleozoic rocks and the excellent correlation between Bouguer gravity and shallow structures indicate a general concordance between shallow Mesozoic and Cenozoic rocks and deeper Paleozoic rocks. Hence, Paleozoic rocks either deformed together with shallower strata, or structures within Paleozoic rocks controlled the development of shallower Neogene and younger structures. Our structural analysis and many other recent studies of the region are indicative of minor right-lateral shear coupled with compression in the Palmyrides

Structure and tectonic evolution of the Anatolian plateau in eastern Turkey

This paper was published by the Geological Society of America (GSA). Copyright 2006, GSA. See also: http://granite.geosociety.org/bookstore/default.asp?oID=0&catID=9&pID=SPE409; http://atlas.geo.cornell.edu/turkey/publications/Barazangi-et-al_2006.htmThe Cenozoic geology and the present lithospheric and upper mantle structure of the Anatolian plateau in eastern Turkey and nearby regions are the result of the final collision and suturing of the continental Arabian plate to the Turkish terranes (i.e., micro-continents). This process of collision and suturing was strongly influenced by three active structures in the region: the Caucasus mountains, the Aegean subduction zone, and the Dead Sea fault system. Understanding these three major tectonic elements are important for the development of a robust model for the formation of the Anatolian plateau. We show that the Anatolian plateau lithosphere in eastern Turkey has no lithospheric mantle, i.e., the crust floats on a partially molten asthenosphere. The average thickness of the crust in the region is approximately 45 km. The uppermost mantle beneath this crustal block strongly attenuates Sn waves and has one of the lowest Pn velocities on earth (about 7.6 km/s). The Anatolian plateau, with an average of 2 km elevation is dissected by numerous active, seismogenic faults (mostly strike-slip and some thrust type). Neogene and Quaternary volcanism with varying composition is widespread and covers more than half of the region. We argue that the northward subduction of the northern and the southern branches of the Neo-Tethyan oceanic lithosphere since the Mesozoic has resulted in the development of arc and back-arc volcanism (i.e., the Pontide and Bitlis systems) and the development of the eastern Anatolian accretionary complex that covers a large area of eastern Turkey. The northward subduction of the southern Neo-Tethys considerably thinned and weakened the overriding Eurasian plate above the descending oceanic lithosphere of the Arabian plate. The final suturing of the continental Arabian plate with the Turkish terranes in the Miocene and the continued convergence of Arabia relative to Eurasia has resulted in the shortening of the accretionary complex both in the forearc and the back-arc regions and the development of a broad zone with numerous strike-slip faults. The mobilization of the Caucasus is also partially a consequence of this convergence. The documented major episode of widespread volcanism at about 11 Ma is probably related to the breakoff of the shallowly descending oceanic segment of the Arabian lithosphere beneath eastern Turkey. The continued convergence of Arabia relative to Eurasia has resulted in the development of the North Anatolian fault (NAF) and subsequently the East Anatolian fault (EAF) in the Pliocene. At about this time, the northern segment of the Dead Sea fault (DSF) also developed in Lebanon and northwest Syria and joined the EAF to form the Anatolian - Arabian - African triple junction in the Maras region of southern Turkey. The development of these fault systems (i.e., NAF, EAF, and DSF) provided the mechanism for the tectonic escape of the Anatolian crustal block towards the Aegean arc system