76 research outputs found
The Gediz River fluvial archive: A benchmark for Quaternary research in Western Anatolia
The Gediz River, one of the principal rivers of Western Anatolia, has an extensive Pleistocene fluvial archive that potentially offers a unique window into fluvial system behaviour on the western margins of Asia during the Quaternary. In this paper we review our work on the Quaternary Gediz River Project (2001–2010) and present new data which leads to a revised stratigraphical model for the Early Pleistocene development of this fluvial system. In previous work we confirmed the preservation of eleven buried Early Pleistocene fluvial terraces of the Gediz River (designated GT11, the oldest and highest, to GT1, the youngest and lowest) which lie beneath the basalt-covered plateaux of the Kula Volcanic Province. Deciphering the information locked in this fluvial archive requires the construction of a robust geochronology. Fortunately, the Gediz archive provides ample opportunity for age-constraint based upon age estimates derived from basaltic lava flows that repeatedly entered the palaeo-Gediz valley floors. In this paper we present, for the first time, our complete dataset of 40Ar/39Ar age estimates and associated palaeomagnetic measurements. These data, which can be directly related to the underlying fluvial deposits, provide age constraints critical to our understanding of this sequence. The new chronology establishes the onset of Quaternary volcanism at ∼1320ka (MIS42). This volcanism, which is associated with GT6, confirms a pre-MIS42 age for terraces GT11-GT7. Evidence from the colluvial sequences directly overlying these early terraces suggests that they formed in response to hydrological and sediment budget changes forced by climate-driven vegetation change. The cyclic formation of terraces and their timing suggests they represent the obliquity-driven climate changes of the Early Pleistocene. By way of contrast the GT5-GT1 terrace sequence, constrained by a lava flow with an age estimate of ∼1247ka, span the time-interval MIS42 – MIS38 and therefore do not match the frequency of climate change as previously suggested. The onset of volcanism breaks the simple linkage of terracing to climate-driven change. These younger terraces more likely reflect a localized terracing process triggered by base level changes forced by volcanic eruptions and associated reactivation of pre-existing faults, lava dam construction, landsliding and subsequent lava-dammed lake drainage. Establishing a firm stratigraphy and geochronology for the Early Pleistocene archive provides a secure framework for future exploitation of this part of the archive and sets the standard as we begin our work on the Middle-Late Pleistocene sequence. We believe this work forms a benchmark study for detailed Quaternary research in Turkey
Comment letters to the National Commission on Commission on Fraudulent Financial Reporting, 1987 (Treadway Commission) Vol. 2
https://egrove.olemiss.edu/aicpa_sop/1662/thumbnail.jp
Initial Studies of Power Plant Construction under a Deregulated West African Power Pool
Abstract — Our research group has been developing models to understand the long-term interactions between investment and performance in the electric power system. In this paper, we discuss some of our initial results in applying these tools to understand the expected pattern of investment in the proposed West African Power Pool (WAPP). The main result shows that the interconnection between countries has a clear impact on the local system prices and investments in new construction but there will still be large regional variations in prices and new construction. Index Terms — Deregulation, investor behavior, market models, power system planning, system dynamics. I
An application of high performance computing to transmission switching
We present a parallel implementation of three transmission switching algorithms. The first is based on a parallel search of all candidate lines, the second is based on a priority listing of lines and the third is based on decomposing the set of candidate lines in smaller subsets that are solved in parallel. We present a duality result that justifies the priority listing of the second algorithm. The We apply the algorithms on an IEEE 118 bus system and compare the relative performance of the algorithms in terms of cost of system operations. We envision the use of high performance computing for implementing the proposed algorithms in a real-time setting in order to exploit topology control of transmission networks for operating the system at minimum cost and for responding to system contingencies
Computational investigation of binding mechanism of substituted pyrazinones targeting corticotropin releasing factor-1 receptor deliberated for anti-depressant drug design
Generalized quasi-static equilibrium computation for vehicle dynamics optimization
Due to the large amount and the diverse nature of both objective criteria and design constraints involved, the vehicle dynamics optimization is a hard problem to handle. In the particular case of computer assisted optimization, the question of vehicle dynamics quality evaluation is a key point in order to get a very efficient process. It must provide relevant and good quality data but, at the same time, be as fast as possible to compute. This work aims to develop a hybrid process, for vehicle evaluation purposes, formed by both time integration simulation and quasi-static equilibrium analysis. This smart association allows to take advantages of these two multibody based numerical processes, leading to a highly efficient evaluation method. Moreover, the quasi-static equilibrium method is improved by a so-called variable exchange method, making the steady state curving analysis as powerful than reliable. This paper describes the generalized quasi-static equilibrium and its introduction into the global optimization process
Demystifying Multibody Dynamics via Undergraduate Projects: an Educational Challenge (Keynote)
Today, multibody dynamics simulation packages are more and more in use in industries. Most of these software are distributed by commercial companies and have been developed by various research teams having previously published scientific papers describing the details of their methods. However, software implementation packages without a detailed theoretical manual are unfortunately not rare and the training courses organized by those companies focus on the working features of their own codes and less on the theoretical bases. As a consequence, there is a real danger of practical engineers misusing a multibody code because they are not aware of the underlying hypotheses and/or limitations included in the code. In facing that situation, and since the number of engineers who are potential users of such software is growing, there is a real need for including the field of Multibody Dynamics (MBD) in a standard engineering education curriculum. Teaching multibody dynamics responds to a specific industrial demand. But in addition to doing that, and thanks to the very large class of practical applications covered by the field, MBD can also be very useful in the global engineering education context. In particular, three basic domains are immediately concerned: classical mechanics, mathematics and numerical methods. We claim that there is a real educational challenge in organizing an activity in which these three domains strongly interact, which helps student appreciate the interest of the underlying theories and which deals with realistic applications and problems to be solved
- …