Physical Sciences and Mathematics Commons^™

Identifying Interesting Instances For Probabilistic Skylines, Yinian Qi, Mikhail J. Atallah

Department of Computer Science Technical Reports

No abstract provided.

Lower Tropospheric Temperature Variability Over The Usa: A Gis Approach, Souleymane Fall, Dev Niyogi, Gilbert L. Rochon

GIS Day

We use the high resolution North American Regional Analysis (NARR) dataset to build for the United States a Temperature Change Index (TCI) based on four contributing variables derived from the layer-averaged temperature and lapse rate of the 1000mb - 700mb layer (near-surface to 3000 meters) for the 1979-2008 period. The analysis uses Geographic Information Systems (GIS) methods to identify distinct regional patterns based on aggregate temperature trends and variability scores. The resulting index allows us to identify and compare regions that experience high (low) temperature trends and variability that are referred to as hot spots (cold spots). The upper Midwest …

Mash-Ups In Abe Models, And The New Epa Waters Web Services, Larry Theller

GIS Day

Documents recent efforts to integrate Purdue's Long-Term Hydrologic Impact Assessment (L-THIA) land use change model with data from Purdue, USEPA, and Michigan State’s Institute of Water Research within Google Maps

Ballistic-Ohmic Quantum Hall Plateau Transition In A Graphene P-N Junction, Tony Low

Birck and NCN Publications

Recent quantum Hall experiments conducted on disordered graphene p-n junction provide evidence that the junction resistance could be described by a simple Ohmic sum of the n and p mediums’ resistances. However in the ballistic limit, theory predicts the existence of chirality-dependent quantum Hall plateaus in a p-n junction. We show that two distinctively separate processes are required for this ballistic-Ohmic plateau transition, namely, (i) hole/electron Landau states mixing and (ii) valley isospin dilution of the incident Landau edge state. These conclusions are obtained by a simple scattering theory argument, and confirmed numerically by performing ensembles of quantum magnetotransport calculations …

Instability In Leapfrog And Forward–Backward Schemes, Wen-Yih Sun

Department of Earth, Atmospheric, and Planetary Sciences Faculty Publications

No abstract provided.

Electronic Transport Properties Of A Tilted Graphene P-N Junction, Tony Low, Joerg Appenzeller

Birck and NCN Publications

Spatial manipulation of current flow in graphene could be achieved through the use of a tilted p-n junction. We show through numerical simulation that a pseudo-Hall effect (i.e., nonequilibrium charge and current density accumulating along one of the sides of a graphene ribbon) can be observed under these conditions. The tilt angle and the p-n transition length are two key parameters in tuning the strength of this effect. This phenomenon can be explained using classical trajectory via ray analysis, and is therefore relatively robust against disorder. Lastly, we propose and simulate a three terminal device that allows direct experimental access …

A Statistical Method For Integrated Data Cleaning And Imputation, Chris Mayfield, Jennifer Neville, Sunil Prabhakar

Department of Computer Science Technical Reports

No abstract provided.

Homomorphic Encryption Based K-Out-Of-N Oblivious Transfer Protocols, Mummoorthy Murugesan, Wei Jiang, Erhan Nergiz, Serkan Uzunbaz

Department of Computer Science Technical Reports

No abstract provided.

Strain Energy And Lateral Friction Force Distributions Of Carbon Nanotubes Manipulated Into Shapes By Atomic Force Microscopy, Mark C. Strus, Roya R. Lahiji, Pablo Ares, Vincente Lopez, Arvind Raman, Ron R. Reifenberger

Other Nanotechnology Publications

The interplay between local mechanical strain energy and lateral frictional forces determines the shape of carbon nanotubes on substrates. In turn, because of its nanometer-size diameter, the shape of a carbon nanotube strongly influences its local electronic, chemical, and mechanical properties. Few, if any, methods exist for resolving the strain energy and static frictional forces along the length of a deformed nanotube supported on a substrate. We present a method using nonlinear elastic rod theory in which we compute the flexural strain energy and static frictional forces along the length of single walled carbon nanotubes (SWCNTs) manipulated into various shapes …

Online Piece-Wise Linear Approximation Of Numerical Streams With Precision Guarantees, Hazem Elmeleegy, Ahmed Elmagarmid, Emmanuel Cecchet, Walid G. Aref, Willy Zwaenepoel

Cyber Center Publications

Continuous “always-on” monitoring is beneficial for a number of applications, but potentially imposes a high load in terms of communication, storage and power consumption when a large number of variables need to be monitored. We introduce two new filtering techniques, swing filters and slide filters, that represent within a prescribed precision a time-varying numerical signal by a piecewise linear function, consisting of connected line segments for swing filters and (mostly) disconnected line segments for slide filters. We demonstrate the effectiveness of swing and slide filters in terms of their compression power by applying them to a reallife data set plus …

Diversity And Strain Specificity Of Plant Cell Wall Degrading Enzymes Revealed By The Draft Genome Of Ruminococcus Flavefaciens Fd-1, Margret E. Berg Miller, Dionysios A. Antonopoulos, Mark Brand, Albert Bari, Alvaro Hernandez, Jyothi Thimmapuram, Bryan A. White, Marco Rincon, Harry J. Flint, Bernard Henrissat, Pedro M. Coutinho

Cyber Center Publications

Ruminococcus flavefaciens is a predominant cellulolytic rumen bacterium, which forms a multi-enzyme cellulosome complex that could play an integral role in the ability of this bacterium to degrade plant cell wall polysaccharides. Identifying the major enzyme types involved in plant cell wall degradation is essential for gaining a better understanding of the cellulolytic capabilities of this organism as well as highlighting potential enzymes for application in improvement of livestock nutrition and for conversion of cellulosic biomass to liquid fuels.

Non-Pinhole Imposters, Voicu Popescu, Kyle Hayward, Paul Rosen, Chris Wyman

Department of Computer Science Technical Reports

No abstract provided.

A Network-Aware Distributed Membership Protocol For Collaborative Defense, David Zage, Carl Livadas, Eve M. Schooler

Department of Computer Science Technical Reports

No abstract provided.

On The Modification Of An Eigenvalue Problem That Preserves An Eigenspace, Maxim Maumov

Department of Computer Science Technical Reports

No abstract provided.

Supporting Real-World Activities In Database Management Systems, Mohamed Eltabakh, Walid G. Aref, Ahmed K. Elmagarmid, Yasin Laura-Silva, Mourad Ouzzani

Department of Computer Science Technical Reports

No abstract provided.

Generalization Of Acid Properties, Brahim Medjahed, Mourad Ouzzani, Ahmed Elmagarmid

Cyber Center Publications

ACID (Atomicity, Consistency, Isolation, and Durability) is a set of properties that guarantee the reliability of database transactions [2]. ACID properties were initially developed with traditional, business-oriented applications (e.g., banking) in mind. Hence, they do not fully support the functional and performance requirements of advanced database applications such as computer-aided design, computer-aided manufacturing, office automation, network management, multidatabases, and mobile databases. For instance, transactions in computer-aided design applications are generally of long duration and preserving the traditional ACID properties in such transactions would require locking resources for long periods of time. This has lead to the generalization of ACID properties …

Beyond K-Anonymity: A Decision Theoretic Framework For Assessing Privacy Risk, Guy Lebanon, Monica Scannapieco, Mohamed Fouad, Elisa Bertino

Cyber Center Publications

An important issue any organization or individual has to face when managing data containing sensitive information, is the risk that can be incurred when releasing such data. Even though data may be sanitized before being released, it is still possible for an adversary to reconstruct the original data using additional information thus resulting in privacy violations. To date, however, a systematic approach to quantify such risks is not available. In this paper we develop a framework, based on statistical decision theory, that assesses the relationship between the disclosed data and the resulting privacy risk. We model the problem of deciding …

Query Mesh: Multiroute, Rimma Nehme, Karen Works, Elke Rundensteiner, Elisa Bertino

Cyber Center Publications

We propose to demonstrate a practical alternative approach to the current state-of-the-art query processing techniques, called the “Query Mesh” (or QM, for short). The main idea of QM is to compute multiple routes (i.e., query plans)1, each designed for a particular subset of data with distinct statistical properties. Based on the execution routes and the data characteristics, a classifier model is induced and is used to partition new data tuples to assign the best routes for their processing. We propose to demonstrate the QM framework in the streaming context using our demo application, called the “Ubi-City”. We will illustrate the …

Protein-Protein Docking Using Region-Based 3d Zernike Descriptors., Vishwesh Venkatraman, Yifeng D. Yang, Lee Sael, Daisuke Kihara

Department of Biological Sciences Faculty Publications

Background

Protein-protein interactions are a pivotal component of many biological processes and mediate a variety of functions. Knowing the tertiary structure of a protein complex is therefore essential for understanding the interaction mechanism. However, experimental techniques to solve the structure of the complex are often found to be difficult. To this end, computational protein-protein docking approaches can provide a useful alternative to address this issue. Prediction of docking conformations relies on methods that effectively capture shape features of the participating proteins while giving due consideration to conformational changes that may occur.

Results

We present a novel protein docking algorithm based …

A Hierarchical Approach To Model Web Query Interfaces For Web Source Integration, Thomas Kabisch, Eduard Dragut, Clement Yu, Ulf Leser

Cyber Center Publications

Much data in the Web is hidden behind Web query interfaces. In most cases the only means to "surface" the content of a Web database is by formulating complex queries on such interfaces. Applications such as Deep Web crawling and Web database integration require an automatic usage of these interfaces. Therefore, an important problem to be addressed is the automatic extraction of query interfaces into an appropriate model. We hypothesize the existence of a set of domain-independent "commonsense design rules" that guides the creation of Web query interfaces. These rules transform query interfaces into schema trees. In this paper we …

Private Queries And Trajectory Anonymization: A Dual Perspective On Location Privacy, Gabriel Ghinita

Cyber Center Publications

The emergence of mobile devices with Internet connectivity (e.g., Wi-Fi) and global positioning capabilities (e.g., GPS) have triggered the widespread development of location-based applications. For instance, users are able to ask queries about points of interest in their proximity. Furthermore, users can act as mobile sensors to monitor traffic flow, or levels of air pollution. However, such applications require users to disclose their locations, which raises serious privacy concerns. With knowledge of user locations, a malicious attacker can infer sensitive information, such as alternative lifestyles or political affiliations. Preserving location privacy is an essential requirement towards the successful deployment of …

The Plant Ionome Coming Into Focus, Lorraine Williams, David Salt

Cyber Center Publications

92 elements have been identified on earth and 17 of these are known to be essential to all plants. The essential elements required in relatively large amounts (>0.1% of dry mass) are called macronutrients and include C, H, O, N, S, P, Ca, K, Mg. Those required in much smaller amounts (<0.01% of dry mass) are referred to as micronutrients or trace elements and include Ni, Mo, Cu, Zn, Mn, B, Fe, and Cl. Plant growth and development depends on a balanced supply of these essential elements and thus the plant has a range of homeostatic mechanisms operating to ensure that this is maintained. Beneficial elements which promote growth and may be essential to some taxa, include Na, Co, Al, Se and Si. Elements such as the heavy metal Cd and the metalloid As have no demonstrated biological function in plants, but are nevertheless taken up and cause severe toxicity in most plant species. The concept for this special issue is the plant ionome, a word coined to encompass all these elements and allow focussed discussion and investigations on the mechanisms that co-ordinately regulate these elements in response to genetic and environmental factors reviewed in Salt et al., 2008).

Foreword For The Special Issue Of Selected Papers From The 1st Acm Sigspatial Workshop On Security And Privacy In Gis And Lbs, Elisa Bertino, Maria Luisa Damiani

Cyber Center Publications

The first Workshop on Security and Privacy in GIS and LBS (SPRINGL 2008) was organized on November 4, 2008 at Irvine (CA) in conjunction with the SIGSPATIAL International Conference on Advances in Geographic Information Systems (ACM GIS 2008). The goal of the SPRINGL workshop series is to provide a forum for researchers working in the area of geospatial data security and privacy. Both security and privacy are critical for geospatial applications because of the dramatic increase and dissemination of geospatial data in several application contexts including homeland security, environmental crises, and natural and industrial disasters. Furthermore, geospatial infrastructures are being …

Location Privacy In Moving-Object Environments, Dan Lin, Elisa Bertino, Reynold Cheng, Sunil Prabhakar

Cyber Center Publications

The expanding use of location-based services has profound implications on the privacy of personal information. If no adequate protection is adopted, information about movements of specific individuals could be disclosed to unauthorized subjects or organizations, thus resulting in privacy breaches. In this paper, we propose a framework for preserving location privacy in moving-object environments. Our approach is based on the idea of sending to the service provider suitably modified location information. Such modifications, that include transformations like scaling, are performed by agents interposed between users and service providers. Agents execute data transformation and the service provider directly processes the transformed …

Application Of 3d Zernike Descriptors To Shape-Based Ligand Similarity Searching, Vishwesh Venkatraman, Padmasini Ramji Chakravarthy, Daisuke Kihara

Department of Biological Sciences Faculty Publications

Background

The identification of promising drug leads from a large database of compounds is an important step in the preliminary stages of drug design. Although shape is known to play a key role in the molecular recognition process, its application to virtual screening poses significant hurdles both in terms of the encoding scheme and speed.

Results

In this study, we have examined the efficacy of the alignment independent three-dimensional Zernike descriptor (3DZD) for fast shape based similarity searching. Performance of this approach was compared with several other methods including the statistical moments based ultrafast shape recognition scheme (USR) and SIMCOMP, …