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2009

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Impact Of Microphone Positional Errors On Speech Intelligibility, Arulkumaran Muthukumarasamy Jan 2009

Impact Of Microphone Positional Errors On Speech Intelligibility, Arulkumaran Muthukumarasamy

University of Kentucky Master's Theses

The speech of a person speaking in a noisy environment can be enhanced through electronic beamforming using spatially distributed microphones. As this approach demands precise information about the microphone locations, its application is limited in places where microphones must be placed quickly or changed on a regular basis. Highly precise calibration or measurement process can be tedious and time consuming. In order to understand tolerable limits on the calibration process, the impact of microphone position error on the intelligibility is examined. Analytical expressions are derived by modeling the microphone position errors as a zero mean uniform distribution. Experiments and simulations …

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Effects Of Calcium Changes On Hysteresis In Restitution Of Action Potential Duration, Kathleen Marie Guzman Jan 2009

Effects Of Calcium Changes On Hysteresis In Restitution Of Action Potential Duration, Kathleen Marie Guzman

University of Kentucky Master's Theses

Sudden cardiac death (SCD) is a leading cause of fatalities. Several methods have been developed to predict instability in myocytes which could lead to SCD. The focus of this study was on altering memory in myocytes, i.e. hysteresis in restitution of action potential duration (APD), by differing levels of calcium. Determination of alteration was implemented by using a diastolic interval (DI) control program that implements a sinusoidal change in DI. Plotting APD versus previous DI, i.e. restitution, produces a hysteresis loop. From these hysteresis loops, five parameters were used to determine measures of memory: area, thickness, overall tilt, max delay …

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Report On Wintering Western Snowy Plovers At Coos Bay North Spit And Impacts To Plovers From The North Jetty Repair Project, Winter 2009, David J. Lauten, Kathleen J. Castelein, Eleanor P. Gaines Jan 2009

Report On Wintering Western Snowy Plovers At Coos Bay North Spit And Impacts To Plovers From The North Jetty Repair Project, Winter 2009, David J. Lauten, Kathleen J. Castelein, Eleanor P. Gaines

Institute for Natural Resources Publications

The Western Snowy Plover (Charadrius alexandrinus nivosus) breeds along the coast of the Pacific Ocean in California, Oregon, and Washington and at alkaline lakes in the interior of the western United States (Page et al. 1991). Loss of habitat, predation pressures, and disturbance have caused the decline of the coastal population of Snowy Plovers and led to the listing of the Pacific Coast Population of Western Snowy Plovers as Threatened on March 5, 1993 (U.S. Fish and Wildlife Service 1993). Oregon Western Snowy Plovers are known to winter along the coast of Oregon as well as migrate to …

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Rounding Up The Usual Suspects: A Logical And Legal Analysis Of Dna Trawling Cases, David H. Kaye Jan 2009

Rounding Up The Usual Suspects: A Logical And Legal Analysis Of Dna Trawling Cases, David H. Kaye

Faculty Scholarship

Courts are beginning to confront a problem that has divided the scientific community - whether identifying a defendant by fishing through a database of DNA types to find a match to a crime-scene sample reduces the significance of a match. For years, the problem seemed academic. Now that the U.S. has more than five million DNA profiles from convicted offenders and suspects in a national, computer-searchable database, the question has assumed more urgency. Increasingly, individuals are being charged with crimes as a result of a match between their recorded profile and the DNA from a victim or scene of a …

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Intellectual Property Law, David L. Mccombs, Phillip B. Philbin, Donald E. Tiller Jan 2009

Intellectual Property Law, David L. Mccombs, Phillip B. Philbin, Donald E. Tiller

SMU Law Review

No abstract provided.

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Does Fair Trade Deliver On Its Core Value Proposition? Effects On Income, Educational Attainment, And Health In Three Countries, Eric J. Arnould, Alejandro Plastina, Dwanye Ball Jan 2009

Does Fair Trade Deliver On Its Core Value Proposition? Effects On Income, Educational Attainment, And Health In Three Countries, Eric J. Arnould, Alejandro Plastina, Dwanye Ball

Department of Marketing: Faculty Publications

Alternative trade organizations (ATOs) based on philosophies of social justice and/or environmental well-being are establishing new channels of trade and marketing. Partisans promote ATOs as systems to transfer benefits from consumers in the wealthy northern hemisphere to producers in the poor southern hemisphere. The central public policy question is whether the well-being of poor agricultural producers in the southern hemisphere is actually being improved by fair-trade practices, or are consumers who buy products on this premise deceived? The research reported here partially answers the question whether participation in a fair-trade coffee marketing channel delivers benefits to smallscale producers in Latin …

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Conceptual Circuit Models Of Neurons, Bo Deng Jan 2009

Conceptual Circuit Models Of Neurons, Bo Deng

Department of Mathematics: Faculty Publications

A systematic circuit approach tomodel neurons with ion pump is presented here by which the voltage-gated current channels are modeled as conductors, the diffusion-induced current channels are modeled as negative resistors, and the one-way ion pumps are modeled as one-way inductors. The newly synthesized models are different from the type of models based on Hodgkin-Huxley (HH) approach which aggregates the electro, the diffusive, and the pump channels of each ion into one conductance channel. We show that our new models not only recover many known properties of the HH type models but also exhibit some new that cannot be extracted …

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Jor: A Journal-Guided Reconstruction Optimization For Raid-Structured Storage Systems, Suzhen Wu, Dan Feng, Hong Jiang, Bo Mao, Lingfang Zeng, Jianxi Chen Jan 2009

Jor: A Journal-Guided Reconstruction Optimization For Raid-Structured Storage Systems, Suzhen Wu, Dan Feng, Hong Jiang, Bo Mao, Lingfang Zeng, Jianxi Chen

School of Computing: Conference and Workshop Papers

This paper proposes a simple and practical RAID reconstruction optimization scheme, called JOurnal-guided Reconstruction (JOR). JOR exploits the fact that significant portions of data blocks in typical disk arrays are unused. JOR monitors the storage space utilization status at the block level to guide the reconstruction process so that only failed data on the used stripes is recovered to the spare disk. In JOR, data consistency is ensured by the requirement that all blocks in a disk array be initialized to zero (written with value zero) during synchronization while all blocks in the spare disk also be initialized to zero …

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An Adaptive Steganography Scheme For Voice Over Ip, Hui Tian, Ke Zhou, Hong Jiang, Yongfeng Huang, Jin Liu, Dan Feng Jan 2009

An Adaptive Steganography Scheme For Voice Over Ip, Hui Tian, Ke Zhou, Hong Jiang, Yongfeng Huang, Jin Liu, Dan Feng

School of Computing: Conference and Workshop Papers

This paper presents an adaptive steganography scheme for Voice over IP (VoIP). Differing from existing steganography techniques for VoIP, this scheme enhances the embedding transparency by taking into account the similarity between Least Significant Bits (LSBs) and embedded messages. Moreover, we introduce the notion of Partial Similarity Value (PSV). By properly setting the threshold PSV, we can adaptively balance the embedding transparency and capacity. We evaluate the effectiveness of this scheme with G.729a as the codec of the cover speech in StegTalk, a covert communication system based on VoIP. The experimental results demonstrate that our technique provides better performance than …

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An Adaptive Steganography Scheme For Voice Over Ip, Hui Tian, Ke Zhou, Hong Jiang, Yongfeng Huang, Jin Liu, Dan Feng Jan 2009

An Adaptive Steganography Scheme For Voice Over Ip, Hui Tian, Ke Zhou, Hong Jiang, Yongfeng Huang, Jin Liu, Dan Feng

School of Computing: Conference and Workshop Papers

This paper presents an adaptive steganography scheme for Voice over IP (VoIP). Differing from existing steganography techniques for VoIP, this scheme enhances the embedding transparency by taking into account the similarity between Least Significant Bits (LSBs) and embedded messages. Moreover, we introduce the notion of Partial Similarity Value (PSV). By properly setting the threshold PSV, we can adaptively balance the embedding transparency and capacity. We evaluate the effectiveness of this scheme with G.729a as the codec of the cover speech in StegTalk, a covert communication system based on VoIP. The experimental results demonstrate that our technique provides better performance than …

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Pilot Study: The Nature And Thickness Of The Unsaturated Zone And Delineation Of Confined Aquifers, Sue Olafsen Lackey, Les Howard Jan 2009

Pilot Study: The Nature And Thickness Of The Unsaturated Zone And Delineation Of Confined Aquifers, Sue Olafsen Lackey, Les Howard

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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Joint Computing And Network Resource Scheduling In A Lambda Grid Network, Vaidhehi Lakshmiraman, Byrav Ramamurthy Jan 2009

Joint Computing And Network Resource Scheduling In A Lambda Grid Network, Vaidhehi Lakshmiraman, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

Data-intensive Grid applications require huge data transfers between grid computing nodes. These computing nodes, where computing jobs are executed, are usually geographically separated. A grid network that employs optical wavelength division multiplexing (WDM) technology and optical switches to interconnect computing resources with dynamically provisioned multi-gigabit rate bandwidth lightpath is called a Lambda Grid network. A computing task may be executed on any one of several computing nodes which possesses the necessary resources. In order to reflect the reality in job scheduling, allocation of network resources for data transfer should be taken into consideration. However, few scheduling methods consider the communication …

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A Cooperative Scheme For Dynamic Window Resizing In P2p Live Streaming, Zhipeng Ouyang, Lisong Xu, Byrav Ramamurthy Jan 2009

A Cooperative Scheme For Dynamic Window Resizing In P2p Live Streaming, Zhipeng Ouyang, Lisong Xu, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

Due to their widespread popularity, Peer-to-Peer (P2P) live streaming systems have become a great challenge for Internet Service Providers (ISPs) as they consume huge amount of Internet bandwidth. By observing that different users may watch a channel with different window sizes, we propose a cooperative scheme called Partial Participation Scheme (PPS) in which different peers request a video stream at different rates based on their window sizes, and a subset of peers viewing the video stream using a small window work as helpers to forward extra data to help other peers using a large window. By reducing streaming rate received …

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Optimal Segment Size For Fixed-Sized Segment Protection In Wavelength-Routed Optical Networks, Raghunath Tewari, Byrav Ramamurthy Jan 2009

Optimal Segment Size For Fixed-Sized Segment Protection In Wavelength-Routed Optical Networks, Raghunath Tewari, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

Protecting a network against link failures is a major challenge faced by network operators. The protection scheme has to address two important objectives - fast recovery and minimizing the amount of backup resources needed. Every protection algorithm is a tradeoff between these two objectives.

In this paper, we study the problem of segment protection. In particular, we investigate what is the optimal segment size that obtains the best tradeoff between the time taken for recovery and minimizing the bandwidth used by the backup segments. We focus on the uniform fixed-length segment protection method, where each primary path is divided into …

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A Flexible Divide-And-Conquer Protocol For Multi-View Peer-To-Peer Live Streaming, Miao Wang, Lisong Xu, Byrav Ramamurthy Jan 2009

A Flexible Divide-And-Conquer Protocol For Multi-View Peer-To-Peer Live Streaming, Miao Wang, Lisong Xu, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

Multi-view peer-to-peer (P2P) live streaming systems have recently emerged, where a user can simultaneously watch multiple channels. Previous work on multi-view P2P streaming solves the fundamental inter-channel bandwidth competition problem at the individual peer level, and thus can be used with very limited types of streaming protocols. In this paper, we propose a new protocol for multi-view P2P streaming, called Divide-and-Conquer (DAC), which efficiently solves the inter-channel bandwidth competition problem using a divide-and-conquer strategy at the channel level, and thus is flexible to work with various streaming protocols. This makes DAC more suitable for upgrading current single-view P2P live streaming …

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Error Control In Wireless Sensor Networks: A Cross Layer Analysis, Mehmet C. Vuran, Ian F. Akyildiz Jan 2009

Error Control In Wireless Sensor Networks: A Cross Layer Analysis, Mehmet C. Vuran, Ian F. Akyildiz

School of Computing: Faculty Publications

Error control is of significant importance for Wireless Sensor Networks (WSNs) because of their severe energy constraints and the low power communication requirements. In this paper, a cross-layer methodology for the analysis of error control schemes in WSNs is presented such that the effects of multi-hop routing and the broadcast nature of the wireless channel are investigated. More specifically, the cross-layer effects of routing, medium access, and physical layers are considered. This analysis enables a comprehensive comparison of forward error correction (FEC) codes, automatic repeat request (ARQ), and hybrid ARQ schemes in WSNs. The validation results show that the developed …

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Smart Templates For Peak Pattern Matching With Comprehensive Two-Dimensional Liquid Chromatography, Stephen E. Reichenbach, Peter W. Carr, Dwight R. Stoll, Qingping Tao Jan 2009

Smart Templates For Peak Pattern Matching With Comprehensive Two-Dimensional Liquid Chromatography, Stephen E. Reichenbach, Peter W. Carr, Dwight R. Stoll, Qingping Tao

School of Computing: Faculty Publications

Comprehensive two-dimensional liquid chromatography (LC × LC) generates information-rich but complex peak patterns that require automated processing for rapid chemical identification and classification. This paper describes a powerful approach and specific methods for peak pattern matching to identify and classify constituent peaks in data from LC × LC and other multidimensional chemical separations. The approach records a prototypical pattern of peaks with retention times and associated metadata, such as chemical identities and classes, in a template. Then, the template pattern is matched to the detected peaks in subsequent data and the metadata are copied from the template to identify and …

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Directed Test Suite Augmentation, Zhihong Xu, Gregg Rothermel Jan 2009

Directed Test Suite Augmentation, Zhihong Xu, Gregg Rothermel

School of Computing: Conference and Workshop Papers

As software evolves, engineers use regression testing to evaluate its fitness for release. Such testing typically begins with existing test cases, and many techniques have been proposed for reusing these cost-effectively. After reusing test cases, however, it is also important to consider code or behavior that has not been exercised by existing test cases and generate new test cases to validate these. This process is known as test suite augmentation. In this paper we present a directed test suite augmentation technique, that utilizes results from reuse of existing test cases together with an incremental concolic testing algorithm to augment …

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Technical Reports (2004 - 2009) Jan 2009

Technical Reports (2004 - 2009)

School of Computing: Technical Reports

Authors of Technical Reports (2005-2009):
Choueiry, Berthe
Cohen, Myra
Deogun, Jitender
Dwyer, Matthew
Elbaum, Sebastian
Goddard, Steve
Henninger, Scott
Jiang, Hong
Lu, Ying
Ramamurthy, Byrav
Rothermel, Gregg
Scott, Stephen
Seth, Sharad
Soh, Leen-Kiat
Srisa-an, Witty
Swanson, David
Variyam, Vinodchandran
Wang, Jun
Xu, Lisong

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Cross-Layer Analysis Of The End-To-End Delay Distribution In Wireless Sensor Networks, Yunbo Wang, Mehmet C. Vuran, Steve Goddard Jan 2009

Cross-Layer Analysis Of The End-To-End Delay Distribution In Wireless Sensor Networks, Yunbo Wang, Mehmet C. Vuran, Steve Goddard

School of Computing: Conference and Workshop Papers

Emerging applications of wireless sensor networks (WSNs) require real-time quality of service (QoS) guarantees to be provided by the network. However, designing real-time scheduling and communication solutions for these networks is challenging since the characteristics of QoS metrics in WSNs are not well known yet. Due to the nature of wireless connectivity, it is infeasible to satisfy worst-case QoS requirements in WSNs. Instead, probabilistic QoS guarantees should be provided, which requires the definition of probabilistic QoS metrics. To provide an analytical tool for the development of real-time solutions, in this paper, the distribution of end-to-end delay in multi-hop WSNs is …

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Using Hadoop As A Grid Storage Element, Brian Bockelman Jan 2009

Using Hadoop As A Grid Storage Element, Brian Bockelman

School of Computing: Conference and Workshop Papers

Hadoop is an open-source data processing framework that includes a scalable, fault- tolerant distributed file system, HDFS. Although HDFS was designed to work in conjunction with Hadoop's job scheduler, we have re-purposed it to serve as a grid storage element by adding GridFTP and SRM servers. We have tested the system thoroughly in order to understand its scalability and fault tolerance. The turn-on of the Large Hadron Collider (LHC) in 2009 poses a significant data management and storage challenge; we have been working to introduce HDFS as a solution for data storage for one LHC experiment, the Compact Muon Solenoid …

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Paleolimnological Evidence Of The Effects On Lakes Of Energy And Mass Transfer From Climate And Humans, Peter R. Leavitt, Sherilyn C. Fritz, N. J. Anderson, P. A. Baker, T. Blenckner, L. Bunting, J. Catalan, D. J. Conley, W. O. Hobbs, E. Jeppesen, A. Korhola, S. Mcgowan, K. Rühland, J. A. Rusak, G. L. Simpson, N. Solovieva, J. Werne Jan 2009

Paleolimnological Evidence Of The Effects On Lakes Of Energy And Mass Transfer From Climate And Humans, Peter R. Leavitt, Sherilyn C. Fritz, N. J. Anderson, P. A. Baker, T. Blenckner, L. Bunting, J. Catalan, D. J. Conley, W. O. Hobbs, E. Jeppesen, A. Korhola, S. Mcgowan, K. Rühland, J. A. Rusak, G. L. Simpson, N. Solovieva, J. Werne

Department of Earth and Atmospheric Sciences: Faculty Publications

The premise of this article is that climate effects on lakes can be quantified most effectively by the integration of process-oriented limnological studies with paleolimnological research, particularly when both disciplines operate within a common conceptual framework. To this end, the energy (E)–mass (m) flux framework (Em flux) is developed and applied to selected retrospective studies to demonstrate that climate variability regulates lake structure and function over diverse temporal and spatial scales through four main pathways: rapid direct transfer of E to the lake surface by irradiance, heat, and wind; slow indirect effects of E via changes in …

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Holocene Carbon Burial By Lakes In Sw Greenland, N. J. Anderson, W. D'Andrea, Sherilyn C. Fritz Jan 2009

Holocene Carbon Burial By Lakes In Sw Greenland, N. J. Anderson, W. D'Andrea, Sherilyn C. Fritz

Department of Earth and Atmospheric Sciences: Faculty Publications

The role of the Arctic in future global change processes is predicted to be important because of the large carbon (C) stocks contained in frozen soils and peatlands. Lakes are an important component of arctic landscapes although their role in storing C is not well prescribed. The area around Kangerlussuaq, SW Greenland (66–68°N, 49–54°W) has ex¬tremely high lake density, with ~20 000 lakes that cover about 14% of the land area. C accumulation rates and standing stock (kg C m−2), representing late- to mid-Holocene C burial, were calculated from AMS 14C-dated sediment cores from 11 lakes. Lake …

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Estimating Hydraulic Conductivity From Drainage Patterns Derived From Dem -- A Case Study In The Oregon Cascades, B. P. Grudzinski, W. Luo, Daryll Pederson Jan 2009

Estimating Hydraulic Conductivity From Drainage Patterns Derived From Dem -- A Case Study In The Oregon Cascades, B. P. Grudzinski, W. Luo, Daryll Pederson

Department of Earth and Atmospheric Sciences: Faculty Publications

Hydraulic conductivity is an important parameter in hydrology which describes the ease with which water moves through porous media. This parameter is also important in understanding the hydrology of Mars. On Earth, this parameter can be measured by conducting controlled experiments in laboratories or conducting pumping tests in the field. This study introduces a new method of estimating hydraulic conductivity from drainage dissection pattern derived from digital elevation model (DEM). This method can be applied to Mars if it is robustly tested on Earth.

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Obliquity-Paced Pliocene West Antarctic Ice Sheet Oscillations, T. Naish, R. D. Powell, R. Levy, G. Wilson, R. Scherer, F. Talarico, L. Krissek, F. Niessen, M. Pompilio, T. J. Wilson, L. Carter, R. Deconto, P. Huybers, R. Mckay, D. Pollard, J. Ross, D. Winter, P. Barrett, G. Browne, R. Cody, E. A. Cowan, J. Crampton, G. Dunbar, N. Dunbar, F. Florindo, C. Gebhardt, I. Graham, M. Hannah, D. Hansaraj, David M. Harwood, D. Helling, S. Henrys, L. Hinnov, G. Kuhn, P. Kyle, A. La¨Ufer, P. Maffioli, D. Magens, K. Mandernack, W. Mcintosh, C. Millan, R. Morin, C. Ohneiser, T. Paulsen, D. Persico, I. Raine, J. Reed, C. Riesselman, L. Sagnotti, D. Schmitt, C. Sjunneskog, P. Strong, M. Taviani, S. Vogel, T. Wilch, T. Williams Jan 2009

Obliquity-Paced Pliocene West Antarctic Ice Sheet Oscillations, T. Naish, R. D. Powell, R. Levy, G. Wilson, R. Scherer, F. Talarico, L. Krissek, F. Niessen, M. Pompilio, T. J. Wilson, L. Carter, R. Deconto, P. Huybers, R. Mckay, D. Pollard, J. Ross, D. Winter, P. Barrett, G. Browne, R. Cody, E. A. Cowan, J. Crampton, G. Dunbar, N. Dunbar, F. Florindo, C. Gebhardt, I. Graham, M. Hannah, D. Hansaraj, David M. Harwood, D. Helling, S. Henrys, L. Hinnov, G. Kuhn, P. Kyle, A. La¨Ufer, P. Maffioli, D. Magens, K. Mandernack, W. Mcintosh, C. Millan, R. Morin, C. Ohneiser, T. Paulsen, D. Persico, I. Raine, J. Reed, C. Riesselman, L. Sagnotti, D. Schmitt, C. Sjunneskog, P. Strong, M. Taviani, S. Vogel, T. Wilch, T. Williams

Department of Earth and Atmospheric Sciences: Faculty Publications

Thirty years after oxygen isotope records frommicrofossils deposited in ocean sediments confirmed the hypothesis that variations in the Earth’s orbital geometry control the ice ages1, fundamental questions remain over the response of the Antarctic ice sheets to orbital cycles2. Furthermore, an understanding of the behaviour of the marinebased West Antarctic ice sheet (WAIS) during the ‘warmerthan- present’ early-Pliocene epoch ( ~5–3Myr ago) is needed to better constrain the possible range of ice-sheet behaviour in the context of future global warming3. Here we present a marine glacial record from the upper 600mof the AND-1B sediment …

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Biostratigraphy Of The Hunter Creek Sandstone, Verdi Basin, Washoe County, Nevada, Thomas S. Kelly, Ross Secord Jan 2009

Biostratigraphy Of The Hunter Creek Sandstone, Verdi Basin, Washoe County, Nevada, Thomas S. Kelly, Ross Secord

Department of Earth and Atmospheric Sciences: Faculty Publications

The Hunter Creek Sandstone of the Verdi Basin, Nevada, yielded a succession of superposed continental faunal assemblages ranging in age from the late Clarendonian (late Miocene) through the late Blancan (late Pliocene) in the North American land mammal age framework, or ca. 10.5-2.5 Ma. We describe two new local faunas from the Hunter Creek Sandstone: the East Verdi local fauna, of late-medial to late Clarendonian age, which includes Dinohippus cf. D. leardi, Camelidae, ?Antilocapridae, and Mammutidae or Gomphotheriidae; and the Mogul local fauna, of Hemphillian age, which includes Dinohippus sp., Rhinocerotidae, Camelidae (at least two species), Mammut sp., and …

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Towards The Standardization Of Sequence Stratigraphy, Octavian Catuneanu, V. Abreu, J. P. Bhattacharya, M. D. Blum, R. W. Dalrymple, P. G. Eriksson, Christopher R. Fielding, W. L. Fisher, W. E. Galloway, M. R. Gibling, K. A. Giles, J. M. Holbrook, R. Jordan, C. G. St.C. Kendall, B. Macurda, O. J. Martinsen, A. D. Miall, J. E. Neal, D. Nummedal, L. Pomar, H. W. Posamentier, B. R. Pratt, J. F. Sarg, K. W. Shanley, R. J. Steel, A. Strasser, M. E. Tucker, C. Winker Jan 2009

Towards The Standardization Of Sequence Stratigraphy, Octavian Catuneanu, V. Abreu, J. P. Bhattacharya, M. D. Blum, R. W. Dalrymple, P. G. Eriksson, Christopher R. Fielding, W. L. Fisher, W. E. Galloway, M. R. Gibling, K. A. Giles, J. M. Holbrook, R. Jordan, C. G. St.C. Kendall, B. Macurda, O. J. Martinsen, A. D. Miall, J. E. Neal, D. Nummedal, L. Pomar, H. W. Posamentier, B. R. Pratt, J. F. Sarg, K. W. Shanley, R. J. Steel, A. Strasser, M. E. Tucker, C. Winker

Department of Earth and Atmospheric Sciences: Faculty Publications

Sequence stratigraphy emphasizes facies relationships and stratal architecture within a chronological framework. Despite its wide use, sequence stratigraphy has yet to be included in any stratigraphic code or guide. This lack of standardization reflects the existence of competing approaches (or models) and confusing or even conflicting terminology. Standardization of sequence stratigraphy requires the definition of the fundamental model-independent concepts, units, bounding surfaces and workflow that outline the foundation of the method. A standardized scheme needs to be sufficiently broad to encompass all possible choices of approach, rather than being limited to a single approach or model.

A sequence stratigraphic framework …

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High-Resolution Calcareous Nannofossil Biostratigraphy For The Coniacian/Santonian Stage Boundary, Western Interior Basin, Stacie A. Blair, David K. Watkins Jan 2009

High-Resolution Calcareous Nannofossil Biostratigraphy For The Coniacian/Santonian Stage Boundary, Western Interior Basin, Stacie A. Blair, David K. Watkins

Department of Earth and Atmospheric Sciences: Faculty Publications

The Ten Mile Creek area (Dallas, Texas) is a proposed Global Stratotype Section and Point (GSSP) candidate for the Coniacian/Santonian Stage boundary. The Santonian Working Group has designated the first appearance of Inoc¬eramus (Cladoceramus) undulatoplicatus as the diagnostic macrofossil bioevent for the base of the Santonian Stage. Cal¬careous nannofossils were examined from sediments of the Bruceville Marl at the proposed GSSP site and from well-preserved sediments of the coeval Smoky Hill Member-type area (northwestern Kansas) of the Niobrara Formation. Nannofossil bioevents were correlated with the lowest stratigraphic occurrence of I. undulatoplicatus to create a high resolution biostratigraphic framework and stratigraphic …

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Does Sedimentary 231Pa/230Th From The Bermuda Rise Monitor Past Atlantic Meridional Overturning Circulation?, Jörg Lippold, Jens Grützner, Diane Winter, Yann Lahaye, Augusto Mangini, Marcus Christl Jan 2009

Does Sedimentary 231Pa/230Th From The Bermuda Rise Monitor Past Atlantic Meridional Overturning Circulation?, Jörg Lippold, Jens Grützner, Diane Winter, Yann Lahaye, Augusto Mangini, Marcus Christl

Department of Earth and Atmospheric Sciences: Faculty Publications

Ocean circulation may have undergone reductions and reinvigorations in the past closely tied to regional climate changes. Measurements of 231Pa/230Th ratios in a sediment core from the Bermuda Rise have been interpreted as evidence that the Atlantic Meridional Overturning Circulation (AMOC) was weakened or completely eliminated during a period of catastrophic iceberg discharges (Heinrich-Event 1, H1). Here we present new data from the Bermuda Rise that show further 231Pa/230Th peaks during Heinrich-2 (H2) and Heinrich-3 (H3). Additionally, a tight correlation between diatom abundances (biogenic silica) and 231Pa/230Th is discovered in this …

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On The Role Of Groundwater And Soil Texture In The Regional Water Balance: An Investigation Of The Nebraska Sand Hills, Usa, Tiejun Wang, Erkan Istanbulluoglu, John D. Lenters, Durelle T. Scott Jan 2009

On The Role Of Groundwater And Soil Texture In The Regional Water Balance: An Investigation Of The Nebraska Sand Hills, Usa, Tiejun Wang, Erkan Istanbulluoglu, John D. Lenters, Durelle T. Scott

Department of Earth and Atmospheric Sciences: Faculty Publications

Partitioning of precipitation between evapotranspiration and runoff at the basin scale is primarily controlled by climate and basin characteristics. Here we use the Budyko hypothesis to investigate the impacts of soil texture and groundwater (e.g., baseflow) on annual and long-term mean annual water balances of basins in a semiarid region located in and around the Sand Hills region of Nebraska, USA. Native grasslands are dominant across the study area with soil textures dramatically different for the Nebraska Sand Hills (primarily sand deposits) and the adjacent regions (mainly less permeable silt loam). For each basin, long-term hydrologic and meteorological data are …

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