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Full-Text Articles in Computer Engineering

Pinpoint: Efficient And Effective Resource Isolation For Mobile Security And Privacy, Paul Ratazzi, Ashok Bommisetti, Nian Ji, Wenliang Du May 2015

Pinpoint: Efficient And Effective Resource Isolation For Mobile Security And Privacy, Paul Ratazzi, Ashok Bommisetti, Nian Ji, Wenliang Du

Electrical Engineering and Computer Science

Virtualization is frequently used to isolate untrusted processes and control their access to sensitive resources. However, isolation usually carries a price in terms of less resource sharing and reduced inter-process communication. In an open architecture such as Android, this price and its impact on performance, usability, and transparency must be carefully considered. Although previous efforts in developing general-purpose isolation solutions have shown that some of these negative sideeffects can be mitigated, doing so involves overcoming significant design challenges by incorporating numerous additional platform complexities not directly related to improved security. Thus, the general purpose solutions become inefficient and burdensome if ...


Instructions-Based Detection Of Sophisticated Obfuscation And Packing, Moustafa Saleh, Edward Paul Ratazzi, Shouhuai Xu Oct 2014

Instructions-Based Detection Of Sophisticated Obfuscation And Packing, Moustafa Saleh, Edward Paul Ratazzi, Shouhuai Xu

Electrical Engineering and Computer Science

Every day thousands of malware are released online. The vast majority of these malware employ some kind of obfuscation ranging from simple XOR encryption, to more sophisticated anti-analysis, packing and encryption techniques. Dynamic analysis methods can unpack the file and reveal its hidden code. However, these methods are very time consuming when compared to static analysis. Moreover, considering the large amount of new malware being produced daily, it is not practical to solely depend on dynamic analysis methods. Therefore, finding an effective way to filter the samples and delegate only obfuscated and suspicious ones to more rigorous tests would significantly ...


Interoperable Credentials Management For Wholesale Banking, Glenn Benson, Shiu-Kai Chin, Sean Croston, Karthick Jayaraman, Susan Older Feb 2011

Interoperable Credentials Management For Wholesale Banking, Glenn Benson, Shiu-Kai Chin, Sean Croston, Karthick Jayaraman, Susan Older

Electrical Engineering and Computer Science

A gap exists between wholesale-banking business practices and security best practices: wholesale banks operate within the boundaries of contract law, while security best practices often relies upon a benevolent trusted party outside the scope of straightforward contracts. While some business domains may be able to bridge this gap, the ultra-high-value transactions used in business-to-business banking substantially increase the size of the gap. The gap becomes most apparent when regarded from the perspective of interoperability. If a single user applies the same credential to sign high-value transactions at multiple banks, then the trusted-party model becomes overly cumbersome and conflicts with an ...


Reference Set Metrics For Multi-Objective Algorithms, Chilukuri K. Mohan, Kishan Mehrotra Jan 2011

Reference Set Metrics For Multi-Objective Algorithms, Chilukuri K. Mohan, Kishan Mehrotra

Electrical Engineering and Computer Science

Several metrics and indicators have been suggested in the past to evaluate multi-objective evolutionary and non-evolutionary algo- rithms. However, these metrics are known to have many problems that make their application sometimes unsound, and sometimes infeasible. This paper proposes a new approach, in which metrics are parameter- ized with respect to a reference set, on which depend the properties of any metric.


Average Run Length Of Two-Span Moving Sum Algorithms, Swarnendu Kar, Kishan G. Mehrotra, Pramod Varshney Mar 2010

Average Run Length Of Two-Span Moving Sum Algorithms, Swarnendu Kar, Kishan G. Mehrotra, Pramod Varshney

Electrical Engineering and Computer Science

Among the various procedures used to detect potential changes in a stochastic process the moving sum algorithms are very popular due to their intuitive appeal and good statistical performance. One of the important design parameters of a change detection algorithm is the expected interval between false positives, also known as the average run length (ARL). In this paper, we have derived closed form expressions of ARL for two special cases - namely the two-span moving sum and filtered derivative algorithms. We have assumed that the random variables are uniformly distributed.


Approximation Of Average Run Length Of Moving Sum Algorithms Using Multivariate Probabilities, Swarnendu Kar, Kishan Mehrotra, Pramod Varshney Mar 2010

Approximation Of Average Run Length Of Moving Sum Algorithms Using Multivariate Probabilities, Swarnendu Kar, Kishan Mehrotra, Pramod Varshney

Electrical Engineering and Computer Science

Among the various procedures used to detect potential changes in a stochastic process the moving sum algorithms are very popular due to their intuitive appeal and good statistical performance. One of the important design parameters of a change detection algorithm is the expected interval between false positives, also known as the average run length (ARL). Computation of the ARL usually involves numerical procedures but in some cases it can be approximated using a series involving multivariate probabilities. In this paper, we present an analysis of this series approach by providing sufficient conditions for convergence and derive an error bound. Using ...


A Clustering Based Discretization For Supervised Learning, Ankit Gupta, Kishan Mehrotra, Chilukuri K. Mohan Nov 2009

A Clustering Based Discretization For Supervised Learning, Ankit Gupta, Kishan Mehrotra, Chilukuri K. Mohan

Electrical Engineering and Computer Science

We address the problem of discretization of continuous variables for machine learning classification algorithms. Existing procedures do not use interdependence between the variables towards this goal. Our proposed method uses clustering to exploit such interdependence. Numerical results show that this improves the classification performance in almost all cases. Even if an existing algorithm can successfully operate with continuous variables, better performance is obtained if variables are first discretized. An additional advantage of discretization is that it reduces the overall time-complexity.


Univercl 1.0 --- Phase I Of A Complete Opencl Implementation, Phil Pratt-Szeliga, Jim Fawcett Sep 2009

Univercl 1.0 --- Phase I Of A Complete Opencl Implementation, Phil Pratt-Szeliga, Jim Fawcett

Electrical Engineering and Computer Science

Recently the Khronos group has released an open specification for OpenCL, the Open Computation Language. OpenCL strives to create a standard language for programming novel computer architectures such as the multi-core CPU, the GPU and accelerators. The programming model is similar to Nvidia's CUDA. UniverCL is a partial implementation of the OpenCL 1.0 Specification that has enough functionality to demonstrate the major components of the specification. It currently includes support for two hardware devices: the multi-core CPU and the Cell Broadband Engine. This technical report captures the work done in Phase I of UniverCL's development and outlines ...


Escudo: A Fine-Grained Protection Model For Web Browsers, Karthick Jayaraman, Wenliang Du, Balamurugan Rajagopalan, Steve J. Chapin Jan 2009

Escudo: A Fine-Grained Protection Model For Web Browsers, Karthick Jayaraman, Wenliang Du, Balamurugan Rajagopalan, Steve J. Chapin

Electrical Engineering and Computer Science

Web applications are no longer simple hyperlinked documents. They have progressively evolved to become highly complex---web pages combine content from several sources (with varying levels of trustworthiness), and incorporate significant portions of client-side code. However, the prevailing web protection model, the same-origin policy, has not adequately evolved to manage the security consequences of this additional complexity. As a result, web applications have become attractive targets of exploitation. We argue that this disconnection between the protection needs of modern web applications and the protection models used by web browsers that manage those applications amounts to a failure of access control. In ...


Mimo Communications In Ad Hoc Networks, Biao Chen, Michael J. Gans Jan 2006

Mimo Communications In Ad Hoc Networks, Biao Chen, Michael J. Gans

Electrical Engineering and Computer Science

We study in this paper the network spectral efficiency in terms of bits/s/Hz of a MIMO (multiple-input multiple output) ad hoc network with K simultaneous communicating transmitter-receiver pairs. Assume that each transmitter is equipped with t antennas and each receiver implements single user detection. We show that in the absence of channel state information (CSI) at the transmitters, the asymptotic network spectral efficiency is limited by r nats/s/Hz as K -> ∞ and is independent of t and the transmit power. With CSI corresponding to the desired receiver available at the transmitter, we demonstrate that the asymptotic spectral ...


Mimo Communications In Ad Hoc Networks, Biao Chen, Michael J. Gans Jan 2006

Mimo Communications In Ad Hoc Networks, Biao Chen, Michael J. Gans

Electrical Engineering and Computer Science

We study in this paper the network spectral efficiency in terms of bits/s/Hz of a MIMO (multiple-input multiple output) ad hoc network with K simultaneous communicating transmitter-receiver pairs. Assume that each transmitter is equipped with t antennas and each receiver implements single user detection. We show that in the absence of channel state information (CSI) at the transmitters, the asymptotic network spectral efficiency is limited by r nats/s/Hz as K -> ∞ and is independent of t and the transmit power. With CSI corresponding to the desired receiver available at the transmitter, we demonstrate that the asymptotic spectral ...


A Beacon-Less Location Discovery Scheme For Wireless Sensor Networks, Lei Feng, Wenliang Du, Peng Ning Jan 2005

A Beacon-Less Location Discovery Scheme For Wireless Sensor Networks, Lei Feng, Wenliang Du, Peng Ning

Electrical Engineering and Computer Science

In wireless sensor networks (WSNs), sensor location plays a critical role in many applications. Having a GPS receiver on every sensor node is costly. In the past, a number of location discovery schemes have been proposed. Most of these schemes share a common feature: they use some special nodes, called beacon nodes, which are assumed to know their own locations (e.g., through GPS receivers or manual configuration). Other sensors discover their locations based on the information provided by these beacon nodes. In this paper, we show that efficient location discovery can be achieved in sensor networks without using beacons ...


Making Svg A Web Service In A Message-Based Mvc Architecture, Xiaohong Qiu, Shrideep Pallickara, Ahmet Uyar Jan 2004

Making Svg A Web Service In A Message-Based Mvc Architecture, Xiaohong Qiu, Shrideep Pallickara, Ahmet Uyar

Electrical Engineering and Computer Science

We reformulate Scalable Vector Graphics browser in a Web Service architecture separating the rendering from the W3C DOM processing of events. We describe this in a message-based Model-View-Controller (M-MVC) architecture and implement it with a powerful publish-subscribe messaging infrastructure. A Web Services oriented architecture with services loosely coupled by the exchange of messages is becoming an increasingly important feature in the deployment of Internet applications. The broad applicability of this approach includes enterprise software, e-Learning, e-Science and e-Business. Our work provides a general framework for integrating Desktop and Web Service applications. We summarize the performance results from detailed tests of ...


A Predictive Sensor Network Using Ant System, Rajani Muraleedharan, Lisa Ann Osadciw Jan 2004

A Predictive Sensor Network Using Ant System, Rajani Muraleedharan, Lisa Ann Osadciw

Electrical Engineering and Computer Science

The need for a robust predictive sensor communication network inspired this research. There are many critical issues in a communication network with different data rate requirements, limited power and bandwidth. Energy consumption is one of the key issues in a sensor network as energy dissipation occurs during routing, communication and monitoring of the environment. This paper covers the routing of a sensor communication network by applying an evolutionary algorithm- the ant system. The issues considered include optimal energy, data fusion from different sensor types and predicting changes in environment with respect to time.


Attack-Resistant Location Estimation In Wireless Sensor Networks, Dongdang Liu, Peng Ning, An Liu, Cliff Wang, Wenliang Kevin Du Jan 2004

Attack-Resistant Location Estimation In Wireless Sensor Networks, Dongdang Liu, Peng Ning, An Liu, Cliff Wang, Wenliang Kevin Du

Electrical Engineering and Computer Science

Many sensor network applications require sensors’ locations to function correctly. Despite the recent advances, location discovery for sensor networks in hostile environments has been mostly overlooked. Most of the existing localization protocols for sensor networks are vulnerable in hostile environments. The security of location discovery can certainly be enhanced by authentication. However, the possible node compromises and the fact that location determination uses certain physical features (e.g., received signal strength) of radio signals make authentication not as effective as in traditional security applications. This paper presents two methods to tolerate malicious attacks against range-based location discovery in sensor networks ...


A Predictive Sensor Network Using Ant System, Rajani Muraleedharan, Lisa Ann Osadciw Jan 2004

A Predictive Sensor Network Using Ant System, Rajani Muraleedharan, Lisa Ann Osadciw

Electrical Engineering and Computer Science

The need for a robust predictive sensor communication network inspired this research. There are many critical issues in a communication network with different data rate requirements, limited power and bandwidth. Energy consumption is one of the key issues in a sensor network as energy dissipation occurs during routing, communication and monitoring of the environment. This paper covers the routing of a sensor communication network by applying an evolutionary algorithm- the ant system. The issues considered include optimal energy, data fusion from different sensor types and predicting changes in environment with respect to time.


A Framework For Aggregating Network Performance In Distributed Brokering Systems, Gurhan Gunduz, Shrideep Pallickara, Geoffrey C. Fox Jan 2003

A Framework For Aggregating Network Performance In Distributed Brokering Systems, Gurhan Gunduz, Shrideep Pallickara, Geoffrey C. Fox

Electrical Engineering and Computer Science

The Internet is presently being used to support increasingly complex interaction models as a result of more and more applications, services and frameworks becoming network-centric. Efficient utilization of network and networked resources is of paramount importance. Network performance gathering is a precursor to any scheme that seeks to provide adaptive routing capabilities for interactions. In this paper we present a network performance aggregation framework that is extensible and appropriate for distributed messaging systems that span multiple realms, disparate communication protocols and support different applications.


A Scalable Durable Grid Event Service, Geoffrey C. Fox, Shrideep Pallickara Jan 2001

A Scalable Durable Grid Event Service, Geoffrey C. Fox, Shrideep Pallickara

Electrical Engineering and Computer Science

It is interesting to study the system and software architecture of environments, which integrate the evolving ideas of computational grids, distributed objects, web services, peer-to-peer networks and message oriented middleware. Such peer-to-peer (P2P) Grids should seamlessly integrate users to themselves and to resources, which are also linked to each other. We can abstract such environments as a distributed system of "clients" which consist either of "users" or "resources" or proxies thereto. These clients must be linked together in a flexible fault tolerant efficient high performance fashion. In this paper, we study the messaging or event system -- termed GES or the ...


A Distributed Spectral-Screening Pct Algorithm, Tiranee Achalakul, Stephen Taylor Jan 2000

A Distributed Spectral-Screening Pct Algorithm, Tiranee Achalakul, Stephen Taylor

Electrical Engineering and Computer Science

This paper describes a novel distributed algorithm for use in remote-sensing, medical image analysis, and surveillance applications. The algorithm combines spectral-screening classification with the principal component transform (PCT), and human-centered mapping. It fuses a multi- or hyper-spectral image set into a single color composite image that maximizes the impact of spectral variation on the human visual system. The algorithm operates on distributed collections of shared-memory multiprocessors that are connected through high-performance networking. Scenes taken from a standard 210 frame remote-sensing data set, collected with the Hyper-spectral Digital Imagery Collection Experiment (HYDICE) airborne imaging spectrometer, are used to assess the algorithms ...


Integrating Security Into The Curriculum, Cynthia E. Irvine, Shiu-Kai Chin, Deborah Frincke Jan 1998

Integrating Security Into The Curriculum, Cynthia E. Irvine, Shiu-Kai Chin, Deborah Frincke

Electrical Engineering and Computer Science

The number of skilled practitioners of computer security who are able to address the complexities of modern technology and are familiar with successful approaches to system security is very small. People want security but are faced with two difficulties. First, they do not know how to achieve it in the context of their enterprises. They may not even know of a way to translate organizational procedures into policies, much less implement a set of mechanisms to enforce those policies. Second, they have no way of knowing whether their chosen mechanisms are effective. The recent US Presidential Commission on Critical Infrastructure ...


Enhancing Spatial Locality Via Data Layout Optimizations, Mahmut Kandemir, Alok Choudhary, J. Ramanujam, N. Shenoy Jan 1998

Enhancing Spatial Locality Via Data Layout Optimizations, Mahmut Kandemir, Alok Choudhary, J. Ramanujam, N. Shenoy

Electrical Engineering and Computer Science

This paper aims to improve locality of references by suitably choosing array layouts. We use a new definition of spatial reuse vectors that takes into account memory layout of arrays. This capability creates two opportunities. First, it allows us to develop an array restructuring framework based on a combination of hyperplane theory and reuse vectors. Second, it allows us to observe the effect of different array layout optimizations on spatial reuse vectors. Since the iteration space based locality optimizations also change the spatial reuse vectors, our approach allows us to compare the iteration-space based and data-space based approaches in terms ...


Compilation Techniques For Out-Of-Core Parallel Computations, Mahmut Kandemir, Alok Choudhary, J. Ramanujam, Rajesh Bordawekar Jan 1998

Compilation Techniques For Out-Of-Core Parallel Computations, Mahmut Kandemir, Alok Choudhary, J. Ramanujam, Rajesh Bordawekar

Electrical Engineering and Computer Science

The difficulty of handling out-of-core data limits the performance of supercomputers as well as the potential of the parallel machines. Since writing an efficient out-of-core version of a program is a difficult task and virtual memory systems do not perform well on scientific computations, we believe that there is a clear need for compiler directed explicit I/O approach for out-of-core computations. In this paper, we first present an out-of-core compilation strategy based on a disk storage abstraction. Then we offer a compiler algorithm to optimize locality of disk accesses in out-of core codes by choosing a good combination of ...


A Global Computing Environment For Networked Resources, Haluk Topcuoglu, Salim Hariri Jan 1997

A Global Computing Environment For Networked Resources, Haluk Topcuoglu, Salim Hariri

Electrical Engineering and Computer Science

Current advances in high-speed networks and WWW technologies have made network computing a cost-effective, high-performance computing alternative. New software tools are being developed to utilize efficiently the network computing environment. Our project, called Virtual Distributed Computing Environment (VDCE), is a high-performance computing environment that allows users to write and evaluate networked applications for different hardware and software configurations using a web interface. In this paper we present the software architecture of VDCE by emphasizing application development and specification, scheduling, and execution/runtime aspects.


Compile-Time Performance Prediction Of Hpf/Fortran 90d, Manish Parashar, Salim Hariri Jan 1996

Compile-Time Performance Prediction Of Hpf/Fortran 90d, Manish Parashar, Salim Hariri

Electrical Engineering and Computer Science

In this paper we present an interpretive approach for accurate and cost-effective performance prediction in a high performance computing environment, and describe the design of a compile-time HPF/Fortran 90D performance prediction framework based on this approach. The performance prediction framework has been implemented as a part of the HPF/Fortran 90D application development environment that integrates it with a HPF/Fortran 90D compiler and a functional interpreter. The current implementation of the environment framework is targeted to the iPSC/860 hypercube multicomputer system. A set of benchmarking kernels and application codes have been used to validate the accuracy, utility ...


A Framework For Integrated Communication And I/O Placement, Rajesh Bordawekar, Alok Choudhary, J Ramanujam Jan 1996

A Framework For Integrated Communication And I/O Placement, Rajesh Bordawekar, Alok Choudhary, J Ramanujam

Electrical Engineering and Computer Science

This paper describes a framework for analyzing dataflow within an out-of-core parallel program. Dataflow properties of FORALL statement are analyzed and a unified I/O and communication placement framework is presented. This placement framework can be applied to many problems, which include eliminating redundant I/O incurred in communication. The framework is validated by applying it for optimizing I/O and communication in out-of-core stencil problems. Experimental performance results on an Intel Paragon show significant reduction in I/O and communication overhead.


A Framework For Integrated Communication And I/O Placement, Rajesh Bordawekar, Alok Choudhary, J Ramanujam Jan 1996

A Framework For Integrated Communication And I/O Placement, Rajesh Bordawekar, Alok Choudhary, J Ramanujam

Electrical Engineering and Computer Science

This paper describes a framework for analyzing dataflow within an out-of-core parallel program. Dataflow properties of FORALL statement are analyzed and a unified I/O and communication placement framework is presented. This placement framework can be applied to many problems, which include eliminating redundant I/O incurred in communication. The framework is validated by applying it for optimizing I/O and communication in out-of-core stencil problems. Experimental performance results on an Intel Paragon show significant reduction in I/O and communication overhead.


Runtime Support For In-Core And Out-Of-Core Data-Parallel Programs, Rajeev Thakur Jan 1995

Runtime Support For In-Core And Out-Of-Core Data-Parallel Programs, Rajeev Thakur

Electrical Engineering and Computer Science

Distributed memory parallel computers or distributed computer systems are widely recognized as the only cost-effective means of achieving teraflops performance in the near future. However, the fact remains that they are difficult to program and advances in software for these machines have not kept pace with advances in hardware. This thesis addresses several issues in providing runtime support for in-core as well as out-of-core programs on distributed memory parallel computers. This runtime support can be directly used in application programs for greater efficiency, portability and ease of programming. It can also be used together with a compiler to translate programs ...


Techniques For Scheduling I/O In A High Performance Multimedia-On-Demand Server, Divyesh Jadav, Chutimet Srinilta, Alok Choudhary, P. B. Berra Jan 1995

Techniques For Scheduling I/O In A High Performance Multimedia-On-Demand Server, Divyesh Jadav, Chutimet Srinilta, Alok Choudhary, P. B. Berra

Electrical Engineering and Computer Science

One of the key components of a multi-user multimedia-on-demand system is the data server. Digitalization of traditionally analog data such as video and audio, and the feasibility of obtaining network bandwidths above the gigabit-per-second range are two important advances that have made possible the realization, in the near future, of interactive distributed multimedia systems. Secondary-to-main memory I/O technology has not kept pace with advances in networking, main memory and CPU processing power. Consequently, the performance of the server has a direct bearing on the overall performance of such a system. In this paper we present a high-performance solution to ...


Architectural Support For Designing Fault-Tolerant Open Distributed Systems, Salim Hariri, Alok Choudhary, Behcet Sarikaya Jan 1992

Architectural Support For Designing Fault-Tolerant Open Distributed Systems, Salim Hariri, Alok Choudhary, Behcet Sarikaya

Electrical Engineering and Computer Science

A distributed system consists of autonomous computing modules that interact with each other using messages. Designing distributed systems is more difficult than designing centralized systems for several reasons. Physical separation and the use of heterogeneous computers complicate interprocessor communication, management of resources, synchronization of cooperating activities, and maintenance of consistency among multiple copies of information. The main advantages of distributed systems include increased fault-tolerance capabilities through the inherent redundancy of resources, improved performance by concurrently executing a single task on several computing modules, resource sharing, and the ability to adapt to a changing environment (extensibility). Distributed systems cover a wide ...